/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
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****************************************************************************/

#include "clangdclient.h"

#include "clangcompletioncontextanalyzer.h"
#include "clangdiagnosticmanager.h"
#include "clangpreprocessorassistproposalitem.h"
#include "clangtextmark.h"
#include "clangutils.h"

#include <clangsupport/sourcelocationscontainer.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/find/searchresultitem.h>
#include <coreplugin/find/searchresultwindow.h>
#include <cplusplus/FindUsages.h>
#include <cplusplus/Icons.h>
#include <cplusplus/MatchingText.h>
#include <cppeditor/cppeditorconstants.h>
#include <cppeditor/cppcodemodelsettings.h>
#include <cppeditor/cppdoxygen.h>
#include <cppeditor/cppeditorwidgetinterface.h>
#include <cppeditor/cppfindreferences.h>
#include <cppeditor/cppmodelmanager.h>
#include <cppeditor/cpptoolsreuse.h>
#include <cppeditor/cppvirtualfunctionassistprovider.h>
#include <cppeditor/cppvirtualfunctionproposalitem.h>
#include <cppeditor/semantichighlighter.h>
#include <languageclient/languageclientinterface.h>
#include <languageclient/languageclientutils.h>
#include <projectexplorer/project.h>
#include <projectexplorer/projecttree.h>
#include <projectexplorer/session.h>
#include <texteditor/basefilefind.h>
#include <texteditor/codeassist/assistinterface.h>
#include <texteditor/codeassist/iassistprocessor.h>
#include <texteditor/codeassist/iassistprovider.h>
#include <texteditor/codeassist/textdocumentmanipulatorinterface.h>
#include <texteditor/texteditorsettings.h>
#include <texteditor/texteditor.h>
#include <utils/algorithm.h>
#include <utils/runextensions.h>

#include <QCheckBox>
#include <QFile>
#include <QHash>
#include <QPair>
#include <QPointer>
#include <QRegularExpression>

#include <set>
#include <unordered_map>

using namespace CPlusPlus;
using namespace Core;
using namespace LanguageClient;
using namespace LanguageServerProtocol;
using namespace ProjectExplorer;

namespace ClangCodeModel {
namespace Internal {

static Q_LOGGING_CATEGORY(clangdLog, "qtc.clangcodemodel.clangd", QtWarningMsg);
static Q_LOGGING_CATEGORY(clangdLogServer, "qtc.clangcodemodel.clangd.server", QtWarningMsg);
static Q_LOGGING_CATEGORY(clangdLogAst, "qtc.clangcodemodel.clangd.ast", QtWarningMsg);
static Q_LOGGING_CATEGORY(clangdLogHighlight, "qtc.clangcodemodel.clangd.highlight", QtWarningMsg);
static QString indexingToken() { return "backgroundIndexProgress"; }

class AstParams : public JsonObject
{
public:
    AstParams() {}
    AstParams(const TextDocumentIdentifier &document, const Range &range = {})
    {
        setTextDocument(document);
        if (range.isValid())
            setRange(range);
    }

    using JsonObject::JsonObject;

    // The open file to inspect.
    TextDocumentIdentifier textDocument() const
    { return typedValue<TextDocumentIdentifier>(textDocumentKey); }
    void setTextDocument(const TextDocumentIdentifier &id) { insert(textDocumentKey, id); }

    // The region of the source code whose AST is fetched. The highest-level node that entirely
    // contains the range is returned.
    Utils::optional<Range> range() const { return optionalValue<Range>(rangeKey); }
    void setRange(const Range &range) { insert(rangeKey, range); }

    bool isValid() const override { return contains(textDocumentKey); }
};

class AstNode : public JsonObject
{
public:
    using JsonObject::JsonObject;

    static constexpr char roleKey[] = "role";
    static constexpr char arcanaKey[] = "arcana";

    // The general kind of node, such as “expression”. Corresponds to clang’s base AST node type,
    // such as Expr. The most common are “expression”, “statement”, “type” and “declaration”.
    QString role() const { return typedValue<QString>(roleKey); }

    // The specific kind of node, such as “BinaryOperator”. Corresponds to clang’s concrete
    // node class, with Expr etc suffix dropped.
    QString kind() const { return typedValue<QString>(kindKey); }

    // Brief additional details, such as ‘||’. Information present here depends on the node kind.
    Utils::optional<QString> detail() const { return optionalValue<QString>(detailKey); }

    // One line dump of information, similar to that printed by clang -Xclang -ast-dump.
    // Only available for certain types of nodes.
    Utils::optional<QString> arcana() const { return optionalValue<QString>(arcanaKey); }

    // The part of the code that produced this node. Missing for implicit nodes, nodes produced
    // by macro expansion, etc.
    Range range() const { return typedValue<Range>(rangeKey); }

    // Descendants describing the internal structure. The tree of nodes is similar to that printed
    // by clang -Xclang -ast-dump, or that traversed by clang::RecursiveASTVisitor.
    Utils::optional<QList<AstNode>> children() const { return optionalArray<AstNode>(childrenKey); }

    bool hasRange() const { return contains(rangeKey); }

    bool arcanaContains(const QString &s) const
    {
        const Utils::optional<QString> arcanaString = arcana();
        return arcanaString && arcanaString->contains(s);
    }

    bool detailIs(const QString &s) const
    {
        return detail() && detail().value() == s;
    }

    bool isMemberFunctionCall() const
    {
        return role() == "expression" && (kind() == "CXXMemberCall"
                || (kind() == "Member" && arcanaContains("member function")));
    }

    bool isPureVirtualDeclaration() const
    {
        return role() == "declaration" && kind() == "CXXMethod" && arcanaContains("virtual pure");
    }

    bool isPureVirtualDefinition() const
    {
        return role() == "declaration" && kind() == "CXXMethod" && arcanaContains("' pure");
    }

    bool mightBeAmbiguousVirtualCall() const
    {
        if (!isMemberFunctionCall())
            return false;
        bool hasBaseCast = false;
        bool hasRecordType = false;
        const QList<AstNode> childList = children().value_or(QList<AstNode>());
        for (const AstNode &c : childList) {
            if (!hasBaseCast && c.detailIs("UncheckedDerivedToBase"))
                hasBaseCast = true;
            if (!hasRecordType && c.role() == "specifier" && c.kind() == "TypeSpec")
                hasRecordType = true;
            if (hasBaseCast && hasRecordType)
                return false;
        }
        return true;
    }

    bool isNamespace() const { return role() == "declaration" && kind() == "Namespace"; }

    QString type() const
    {
        const Utils::optional<QString> arcanaString = arcana();
        if (!arcanaString)
            return {};
        return typeFromPos(*arcanaString, 0);
    }

    QString typeFromPos(const QString &s, int pos) const
    {
        const int quote1Offset = s.indexOf('\'', pos);
        if (quote1Offset == -1)
            return {};
        const int quote2Offset = s.indexOf('\'', quote1Offset + 1);
        if (quote2Offset == -1)
            return {};
        if (s.mid(quote2Offset + 1, 2) == ":'")
            return typeFromPos(s, quote2Offset + 2);
        return s.mid(quote1Offset + 1, quote2Offset - quote1Offset - 1);
    }

    HelpItem::Category qdocCategoryForDeclaration(HelpItem::Category fallback)
    {
        const auto childList = children();
        if (!childList || childList->size() < 2)
            return fallback;
        const AstNode c1 = childList->first();
        if (c1.role() != "type" || c1.kind() != "Auto")
            return fallback;
        QList<AstNode> typeCandidates = {childList->at(1)};
        while (!typeCandidates.isEmpty()) {
            const AstNode n = typeCandidates.takeFirst();
            if (n.role() == "type") {
                if (n.kind() == "Enum")
                    return HelpItem::Enum;
                if (n.kind() == "Record")
                    return HelpItem::ClassOrNamespace;
                return fallback;
            }
            typeCandidates << n.children().value_or(QList<AstNode>());
        }
        return fallback;
    }

    // Returns true <=> the type is "recursively const".
    // E.g. returns true for "const int &", "const int *" and "const int * const *",
    // and false for "int &" and "const int **".
    // For non-pointer types such as "int", we check whether they are uses as lvalues
    // or rvalues.
    bool hasConstType() const
    {
        QString theType = type();
        if (theType.endsWith("const"))
            theType.chop(5);
        const int xrefCount = theType.count("&&");
        const int refCount = theType.count('&') - 2 * xrefCount;
        const int ptrRefCount = theType.count('*') + refCount;
        const int constCount = theType.count("const");
        if (ptrRefCount == 0)
            return constCount > 0 || detailIs("LValueToRValue") || arcanaContains("xvalue");
        return ptrRefCount <= constCount;
    }

    bool childContainsRange(int index, const Range &range) const
    {
        const Utils::optional<QList<AstNode>> childList = children();
        return childList && childList->size() > index
                && childList->at(index).range().contains(range);
    }

    bool hasChildWithRole(const QString &role) const
    {
        return Utils::contains(children().value_or(QList<AstNode>()), [&role](const AstNode &c) {
            return c.role() == role;
        });
    }

    QString operatorString() const
    {
        if (kind() == "BinaryOperator")
            return detail().value_or(QString());
        QTC_ASSERT(kind() == "CXXOperatorCall", return {});
        const Utils::optional<QString> arcanaString = arcana();
        if (!arcanaString)
            return {};
        const int closingQuoteOffset = arcanaString->lastIndexOf('\'');
        if (closingQuoteOffset <= 0)
            return {};
        const int openingQuoteOffset = arcanaString->lastIndexOf('\'', closingQuoteOffset - 1);
        if (openingQuoteOffset == -1)
            return {};
        return arcanaString->mid(openingQuoteOffset + 1, closingQuoteOffset
                                 - openingQuoteOffset - 1);
    }

    // For debugging.
    void print(int indent = 0) const
    {
        (qDebug().noquote() << QByteArray(indent, ' ')).quote() << role() << kind()
                 << detail().value_or(QString()) << arcana().value_or(QString())
                 << range();
        for (const AstNode &c : children().value_or(QList<AstNode>()))
            c.print(indent + 2);
    }

    bool isValid() const override
    {
        return contains(roleKey) && contains(kindKey);
    }
};

static QList<AstNode> getAstPath(const AstNode &root, const Range &range)
{
    QList<AstNode> path;
    QList<AstNode> queue{root};
    bool isRoot = true;
    while (!queue.isEmpty()) {
        AstNode curNode = queue.takeFirst();
        if (!isRoot && !curNode.hasRange())
            continue;
        if (curNode.range() == range)
            return path << curNode;
        if (isRoot || curNode.range().contains(range)) {
            path << curNode;
            const auto children = curNode.children();
            if (!children)
                break;
            queue = children.value();
        }
        isRoot = false;
    }
    return path;
}

static Usage::Type getUsageType(const QList<AstNode> &path)
{
    bool potentialWrite = false;
    const bool symbolIsDataType = path.last().role() == "type" && path.last().kind() == "Record";
    for (auto pathIt = path.rbegin(); pathIt != path.rend(); ++pathIt) {
        if (pathIt->arcanaContains("non_odr_use_unevaluated"))
            return Usage::Type::Other;
        if (pathIt->kind() == "CXXDelete")
            return Usage::Type::Write;
        if (pathIt->kind() == "CXXNew")
            return Usage::Type::Other;
        if (pathIt->kind() == "Switch" || pathIt->kind() == "If")
            return Usage::Type::Read;
        if (pathIt->kind() == "Call" || pathIt->kind() == "CXXMemberCall")
            return potentialWrite ? Usage::Type::WritableRef : Usage::Type::Read;
        if ((pathIt->kind() == "DeclRef" || pathIt->kind() == "Member")
                && pathIt->arcanaContains("lvalue")) {
            potentialWrite = true;
        }
        if (pathIt->role() == "declaration") {
            if (symbolIsDataType)
                return Usage::Type::Other;
            if (pathIt->arcanaContains("cinit")) {
                if (pathIt == path.rbegin())
                    return Usage::Type::Initialization;
                if (pathIt->childContainsRange(0, path.last().range()))
                    return Usage::Type::Initialization;
                if (!pathIt->hasConstType())
                    return Usage::Type::WritableRef;
                return Usage::Type::Read;
            }
            return Usage::Type::Declaration;
        }
        if (pathIt->kind() == "MemberInitializer")
            return pathIt == path.rbegin() ? Usage::Type::Write : Usage::Type::Read;
        if (pathIt->kind() == "UnaryOperator"
                && (pathIt->detailIs("++") || pathIt->detailIs("--"))) {
            return Usage::Type::Write;
        }

        // LLVM uses BinaryOperator only for built-in types; for classes, CXXOperatorCall
        // is used. The latter has an additional node at index 0, so the left-hand side
        // of an assignment is at index 1.
        const bool isBinaryOp = pathIt->kind() == "BinaryOperator";
        const bool isOpCall = pathIt->kind() == "CXXOperatorCall";
        if (isBinaryOp || isOpCall) {
            if (isOpCall && symbolIsDataType) // Constructor invocation.
                return Usage::Type::Other;

            const QString op = pathIt->operatorString();
            if (op.endsWith("=") && op != "==") { // Assignment.
                const int lhsIndex = isBinaryOp ? 0 : 1;
                if (pathIt->childContainsRange(lhsIndex, path.last().range()))
                    return Usage::Type::Write;
                return potentialWrite ? Usage::Type::WritableRef : Usage::Type::Read;
            }
            return Usage::Type::Read;
        }

        if (pathIt->kind() == "ImplicitCast") {
            if (pathIt->detailIs("FunctionToPointerDecay"))
                return Usage::Type::Other;
            if (pathIt->hasConstType())
                return Usage::Type::Read;
            potentialWrite = true;
            continue;
        }
    }

    return Usage::Type::Other;
}

class AstRequest : public Request<AstNode, std::nullptr_t, AstParams>
{
public:
    using Request::Request;
    explicit AstRequest(const AstParams &params) : Request("textDocument/ast", params) {}
};

class SymbolDetails : public JsonObject
{
public:
    using JsonObject::JsonObject;

    static constexpr char usrKey[] = "usr";

    // the unqualified name of the symbol
    QString name() const { return typedValue<QString>(nameKey); }

    // the enclosing namespace, class etc (without trailing ::)
    // [NOTE: This is not true, the trailing colons are included]
    QString containerName() const { return typedValue<QString>(containerNameKey); }

    // the clang-specific “unified symbol resolution” identifier
    QString usr() const { return typedValue<QString>(usrKey); }

    // the clangd-specific opaque symbol ID
    Utils::optional<QString> id() const { return optionalValue<QString>(idKey); }

    bool isValid() const override
    {
        return contains(nameKey) && contains(containerNameKey) && contains(usrKey);
    }
};

class SymbolInfoRequest : public Request<LanguageClientArray<SymbolDetails>, std::nullptr_t, TextDocumentPositionParams>
{
public:
    using Request::Request;
    explicit SymbolInfoRequest(const TextDocumentPositionParams &params)
        : Request("textDocument/symbolInfo", params) {}
};

static BaseClientInterface *clientInterface(Project *project, const Utils::FilePath &jsonDbDir)
{
    QString indexingOption = "--background-index";
    const CppEditor::ClangdSettings settings(CppEditor::ClangdProjectSettings(project).settings());
    if (!settings.indexingEnabled())
        indexingOption += "=0";
    Utils::CommandLine cmd{settings.clangdFilePath(), {indexingOption, "--limit-results=0"}};
    if (settings.workerThreadLimit() != 0)
        cmd.addArg("-j=" + QString::number(settings.workerThreadLimit()));
    if (!jsonDbDir.isEmpty())
        cmd.addArg("--compile-commands-dir=" + jsonDbDir.toString());
    if (clangdLogServer().isDebugEnabled())
        cmd.addArgs({"--log=verbose", "--pretty"});
    const auto interface = new StdIOClientInterface;
    interface->setCommandLine(cmd);
    return interface;
}

class ReferencesFileData {
public:
    QList<QPair<Range, QString>> rangesAndLineText;
    QString fileContent;
    AstNode ast;
};
class ReplacementData {
public:
    QString oldSymbolName;
    QString newSymbolName;
    QSet<Utils::FilePath> fileRenameCandidates;
};
class ReferencesData {
public:
    QMap<DocumentUri, ReferencesFileData> fileData;
    QList<MessageId> pendingAstRequests;
    QPointer<SearchResult> search;
    Utils::optional<ReplacementData> replacementData;
    quint64 key;
    bool canceled = false;
    bool categorize = CppEditor::codeModelSettings()->categorizeFindReferences();
};

using SymbolData = QPair<QString, Utils::Link>;
using SymbolDataList = QList<SymbolData>;

class ClangdClient::VirtualFunctionAssistProcessor : public TextEditor::IAssistProcessor
{
public:
    VirtualFunctionAssistProcessor(ClangdClient::Private *data) : m_data(data) {}

    void cancel() override;
    bool running() override { return m_data; }

    void update();
    void finalize();

private:
    TextEditor::IAssistProposal *perform(const TextEditor::AssistInterface *) override
    {
        return nullptr;
    }

    TextEditor::IAssistProposal *immediateProposal(const TextEditor::AssistInterface *) override
    {
        return createProposal(false);
    }

    void resetData();

    TextEditor::IAssistProposal *immediateProposalImpl() const;
    TextEditor::IAssistProposal *createProposal(bool final) const;
    CppEditor::VirtualFunctionProposalItem *createEntry(const QString &name,
                                                       const Utils::Link &link) const;

    ClangdClient::Private *m_data = nullptr;
};

class ClangdClient::VirtualFunctionAssistProvider : public TextEditor::IAssistProvider
{
public:
    VirtualFunctionAssistProvider(ClangdClient::Private *data) : m_data(data) {}

private:
    RunType runType() const override { return Asynchronous; }
    TextEditor::IAssistProcessor *createProcessor() const override;

    ClangdClient::Private * const m_data;
};

class ClangdClient::FollowSymbolData {
public:
    FollowSymbolData(ClangdClient *q, quint64 id, const QTextCursor &cursor,
                     CppEditor::CppEditorWidgetInterface *editorWidget,
                     const DocumentUri &uri, Utils::ProcessLinkCallback &&callback,
                     bool openInSplit)
        : q(q), id(id), cursor(cursor), editorWidget(editorWidget), uri(uri),
          callback(std::move(callback)), virtualFuncAssistProvider(q->d),
          openInSplit(openInSplit) {}

    ~FollowSymbolData()
    {
        closeTempDocuments();
        if (virtualFuncAssistProcessor)
            virtualFuncAssistProcessor->cancel();
        for (const MessageId &id : qAsConst(pendingSymbolInfoRequests))
            q->cancelRequest(id);
        for (const MessageId &id : qAsConst(pendingGotoImplRequests))
            q->cancelRequest(id);
        for (const MessageId &id : qAsConst(pendingGotoDefRequests))
            q->cancelRequest(id);
    }

    void closeTempDocuments()
    {
        for (const Utils::FilePath &fp : qAsConst(openedFiles)) {
            if (!q->documentForFilePath(fp))
                q->closeExtraFile(fp);
        }
        openedFiles.clear();
    }

    bool isEditorWidgetStillAlive() const
    {
        return Utils::anyOf(EditorManager::visibleEditors(), [this](IEditor *editor) {
            const auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor);
            return textEditor && dynamic_cast<CppEditor::CppEditorWidgetInterface *>(
                    textEditor->editorWidget()) == editorWidget;
        });
    }

    ClangdClient * const q;
    const quint64 id;
    const QTextCursor cursor;
    CppEditor::CppEditorWidgetInterface * const editorWidget;
    const DocumentUri uri;
    const Utils::ProcessLinkCallback callback;
    VirtualFunctionAssistProvider virtualFuncAssistProvider;
    QList<MessageId> pendingSymbolInfoRequests;
    QList<MessageId> pendingGotoImplRequests;
    QList<MessageId> pendingGotoDefRequests;
    const bool openInSplit;

    Utils::Link defLink;
    QList<Utils::Link> allLinks;
    QHash<Utils::Link, Utils::Link> declDefMap;
    Utils::optional<AstNode> cursorNode;
    AstNode defLinkNode;
    SymbolDataList symbolsToDisplay;
    std::set<Utils::FilePath> openedFiles;
    VirtualFunctionAssistProcessor *virtualFuncAssistProcessor = nullptr;
    bool finished = false;
};

class SwitchDeclDefData {
public:
    SwitchDeclDefData(quint64 id, TextEditor::TextDocument *doc, const QTextCursor &cursor,
                      CppEditor::CppEditorWidgetInterface *editorWidget,
                      Utils::ProcessLinkCallback &&callback)
        : id(id), document(doc), uri(DocumentUri::fromFilePath(doc->filePath())),
          cursor(cursor), editorWidget(editorWidget), callback(std::move(callback)) {}

    Utils::optional<AstNode> getFunctionNode() const
    {
        QTC_ASSERT(ast, return {});

        const QList<AstNode> path = getAstPath(*ast, Range(cursor));
        for (auto it = path.rbegin(); it != path.rend(); ++it) {
            if (it->role() == "declaration"
                    && (it->kind() == "CXXMethod" || it->kind() == "CXXConversion"
                        || it->kind() == "CXXConstructor" || it->kind() == "CXXDestructor")) {
                return *it;
            }
        }
        return {};
    }

    QTextCursor cursorForFunctionName(const AstNode &functionNode) const
    {
        QTC_ASSERT(docSymbols, return {});

        const auto symbolList = Utils::get_if<QList<DocumentSymbol>>(&*docSymbols);
        if (!symbolList)
            return {};
        const Range &astRange = functionNode.range();
        QList symbolsToCheck = *symbolList;
        while (!symbolsToCheck.isEmpty()) {
            const DocumentSymbol symbol = symbolsToCheck.takeFirst();
            if (symbol.range() == astRange)
                return symbol.selectionRange().start().toTextCursor(document->document());
            if (symbol.range().contains(astRange))
                symbolsToCheck << symbol.children().value_or(QList<DocumentSymbol>());
        }
        return {};
    }

    const quint64 id;
    const QPointer<TextEditor::TextDocument> document;
    const DocumentUri uri;
    const QTextCursor cursor;
    CppEditor::CppEditorWidgetInterface * const editorWidget;
    Utils::ProcessLinkCallback callback;
    Utils::optional<DocumentSymbolsResult> docSymbols;
    Utils::optional<AstNode> ast;
};

class LocalRefsData {
public:
    LocalRefsData(quint64 id, TextEditor::TextDocument *doc, const QTextCursor &cursor,
                      CppEditor::RefactoringEngineInterface::RenameCallback &&callback)
        : id(id), document(doc), cursor(cursor), callback(std::move(callback)),
          uri(DocumentUri::fromFilePath(doc->filePath())), revision(doc->document()->revision())
    {}

    ~LocalRefsData()
    {
        if (callback)
            callback({}, {}, revision);
    }

    const quint64 id;
    const QPointer<TextEditor::TextDocument> document;
    const QTextCursor cursor;
    CppEditor::RefactoringEngineInterface::RenameCallback callback;
    const DocumentUri uri;
    const int revision;
};

class DiagnosticsCapabilities : public JsonObject
{
public:
    using JsonObject::JsonObject;
    void enableCategorySupport() { insert("categorySupport", true); }
    void enableCodeActionsInline() {insert("codeActionsInline", true);}
};

class ClangdTextDocumentClientCapabilities : public TextDocumentClientCapabilities
{
public:
    using TextDocumentClientCapabilities::TextDocumentClientCapabilities;


    void setPublishDiagnostics(const DiagnosticsCapabilities &caps)
    { insert("publishDiagnostics", caps); }
};

class DoxygenAssistProcessor : public TextEditor::IAssistProcessor
{
public:
    DoxygenAssistProcessor(int position, unsigned completionOperator,
                           const ProposalHandler &handler)
        : m_position(position), m_completionOperator(completionOperator), m_handler(handler) {}

private:
    TextEditor::IAssistProposal *perform(const TextEditor::AssistInterface *) override
    {
        QList<TextEditor::AssistProposalItemInterface *> completions;
        for (int i = 1; i < CppEditor::T_DOXY_LAST_TAG; ++i) {
            const auto item = new ClangPreprocessorAssistProposalItem;
            item->setText(QLatin1String(CppEditor::doxygenTagSpell(i)));
            item->setIcon(CPlusPlus::Icons::keywordIcon());
            item->setCompletionOperator(m_completionOperator);
            completions.append(item);
        }
        TextEditor::GenericProposalModelPtr model(new TextEditor::GenericProposalModel);
        model->loadContent(completions);
        const auto proposal = new TextEditor::GenericProposal(m_position, model);
        if (m_handler) {
            m_handler(proposal);
            return nullptr;
        }
        return proposal;
    }

    const int m_position;
    const unsigned m_completionOperator;
    const ProposalHandler m_handler;
};

class DoxygenAssistProvider : public TextEditor::IAssistProvider
{
public:
    void setProposalHandler(const ProposalHandler &handler) { m_proposalHandler = handler; }

    void setParameters(int position, unsigned completionOperator)
    {
        m_position = position;
        m_completionOperator = completionOperator;
    }

private:
    RunType runType() const override { return Synchronous; }
    TextEditor::IAssistProcessor *createProcessor() const override
    {
        return new DoxygenAssistProcessor(m_position, m_completionOperator, m_proposalHandler);
    }

    ProposalHandler m_proposalHandler;
    int m_position = 0;
    unsigned m_completionOperator = 0;
};

class ClangdClient::Private
{
public:
    Private(ClangdClient *q, Project *project)
        : q(q), settings(CppEditor::ClangdProjectSettings(project).settings()) {}

    void findUsages(TextEditor::TextDocument *document, const QTextCursor &cursor,
                    const QString &searchTerm, const Utils::optional<QString> &replacement);
    void handleFindUsagesResult(quint64 key, const QList<Location> &locations);
    static void handleRenameRequest(const SearchResult *search,
                                    const ReplacementData &replacementData,
                                    const QString &newSymbolName,
                                    const QList<Core::SearchResultItem> &checkedItems,
                                    bool preserveCase);
    void addSearchResultsForFile(ReferencesData &refData, const Utils::FilePath &file,
                                 const ReferencesFileData &fileData);
    void reportAllSearchResultsAndFinish(ReferencesData &data);
    void finishSearch(const ReferencesData &refData, bool canceled);

    void handleGotoDefinitionResult();
    void sendGotoImplementationRequest(const Utils::Link &link);
    void handleGotoImplementationResult(const GotoImplementationRequest::Response &response);
    void handleDocumentInfoResults();

    void handleDeclDefSwitchReplies();

    QString searchTermFromCursor(const QTextCursor &cursor) const;

    void setHelpItemForTooltip(const MessageId &token, const QString &fqn = {},
                               HelpItem::Category category = HelpItem::Unknown,
                               const QString &type = {});

    void handleSemanticTokens(TextEditor::TextDocument *doc,
                              const QList<ExpandedSemanticToken> &tokens);

    void applyCompletionItem(const CompletionItem &item,
                             TextEditor::TextDocumentManipulatorInterface &manipulator,
                             QChar typedChar);

    ClangdClient * const q;
    const CppEditor::ClangdSettings::Data settings;
    DoxygenAssistProvider doxygenAssistProvider;
    QHash<quint64, ReferencesData> runningFindUsages;
    Utils::optional<FollowSymbolData> followSymbolData;
    Utils::optional<SwitchDeclDefData> switchDeclDefData;
    Utils::optional<LocalRefsData> localRefsData;
    Utils::optional<QVersionNumber> versionNumber;
    std::unordered_map<TextEditor::TextDocument *, CppEditor::SemanticHighlighter> highlighters;
    quint64 nextJobId = 0;
    bool isFullyIndexed = false;
    bool isTesting = false;
};

class ClangdCompletionCapabilities : public TextDocumentClientCapabilities::CompletionCapabilities
{
public:
    explicit ClangdCompletionCapabilities(const JsonObject &object)
        : TextDocumentClientCapabilities::CompletionCapabilities(object)
    {
        insert("editsNearCursor", true); // For dot-to-arrow correction.
    }
};

ClangdClient::ClangdClient(Project *project, const Utils::FilePath &jsonDbDir)
    : Client(clientInterface(project, jsonDbDir)), d(new Private(this, project))
{
    setName(tr("clangd"));
    LanguageFilter langFilter;
    langFilter.mimeTypes = QStringList{"text/x-chdr", "text/x-csrc",
            "text/x-c++hdr", "text/x-c++src", "text/x-objc++src", "text/x-objcsrc"};
    setSupportedLanguage(langFilter);
    setActivateDocumentAutomatically(true);
    if (!project) {
        QJsonObject initOptions;
        const QStringList clangOptions = createClangOptions(
                    *CppEditor::CppModelManager::instance()->fallbackProjectPart(), {},
                    warningsConfigForProject(nullptr), optionsForProject(nullptr));
        initOptions.insert("fallbackFlags", QJsonArray::fromStringList(clangOptions));
        setInitializationOptions(initOptions);
    }
    ClientCapabilities caps = Client::defaultClientCapabilities();
    Utils::optional<TextDocumentClientCapabilities> textCaps = caps.textDocument();
    if (textCaps) {
        ClangdTextDocumentClientCapabilities clangdTextCaps(*textCaps);
        clangdTextCaps.clearDocumentHighlight();
        DiagnosticsCapabilities diagnostics;
        diagnostics.enableCategorySupport();
        diagnostics.enableCodeActionsInline();
        clangdTextCaps.setPublishDiagnostics(diagnostics);
        Utils::optional<TextDocumentClientCapabilities::CompletionCapabilities> completionCaps
                = textCaps->completion();
        if (completionCaps)
            clangdTextCaps.setCompletion(ClangdCompletionCapabilities(*completionCaps));
        caps.setTextDocument(clangdTextCaps);
    }
    caps.clearExperimental();
    setClientCapabilities(caps);
    setLocatorsEnabled(false);
    setAutoRequestCodeActions(false); // clangd sends code actions inside diagnostics
    setProgressTitleForToken(indexingToken(), tr("Parsing C/C++ Files (clangd)"));
    setCurrentProject(project);
    setDocumentChangeUpdateThreshold(d->settings.documentUpdateThreshold);

    const auto textMarkCreator = [this](const Utils::FilePath &filePath,
            const Diagnostic &diag) { return new ClangdTextMark(filePath, diag, this); };
    const auto hideDiagsHandler = []{ ClangDiagnosticManager::clearTaskHubIssues(); };
    setDiagnosticsHandlers(textMarkCreator, hideDiagsHandler);

    static const auto symbolStringifier = [](SymbolKind kind, const QString &name,
            const QString &detail) -> QString
    {
        switch (kind) {
        case LanguageServerProtocol::SymbolKind::Constructor:
            return name + detail;
        case LanguageServerProtocol::SymbolKind::Method:
        case LanguageServerProtocol::SymbolKind::Function: {
            const int parenOffset = detail.indexOf(" (");
            if (parenOffset == -1)
                return name;
            return name + detail.mid(parenOffset + 1) + " -> " + detail.mid(0, parenOffset);
        }
        case LanguageServerProtocol::SymbolKind::Variable:
        case LanguageServerProtocol::SymbolKind::Field:
        case LanguageServerProtocol::SymbolKind::Constant:
            if (detail.isEmpty())
                return name;
            return name + " -> " + detail;
        default:
            return name;
        }
    };
    setSymbolStringifier(symbolStringifier);

    setSemanticTokensHandler([this](TextEditor::TextDocument *doc,
                                    const QList<ExpandedSemanticToken> &tokens) {
        d->handleSemanticTokens(doc, tokens);
    });

    hoverHandler()->setHelpItemProvider([this](const HoverRequest::Response &response,
                                               const DocumentUri &uri) {
        gatherHelpItemForTooltip(response, uri);
    });
    setCompletionItemsTransformer([](const Utils::FilePath &filePath, const QString &content,
                                     int pos,  const QList<CompletionItem> &items) {
        qCDebug(clangdLog) << "received" << items.count() << "completions";

        // If there are signals among the candidates, we employ the built-in code model to find out
        // whether the cursor was on the second argument of a (dis)connect() call.
        // If so, we offer only signals, as nothing else makes sense in that context.
        static const auto criterion = [](const CompletionItem &ci) {
            const Utils::optional<MarkupOrString> doc = ci.documentation();
            if (!doc)
                return false;
            QString docText;
            if (Utils::holds_alternative<QString>(*doc))
                docText = Utils::get<QString>(*doc);
            else if (Utils::holds_alternative<MarkupContent>(*doc))
                docText = Utils::get<MarkupContent>(*doc).content();
            return docText.contains("Annotation: qt_signal");
        };
        if (pos != -1 && Utils::anyOf(items, criterion) && CppEditor::CppModelManager::instance()
                ->positionRequiresSignal(filePath.toString(), content.toUtf8(), pos)) {
            return Utils::filtered(items, criterion);
        }
        return items;
    });
    setCompletionApplyHelper([this](const CompletionItem &item,
            TextEditor::TextDocumentManipulatorInterface &manipulator, QChar typedChar) {
        d->applyCompletionItem(item, manipulator, typedChar);
    });

    connect(this, &Client::workDone, this,
            [this, p = QPointer(project)](const ProgressToken &token) {
        const QString * const val = Utils::get_if<QString>(&token);
        if (val && *val == indexingToken()) {
            d->isFullyIndexed = true;
            emit indexingFinished();
#ifdef WITH_TESTS
            if (p)
                emit p->indexingFinished("Indexer.Clangd");
#endif
        }
    });

    connect(this, &Client::initialized, this, [this] {
        // If we get this signal while there are pending searches, it means that
        // the client was re-initialized, i.e. clangd crashed.

        // Report all search results found so far.
        for (quint64 key : d->runningFindUsages.keys())
            d->reportAllSearchResultsAndFinish(d->runningFindUsages[key]);
        QTC_CHECK(d->runningFindUsages.isEmpty());
    });

    connect(documentSymbolCache(), &DocumentSymbolCache::gotSymbols, this,
            [this](const DocumentUri &uri, const DocumentSymbolsResult &symbols) {
        if (!d->switchDeclDefData || d->switchDeclDefData->uri != uri)
            return;
        d->switchDeclDefData->docSymbols = symbols;
        if (d->switchDeclDefData->ast)
            d->handleDeclDefSwitchReplies();
    });

    start();
}

ClangdClient::~ClangdClient()
{
    if (d->followSymbolData) {
        d->followSymbolData->openedFiles.clear();
        d->followSymbolData->pendingSymbolInfoRequests.clear();
        d->followSymbolData->pendingGotoImplRequests.clear();
        d->followSymbolData->pendingGotoDefRequests.clear();
    }
    delete d;
}

bool ClangdClient::isFullyIndexed() const { return d->isFullyIndexed; }

void ClangdClient::openExtraFile(const Utils::FilePath &filePath, const QString &content)
{
    QFile cxxFile(filePath.toString());
    if (content.isEmpty() && !cxxFile.open(QIODevice::ReadOnly))
        return;
    TextDocumentItem item;
    item.setLanguageId("cpp");
    item.setUri(DocumentUri::fromFilePath(filePath));
    item.setText(!content.isEmpty() ? content : QString::fromUtf8(cxxFile.readAll()));
    item.setVersion(0);
    sendContent(DidOpenTextDocumentNotification(DidOpenTextDocumentParams(item)),
                SendDocUpdates::Ignore);
}

void ClangdClient::closeExtraFile(const Utils::FilePath &filePath)
{
    sendContent(DidCloseTextDocumentNotification(DidCloseTextDocumentParams(
            TextDocumentIdentifier{DocumentUri::fromFilePath(filePath)})),
                SendDocUpdates::Ignore);
}

void ClangdClient::findUsages(TextEditor::TextDocument *document, const QTextCursor &cursor,
                              const Utils::optional<QString> &replacement)
{
    // Quick check: Are we even on anything searchable?
    if (d->searchTermFromCursor(cursor).isEmpty())
        return;

    // Get the proper spelling of the search term from clang, so we can put it into the
    // search widget.
    const TextDocumentIdentifier docId(DocumentUri::fromFilePath(document->filePath()));
    const TextDocumentPositionParams params(docId, Range(cursor).start());
    SymbolInfoRequest symReq(params);
    symReq.setResponseCallback([this, doc = QPointer(document), cursor, replacement]
                               (const SymbolInfoRequest::Response &response) {
        if (!doc)
            return;
        const auto result = response.result();
        if (!result)
            return;
        const auto list = Utils::get_if<QList<SymbolDetails>>(&result.value());
        if (!list || list->isEmpty())
            return;
        const SymbolDetails &sd = list->first();
        if (sd.name().isEmpty())
            return;
        d->findUsages(doc.data(), cursor, sd.name(), replacement);
    });
    sendContent(symReq);
}

void ClangdClient::handleDiagnostics(const PublishDiagnosticsParams &params)
{
    const DocumentUri &uri = params.uri();
    Client::handleDiagnostics(params);
    for (const Diagnostic &diagnostic : params.diagnostics()) {
        const ClangdDiagnostic clangdDiagnostic(diagnostic);
        for (const CodeAction &action : clangdDiagnostic.codeActions().value_or(QList<CodeAction>{}))
            LanguageClient::updateCodeActionRefactoringMarker(this, action, uri);
    }
}

void ClangdClient::handleDocumentClosed(TextEditor::TextDocument *doc)
{
    d->highlighters.erase(doc);
}

QVersionNumber ClangdClient::versionNumber() const
{
    if (d->versionNumber)
        return d->versionNumber.value();

    const QRegularExpression versionPattern("^clangd version (\\d+)\\.(\\d+)\\.(\\d+).*$");
    QTC_CHECK(versionPattern.isValid());
    const QRegularExpressionMatch match = versionPattern.match(serverVersion());
    if (match.isValid()) {
        d->versionNumber.emplace({match.captured(1).toInt(), match.captured(2).toInt(),
                                 match.captured(3).toInt()});
    } else {
        qCWarning(clangdLog) << "Failed to parse clangd server string" << serverVersion();
        d->versionNumber.emplace({0});
    }
    return d->versionNumber.value();
}

CppEditor::ClangdSettings::Data ClangdClient::settingsData() const { return d->settings; }

void ClangdClient::Private::findUsages(TextEditor::TextDocument *document,
        const QTextCursor &cursor, const QString &searchTerm,
        const Utils::optional<QString> &replacement)
{
    ReferencesData refData;
    refData.key = nextJobId++;
    if (replacement) {
        ReplacementData replacementData;
        replacementData.oldSymbolName = searchTerm;
        replacementData.newSymbolName = *replacement;
        if (replacementData.newSymbolName.isEmpty())
            replacementData.newSymbolName = replacementData.oldSymbolName;
        refData.replacementData = replacementData;
    }

    refData.search = SearchResultWindow::instance()->startNewSearch(
                tr("C++ Usages:"),
                {},
                searchTerm,
                replacement ? SearchResultWindow::SearchAndReplace : SearchResultWindow::SearchOnly,
                SearchResultWindow::PreserveCaseDisabled,
                "CppEditor");
    if (refData.categorize)
        refData.search->setFilter(new CppEditor::CppSearchResultFilter);
    if (refData.replacementData) {
        refData.search->setTextToReplace(refData.replacementData->newSymbolName);
        const auto renameFilesCheckBox = new QCheckBox;
        renameFilesCheckBox->setVisible(false);
        refData.search->setAdditionalReplaceWidget(renameFilesCheckBox);
        const auto renameHandler =
                [search = refData.search](const QString &newSymbolName,
                                          const QList<SearchResultItem> &checkedItems,
                                          bool preserveCase) {
            const auto replacementData = search->userData().value<ReplacementData>();
            Private::handleRenameRequest(search, replacementData, newSymbolName, checkedItems,
                                         preserveCase);
        };
        connect(refData.search, &SearchResult::replaceButtonClicked, renameHandler);
    }
    connect(refData.search, &SearchResult::activated, [](const SearchResultItem& item) {
        Core::EditorManager::openEditorAtSearchResult(item);
    });
    SearchResultWindow::instance()->popup(IOutputPane::ModeSwitch | IOutputPane::WithFocus);
    runningFindUsages.insert(refData.key, refData);

    const Utils::optional<MessageId> requestId = q->symbolSupport().findUsages(
                document, cursor, [this, key = refData.key](const QList<Location> &locations) {
        handleFindUsagesResult(key, locations);
    });

    if (!requestId) {
        finishSearch(refData, false);
        return;
    }
    QObject::connect(refData.search, &SearchResult::cancelled, q, [this, requestId, key = refData.key] {
        const auto refData = runningFindUsages.find(key);
        if (refData == runningFindUsages.end())
            return;
        q->cancelRequest(*requestId);
        refData->canceled = true;
        refData->search->disconnect(q);
        finishSearch(*refData, true);
    });
}

void ClangdClient::enableTesting()
{
    d->isTesting = true;
    setCompletionProposalHandler([this](TextEditor::IAssistProposal *proposal) {
        emit proposalReady(proposal);
    });
    setFunctionHintProposalHandler([this](TextEditor::IAssistProposal *proposal) {
        emit proposalReady(proposal);
    });
    d->doxygenAssistProvider.setProposalHandler([this](TextEditor::IAssistProposal *proposal) {
        QMetaObject::invokeMethod(this, [this, proposal] { emit proposalReady(proposal); },
                                  Qt::QueuedConnection);
    });
}

void ClangdClient::openEditorDocument(TextEditor::BaseTextEditor *editor)
{
    if (!documentOpen(editor->textDocument()))
        openDocument(editor->textDocument());
    const auto assistRequestHandler = [self = QPointer(this)](
            TextEditor::TextEditorWidget *editorWidget, TextEditor::AssistKind kind,
            TextEditor::IAssistProvider *provider) {
        if (!self)
            return false;
        if (kind != TextEditor::Completion || provider)
            return false;
        ClangCompletionContextAnalyzer contextAnalyzer(editorWidget->document(),
                                                       editorWidget->position(), false, {});
        contextAnalyzer.analyze();
        self->setSnippetsGroup(contextAnalyzer.addSnippets()
                               ? CppEditor::Constants::CPP_SNIPPETS_GROUP_ID : QString());
        switch (contextAnalyzer.completionAction()) {
        case ClangCompletionContextAnalyzer::PassThroughToLibClangAfterLeftParen:
            qCDebug(clangdLog) << "completion changed to function hint";
            editorWidget->invokeAssist(TextEditor::FunctionHint, provider);
            return true;
        case ClangCompletionContextAnalyzer::CompleteDoxygenKeyword:
            self->d->doxygenAssistProvider.setParameters(contextAnalyzer.positionForProposal(),
                                                         contextAnalyzer.completionOperator());
            editorWidget->invokeAssist(kind, &self->d->doxygenAssistProvider);
            return true;
        default:
            break;
        }
        return false;
    };
    editor->editorWidget()->setAssistRequestHandler(assistRequestHandler);
}

void ClangdClient::Private::handleFindUsagesResult(quint64 key, const QList<Location> &locations)
{
    const auto refData = runningFindUsages.find(key);
    if (refData == runningFindUsages.end())
        return;
    if (!refData->search || refData->canceled) {
        finishSearch(*refData, true);
        return;
    }
    refData->search->disconnect(q);

    qCDebug(clangdLog) << "found" << locations.size() << "locations";
    if (locations.isEmpty()) {
        finishSearch(*refData, false);
        return;
    }

    QObject::connect(refData->search, &SearchResult::cancelled, q, [this, key] {
        const auto refData = runningFindUsages.find(key);
        if (refData == runningFindUsages.end())
            return;
        refData->canceled = true;
        refData->search->disconnect(q);
        for (const MessageId &id : qAsConst(refData->pendingAstRequests))
            q->cancelRequest(id);
        refData->pendingAstRequests.clear();
        finishSearch(*refData, true);
    });

    for (const Location &loc : locations) // TODO: Can contain duplicates. Rather fix in clang than work around it here.
        refData->fileData[loc.uri()].rangesAndLineText << qMakePair(loc.range(), QString()); // TODO: Can we assume that locations for the same file are grouped?
    for (auto it = refData->fileData.begin(); it != refData->fileData.end(); ++it) {
        const QStringList lines = SymbolSupport::getFileContents(it.key().toFilePath());
        it->fileContent = lines.join('\n');
        for (auto &rangeWithText : it.value().rangesAndLineText) {
            const int lineNo = rangeWithText.first.start().line();
            if (lineNo >= 0 && lineNo < lines.size())
                rangeWithText.second = lines.at(lineNo);
        }
    }

    qCDebug(clangdLog) << "document count is" << refData->fileData.size();
    if (refData->replacementData || q->versionNumber() < QVersionNumber(13)
            || !refData->categorize) {
        qCDebug(clangdLog) << "skipping AST retrieval";
        reportAllSearchResultsAndFinish(*refData);
        return;
    }

    for (auto it = refData->fileData.begin(); it != refData->fileData.end(); ++it) {
        const bool extraOpen = !q->documentForFilePath(it.key().toFilePath());
        if (extraOpen)
            q->openExtraFile(it.key().toFilePath(), it->fileContent);
        it->fileContent.clear();

        AstParams params;
        params.setTextDocument(TextDocumentIdentifier(it.key()));
        AstRequest request(params);
        request.setResponseCallback([this, key, loc = it.key(), request]
                                    (AstRequest::Response response) {
            qCDebug(clangdLog) << "AST response for" << loc.toFilePath();
            const auto refData = runningFindUsages.find(key);
            if (refData == runningFindUsages.end())
                return;
            if (!refData->search || refData->canceled)
                return;
            ReferencesFileData &data = refData->fileData[loc];
            const auto result = response.result();
            if (result)
                data.ast = *result;
            refData->pendingAstRequests.removeOne(request.id());
            qCDebug(clangdLog) << refData->pendingAstRequests.size()
                               << "AST requests still pending";
            addSearchResultsForFile(*refData, loc.toFilePath(), data);
            refData->fileData.remove(loc);
            if (refData->pendingAstRequests.isEmpty()) {
                qDebug(clangdLog) << "retrieved all ASTs";
                finishSearch(*refData, false);
            }
        });
        qCDebug(clangdLog) << "requesting AST for" << it.key().toFilePath();
        refData->pendingAstRequests << request.id();
        q->sendContent(request, SendDocUpdates::Ignore);

        if (extraOpen)
            q->closeExtraFile(it.key().toFilePath());
    }
}

void ClangdClient::Private::handleRenameRequest(const SearchResult *search,
                                                const ReplacementData &replacementData,
                                                const QString &newSymbolName,
                                                const QList<SearchResultItem> &checkedItems,
                                                bool preserveCase)
{
    const Utils::FilePaths filePaths = TextEditor::BaseFileFind::replaceAll(newSymbolName,
                                                                            checkedItems,
                                                                            preserveCase);
    if (!filePaths.isEmpty())
        SearchResultWindow::instance()->hide();

    const auto renameFilesCheckBox = qobject_cast<QCheckBox *>(search->additionalReplaceWidget());
    QTC_ASSERT(renameFilesCheckBox, return);
    if (!renameFilesCheckBox->isChecked())
        return;

    QVector<Node *> fileNodes;
    for (const Utils::FilePath &file : replacementData.fileRenameCandidates) {
        Node * const node = ProjectTree::nodeForFile(file);
        if (node)
            fileNodes << node;
    }
    if (!fileNodes.isEmpty())
        CppEditor::renameFilesForSymbol(replacementData.oldSymbolName, newSymbolName, fileNodes);
}

void ClangdClient::Private::addSearchResultsForFile(ReferencesData &refData,
        const Utils::FilePath &file,
        const ReferencesFileData &fileData)
{
    QList<SearchResultItem> items;
    qCDebug(clangdLog) << file << "has valid AST:" << fileData.ast.isValid();
    for (const auto &rangeWithText : fileData.rangesAndLineText) {
        const Range &range = rangeWithText.first;
        const Usage::Type usageType = fileData.ast.isValid()
                ? getUsageType(getAstPath(fileData.ast, qAsConst(range)))
                : Usage::Type::Other;
        SearchResultItem item;
        item.setUserData(int(usageType));
        item.setStyle(CppEditor::colorStyleForUsageType(usageType));
        item.setFilePath(file);
        item.setMainRange(SymbolSupport::convertRange(range));
        item.setUseTextEditorFont(true);
        item.setLineText(rangeWithText.second);
        if (refData.search->supportsReplace()) {
            const bool fileInSession = SessionManager::projectForFile(file);
            item.setSelectForReplacement(fileInSession);
            if (fileInSession && file.baseName().compare(
                        refData.replacementData->oldSymbolName,
                        Qt::CaseInsensitive) == 0) {
                refData.replacementData->fileRenameCandidates << file; // TODO: We want to do this only for types. Use SymbolInformation once we have it.
            }
        }
        items << item;
    }
    if (isTesting)
        emit q->foundReferences(items);
    else
        refData.search->addResults(items, SearchResult::AddOrdered);
}

void ClangdClient::Private::reportAllSearchResultsAndFinish(ReferencesData &refData)
{
    for (auto it = refData.fileData.begin(); it != refData.fileData.end(); ++it)
        addSearchResultsForFile(refData, it.key().toFilePath(), it.value());
    finishSearch(refData, refData.canceled);
}

void ClangdClient::Private::finishSearch(const ReferencesData &refData, bool canceled)
{
    if (isTesting) {
        emit q->findUsagesDone();
    } else if (refData.search) {
        refData.search->finishSearch(canceled);
        refData.search->disconnect(q);
        if (refData.replacementData) {
            const auto renameCheckBox = qobject_cast<QCheckBox *>(
                        refData.search->additionalReplaceWidget());
            QTC_CHECK(renameCheckBox);
            const QSet<Utils::FilePath> files = refData.replacementData->fileRenameCandidates;
            renameCheckBox->setText(tr("Re&name %n files", nullptr, files.size()));
            const QStringList filesForUser = Utils::transform<QStringList>(files,
                        [](const Utils::FilePath &fp) { return fp.toUserOutput(); });
            renameCheckBox->setToolTip(tr("Files:\n%1").arg(filesForUser.join('\n')));
            renameCheckBox->setVisible(true);
            refData.search->setUserData(QVariant::fromValue(*refData.replacementData));
        }
    }
    runningFindUsages.remove(refData.key);
}

void ClangdClient::followSymbol(
        TextEditor::TextDocument *document,
        const QTextCursor &cursor,
        CppEditor::CppEditorWidgetInterface *editorWidget,
        Utils::ProcessLinkCallback &&callback,
        bool resolveTarget,
        bool openInSplit
        )
{
    QTC_ASSERT(documentOpen(document), openDocument(document));
    if (!resolveTarget) {
        d->followSymbolData.reset();
        symbolSupport().findLinkAt(document, cursor, std::move(callback), false);
        return;
    }

    qCDebug(clangdLog) << "follow symbol requested" << document->filePath()
                       << cursor.blockNumber() << cursor.positionInBlock();
    d->followSymbolData.emplace(this, ++d->nextJobId, cursor, editorWidget,
                                DocumentUri::fromFilePath(document->filePath()),
                                std::move(callback), openInSplit);

    // Step 1: Follow the symbol via "Go to Definition". At the same time, request the
    //         AST node corresponding to the cursor position, so we can find out whether
    //         we have to look for overrides.
    const auto gotoDefCallback = [this, id = d->followSymbolData->id](const Utils::Link &link) {
        qCDebug(clangdLog) << "received go to definition response";
        if (!link.hasValidTarget()) {
            d->followSymbolData.reset();
            return;
        }
        if (!d->followSymbolData || id != d->followSymbolData->id)
            return;
        d->followSymbolData->defLink = link;
        if (d->followSymbolData->cursorNode)
            d->handleGotoDefinitionResult();
    };
    symbolSupport().findLinkAt(document, cursor, std::move(gotoDefCallback), true);

    if (versionNumber() < QVersionNumber(12)) {
        d->followSymbolData->cursorNode.emplace(AstNode());
        return;
    }

    AstRequest astRequest(AstParams(TextDocumentIdentifier(d->followSymbolData->uri),
                                    Range(cursor)));
    astRequest.setResponseCallback([this, id = d->followSymbolData->id](
                                   const AstRequest::Response &response) {
        qCDebug(clangdLog) << "received ast response for cursor";
        if (!d->followSymbolData || d->followSymbolData->id != id)
            return;
        const auto result = response.result();
        if (result)
            d->followSymbolData->cursorNode = *result;
        else
            d->followSymbolData->cursorNode.emplace(AstNode());
        if (d->followSymbolData->defLink.hasValidTarget())
            d->handleGotoDefinitionResult();
    });
    sendContent(astRequest, SendDocUpdates::Ignore);
}

void ClangdClient::switchDeclDef(TextEditor::TextDocument *document, const QTextCursor &cursor,
                                 CppEditor::CppEditorWidgetInterface *editorWidget,
                                 Utils::ProcessLinkCallback &&callback)
{
    QTC_ASSERT(documentOpen(document), openDocument(document));

    qCDebug(clangdLog) << "switch decl/dev requested" << document->filePath()
                       << cursor.blockNumber() << cursor.positionInBlock();
    d->switchDeclDefData.emplace(++d->nextJobId, document, cursor, editorWidget,
                                 std::move(callback));

    // Retrieve AST and document symbols.
    AstParams astParams;
    astParams.setTextDocument(TextDocumentIdentifier(d->switchDeclDefData->uri));
    AstRequest astRequest(astParams);
    astRequest.setResponseCallback([this, id = d->switchDeclDefData->id]
                                   (const AstRequest::Response &response) {
        qCDebug(clangdLog) << "received ast for decl/def switch";
        if (!d->switchDeclDefData || d->switchDeclDefData->id != id
                || !d->switchDeclDefData->document)
            return;
        const auto result = response.result();
        if (!result) {
            d->switchDeclDefData.reset();
            return;
        }
        d->switchDeclDefData->ast = *result;
        if (d->switchDeclDefData->docSymbols)
            d->handleDeclDefSwitchReplies();

    });
    sendContent(astRequest, SendDocUpdates::Ignore);
    documentSymbolCache()->requestSymbols(d->switchDeclDefData->uri);

}

void ClangdClient::findLocalUsages(TextEditor::TextDocument *document, const QTextCursor &cursor,
        CppEditor::RefactoringEngineInterface::RenameCallback &&callback)
{
    QTC_ASSERT(documentOpen(document), openDocument(document));

    qCDebug(clangdLog) << "local references requested" << document->filePath()
                       << (cursor.blockNumber() + 1) << (cursor.positionInBlock() + 1);

    d->localRefsData.emplace(++d->nextJobId, document, cursor, std::move(callback));
    const QString searchTerm = d->searchTermFromCursor(cursor);
    if (searchTerm.isEmpty()) {
        d->localRefsData.reset();
        return;
    }

    // Step 1: Go to definition
    const auto gotoDefCallback = [this, id = d->localRefsData->id](const Utils::Link &link) {
        qCDebug(clangdLog) << "received go to definition response" << link.targetFilePath
                           << link.targetLine << (link.targetColumn + 1);
        if (!d->localRefsData || id != d->localRefsData->id)
            return;
        if (!link.hasValidTarget()) {
            d->localRefsData.reset();
            return;
        }

        // Step 2: Get AST and check whether it's a local variable.
        AstRequest astRequest(AstParams(TextDocumentIdentifier(d->localRefsData->uri)));
        astRequest.setResponseCallback([this, link, id](const AstRequest::Response &response) {
            qCDebug(clangdLog) << "received ast response";
            if (!d->localRefsData || id != d->localRefsData->id)
                return;
            const auto result = response.result();
            if (!result || !d->localRefsData->document) {
                d->localRefsData.reset();
                return;
            }

            const Position linkPos(link.targetLine - 1, link.targetColumn);
            const QList<AstNode> astPath = getAstPath(*result, Range(linkPos, linkPos));
            bool isVar = false;
            for (auto it = astPath.rbegin(); it != astPath.rend(); ++it) {
                if (it->role() == "declaration" && it->kind() == "Function") {
                    if (!isVar)
                        break;

                    // Step 3: Find references.
                    qCDebug(clangdLog) << "finding references for local var";
                    symbolSupport().findUsages(d->localRefsData->document,
                                               d->localRefsData->cursor,
                                               [this, id](const QList<Location> &locations) {
                        qCDebug(clangdLog) << "found" << locations.size() << "local references";
                        if (!d->localRefsData || id != d->localRefsData->id)
                            return;
                        ClangBackEnd::SourceLocationsContainer container;
                        for (const Location &loc : locations) {
                            container.insertSourceLocation({}, loc.range().start().line() + 1,
                                                           loc.range().start().character() + 1);
                        }

                        // The callback only uses the symbol length, so we just create a dummy.
                        // Note that the calculation will be wrong for identifiers with
                        // embedded newlines, but we've never supported that.
                        QString symbol;
                        if (!locations.isEmpty()) {
                            const Range r = locations.first().range();
                            symbol = QString(r.end().character() - r.start().character(), 'x');
                        }
                        d->localRefsData->callback(symbol, container, d->localRefsData->revision);
                        d->localRefsData->callback = {};
                        d->localRefsData.reset();
                    });
                    return;
                }
                if (!isVar && it->role() == "declaration"
                        && (it->kind() == "Var" || it->kind() == "ParmVar")) {
                    isVar = true;
                }
            }
            d->localRefsData.reset();
        });
        qCDebug(clangdLog) << "sending ast request for link";
        sendContent(astRequest, SendDocUpdates::Ignore);
    };
    symbolSupport().findLinkAt(document, cursor, std::move(gotoDefCallback), true);
}

void ClangdClient::gatherHelpItemForTooltip(const HoverRequest::Response &hoverResponse,
                                            const DocumentUri &uri)
{
    if (const Utils::optional<Hover> result = hoverResponse.result()) {
        const HoverContent content = result->content();
        const MarkupContent * const markup = Utils::get_if<MarkupContent>(&content);
        if (markup) {
            const QString markupString = markup->content();

            // Macros aren't locatable via the AST, so parse the formatted string.
            static const QString magicMacroPrefix = "### macro `";
            if (markupString.startsWith(magicMacroPrefix)) {
                const int nameStart = magicMacroPrefix.length();
                const int closingQuoteIndex = markupString.indexOf('`', nameStart);
                if (closingQuoteIndex != -1) {
                    const QString macroName = markupString.mid(nameStart,
                                                               closingQuoteIndex - nameStart);
                    d->setHelpItemForTooltip(hoverResponse.id(), macroName, HelpItem::Macro);
                    return;
                }
            }

            // Is it the file path for an include directive?
            QString cleanString = markupString;
            cleanString.remove('`');
            const QStringList lines = cleanString.trimmed().split('\n');
            if (!lines.isEmpty()) {
                const auto filePath = Utils::FilePath::fromUserInput(lines.last().simplified());
                if (filePath.exists()) {
                    d->setHelpItemForTooltip(hoverResponse.id(), filePath.fileName(),
                                             HelpItem::Brief);
                    return;
                }
            }
        }
    }

    AstRequest req((AstParams(TextDocumentIdentifier(uri))));
    req.setResponseCallback([this, uri, hoverResponse](const AstRequest::Response &response) {
        const MessageId id = hoverResponse.id();
        const AstNode ast = response.result().value_or(AstNode());
        const Range range = hoverResponse.result()->range().value_or(Range());
        const QList<AstNode> path = getAstPath(ast, range);
        if (path.isEmpty()) {
            d->setHelpItemForTooltip(id);
            return;
        }
        AstNode node = path.last();
        if (node.role() == "expression" && node.kind() == "ImplicitCast") {
            const Utils::optional<QList<AstNode>> children = node.children();
            if (children && !children->isEmpty())
                node = children->first();
        }
        while (node.kind() == "Qualified") {
            const Utils::optional<QList<AstNode>> children = node.children();
            if (children && !children->isEmpty())
                node = children->first();
        }
        if (clangdLogAst().isDebugEnabled())
            node.print(0);

        QString type = node.type();
        const auto stripTemplatePartOffType = [&type] {
            const int angleBracketIndex = type.indexOf('<');
            if (angleBracketIndex != -1)
                type = type.left(angleBracketIndex);
        };

        const bool isMemberFunction = node.role() == "expression" && node.kind() == "Member"
                && (node.arcanaContains("member function") || type.contains('('));
        const bool isFunction = node.role() == "expression" && node.kind() == "DeclRef"
                && type.contains('(');
        if (isMemberFunction || isFunction) {
            const TextDocumentPositionParams params(TextDocumentIdentifier(uri), range.start());
            SymbolInfoRequest symReq(params);
            symReq.setResponseCallback([this, id, type, isFunction]
                                       (const SymbolInfoRequest::Response &response) {
                qCDebug(clangdLog) << "handling symbol info reply";
                QString fqn;
                if (const auto result = response.result()) {
                    if (const auto list = Utils::get_if<QList<SymbolDetails>>(&result.value())) {
                        if (!list->isEmpty()) {
                           const SymbolDetails &sd = list->first();
                           fqn = sd.containerName() + sd.name();
                        }
                    }
                }

                // Unfortunately, the arcana string contains the signature only for
                // free functions, so we can't distinguish member function overloads.
                // But since HtmlDocExtractor::getFunctionDescription() is always called
                // with mainOverload = true, such information would get ignored anyway.
                d->setHelpItemForTooltip(id, fqn, HelpItem::Function, isFunction ? type : "()");
            });
            sendContent(symReq, SendDocUpdates::Ignore);
            return;
        }
        if ((node.role() == "expression" && node.kind() == "DeclRef")
                || (node.role() == "declaration"
                    && (node.kind() == "Var" || node.kind() == "ParmVar"
                        || node.kind() == "Field"))) {
            if (node.arcanaContains("EnumConstant")) {
                d->setHelpItemForTooltip(id, node.detail().value_or(QString()),
                                         HelpItem::Enum, type);
                return;
            }
            stripTemplatePartOffType();
            type.remove("&").remove("*").remove("const ").remove(" const")
                    .remove("volatile ").remove(" volatile");
            type = type.simplified();
            if (type != "int" && !type.contains(" int")
                    && type != "char" && !type.contains(" char")
                    && type != "double" && !type.contains(" double")
                    && type != "float" && type != "bool") {
                d->setHelpItemForTooltip(id, type, node.qdocCategoryForDeclaration(
                                             HelpItem::ClassOrNamespace));
            } else {
                d->setHelpItemForTooltip(id);
            }
            return;
        }
        if (node.isNamespace()) {
            QString ns = node.detail().value_or(QString());
            for (auto it = path.rbegin() + 1; it != path.rend(); ++it) {
                if (it->isNamespace()) {
                    const QString name = it->detail().value_or(QString());
                    if (!name.isEmpty())
                        ns.prepend("::").prepend(name);
                }
            }
            d->setHelpItemForTooltip(hoverResponse.id(), ns, HelpItem::ClassOrNamespace);
            return;
        }
        if (node.role() == "type") {
            if (node.kind() == "Enum") {
                d->setHelpItemForTooltip(id, node.detail().value_or(QString()), HelpItem::Enum);
            } else if (node.kind() == "Record" || node.kind() == "TemplateSpecialization") {
                stripTemplatePartOffType();
                d->setHelpItemForTooltip(id, type, HelpItem::ClassOrNamespace);
            } else if (node.kind() == "Typedef") {
                d->setHelpItemForTooltip(id, type, HelpItem::Typedef);
            } else {
                d->setHelpItemForTooltip(id);
            }
            return;
        }
        if (node.role() == "expression" && node.kind() == "CXXConstruct") {
            const QString name = node.detail().value_or(QString());
            if (!name.isEmpty())
                type = name;
            d->setHelpItemForTooltip(id, type, HelpItem::ClassOrNamespace);
        }
        if (node.role() == "specifier" && node.kind() == "NamespaceAlias") {
            d->setHelpItemForTooltip(id, node.detail().value_or(QString()).chopped(2),
                                     HelpItem::ClassOrNamespace);
            return;
        }
        d->setHelpItemForTooltip(id);
    });
    sendContent(req, SendDocUpdates::Ignore);
}

void ClangdClient::Private::handleGotoDefinitionResult()
{
    QTC_ASSERT(followSymbolData->defLink.hasValidTarget(), return);

    qCDebug(clangdLog) << "handling go to definition result";

    // No dis-ambiguation necessary. Call back with the link and finish.
    if (!followSymbolData->cursorNode->mightBeAmbiguousVirtualCall()
            && !followSymbolData->cursorNode->isPureVirtualDeclaration()) {
        followSymbolData->callback(followSymbolData->defLink);
        followSymbolData.reset();
        return;
    }

    // Step 2: Get all possible overrides via "Go to Implementation".
    // Note that we have to do this for all member function calls, because
    // we cannot tell here whether the member function is virtual.
    followSymbolData->allLinks << followSymbolData->defLink;
    sendGotoImplementationRequest(followSymbolData->defLink);
}

void ClangdClient::Private::sendGotoImplementationRequest(const Utils::Link &link)
{
    if (!q->documentForFilePath(link.targetFilePath)
        && followSymbolData->openedFiles.insert(link.targetFilePath).second) {
        q->openExtraFile(link.targetFilePath);
    }
    const Position position(link.targetLine - 1, link.targetColumn);
    const TextDocumentIdentifier documentId(DocumentUri::fromFilePath(link.targetFilePath));
    GotoImplementationRequest req(TextDocumentPositionParams(documentId, position));
    req.setResponseCallback([this, id = followSymbolData->id, reqId = req.id()](
                            const GotoImplementationRequest::Response &response) {
        qCDebug(clangdLog) << "received go to implementation reply";
        if (!followSymbolData || id != followSymbolData->id)
            return;
        followSymbolData->pendingGotoImplRequests.removeOne(reqId);
        handleGotoImplementationResult(response);
    });
    q->sendContent(req, SendDocUpdates::Ignore);
    followSymbolData->pendingGotoImplRequests << req.id();
    qCDebug(clangdLog) << "sending go to implementation request" << link.targetLine;
}

void ClangdClient::Private::handleGotoImplementationResult(
        const GotoImplementationRequest::Response &response)
{
    if (const Utils::optional<GotoResult> &result = response.result()) {
        QList<Utils::Link> newLinks;
        if (const auto ploc = Utils::get_if<Location>(&*result))
            newLinks = {ploc->toLink()};
        if (const auto plloc = Utils::get_if<QList<Location>>(&*result))
            newLinks = Utils::transform(*plloc, &Location::toLink);
        for (const Utils::Link &link : qAsConst(newLinks)) {
            if (!followSymbolData->allLinks.contains(link)) {
                followSymbolData->allLinks << link;

                // We must do this recursively, because clangd reports only the first
                // level of overrides.
                sendGotoImplementationRequest(link);
            }
        }
    }

    // We didn't find any further candidates, so jump to the original definition link.
    if (followSymbolData->allLinks.size() == 1
            && followSymbolData->pendingGotoImplRequests.isEmpty()) {
        followSymbolData->callback(followSymbolData->allLinks.first());
        followSymbolData.reset();
        return;
    }

    // As soon as we know that there is more than one candidate, we start the code assist
    // procedure, to let the user know that things are happening.
    if (followSymbolData->allLinks.size() > 1 && !followSymbolData->virtualFuncAssistProcessor
            && followSymbolData->isEditorWidgetStillAlive()) {
        followSymbolData->editorWidget->invokeTextEditorWidgetAssist(
                    TextEditor::FollowSymbol, &followSymbolData->virtualFuncAssistProvider);
    }

    if (!followSymbolData->pendingGotoImplRequests.isEmpty())
        return;

    // Step 3: We are done looking for overrides, and we found at least one.
    //         Make a symbol info request for each link to get the class names.
    //         Also get the AST for the base declaration, so we can find out whether it's
    //         pure virtual and mark it accordingly.
    //         In addition, we need to follow all override links, because for these, clangd
    //         gives us the declaration instead of the definition.
    for (const Utils::Link &link : qAsConst(followSymbolData->allLinks)) {
        if (!q->documentForFilePath(link.targetFilePath)
                && followSymbolData->openedFiles.insert(link.targetFilePath).second) {
            q->openExtraFile(link.targetFilePath);
        }
        const TextDocumentIdentifier doc(DocumentUri::fromFilePath(link.targetFilePath));
        const Position pos(link.targetLine - 1, link.targetColumn);
        const TextDocumentPositionParams params(doc, pos);
        SymbolInfoRequest symReq(params);
        symReq.setResponseCallback([this, link, id = followSymbolData->id, reqId = symReq.id()](
                                const SymbolInfoRequest::Response &response) {
            qCDebug(clangdLog) << "handling symbol info reply"
                               << link.targetFilePath.toUserOutput() << link.targetLine;
            if (!followSymbolData || id != followSymbolData->id)
                return;
            if (const auto result = response.result()) {
                if (const auto list = Utils::get_if<QList<SymbolDetails>>(&result.value())) {
                    if (!list->isEmpty()) {
                        // According to the documentation, we should receive a single
                        // object here, but it's a list. No idea what it means if there's
                        // more than one entry. We choose the first one.
                        const SymbolDetails &sd = list->first();
                        followSymbolData->symbolsToDisplay << qMakePair(sd.containerName()
                                                                        + sd.name(), link);
                    }
                }
            }
            followSymbolData->pendingSymbolInfoRequests.removeOne(reqId);
            followSymbolData->virtualFuncAssistProcessor->update();
            if (followSymbolData->pendingSymbolInfoRequests.isEmpty()
                    && followSymbolData->pendingGotoDefRequests.isEmpty()
                    && followSymbolData->defLinkNode.isValid()) {
                handleDocumentInfoResults();
            }
        });
        followSymbolData->pendingSymbolInfoRequests << symReq.id();
        qCDebug(clangdLog) << "sending symbol info request";
        q->sendContent(symReq, SendDocUpdates::Ignore);

        if (link == followSymbolData->defLink)
            continue;

        GotoDefinitionRequest defReq(params);
        defReq.setResponseCallback([this, link, id = followSymbolData->id, reqId = defReq.id()]
                (const GotoDefinitionRequest::Response &response) {
            qCDebug(clangdLog) << "handling additional go to definition reply for"
                               << link.targetFilePath << link.targetLine;
            if (!followSymbolData || id != followSymbolData->id)
                return;
            Utils::Link newLink;
            if (Utils::optional<GotoResult> _result = response.result()) {
                const GotoResult result = _result.value();
                if (const auto ploc = Utils::get_if<Location>(&result)) {
                    newLink = ploc->toLink();
                } else if (const auto plloc = Utils::get_if<QList<Location>>(&result)) {
                    if (!plloc->isEmpty())
                        newLink = plloc->value(0).toLink();
                }
            }
            qCDebug(clangdLog) << "def link is" << newLink.targetFilePath << newLink.targetLine;
            followSymbolData->declDefMap.insert(link, newLink);
            followSymbolData->pendingGotoDefRequests.removeOne(reqId);
            if (followSymbolData->pendingSymbolInfoRequests.isEmpty()
                    && followSymbolData->pendingGotoDefRequests.isEmpty()
                    && followSymbolData->defLinkNode.isValid()) {
                handleDocumentInfoResults();
            }
        });
        followSymbolData->pendingGotoDefRequests << defReq.id();
        qCDebug(clangdLog) << "sending additional go to definition request"
                           << link.targetFilePath << link.targetLine;
        q->sendContent(defReq, SendDocUpdates::Ignore);
    }

    const DocumentUri defLinkUri
            = DocumentUri::fromFilePath(followSymbolData->defLink.targetFilePath);
    const Position defLinkPos(followSymbolData->defLink.targetLine - 1,
                              followSymbolData->defLink.targetColumn);
    AstRequest astRequest(AstParams(TextDocumentIdentifier(defLinkUri),
                                    Range(defLinkPos, defLinkPos)));
    astRequest.setResponseCallback([this, id = followSymbolData->id](
                                   const AstRequest::Response &response) {
        qCDebug(clangdLog) << "received ast response for def link";
        if (!followSymbolData || followSymbolData->id != id)
            return;
        const auto result = response.result();
        if (result)
            followSymbolData->defLinkNode = *result;
        if (followSymbolData->pendingSymbolInfoRequests.isEmpty()
                && followSymbolData->pendingGotoDefRequests.isEmpty()) {
            handleDocumentInfoResults();
        }
    });
    qCDebug(clangdLog) << "sending ast request for def link";
    q->sendContent(astRequest, SendDocUpdates::Ignore);
}

void ClangdClient::Private::handleDocumentInfoResults()
{
    followSymbolData->closeTempDocuments();

    // If something went wrong, we just follow the original link.
    if (followSymbolData->symbolsToDisplay.isEmpty()) {
        followSymbolData->callback(followSymbolData->defLink);
        followSymbolData.reset();
        return;
    }
    if (followSymbolData->symbolsToDisplay.size() == 1) {
        followSymbolData->callback(followSymbolData->symbolsToDisplay.first().second);
        followSymbolData.reset();
        return;
    }
    QTC_ASSERT(followSymbolData->virtualFuncAssistProcessor
               && followSymbolData->virtualFuncAssistProcessor->running(),
               followSymbolData.reset(); return);
    followSymbolData->virtualFuncAssistProcessor->finalize();
}

void ClangdClient::Private::handleDeclDefSwitchReplies()
{
    if (!switchDeclDefData->document) {
        switchDeclDefData.reset();
        return;
    }

    // Find the function declaration or definition associated with the cursor.
    // For instance, the cursor could be somwehere inside a function body or
    // on a function return type, or ...
    if (clangdLogAst().isDebugEnabled())
        switchDeclDefData->ast->print(0);
    const Utils::optional<AstNode> functionNode = switchDeclDefData->getFunctionNode();
    if (!functionNode) {
        switchDeclDefData.reset();
        return;
    }

    // Unfortunately, the AST does not contain the location of the actual function name symbol,
    // so we have to look for it in the document symbols.
    const QTextCursor funcNameCursor = switchDeclDefData->cursorForFunctionName(*functionNode);
    if (!funcNameCursor.isNull()) {
        q->followSymbol(switchDeclDefData->document.data(), funcNameCursor,
                        switchDeclDefData->editorWidget, std::move(switchDeclDefData->callback),
                        true, false);
    }
    switchDeclDefData.reset();
}

QString ClangdClient::Private::searchTermFromCursor(const QTextCursor &cursor) const
{
    QTextCursor termCursor(cursor);
    termCursor.select(QTextCursor::WordUnderCursor);
    return termCursor.selectedText();
}

void ClangdClient::Private::setHelpItemForTooltip(const MessageId &token, const QString &fqn,
                                                  HelpItem::Category category,
                                                  const QString &type)
{
    QStringList helpIds;
    QString mark;
    if (!fqn.isEmpty()) {
        helpIds << fqn;
        int sepSearchStart = 0;
        while (true) {
            sepSearchStart = fqn.indexOf("::", sepSearchStart);
            if (sepSearchStart == -1)
                break;
            sepSearchStart += 2;
            helpIds << fqn.mid(sepSearchStart);
        }
        mark = helpIds.last();
        if (category == HelpItem::Function)
            mark += type.mid(type.indexOf('('));
    }
    if (category == HelpItem::Enum && !type.isEmpty())
        mark = type;

    HelpItem helpItem(helpIds, mark, category);
    if (isTesting)
        emit q->helpItemGathered(helpItem);
    else
        q->hoverHandler()->setHelpItem(token, helpItem);
}

static void collectExtraResults(QFutureInterface<TextEditor::HighlightingResult> &future,
                                TextEditor::HighlightingResults &results, const AstNode &ast,
                                QTextDocument *doc, const QString &docContent)
{
    if (!ast.isValid())
        return;

    static const auto lessThan = [](const TextEditor::HighlightingResult &r1,
                                    const TextEditor::HighlightingResult &r2) {
        return r1.line < r2.line || (r1.line == r2.line && r1.column < r2.column)
                || (r1.line == r2.line && r1.column == r2.column && r1.length < r2.length);
    };
    const auto insert = [&](const TextEditor::HighlightingResult &result) {
        if (!result.isValid()) // Some nodes don't have a range.
            return;
        const auto it = std::lower_bound(results.begin(), results.end(), result, lessThan);
        if (it == results.end() || *it != result) {
            qCDebug(clangdLogHighlight) << "adding additional highlighting result"
                               << result.line << result.column << result.length;
            results.insert(it, result);
            return;
        }

        // This is for conversion operators, whose type part is only reported as a type by clangd.
        if ((it->textStyles.mainStyle == TextEditor::C_TYPE
             || it->textStyles.mainStyle == TextEditor::C_PRIMITIVE_TYPE)
                && !result.textStyles.mixinStyles.empty()
                && result.textStyles.mixinStyles.at(0) == TextEditor::C_OPERATOR) {
            it->textStyles.mixinStyles = result.textStyles.mixinStyles;
        }
    };
    const auto setFromRange = [doc](TextEditor::HighlightingResult &result, const Range &range) {
        if (!range.isValid())
            return;
        const Position startPos = range.start();
        const Position endPos = range.end();
        result.line = startPos.line() + 1;
        result.column = startPos.character() + 1;
        result.length = endPos.toPositionInDocument(doc) - startPos.toPositionInDocument(doc);
    };
    static const auto onlyIndexOf = [](const QStringView &view, const QStringView &s,
                                       int from = 0) {
        const int firstIndex = view.indexOf(s, from);
        if (firstIndex == -1)
            return -1;
        const int nextIndex = view.indexOf(s, firstIndex + 1);

        // The second condion deals with the off-by-one error in TemplateSpecialization nodes;
        // see below.
        return nextIndex == -1 || nextIndex == firstIndex + 1 ? firstIndex : -1;
    };

    QList<AstNode> nodes = {ast};
    while (!nodes.isEmpty()) {
        if (future.isCanceled())
            return;
        const AstNode node = nodes.takeFirst();
        const QList<AstNode> children = node.children().value_or(QList<AstNode>());
        nodes << children;

        if (node.kind().endsWith("Literal")) {
            TextEditor::HighlightingResult result;
            result.useTextSyles = true;
            const bool isStringLike = node.kind().startsWith("String")
                    || node.kind().startsWith("Character");
            result.textStyles.mainStyle = isStringLike
                    ? TextEditor::C_STRING : TextEditor::C_NUMBER;
            setFromRange(result, node.range());
            insert(result);
            continue;
        }
        if (node.role() == "type" && node.kind() == "Builtin") {
            TextEditor::HighlightingResult result;
            result.useTextSyles = true;
            result.textStyles.mainStyle = TextEditor::C_PRIMITIVE_TYPE;
            setFromRange(result, node.range());
            insert(result);
            continue;
        }

        const bool isExpression = node.role() == "expression";
        const bool isDeclaration = node.role() == "declaration";

        // Unfortunately, the exact position of a specific token is usually not
        // recorded in the AST, so if we need that, we have to search for it textually.
        // In corner cases, this might get sabotaged by e.g. comments, in which case we give up.
        const auto posForNodeStart = [doc](const AstNode &node) {
            return Utils::Text::positionInText(doc, node.range().start().line() + 1,
                                               node.range().start().character() + 1);
        };
        const auto posForNodeEnd = [doc](const AstNode &node) {
            return Utils::Text::positionInText(doc, node.range().end().line() + 1,
                                               node.range().end().character() + 1);
        };
        const int nodeStartPos = posForNodeStart(node);
        const int nodeEndPos = posForNodeEnd(node);

        // Match question mark and colon in ternary operators.
        if (isExpression && node.kind() == "ConditionalOperator") {
            if (children.size() != 3)
                continue;

            // The question mark is between sub-expressions 1 and 2, the colon is between
            // sub-expressions 2 and 3.
            const int searchStartPosQuestionMark = posForNodeEnd(children.first());
            const int searchEndPosQuestionMark = posForNodeStart(children.at(1));
            QStringView content = QStringView(docContent).mid(searchStartPosQuestionMark,
                searchEndPosQuestionMark - searchStartPosQuestionMark);
            const int questionMarkPos = onlyIndexOf(content, QStringView(QStringLiteral("?")));
            if (questionMarkPos == -1)
                continue;
            const int searchStartPosColon = posForNodeEnd(children.at(1));
            const int searchEndPosColon = posForNodeStart(children.at(2));
            content = QStringView(docContent).mid(searchStartPosColon,
                searchEndPosColon - searchStartPosColon);
            const int colonPos = onlyIndexOf(content, QStringView(QStringLiteral(":")));
            if (colonPos == -1)
                continue;

            const int absQuestionMarkPos = searchStartPosQuestionMark + questionMarkPos;
            const int absColonPos = searchStartPosColon + colonPos;
            if (absQuestionMarkPos > absColonPos)
                continue;

            TextEditor::HighlightingResult result;
            result.useTextSyles = true;
            result.textStyles.mainStyle = TextEditor::C_PUNCTUATION;
            result.textStyles.mixinStyles.push_back(TextEditor::C_OPERATOR);
            Utils::Text::convertPosition(doc, absQuestionMarkPos, &result.line, &result.column);
            result.length = 1;
            result.kind = CppEditor::SemanticHighlighter::TernaryIf;
            insert(result);
            Utils::Text::convertPosition(doc, absColonPos, &result.line, &result.column);
            result.kind = CppEditor::SemanticHighlighter::TernaryElse;
            insert(result);
            continue;
        }

        // The following functions are for matching the "<" and ">" brackets of template
        // declarations, specializations and instantiations.
        const auto insertAngleBracketInfo = [&docContent, doc, &insert](
                int searchStart1, int searchEnd1, int searchStart2, int searchEnd2) {
            const int openingAngleBracketPos = onlyIndexOf(
                        QStringView(docContent).mid(searchStart1, searchEnd1 - searchStart1),
                        QStringView(QStringLiteral("<")));
            if (openingAngleBracketPos == -1)
                return;
            const int absOpeningAngleBracketPos = searchStart1 + openingAngleBracketPos;
            if (absOpeningAngleBracketPos > searchStart2)
                searchStart2 = absOpeningAngleBracketPos + 1;
            if (searchStart2 >= searchEnd2)
                return;
            const int closingAngleBracketPos = onlyIndexOf(
                        QStringView(docContent).mid(searchStart2, searchEnd2 - searchStart2),
                        QStringView(QStringLiteral(">")));
            if (closingAngleBracketPos == -1)
                return;

            const int absClosingAngleBracketPos = searchStart2 + closingAngleBracketPos;
            if (absOpeningAngleBracketPos > absClosingAngleBracketPos)
                return;

            TextEditor::HighlightingResult result;
            result.useTextSyles = true;
            result.textStyles.mainStyle = TextEditor::C_PUNCTUATION;
            Utils::Text::convertPosition(doc, absOpeningAngleBracketPos,
                                         &result.line, &result.column);
            result.length = 1;
            result.kind = CppEditor::SemanticHighlighter::AngleBracketOpen;
            insert(result);
            Utils::Text::convertPosition(doc, absClosingAngleBracketPos,
                                         &result.line, &result.column);
            result.kind = CppEditor::SemanticHighlighter::AngleBracketClose;
            insert(result);
        };

        if (isDeclaration && (node.kind() == "FunctionTemplate"
                              || node.kind() == "ClassTemplate")) {
            // The child nodes are the template parameters and and the function or class.
            // The opening angle bracket is before the first child node, the closing angle
            // bracket is before the function child node and after the last param node.
            const QString classOrFunctionKind = QLatin1String(node.kind() == "FunctionTemplate"
                    ? "Function" : "CXXRecord");
            const auto functionOrClassIt = std::find_if(children.begin(), children.end(),
                                                 [&classOrFunctionKind](const AstNode &n) {
                return n.role() == "declaration" && n.kind() == classOrFunctionKind;
            });
            if (functionOrClassIt == children.end() || functionOrClassIt == children.begin())
                continue;
            const int firstTemplateParamStartPos = posForNodeStart(children.first());
            const int lastTemplateParamEndPos = posForNodeEnd(*(functionOrClassIt - 1));
            const int functionOrClassStartPos = posForNodeStart(*functionOrClassIt);
            insertAngleBracketInfo(nodeStartPos, firstTemplateParamStartPos,
                                   lastTemplateParamEndPos, functionOrClassStartPos);
            continue;
        }

        static const auto findTemplateParam = [](const AstNode &n) {
            return n.role() == "declaration" && (n.kind() == "TemplateTypeParm"
                                                 || n.kind() == "NonTypeTemplateParm");
        };

        if (isDeclaration && node.kind() == "TypeAliasTemplate") {
            // Children are one node of type TypeAlias and the template parameters.
            // The opening angle bracket is before the first parameter and the closing
            // angle bracket is after the last parameter.
            // The TypeAlias node seems to appear first in the AST, even though lexically
            // is comes after the parameters. We don't rely on the order here.
            // Note that there is a second pair of angle brackets. That one is part of
            // a TemplateSpecialization, which is handled further below.
            const auto firstTemplateParam = std::find_if(children.begin(), children.end(),
                                                         findTemplateParam);
            if (firstTemplateParam == children.end())
                continue;
            const auto lastTemplateParam = std::find_if(children.rbegin(), children.rend(),
                                                        findTemplateParam);
            QTC_ASSERT(lastTemplateParam != children.rend(), continue);
            const auto typeAlias = std::find_if(children.begin(), children.end(),
                [](const AstNode &n) { return n.kind() == "TypeAlias"; });
            if (typeAlias == children.end())
                continue;

            const int firstTemplateParamStartPos = posForNodeStart(*firstTemplateParam);
            const int lastTemplateParamEndPos = posForNodeEnd(*lastTemplateParam);
            const int searchEndPos = posForNodeStart(*typeAlias);
            insertAngleBracketInfo(nodeStartPos, firstTemplateParamStartPos,
                                   lastTemplateParamEndPos, searchEndPos);
            continue;
        }

        if (isDeclaration && node.kind() == "ClassTemplateSpecialization") {
            // There is one child of kind TemplateSpecialization. The first pair
            // of angle brackets comes before that.
            if (children.size() == 1) {
                const int childNodePos = posForNodeStart(children.first());
                insertAngleBracketInfo(nodeStartPos, childNodePos, nodeStartPos, childNodePos);
            }
            continue;
        }

        if (isDeclaration && node.kind() == "TemplateTemplateParm") {
            // The child nodes are template arguments and template parameters.
            // Arguments seem to appear before parameters in the AST, even though they
            // come after them in the source code. We don't rely on the order here.
            const auto firstTemplateParam = std::find_if(children.begin(), children.end(),
                                                         findTemplateParam);
            if (firstTemplateParam == children.end())
                continue;
            const auto lastTemplateParam = std::find_if(children.rbegin(), children.rend(),
                                                        findTemplateParam);
            QTC_ASSERT(lastTemplateParam != children.rend(), continue);
            const auto templateArg = std::find_if(children.begin(), children.end(),
                [](const AstNode &n) { return n.role() == "template argument"; });

            const int firstTemplateParamStartPos = posForNodeStart(*firstTemplateParam);
            const int lastTemplateParamEndPos = posForNodeEnd(*lastTemplateParam);
            const int searchEndPos = templateArg == children.end()
                    ? nodeEndPos : posForNodeStart(*templateArg);
            insertAngleBracketInfo(nodeStartPos, firstTemplateParamStartPos,
                                   lastTemplateParamEndPos, searchEndPos);
            continue;
        }

        // {static,dynamic,reinterpret}_cast<>().
        if (isExpression && node.kind().startsWith("CXX") && node.kind().endsWith("Cast")) {
            // First child is type, second child is expression.
            // The opening angle bracket is before the first child, the closing angle bracket
            // is between the two children.
            if (children.size() == 2) {
                insertAngleBracketInfo(nodeStartPos, posForNodeStart(children.first()),
                                       posForNodeEnd(children.first()),
                                       posForNodeStart(children.last()));
            }
            continue;
        }

        if (node.kind() == "TemplateSpecialization") {
            // First comes the template type, then the template arguments.
            // The opening angle bracket is before the first template argument,
            // the closing angle bracket is after the last template argument.
            // The first child node has no range, so we start searching at the parent node.
            if (children.size() >= 2) {
                int searchStart2 = posForNodeEnd(children.last());
                int searchEnd2 = nodeEndPos;

                // There is a weird off-by-one error on the clang side: If there is a
                // nested template instantiation *and* there is no space between
                // the closing angle brackets, then the inner TemplateSpecialization node's range
                // will extend one character too far, covering the outer's closing angle bracket.
                // This is what we are correcting for here.
                // TODO: Can we fix this in clang?
                if (searchStart2 == searchEnd2)
                    --searchStart2;
                insertAngleBracketInfo(nodeStartPos, posForNodeStart(children.at(1)),
                                       searchStart2, searchEnd2);
            }
            continue;
        }

        if (!isExpression && !isDeclaration)
            continue;

        // Operators, overloaded ones in particular.
        static const QString operatorPrefix = "operator";
        QString detail = node.detail().value_or(QString());
        const bool isCallToNew = node.kind() == "CXXNew";
        const bool isCallToDelete = node.kind() == "CXXDelete";
        if (!isCallToNew && !isCallToDelete
                && (!detail.startsWith(operatorPrefix) || detail == operatorPrefix)) {
            continue;
        }

        if (!isCallToNew && !isCallToDelete)
            detail.remove(0, operatorPrefix.length());

        TextEditor::HighlightingResult result;
        result.useTextSyles = true;
        const bool isConversionOp = node.kind() == "CXXConversion";
        const bool isOverloaded = !isConversionOp
                && (isDeclaration || ((!isCallToNew && !isCallToDelete)
                                      || node.arcanaContains("CXXMethod")));
        result.textStyles.mainStyle = isConversionOp
                ? TextEditor::C_PRIMITIVE_TYPE
                : isCallToNew || isCallToDelete || detail.at(0).isSpace()
                  ? TextEditor::C_KEYWORD : TextEditor::C_PUNCTUATION;
        result.textStyles.mixinStyles.push_back(TextEditor::C_OPERATOR);
        if (isOverloaded)
            result.textStyles.mixinStyles.push_back(TextEditor::C_OVERLOADED_OPERATOR);
        if (isDeclaration)
            result.textStyles.mixinStyles.push_back(TextEditor::C_DECLARATION);

        const QStringView nodeText = QStringView(docContent)
                .mid(nodeStartPos, nodeEndPos - nodeStartPos);

        if (isCallToNew || isCallToDelete) {
            result.line = node.range().start().line() + 1;
            result.column = node.range().start().character() + 1;
            result.length = isCallToNew ? 3 : 6;
            insert(result);
            if (node.arcanaContains("array")) {
                const int openingBracketOffset = nodeText.indexOf('[');
                if (openingBracketOffset == -1)
                    continue;
                const int closingBracketOffset = nodeText.lastIndexOf(']');
                if (closingBracketOffset == -1 || closingBracketOffset < openingBracketOffset)
                    continue;

                result.textStyles.mainStyle = TextEditor::C_PUNCTUATION;
                result.length = 1;
                Utils::Text::convertPosition(doc,
                                             nodeStartPos + openingBracketOffset,
                                             &result.line, &result.column);
                insert(result);
                Utils::Text::convertPosition(doc,
                                             nodeStartPos + closingBracketOffset,
                                             &result.line, &result.column);
                insert(result);
            }
            continue;
        }

        if (isExpression && (detail == QLatin1String("()") || detail == QLatin1String("[]"))) {
            result.line = node.range().start().line() + 1;
            result.column = node.range().start().character() + 1;
            result.length = 1;
            insert(result);
            result.line = node.range().end().line() + 1;
            result.column = node.range().end().character();
            insert(result);
            continue;
        }

        const int opStringLen = detail.at(0).isSpace() ? detail.length() - 1 : detail.length();

        // The simple case: Call to operator+, +=, * etc.
        if (nodeEndPos - nodeStartPos == opStringLen) {
            setFromRange(result, node.range());
            insert(result);
            continue;
        }

        const int prefixOffset = nodeText.indexOf(operatorPrefix);
        if (prefixOffset == -1)
            continue;

        const bool isArray = detail == "[]";
        const bool isCall = detail == "()";
        const bool isArrayNew = detail == " new[]";
        const bool isArrayDelete = detail == " delete[]";
        const QStringView searchTerm = isArray || isCall
                ? QStringView(detail).chopped(1) : isArrayNew || isArrayDelete
                  ? QStringView(detail).chopped(2) : detail;
        const int opStringOffset = nodeText.indexOf(searchTerm, prefixOffset
                                                    + operatorPrefix.length());
        if (opStringOffset == -1 || nodeText.indexOf(operatorPrefix, opStringOffset) != -1)
            continue;

        const int opStringOffsetInDoc = nodeStartPos + opStringOffset
                + detail.length() - opStringLen;
        Utils::Text::convertPosition(doc, opStringOffsetInDoc, &result.line, &result.column);
        result.length = opStringLen;
        if (isArray || isCall)
            result.length = 1;
        else if (isArrayNew || isArrayDelete)
            result.length -= 2;
        if (!isArray && !isCall)
            insert(result);
        if (!isArray && !isCall && !isArrayNew && !isArrayDelete)
            continue;

        result.textStyles.mainStyle = TextEditor::C_PUNCTUATION;
        result.length = 1;
        const int openingParenOffset = nodeText.indexOf(
                    isCall ? '(' : '[', prefixOffset + operatorPrefix.length());
        if (openingParenOffset == -1)
            continue;
        const int closingParenOffset = nodeText.indexOf(isCall ? ')' : ']', openingParenOffset + 1);
        if (closingParenOffset == -1 || closingParenOffset < openingParenOffset)
            continue;
        Utils::Text::convertPosition(doc, nodeStartPos + openingParenOffset,
                                     &result.line, &result.column);
        insert(result);
        Utils::Text::convertPosition(doc, nodeStartPos + closingParenOffset,
                                     &result.line, &result.column);
        insert(result);
    }
}

// clangd reports also the #ifs, #elses and #endifs around the disabled code as disabled,
// and not even in a consistent manner. We don't want this, so we have to clean up here.
// TODO: Fix in clangd?
static void cleanupDisabledCode(TextEditor::HighlightingResults &results, QTextDocument *doc,
                                const QString &docContent)
{
    bool inDisabled = false;
    for (auto it = results.begin(); it != results.end();) {
        const bool wasInDisabled = inDisabled;
        if (it->textStyles.mainStyle != TextEditor::C_DISABLED_CODE) {
            inDisabled = false;
            ++it;
            continue;
        }

        inDisabled = true;
        const int pos = Utils::Text::positionInText(doc, it->line, it->column);
        const QStringView content(QStringView(docContent).mid(pos, it->length).trimmed());
        if (!content.startsWith(QLatin1String("#if"))
                && !content.startsWith(QLatin1String("#elif"))
                && !content.startsWith(QLatin1String("#else"))
                && !content.startsWith(QLatin1String("#endif"))) {
            ++it;
            continue;
        }

        if (!wasInDisabled) {
            // The #if or #else that starts disabled code should not be disabled.
            it = results.erase(it);
            continue;
        }

        if (wasInDisabled && (it + 1 == results.end()
                || (it + 1)->textStyles.mainStyle != TextEditor::C_DISABLED_CODE)) {
            // The #else or #endif that ends disabled code should not be disabled.
            it = results.erase(it);
            continue;
        }
        ++it;
    }
}

static void semanticHighlighter(QFutureInterface<TextEditor::HighlightingResult> &future,
                                const QList<ExpandedSemanticToken> &tokens,
                                const QString &docContents, const AstNode &ast)
{
    if (future.isCanceled()) {
        future.reportFinished();
        return;
    }

    QTextDocument doc(docContents);
    const auto isOutputParameter = [&ast](const ExpandedSemanticToken &token) {
        if (token.type != "variable" && token.type != "property" && token.type != "parameter")
            return false;
        const Position pos(token.line - 1, token.column - 1);
        const QList<AstNode> path = getAstPath(ast, Range(pos, pos));
        if (path.size() < 2)
            return false;
        if (path.last().hasConstType())
            return false;
        for (auto it = path.rbegin() + 1; it != path.rend(); ++it) {
            if (it->kind() == "Call" || it->kind() == "CXXConstruct"
                    || it->kind() == "MemberInitializer") {
                return true;
            }
            if (it->kind().endsWith("Cast") && it->hasConstType())
                return false;
        }
        return false;
    };

    const auto toResult = [&ast, &isOutputParameter](const ExpandedSemanticToken &token) {
        TextEditor::TextStyles styles;
        if (token.type == "variable") {
            if (token.modifiers.contains("functionScope")) {
                styles.mainStyle = TextEditor::C_LOCAL;
            } else if (token.modifiers.contains("classScope")) {
                styles.mainStyle = TextEditor::C_FIELD;
            } else if (token.modifiers.contains("fileScope")
                       || token.modifiers.contains("globalScope")) {
                styles.mainStyle = TextEditor::C_GLOBAL;
            }
        } else if (token.type == "function" || token.type == "method") {
            if (token.modifiers.contains("virtual"))
                styles.mainStyle = TextEditor::C_VIRTUAL_METHOD;
            else
                styles.mainStyle = TextEditor::C_FUNCTION;
            if (ast.isValid()) {
                const Position pos(token.line - 1, token.column - 1);
                const QList<AstNode> path = getAstPath(ast, Range(pos, pos));
                if (path.length() > 1) {
                    const AstNode declNode = path.at(path.length() - 2);
                    if (declNode.kind() == "Function" || declNode.kind() == "CXXMethod") {

                        // TODO: Remove this once we can assume clangd >= 14.
                        if (declNode.arcanaContains("' virtual"))
                            styles.mainStyle = TextEditor::C_VIRTUAL_METHOD;

                        if (declNode.hasChildWithRole("statement"))
                            styles.mixinStyles.push_back(TextEditor::C_FUNCTION_DEFINITION);
                    }
                }
            }
        } else if (token.type == "class") {
            styles.mainStyle = TextEditor::C_TYPE;

            // clang hardly ever differentiates between constructors and the associated class,
            // whereas we highlight constructors as functions.
            if (ast.isValid()) {
                const Position pos(token.line - 1, token.column - 1);
                const QList<AstNode> path = getAstPath(ast, Range(pos, pos));
                if (!path.isEmpty()) {
                    if (path.last().kind() == "CXXConstructor") {
                        if (!path.last().arcanaContains("implicit"))
                            styles.mainStyle = TextEditor::C_FUNCTION;
                    } else if (path.last().kind() == "Record" && path.length() > 1) {
                        const AstNode node = path.at(path.length() - 2);
                        if (node.kind() == "CXXDestructor" && !node.arcanaContains("implicit")) {
                            styles.mainStyle = TextEditor::C_FUNCTION;
                            // TODO: "declaration" modifier is missing for destructors; fix in clangd
                            // (the scope is also wrong)
                            if (node.role() == "declaration")
                                styles.mixinStyles.push_back(TextEditor::C_DECLARATION);
                        }
                    }
                }
            }
        } else if (token.type == "comment") { // "comment" means code disabled via the preprocessor
            styles.mainStyle = TextEditor::C_DISABLED_CODE;
        } else if (token.type == "namespace") {
            styles.mainStyle = TextEditor::C_TYPE;
        } else if (token.type == "property") {
            styles.mainStyle = TextEditor::C_FIELD;
        } else if (token.type == "enum") {
            styles.mainStyle = TextEditor::C_TYPE;
            styles.mixinStyles.push_back(TextEditor::C_ENUMERATION);
        } else if (token.type == "enumMember") {
            styles.mainStyle = TextEditor::C_ENUMERATION;
        } else if (token.type == "parameter") {
            styles.mainStyle = TextEditor::C_PARAMETER;
        } else if (token.type == "macro") {
            styles.mainStyle = TextEditor::C_PREPROCESSOR;
        } else if (token.type == "type") {
            styles.mainStyle = TextEditor::C_TYPE;
        } else if (token.type == "typeParameter") {
            styles.mainStyle = TextEditor::C_TYPE;
        }
        if (token.modifiers.contains("declaration"))
            styles.mixinStyles.push_back(TextEditor::C_DECLARATION);
        if (isOutputParameter(token))
            styles.mixinStyles.push_back(TextEditor::C_OUTPUT_ARGUMENT);
        qCDebug(clangdLogHighlight) << "adding highlighting result"
                           << token.line << token.column << token.length << int(styles.mainStyle);
        return TextEditor::HighlightingResult(token.line, token.column, token.length, styles);
    };

    TextEditor::HighlightingResults results = Utils::transform(tokens, toResult);
    cleanupDisabledCode(results, &doc, docContents);
    collectExtraResults(future, results, ast, &doc, docContents);
    if (!future.isCanceled()) {
        qCDebug(clangdLog) << "reporting" << results.size() << "highlighting results";
        future.reportResults(QVector<TextEditor::HighlightingResult>(results.cbegin(),
                                                                     results.cend()));
    }
    future.reportFinished();
}

// Unfortunately, clangd ignores almost everything except symbols when sending
// semantic token info, so we need to consult the AST for additional information.
// In particular, we inspect the following constructs:
//    - Raw string literals, because our built-in lexer does not parse them properly.
//      While we're at it, we also handle other types of literals.
//    - Ternary expressions (for the matching of "?" and ":").
//    - Template declarations and instantiations (for the matching of "<" and ">").
//    - Function declarations, to find out whether a declaration is also a definition.
//    - Function arguments, to find out whether they correspond to output parameters.
//    - We consider most other tokens to be simple enough to be handled by the built-in code model.
//      Sometimes we have no choice, as for #include directives, which appear neither
//      in the semantic tokens nor in the AST.
void ClangdClient::Private::handleSemanticTokens(TextEditor::TextDocument *doc,
                                                 const QList<ExpandedSemanticToken> &tokens)
{
    qCDebug(clangdLog()) << "handling LSP tokens" << doc->filePath() << tokens.size();
    for (const ExpandedSemanticToken &t : tokens)
        qCDebug(clangdLogHighlight()) << '\t' << t.line << t.column << t.length << t.type
                                      << t.modifiers;

    // TODO: Cache ASTs
    AstParams params(TextDocumentIdentifier(DocumentUri::fromFilePath(doc->filePath())));
    AstRequest astReq(params);
    astReq.setResponseCallback([this, tokens, doc](const AstRequest::Response &response) {
        if (!q->documentOpen(doc))
            return;
        const Utils::optional<AstNode> ast = response.result();
        if (ast && clangdLogAst().isDebugEnabled())
            ast->print();

        const auto runner = [tokens, text = doc->document()->toPlainText(),
                             theAst = ast ? *ast : AstNode()] {
            return Utils::runAsync(semanticHighlighter, tokens, text, theAst);
        };

        if (isTesting) {
            const auto watcher = new QFutureWatcher<TextEditor::HighlightingResult>(q);
            connect(watcher, &QFutureWatcher<TextEditor::HighlightingResult>::finished,
                    q, [this, watcher, fp = doc->filePath()] {
                emit q->highlightingResultsReady(watcher->future().results(), fp);
                watcher->deleteLater();
            });
            watcher->setFuture(runner());
            return;
        }

        auto it = highlighters.find(doc);
        if (it == highlighters.end()) {
            it = highlighters.emplace(doc, doc).first;
        } else {
            it->second.updateFormatMapFromFontSettings();
        }
        it->second.setHighlightingRunner(runner);
        it->second.run();
    });
    q->sendContent(astReq, SendDocUpdates::Ignore);
}

void ClangdClient::Private::applyCompletionItem(const CompletionItem &item,
        TextEditor::TextDocumentManipulatorInterface &manipulator, QChar typedChar)
{
    const auto edit = item.textEdit();
    if (!edit)
        return;

    const auto kind = static_cast<CompletionItemKind::Kind>(
                item.kind().value_or(CompletionItemKind::Text));
    if (kind != CompletionItemKind::Function && kind != CompletionItemKind::Method
            && kind != CompletionItemKind::Constructor) {
        applyTextEdit(manipulator, *edit, true);
        return;
    }

    const QString rawInsertText = edit->newText();
    const int firstParenOffset = rawInsertText.indexOf('(');
    const int lastParenOffset = rawInsertText.lastIndexOf(')');
    if (firstParenOffset == -1 || lastParenOffset == -1) {
        applyTextEdit(manipulator, *edit, true);
        return;
    }

    const QString detail = item.detail().value_or(QString());
    const TextEditor::CompletionSettings &completionSettings
            = TextEditor::TextEditorSettings::completionSettings();
    QString textToBeInserted = rawInsertText.left(firstParenOffset);
    QString extraCharacters;
    int cursorOffset = 0;
    bool setAutoCompleteSkipPos = false;
    const QTextDocument * const doc = manipulator.textCursorAt(
                manipulator.currentPosition()).document();
    const Range range = edit->range();
    const int rangeStart = range.start().toPositionInDocument(doc);
    const int rangeLength = range.end().toPositionInDocument(doc) - rangeStart;

    if (completionSettings.m_autoInsertBrackets) {
        // If the user typed the opening parenthesis, they'll likely also type the closing one,
        // in which case it would be annoying if we put the cursor after the already automatically
        // inserted closing parenthesis.
        const bool skipClosingParenthesis = typedChar != '(';
        QTextCursor cursor = manipulator.textCursorAt(rangeStart);

        bool abandonParen = false;
        if (matchPreviousWord(manipulator, cursor, "&")) {
            moveToPreviousWord(manipulator, cursor);
            moveToPreviousChar(manipulator, cursor);
            const QChar prevChar = manipulator.characterAt(cursor.position());
            cursor.setPosition(rangeStart);
            abandonParen = QString("(;,{}=").contains(prevChar);
        }
        if (!abandonParen)
            abandonParen = isAtUsingDeclaration(manipulator, rangeStart);
        if (!abandonParen && matchPreviousWord(manipulator, cursor, detail)) // function definition?
            abandonParen = true;
        if (!abandonParen) {
            if (completionSettings.m_spaceAfterFunctionName)
                extraCharacters += ' ';
            extraCharacters += '(';
            if (typedChar == '(')
                typedChar = {};

            // If the function doesn't return anything, automatically place the semicolon,
            // unless we're doing a scope completion (then it might be function definition).
            const QChar characterAtCursor = manipulator.characterAt(manipulator.currentPosition());
            bool endWithSemicolon = typedChar == ';';
            const QChar semicolon = typedChar.isNull() ? QLatin1Char(';') : typedChar;
            if (endWithSemicolon && characterAtCursor == semicolon) {
                endWithSemicolon = false;
                typedChar = {};
            }

            // If the function takes no arguments, automatically place the closing parenthesis
            if (firstParenOffset + 1 == lastParenOffset && skipClosingParenthesis) {
                extraCharacters += QLatin1Char(')');
                if (endWithSemicolon) {
                    extraCharacters += semicolon;
                    typedChar = {};
                }
            } else {
                const QChar lookAhead = manipulator.characterAt(manipulator.currentPosition() + 1);
                if (MatchingText::shouldInsertMatchingText(lookAhead)) {
                    extraCharacters += ')';
                    --cursorOffset;
                    setAutoCompleteSkipPos = true;
                    if (endWithSemicolon) {
                        extraCharacters += semicolon;
                        --cursorOffset;
                        typedChar = {};
                    }
                }
            }
        }
    }

    // Append an unhandled typed character, adjusting cursor offset when it had been adjusted before
    if (!typedChar.isNull()) {
        extraCharacters += typedChar;
        if (cursorOffset != 0)
            --cursorOffset;
    }

    textToBeInserted += extraCharacters;

    const bool isReplaced = manipulator.replace(rangeStart, rangeLength, textToBeInserted);
    manipulator.setCursorPosition(rangeStart + textToBeInserted.length());
    if (isReplaced) {
        if (cursorOffset)
            manipulator.setCursorPosition(manipulator.currentPosition() + cursorOffset);
        if (setAutoCompleteSkipPos)
            manipulator.setAutoCompleteSkipPosition(manipulator.currentPosition());
    }

    if (auto additionalEdits = item.additionalTextEdits()) {
        for (const auto &edit : *additionalEdits)
            applyTextEdit(manipulator, edit);
    }
}

void ClangdClient::VirtualFunctionAssistProcessor::cancel()
{
    resetData();
}

void ClangdClient::VirtualFunctionAssistProcessor::update()
{
    if (!m_data->followSymbolData->isEditorWidgetStillAlive())
        return;
    setAsyncProposalAvailable(createProposal(false));
}

void ClangdClient::VirtualFunctionAssistProcessor::finalize()
{
    if (!m_data->followSymbolData->isEditorWidgetStillAlive())
        return;
    const auto proposal = createProposal(true);
    if (m_data->followSymbolData->editorWidget->inTestMode) {
        m_data->followSymbolData->symbolsToDisplay.clear();
        const auto immediateProposal = createProposal(false);
        m_data->followSymbolData->editorWidget->setProposals(immediateProposal, proposal);
    } else {
        setAsyncProposalAvailable(proposal);
    }
    resetData();
}

void ClangdClient::VirtualFunctionAssistProcessor::resetData()
{
    if (!m_data)
        return;
    m_data->followSymbolData->virtualFuncAssistProcessor = nullptr;
    m_data->followSymbolData.reset();
    m_data = nullptr;
}

TextEditor::IAssistProposal *ClangdClient::VirtualFunctionAssistProcessor::createProposal(bool final) const
{
    QTC_ASSERT(m_data && m_data->followSymbolData, return nullptr);

    QList<TextEditor::AssistProposalItemInterface *> items;
    bool needsBaseDeclEntry = !m_data->followSymbolData->defLinkNode.range()
            .contains(Position(m_data->followSymbolData->cursor));
    for (const SymbolData &symbol : qAsConst(m_data->followSymbolData->symbolsToDisplay)) {
        Utils::Link link = symbol.second;
        if (m_data->followSymbolData->defLink == link) {
            if (!needsBaseDeclEntry)
                continue;
            needsBaseDeclEntry = false;
        } else {
            const Utils::Link defLink = m_data->followSymbolData->declDefMap.value(symbol.second);
            if (defLink.hasValidTarget())
                link = defLink;
        }
        items << createEntry(symbol.first, link);
    }
    if (needsBaseDeclEntry)
        items << createEntry({}, m_data->followSymbolData->defLink);
    if (!final) {
        const auto infoItem = new CppEditor::VirtualFunctionProposalItem({}, false);
        infoItem->setText(ClangdClient::tr("collecting overrides ..."));
        infoItem->setOrder(-1);
        items << infoItem;
    }

    return new CppEditor::VirtualFunctionProposal(
                m_data->followSymbolData->cursor.position(),
                items, m_data->followSymbolData->openInSplit);
}

CppEditor::VirtualFunctionProposalItem *
ClangdClient::VirtualFunctionAssistProcessor::createEntry(const QString &name,
                                                          const Utils::Link &link) const
{
    const auto item = new CppEditor::VirtualFunctionProposalItem(
                link, m_data->followSymbolData->openInSplit);
    QString text = name;
    if (link == m_data->followSymbolData->defLink) {
        item->setOrder(1000); // Ensure base declaration is on top.
        if (text.isEmpty()) {
            text = ClangdClient::tr("<base declaration>");
        } else if (m_data->followSymbolData->defLinkNode.isPureVirtualDeclaration()
                   || m_data->followSymbolData->defLinkNode.isPureVirtualDefinition()) {
            text += " = 0";
        }
    }
    item->setText(text);
    return item;
}

TextEditor::IAssistProcessor *ClangdClient::VirtualFunctionAssistProvider::createProcessor() const
{
    return m_data->followSymbolData->virtualFuncAssistProcessor
            = new VirtualFunctionAssistProcessor(m_data);
}

Utils::optional<QList<CodeAction> > ClangdDiagnostic::codeActions() const
{
    return optionalArray<LanguageServerProtocol::CodeAction>("codeActions");
}

QString ClangdDiagnostic::category() const
{
    return typedValue<QString>("category");
}

} // namespace Internal
} // namespace ClangCodeModel

Q_DECLARE_METATYPE(ClangCodeModel::Internal::ReplacementData)