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** Copyright (C) 2018 The Qt Company Ltd.
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**
** This file is part of Qt Creator.
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** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#include "client.h"

#include "languageclientinterface.h"
#include "languageclientmanager.h"
#include "languageclientutils.h"
#include "semantichighlightsupport.h"

#include <coreplugin/editormanager/documentmodel.h>
#include <coreplugin/icore.h>
#include <coreplugin/idocument.h>
#include <coreplugin/messagemanager.h>
#include <coreplugin/progressmanager/progressmanager.h>

#include <languageserverprotocol/completion.h>
#include <languageserverprotocol/diagnostics.h>
#include <languageserverprotocol/languagefeatures.h>
#include <languageserverprotocol/messages.h>
#include <languageserverprotocol/servercapabilities.h>
#include <languageserverprotocol/workspace.h>
#include <languageserverprotocol/progresssupport.h>

#include <projectexplorer/project.h>
#include <projectexplorer/session.h>

#include <texteditor/codeassist/documentcontentcompletion.h>
#include <texteditor/codeassist/iassistprocessor.h>
#include <texteditor/ioutlinewidget.h>
#include <texteditor/syntaxhighlighter.h>
#include <texteditor/tabsettings.h>
#include <texteditor/textdocument.h>
#include <texteditor/texteditor.h>
#include <texteditor/texteditoractionhandler.h>
#include <texteditor/texteditorsettings.h>

#include <utils/mimetypes/mimedatabase.h>
#include <utils/qtcprocess.h>


#include <QDebug>
#include <QLoggingCategory>
#include <QMessageBox>
#include <QPointer>
#include <QPushButton>
#include <QTextBlock>
#include <QTextCursor>
#include <QTextDocument>
#include <QTimer>

using namespace LanguageServerProtocol;
using namespace Utils;

namespace LanguageClient {

static Q_LOGGING_CATEGORY(LOGLSPCLIENT, "qtc.languageclient.client", QtWarningMsg);

Client::Client(BaseClientInterface *clientInterface)
    : m_id(Utils::Id::fromString(QUuid::createUuid().toString()))
    , m_clientInterface(clientInterface)
    , m_diagnosticManager(this)
    , m_documentSymbolCache(this)
    , m_hoverHandler(this)
    , m_symbolSupport(this)
    , m_tokentSupport(this)
{
    m_clientProviders.completionAssistProvider = new LanguageClientCompletionAssistProvider(this);
    m_clientProviders.functionHintProvider = new FunctionHintAssistProvider(this);
    m_clientProviders.quickFixAssistProvider = new LanguageClientQuickFixProvider(this);

    m_documentUpdateTimer.setSingleShot(true);
    m_documentUpdateTimer.setInterval(500);
    connect(&m_documentUpdateTimer, &QTimer::timeout, this, &Client::sendPostponedDocumentUpdates);

    m_contentHandler.insert(JsonRpcMessageHandler::jsonRpcMimeType(),
                            &JsonRpcMessageHandler::parseContent);
    QTC_ASSERT(clientInterface, return);
    connect(clientInterface, &BaseClientInterface::messageReceived, this, &Client::handleMessage);
    connect(clientInterface, &BaseClientInterface::error, this, &Client::setError);
    connect(clientInterface, &BaseClientInterface::finished, this, &Client::finished);
    connect(TextEditor::TextEditorSettings::instance(),
            &TextEditor::TextEditorSettings::fontSettingsChanged,
            this,
            &Client::rehighlight);

    m_tokentSupport.setTokenTypesMap(SemanticTokens::defaultTokenTypesMap());
    m_tokentSupport.setTokenModifiersMap(SemanticTokens::defaultTokenModifiersMap());
}

QString Client::name() const
{
    if (m_project && !m_project->displayName().isEmpty())
        return tr("%1 for %2").arg(m_displayName, m_project->displayName());
    return m_displayName;
}

static void updateEditorToolBar(QList<TextEditor::TextDocument *> documents)
{
    for (TextEditor::TextDocument *document : documents) {
        for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document))
            updateEditorToolBar(editor);
    }
}

Client::~Client()
{
    using namespace TextEditor;
    // FIXME: instead of replacing the completion provider in the text document store the
    // completion provider as a prioritised list in the text document
    // temporary container needed since m_resetAssistProvider is changed in resetAssistProviders
    for (TextDocument *document : m_resetAssistProvider.keys())
        resetAssistProviders(document);
    const QList<Core::IEditor *> &editors = Core::DocumentModel::editorsForOpenedDocuments();
    for (Core::IEditor *editor : editors) {
        if (auto textEditor = qobject_cast<BaseTextEditor *>(editor)) {
            TextEditorWidget *widget = textEditor->editorWidget();
            widget->setRefactorMarkers(RefactorMarker::filterOutType(widget->refactorMarkers(), id()));
            widget->removeHoverHandler(&m_hoverHandler);
        }
    }
    for (auto it = m_highlights.cbegin(); it != m_highlights.cend(); ++it) {
        const DocumentUri &uri = it.key();
        if (TextDocument *doc = TextDocument::textDocumentForFilePath(uri.toFilePath())) {
            if (TextEditor::SyntaxHighlighter *highlighter = doc->syntaxHighlighter())
                highlighter->clearAllExtraFormats();
        }
    }
    for (IAssistProcessor *processor : qAsConst(m_runningAssistProcessors))
        processor->setAsyncProposalAvailable(nullptr);
    qDeleteAll(m_documentHighlightsTimer);
    m_documentHighlightsTimer.clear();
    updateEditorToolBar(m_openedDocument.keys());
    // do not handle messages while shutting down
    disconnect(m_clientInterface.data(), &BaseClientInterface::messageReceived,
               this, &Client::handleMessage);
}

static ClientCapabilities generateClientCapabilities()
{
    ClientCapabilities capabilities;
    WorkspaceClientCapabilities workspaceCapabilities;
    workspaceCapabilities.setWorkspaceFolders(true);
    workspaceCapabilities.setApplyEdit(true);
    DynamicRegistrationCapabilities allowDynamicRegistration;
    allowDynamicRegistration.setDynamicRegistration(true);
    workspaceCapabilities.setDidChangeConfiguration(allowDynamicRegistration);
    workspaceCapabilities.setExecuteCommand(allowDynamicRegistration);
    workspaceCapabilities.setConfiguration(true);
    capabilities.setWorkspace(workspaceCapabilities);

    TextDocumentClientCapabilities documentCapabilities;
    TextDocumentClientCapabilities::SynchronizationCapabilities syncCapabilities;
    syncCapabilities.setDynamicRegistration(true);
    syncCapabilities.setWillSave(true);
    syncCapabilities.setWillSaveWaitUntil(false);
    syncCapabilities.setDidSave(true);
    documentCapabilities.setSynchronization(syncCapabilities);

    SymbolCapabilities symbolCapabilities;
    SymbolCapabilities::SymbolKindCapabilities symbolKindCapabilities;
    symbolKindCapabilities.setValueSet(
        {SymbolKind::File,       SymbolKind::Module,       SymbolKind::Namespace,
         SymbolKind::Package,    SymbolKind::Class,        SymbolKind::Method,
         SymbolKind::Property,   SymbolKind::Field,        SymbolKind::Constructor,
         SymbolKind::Enum,       SymbolKind::Interface,    SymbolKind::Function,
         SymbolKind::Variable,   SymbolKind::Constant,     SymbolKind::String,
         SymbolKind::Number,     SymbolKind::Boolean,      SymbolKind::Array,
         SymbolKind::Object,     SymbolKind::Key,          SymbolKind::Null,
         SymbolKind::EnumMember, SymbolKind::Struct,       SymbolKind::Event,
         SymbolKind::Operator,   SymbolKind::TypeParameter});
    symbolCapabilities.setSymbolKind(symbolKindCapabilities);
    symbolCapabilities.setHierarchicalDocumentSymbolSupport(true);
    documentCapabilities.setDocumentSymbol(symbolCapabilities);

    TextDocumentClientCapabilities::SemanticHighlightingCapabilities semanticHighlight;
    semanticHighlight.setSemanticHighlighting(true);
    documentCapabilities.setSemanticHighlightingCapabilities(semanticHighlight);

    TextDocumentClientCapabilities::CompletionCapabilities completionCapabilities;
    completionCapabilities.setDynamicRegistration(true);
    TextDocumentClientCapabilities::CompletionCapabilities::CompletionItemKindCapabilities
        completionItemKindCapabilities;
    completionItemKindCapabilities.setValueSet(
        {CompletionItemKind::Text,         CompletionItemKind::Method,
         CompletionItemKind::Function,     CompletionItemKind::Constructor,
         CompletionItemKind::Field,        CompletionItemKind::Variable,
         CompletionItemKind::Class,        CompletionItemKind::Interface,
         CompletionItemKind::Module,       CompletionItemKind::Property,
         CompletionItemKind::Unit,         CompletionItemKind::Value,
         CompletionItemKind::Enum,         CompletionItemKind::Keyword,
         CompletionItemKind::Snippet,      CompletionItemKind::Color,
         CompletionItemKind::File,         CompletionItemKind::Reference,
         CompletionItemKind::Folder,       CompletionItemKind::EnumMember,
         CompletionItemKind::Constant,     CompletionItemKind::Struct,
         CompletionItemKind::Event,        CompletionItemKind::Operator,
         CompletionItemKind::TypeParameter});
    completionCapabilities.setCompletionItemKind(completionItemKindCapabilities);
    TextDocumentClientCapabilities::CompletionCapabilities::CompletionItemCapbilities
        completionItemCapbilities;
    completionItemCapbilities.setSnippetSupport(true);
    completionItemCapbilities.setCommitCharacterSupport(true);
    completionCapabilities.setCompletionItem(completionItemCapbilities);
    documentCapabilities.setCompletion(completionCapabilities);

    TextDocumentClientCapabilities::CodeActionCapabilities codeActionCapabilities;
    TextDocumentClientCapabilities::CodeActionCapabilities::CodeActionLiteralSupport literalSupport;
    literalSupport.setCodeActionKind(
        TextDocumentClientCapabilities::CodeActionCapabilities::CodeActionLiteralSupport::
            CodeActionKind(QList<QString>{"*"}));
    codeActionCapabilities.setCodeActionLiteralSupport(literalSupport);
    documentCapabilities.setCodeAction(codeActionCapabilities);

    TextDocumentClientCapabilities::HoverCapabilities hover;
    hover.setContentFormat({MarkupKind::markdown, MarkupKind::plaintext});
    hover.setDynamicRegistration(true);
    documentCapabilities.setHover(hover);

    TextDocumentClientCapabilities::RenameClientCapabilities rename;
    rename.setPrepareSupport(true);
    rename.setDynamicRegistration(true);
    documentCapabilities.setRename(rename);

    TextDocumentClientCapabilities::SignatureHelpCapabilities signatureHelp;
    signatureHelp.setDynamicRegistration(true);
    TextDocumentClientCapabilities::SignatureHelpCapabilities::SignatureInformationCapabilities info;
    info.setDocumentationFormat({MarkupKind::markdown, MarkupKind::plaintext});
    signatureHelp.setSignatureInformation(info);
    documentCapabilities.setSignatureHelp(signatureHelp);

    documentCapabilities.setReferences(allowDynamicRegistration);
    documentCapabilities.setDocumentHighlight(allowDynamicRegistration);
    documentCapabilities.setDefinition(allowDynamicRegistration);
    documentCapabilities.setTypeDefinition(allowDynamicRegistration);
    documentCapabilities.setImplementation(allowDynamicRegistration);
    documentCapabilities.setFormatting(allowDynamicRegistration);
    documentCapabilities.setRangeFormatting(allowDynamicRegistration);
    documentCapabilities.setOnTypeFormatting(allowDynamicRegistration);
    SemanticTokensClientCapabilities tokens;
    tokens.setDynamicRegistration(true);
    FullSemanticTokenOptions tokenOptions;
    tokenOptions.setDelta(true);
    SemanticTokensClientCapabilities::Requests tokenRequests;
    tokenRequests.setFull(tokenOptions);
    tokens.setRequests(tokenRequests);
    tokens.setTokenTypes({"type",
                          "class",
                          "enumMember",
                          "typeParameter",
                          "parameter",
                          "variable",
                          "function",
                          "macro",
                          "keyword",
                          "comment",
                          "string",
                          "number",
                          "operator"});
    tokens.setTokenModifiers({"declaration", "definition"});
    tokens.setFormats({"relative"});
    documentCapabilities.setSemanticTokens(tokens);
    capabilities.setTextDocument(documentCapabilities);

    WindowClientClientCapabilities window;
    window.setWorkDoneProgress(true);
    capabilities.setWindow(window);

    return capabilities;
}

void Client::initialize()
{
    using namespace ProjectExplorer;
    QTC_ASSERT(m_clientInterface, return);
    QTC_ASSERT(m_state == Uninitialized, return);
    qCDebug(LOGLSPCLIENT) << "initializing language server " << m_displayName;
    InitializeParams params;
    params.setCapabilities(m_clientCapabilities);
    params.setInitializationOptions(m_initializationOptions);
    if (m_project) {
        params.setRootUri(DocumentUri::fromFilePath(m_project->projectDirectory()));
        params.setWorkSpaceFolders(Utils::transform(SessionManager::projects(), [](Project *pro) {
            return WorkSpaceFolder(DocumentUri::fromFilePath(pro->projectDirectory()),
                                   pro->displayName());
        }));
    }
    InitializeRequest initRequest(params);
    initRequest.setResponseCallback([this](const InitializeRequest::Response &initResponse){
        initializeCallback(initResponse);
    });
    // directly send data otherwise the state check would fail;
    if (Utils::optional<ResponseHandler> responseHandler = initRequest.responseHandler())
        m_responseHandlers[responseHandler->id] = responseHandler->callback;

    LanguageClientManager::logBaseMessage(LspLogMessage::ClientMessage,
                                          name(),
                                          initRequest.toBaseMessage());
    m_clientInterface->sendMessage(initRequest.toBaseMessage());
    m_state = InitializeRequested;
}

void Client::shutdown()
{
    QTC_ASSERT(m_state == Initialized, emit finished(); return);
    qCDebug(LOGLSPCLIENT) << "shutdown language server " << m_displayName;
    ShutdownRequest shutdown;
    shutdown.setResponseCallback([this](const ShutdownRequest::Response &shutdownResponse){
        shutDownCallback(shutdownResponse);
    });
    sendContent(shutdown);
    m_state = ShutdownRequested;
}

Client::State Client::state() const
{
    return m_state;
}

ClientCapabilities Client::defaultClientCapabilities()
{
    return generateClientCapabilities();
}

void Client::setClientCapabilities(const LanguageServerProtocol::ClientCapabilities &caps)
{
    m_clientCapabilities = caps;
}

void Client::openDocument(TextEditor::TextDocument *document)
{
    using namespace TextEditor;
    if (!isSupportedDocument(document))
        return;

    m_openedDocument[document] = document->plainText();

    if (m_state != Initialized)
        return;

    const FilePath &filePath = document->filePath();
    const QString method(DidOpenTextDocumentNotification::methodName);
    if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
        if (!registered.value())
            return;
        const TextDocumentRegistrationOptions option(
            m_dynamicCapabilities.option(method).toObject());
        if (option.isValid()
            && !option.filterApplies(filePath, Utils::mimeTypeForName(document->mimeType()))) {
            return;
        }
    } else if (Utils::optional<ServerCapabilities::TextDocumentSync> _sync
               = m_serverCapabilities.textDocumentSync()) {
        if (auto options = Utils::get_if<TextDocumentSyncOptions>(&_sync.value())) {
            if (!options->openClose().value_or(true))
                return;
        }
    }
    connect(document, &TextDocument::contentsChangedWithPosition, this,
            [this, document](int position, int charsRemoved, int charsAdded) {
        documentContentsChanged(document, position, charsRemoved, charsAdded);
    });
    TextDocumentItem item;
    item.setLanguageId(TextDocumentItem::mimeTypeToLanguageId(document->mimeType()));
    item.setUri(DocumentUri::fromFilePath(filePath));
    item.setText(document->plainText());
    if (!m_documentVersions.contains(filePath))
        m_documentVersions[filePath] = 0;
    item.setVersion(m_documentVersions[filePath]);
    sendContent(DidOpenTextDocumentNotification(DidOpenTextDocumentParams(item)));

    const Client *currentClient = LanguageClientManager::clientForDocument(document);
    if (currentClient == this) {
        // this is the active client for the document so directly activate it
        activateDocument(document);
    } else if (m_activateDocAutomatically && currentClient == nullptr) {
        // there is no client for this document so assign it to this server
        LanguageClientManager::openDocumentWithClient(document, this);
    }
}

void Client::sendContent(const IContent &content)
{
    QTC_ASSERT(m_clientInterface, return);
    QTC_ASSERT(m_state == Initialized, return);
    sendPostponedDocumentUpdates();
    if (Utils::optional<ResponseHandler> responseHandler = content.responseHandler())
        m_responseHandlers[responseHandler->id] = responseHandler->callback;
    QString error;
    if (!QTC_GUARD(content.isValid(&error)))
        Core::MessageManager::writeFlashing(error);
    const BaseMessage message = content.toBaseMessage();
    LanguageClientManager::logBaseMessage(LspLogMessage::ClientMessage, name(), message);
    m_clientInterface->sendMessage(message);
}

void Client::cancelRequest(const MessageId &id)
{
    m_responseHandlers.remove(id);
    sendContent(CancelRequest(CancelParameter(id)));
}

void Client::closeDocument(TextEditor::TextDocument *document)
{
    deactivateDocument(document);
    const DocumentUri &uri = DocumentUri::fromFilePath(document->filePath());
    m_highlights[uri].clear();
    if (m_openedDocument.remove(document) != 0 && m_state == Initialized) {
        DidCloseTextDocumentParams params(TextDocumentIdentifier{uri});
        sendContent(DidCloseTextDocumentNotification(params));
    }
}

void Client::updateCompletionProvider(TextEditor::TextDocument *document)
{
    bool useLanguageServer = m_serverCapabilities.completionProvider().has_value();
    auto clientCompletionProvider = static_cast<LanguageClientCompletionAssistProvider *>(
        m_clientProviders.completionAssistProvider.data());
    if (m_dynamicCapabilities.isRegistered(CompletionRequest::methodName).value_or(false)) {
        const QJsonValue &options = m_dynamicCapabilities.option(CompletionRequest::methodName);
        const TextDocumentRegistrationOptions docOptions(options);
        useLanguageServer = docOptions.filterApplies(document->filePath(),
                                                     Utils::mimeTypeForName(document->mimeType()));

        const ServerCapabilities::CompletionOptions completionOptions(options);
        if (completionOptions.isValid())
            clientCompletionProvider->setTriggerCharacters(completionOptions.triggerCharacters());
    }

    if (document->completionAssistProvider() != clientCompletionProvider) {
        if (useLanguageServer) {
            m_resetAssistProvider[document].completionAssistProvider
                = document->completionAssistProvider();
            document->setCompletionAssistProvider(clientCompletionProvider);
        }
    } else if (!useLanguageServer) {
        document->setCompletionAssistProvider(
            m_resetAssistProvider[document].completionAssistProvider);
    }
}

void Client::updateFunctionHintProvider(TextEditor::TextDocument *document)
{
    bool useLanguageServer = m_serverCapabilities.signatureHelpProvider().has_value();
    auto clientFunctionHintProvider = static_cast<FunctionHintAssistProvider *>(
        m_clientProviders.functionHintProvider.data());
    if (m_dynamicCapabilities.isRegistered(SignatureHelpRequest::methodName).value_or(false)) {
        const QJsonValue &options = m_dynamicCapabilities.option(SignatureHelpRequest::methodName);
        const TextDocumentRegistrationOptions docOptions(options);
        useLanguageServer = docOptions.filterApplies(document->filePath(),
                                                     Utils::mimeTypeForName(document->mimeType()));

        const ServerCapabilities::SignatureHelpOptions signatureOptions(options);
        if (signatureOptions.isValid())
            clientFunctionHintProvider->setTriggerCharacters(signatureOptions.triggerCharacters());
    }

    if (document->functionHintAssistProvider() != clientFunctionHintProvider) {
        if (useLanguageServer) {
            m_resetAssistProvider[document].functionHintProvider
                = document->functionHintAssistProvider();
            document->setFunctionHintAssistProvider(clientFunctionHintProvider);
        }
    } else if (!useLanguageServer) {
        document->setFunctionHintAssistProvider(
            m_resetAssistProvider[document].functionHintProvider);
    }
}

void Client::requestDocumentHighlights(TextEditor::TextEditorWidget *widget)
{
    const auto uri = DocumentUri::fromFilePath(widget->textDocument()->filePath());
    if (m_dynamicCapabilities.isRegistered(DocumentHighlightsRequest::methodName).value_or(false)) {
        TextDocumentRegistrationOptions option(
            m_dynamicCapabilities.option(DocumentHighlightsRequest::methodName));
        if (!option.filterApplies(widget->textDocument()->filePath()))
            return;
    } else {
        Utils::optional<Utils::variant<bool, WorkDoneProgressOptions>> provider
            = m_serverCapabilities.documentHighlightProvider();
        if (!provider.has_value())
            return;
        if (Utils::holds_alternative<bool>(*provider) && !Utils::get<bool>(*provider))
            return;
    }

    if (m_highlightRequests.contains(widget))
        cancelRequest(m_highlightRequests.take(widget));

    DocumentHighlightsRequest request(
        TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(widget->textCursor())));
    auto connection = connect(widget, &QObject::destroyed, this, [this, widget]() {
        if (m_highlightRequests.contains(widget))
            cancelRequest(m_highlightRequests.take(widget));
    });
    request.setResponseCallback(
        [widget, this, uri, connection]
        (const DocumentHighlightsRequest::Response &response)
        {
            m_highlightRequests.remove(widget);
            disconnect(connection);
            const Id &id = TextEditor::TextEditorWidget::CodeSemanticsSelection;
            QList<QTextEdit::ExtraSelection> selections;
            const Utils::optional<DocumentHighlightsResult> &result = response.result();
            if (!result.has_value() || holds_alternative<std::nullptr_t>(result.value())) {
                widget->setExtraSelections(id, selections);
                return;
            }

            const QTextCharFormat &format =
                widget->textDocument()->fontSettings().toTextCharFormat(TextEditor::C_OCCURRENCES);
            QTextDocument *document = widget->document();
            for (const auto &highlight : get<QList<DocumentHighlight>>(result.value())) {
                QTextEdit::ExtraSelection selection{widget->textCursor(), format};
                const int &start = highlight.range().start().toPositionInDocument(document);
                const int &end = highlight.range().end().toPositionInDocument(document);
                if (start < 0 || end < 0)
                    continue;
                selection.cursor.setPosition(start);
                selection.cursor.setPosition(end, QTextCursor::KeepAnchor);
                selections << selection;
            }
            widget->setExtraSelections(id, selections);
        });
    m_highlightRequests[widget] = request.id();
    sendContent(request);
}

void Client::activateDocument(TextEditor::TextDocument *document)
{
    const FilePath &filePath = document->filePath();
    auto uri = DocumentUri::fromFilePath(filePath);
    m_diagnosticManager.showDiagnostics(uri, m_documentVersions.value(filePath));
    SemanticHighligtingSupport::applyHighlight(document, m_highlights.value(uri), capabilities());
    m_tokentSupport.updateSemanticTokens(document);
    // only replace the assist provider if the language server support it
    updateCompletionProvider(document);
    updateFunctionHintProvider(document);
    if (m_serverCapabilities.codeActionProvider()) {
        m_resetAssistProvider[document].quickFixAssistProvider = document->quickFixAssistProvider();
        document->setQuickFixAssistProvider(m_clientProviders.quickFixAssistProvider);
    }
    document->setFormatter(new LanguageClientFormatter(document, this));
    for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document)) {
        updateEditorToolBar(editor);
        if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor)) {
            TextEditor::TextEditorWidget *widget = textEditor->editorWidget();
            widget->addHoverHandler(&m_hoverHandler);
            requestDocumentHighlights(widget);
            if (symbolSupport().supportsRename(document))
                widget->addOptionalActions(TextEditor::TextEditorActionHandler::RenameSymbol);
        }
    }
}

void Client::deactivateDocument(TextEditor::TextDocument *document)
{
    m_diagnosticManager.hideDiagnostics(document);
    resetAssistProviders(document);
    document->setFormatter(nullptr);
    if (m_serverCapabilities.semanticHighlighting().has_value()) {
        if (TextEditor::SyntaxHighlighter *highlighter = document->syntaxHighlighter())
            highlighter->clearAllExtraFormats();
    }
    for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document)) {
        if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor)) {
            TextEditor::TextEditorWidget *widget = textEditor->editorWidget();
            widget->removeHoverHandler(&m_hoverHandler);
            widget->setExtraSelections(TextEditor::TextEditorWidget::CodeSemanticsSelection, {});
        }
    }
}

bool Client::documentOpen(const TextEditor::TextDocument *document) const
{
    return m_openedDocument.contains(const_cast<TextEditor::TextDocument *>(document));
}

TextEditor::TextDocument *Client::documentForFilePath(const Utils::FilePath &file) const
{
    for (auto it = m_openedDocument.cbegin(); it != m_openedDocument.cend(); ++it) {
        if (it.key()->filePath() == file)
            return it.key();
    }
    return nullptr;
}

void Client::documentContentsSaved(TextEditor::TextDocument *document)
{
    if (!m_openedDocument.contains(document))
        return;
    bool sendMessage = true;
    bool includeText = false;
    const QString method(DidSaveTextDocumentNotification::methodName);
    if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
        sendMessage = registered.value();
        if (sendMessage) {
            const TextDocumentSaveRegistrationOptions option(
                        m_dynamicCapabilities.option(method).toObject());
            if (option.isValid()) {
                sendMessage = option.filterApplies(document->filePath(),
                                                   Utils::mimeTypeForName(document->mimeType()));
                includeText = option.includeText().value_or(includeText);
            }
        }
    } else if (Utils::optional<ServerCapabilities::TextDocumentSync> _sync
               = m_serverCapabilities.textDocumentSync()) {
        if (auto options = Utils::get_if<TextDocumentSyncOptions>(&_sync.value())) {
            if (Utils::optional<SaveOptions> saveOptions = options->save())
                includeText = saveOptions.value().includeText().value_or(includeText);
        }
    }
    if (!sendMessage)
        return;
    DidSaveTextDocumentParams params(
                TextDocumentIdentifier(DocumentUri::fromFilePath(document->filePath())));
    if (includeText)
        params.setText(document->plainText());
    sendContent(DidSaveTextDocumentNotification(params));
}

void Client::documentWillSave(Core::IDocument *document)
{
    const FilePath &filePath = document->filePath();
    auto textDocument = qobject_cast<TextEditor::TextDocument *>(document);
    if (!m_openedDocument.contains(textDocument))
        return;
    bool sendMessage = true;
    const QString method(WillSaveTextDocumentNotification::methodName);
    if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
        sendMessage = registered.value();
        if (sendMessage) {
            const TextDocumentRegistrationOptions option(m_dynamicCapabilities.option(method));
            if (option.isValid()) {
                sendMessage = option.filterApplies(filePath,
                                                   Utils::mimeTypeForName(document->mimeType()));
            }
        }
    } else if (Utils::optional<ServerCapabilities::TextDocumentSync> _sync
               = m_serverCapabilities.textDocumentSync()) {
        if (auto options = Utils::get_if<TextDocumentSyncOptions>(&_sync.value()))
            sendMessage = options->willSave().value_or(sendMessage);
    }
    if (!sendMessage)
        return;
    const WillSaveTextDocumentParams params(
        TextDocumentIdentifier(DocumentUri::fromFilePath(filePath)));
    sendContent(WillSaveTextDocumentNotification(params));
}

void Client::documentContentsChanged(TextEditor::TextDocument *document,
                                     int position,
                                     int charsRemoved,
                                     int charsAdded)
{
    if (!m_openedDocument.contains(document) || !reachable())
        return;
    const QString method(DidChangeTextDocumentNotification::methodName);
    TextDocumentSyncKind syncKind = m_serverCapabilities.textDocumentSyncKindHelper();
    if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
        syncKind = registered.value() ? TextDocumentSyncKind::None : TextDocumentSyncKind::Full;
        if (syncKind != TextDocumentSyncKind::None) {
            const TextDocumentChangeRegistrationOptions option(
                                    m_dynamicCapabilities.option(method).toObject());
            syncKind = option.isValid() ? option.syncKind() : syncKind;
        }
    }

    if (syncKind != TextDocumentSyncKind::None) {
        if (syncKind == TextDocumentSyncKind::Incremental) {
            DidChangeTextDocumentParams::TextDocumentContentChangeEvent change;
            QTextDocument oldDoc(m_openedDocument[document]);
            QTextCursor cursor(&oldDoc);
            // Workaround https://bugreports.qt.io/browse/QTBUG-80662
            // The contentsChanged gives a character count that can be wrong for QTextCursor
            // when there are special characters removed/added (like formating characters).
            // Also, characterCount return the number of characters + 1 because of the hidden
            // paragraph separator character.
            // This implementation is based on QWidgetTextControlPrivate::_q_contentsChanged.
            // For charsAdded, textAt handles the case itself.
            cursor.setPosition(qMin(oldDoc.characterCount() - 1, position + charsRemoved));
            cursor.setPosition(position, QTextCursor::KeepAnchor);
            change.setRange(Range(cursor));
            change.setRangeLength(cursor.selectionEnd() - cursor.selectionStart());
            change.setText(document->textAt(position, charsAdded));
            m_documentsToUpdate[document] << change;
        } else {
            m_documentsToUpdate[document] = {
                DidChangeTextDocumentParams::TextDocumentContentChangeEvent(document->plainText())};
        }
        m_openedDocument[document] = document->plainText();
    }

    using namespace TextEditor;
    for (BaseTextEditor *editor : BaseTextEditor::textEditorsForDocument(document)) {
        if (TextEditorWidget *widget = editor->editorWidget()) {
            widget->setRefactorMarkers(
                RefactorMarker::filterOutType(widget->refactorMarkers(), id()));
        }
    }

    m_documentUpdateTimer.start();
}

void Client::registerCapabilities(const QList<Registration> &registrations)
{
    m_dynamicCapabilities.registerCapability(registrations);
    for (const Registration &registration : registrations) {
        if (registration.method() == CompletionRequest::methodName) {
            for (auto document : m_openedDocument.keys())
                updateCompletionProvider(document);
        }
        if (registration.method() == SignatureHelpRequest::methodName) {
            for (auto document : m_openedDocument.keys())
                updateFunctionHintProvider(document);
        }
        if (registration.method() == "textDocument/semanticTokens") {
            SemanticTokensOptions options(registration.registerOptions());
            if (options.isValid())
                m_tokentSupport.setLegend(options.legend());
            for (auto document : m_openedDocument.keys())
                m_tokentSupport.updateSemanticTokens(document);
        }
    }
    emit capabilitiesChanged(m_dynamicCapabilities);
}

void Client::unregisterCapabilities(const QList<Unregistration> &unregistrations)
{
    m_dynamicCapabilities.unregisterCapability(unregistrations);
    for (const Unregistration &unregistration : unregistrations) {
        if (unregistration.method() == CompletionRequest::methodName) {
            for (auto document : m_openedDocument.keys())
                updateCompletionProvider(document);
        }
        if (unregistration.method() == SignatureHelpRequest::methodName) {
            for (auto document : m_openedDocument.keys())
                updateFunctionHintProvider(document);
        }
        if (unregistration.method() == "textDocument/semanticTokens") {
            for (auto document : m_openedDocument.keys())
                m_tokentSupport.updateSemanticTokens(document);
        }
    }
    emit capabilitiesChanged(m_dynamicCapabilities);
}

TextEditor::HighlightingResult createHighlightingResult(const SymbolInformation &info)
{
    if (!info.isValid())
        return {};
    const Position &start = info.location().range().start();
    return TextEditor::HighlightingResult(start.line() + 1,
                                          start.character() + 1,
                                          info.name().length(),
                                          info.kind());
}

void Client::cursorPositionChanged(TextEditor::TextEditorWidget *widget)
{
    TextEditor::TextDocument *document = widget->textDocument();
    if (m_documentsToUpdate.contains(document))
        return; // we are currently changing this document so postpone the DocumentHighlightsRequest
    QTimer *timer = m_documentHighlightsTimer[widget];
    if (!timer) {
        const auto uri = DocumentUri::fromFilePath(widget->textDocument()->filePath());
        if (m_highlightRequests.contains(widget))
            cancelRequest(m_highlightRequests.take(widget));
        timer = new QTimer;
        timer->setSingleShot(true);
        m_documentHighlightsTimer.insert(widget, timer);
        auto connection = connect(widget, &QWidget::destroyed, this, [widget, this]() {
            delete m_documentHighlightsTimer.take(widget);
        });
        connect(timer, &QTimer::timeout, this, [this, widget, connection]() {
            disconnect(connection);
            requestDocumentHighlights(widget);
            m_documentHighlightsTimer.take(widget)->deleteLater();
        });
    }
    const Id selectionsId(TextEditor::TextEditorWidget::CodeSemanticsSelection);
    const QList semanticSelections = widget->extraSelections(selectionsId);
    if (!semanticSelections.isEmpty()) {
        auto selectionContainsPos =
            [pos = widget->position()](const QTextEdit::ExtraSelection &selection) {
                const QTextCursor cursor = selection.cursor;
                return cursor.selectionStart() <= pos && cursor.selectionEnd() >= pos;
            };
        if (!Utils::anyOf(semanticSelections, selectionContainsPos))
            widget->setExtraSelections(selectionsId, {});
    }
    timer->start(250);
}

SymbolSupport &Client::symbolSupport()
{
    return m_symbolSupport;
}

void Client::requestCodeActions(const DocumentUri &uri, const QList<Diagnostic> &diagnostics)
{
    const Utils::FilePath fileName = uri.toFilePath();
    TextEditor::TextDocument *doc = TextEditor::TextDocument::textDocumentForFilePath(fileName);
    if (!doc)
        return;

    CodeActionParams codeActionParams;
    CodeActionParams::CodeActionContext context;
    context.setDiagnostics(diagnostics);
    codeActionParams.setContext(context);
    codeActionParams.setTextDocument(TextDocumentIdentifier(uri));
    Position start(0, 0);
    const QTextBlock &lastBlock = doc->document()->lastBlock();
    Position end(lastBlock.blockNumber(), lastBlock.length() - 1);
    codeActionParams.setRange(Range(start, end));
    CodeActionRequest request(codeActionParams);
    request.setResponseCallback(
        [uri, self = QPointer<Client>(this)](const CodeActionRequest::Response &response) {
        if (self)
            self->handleCodeActionResponse(response, uri);
    });
    requestCodeActions(request);
}

void Client::requestCodeActions(const CodeActionRequest &request)
{
    if (!request.isValid(nullptr))
        return;

    const Utils::FilePath fileName
        = request.params().value_or(CodeActionParams()).textDocument().uri().toFilePath();

    const QString method(CodeActionRequest::methodName);
    if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
        if (!registered.value())
            return;
        const TextDocumentRegistrationOptions option(
            m_dynamicCapabilities.option(method).toObject());
        if (option.isValid() && !option.filterApplies(fileName))
            return;
    } else {
        Utils::variant<bool, CodeActionOptions> provider
            = m_serverCapabilities.codeActionProvider().value_or(false);
        if (!(Utils::holds_alternative<CodeActionOptions>(provider) || Utils::get<bool>(provider)))
            return;
    }

    sendContent(request);
}

void Client::handleCodeActionResponse(const CodeActionRequest::Response &response,
                                          const DocumentUri &uri)
{
    if (const Utils::optional<CodeActionRequest::Response::Error> &error = response.error())
        log(*error);
    if (const Utils::optional<CodeActionResult> &_result = response.result()) {
        const CodeActionResult &result = _result.value();
        if (auto list = Utils::get_if<QList<Utils::variant<Command, CodeAction>>>(&result)) {
            for (const Utils::variant<Command, CodeAction> &item : *list) {
                if (auto action = Utils::get_if<CodeAction>(&item))
                    updateCodeActionRefactoringMarker(this, *action, uri);
                else if (auto command = Utils::get_if<Command>(&item)) {
                    Q_UNUSED(command) // todo
                }
            }
        }
    }
}

void Client::executeCommand(const Command &command)
{
    const QString method(ExecuteCommandRequest::methodName);
    bool serverSupportsExecuteCommand = m_serverCapabilities.executeCommandProvider().has_value();
    serverSupportsExecuteCommand = m_dynamicCapabilities
                                       .isRegistered(ExecuteCommandRequest::methodName)
                                       .value_or(serverSupportsExecuteCommand);
    if (serverSupportsExecuteCommand)
        sendContent(ExecuteCommandRequest(ExecuteCommandParams(command)));
}

const ProjectExplorer::Project *Client::project() const
{
    return m_project;
}

void Client::setCurrentProject(ProjectExplorer::Project *project)
{
    m_project = project;
}

void Client::projectOpened(ProjectExplorer::Project *project)
{
    if (!sendWorkspceFolderChanges())
        return;
    WorkspaceFoldersChangeEvent event;
    event.setAdded({WorkSpaceFolder(DocumentUri::fromFilePath(project->projectDirectory()),
                                    project->displayName())});
    DidChangeWorkspaceFoldersParams params;
    params.setEvent(event);
    DidChangeWorkspaceFoldersNotification change(params);
    sendContent(change);
}

void Client::projectClosed(ProjectExplorer::Project *project)
{
    if (sendWorkspceFolderChanges()) {
        WorkspaceFoldersChangeEvent event;
        event.setRemoved({WorkSpaceFolder(DocumentUri::fromFilePath(project->projectDirectory()),
                                          project->displayName())});
        DidChangeWorkspaceFoldersParams params;
        params.setEvent(event);
        DidChangeWorkspaceFoldersNotification change(params);
        sendContent(change);
    }
    if (project == m_project) {
        if (m_state == Initialized) {
            shutdown();
        } else {
            m_state = Shutdown; // otherwise the manager would try to restart this server
            emit finished();
        }
        m_project = nullptr;
    }
}

void Client::setSupportedLanguage(const LanguageFilter &filter)
{
    m_languagFilter = filter;
}

void Client::setActivateDocumentAutomatically(bool enabled)
{
    m_activateDocAutomatically = enabled;
}

void Client::setInitializationOptions(const QJsonObject &initializationOptions)
{
    m_initializationOptions = initializationOptions;
}

bool Client::isSupportedDocument(const TextEditor::TextDocument *document) const
{
    QTC_ASSERT(document, return false);
    return m_languagFilter.isSupported(document);
}

bool Client::isSupportedFile(const Utils::FilePath &filePath, const QString &mimeType) const
{
    return m_languagFilter.isSupported(filePath, mimeType);
}

bool Client::isSupportedUri(const DocumentUri &uri) const
{
    const FilePath &filePath = uri.toFilePath();
    return m_languagFilter.isSupported(filePath, Utils::mimeTypeForFile(filePath).name());
}

void Client::addAssistProcessor(TextEditor::IAssistProcessor *processor)
{
    m_runningAssistProcessors.insert(processor);
}

void Client::removeAssistProcessor(TextEditor::IAssistProcessor *processor)
{
    m_runningAssistProcessors.remove(processor);
}

QList<Diagnostic> Client::diagnosticsAt(const DocumentUri &uri, const QTextCursor &cursor) const
{
    return m_diagnosticManager.diagnosticsAt(uri, cursor);
}

bool Client::hasDiagnostic(const LanguageServerProtocol::DocumentUri &uri,
                           const LanguageServerProtocol::Diagnostic &diag) const
{
    return m_diagnosticManager.hasDiagnostic(uri, documentForFilePath(uri.toFilePath()), diag);
}

void Client::setDiagnosticsHandlers(const TextMarkCreator &textMarkCreator,
                                    const HideDiagnosticsHandler &hideHandler)
{
    m_diagnosticManager.setDiagnosticsHandlers(textMarkCreator, hideHandler);
}

void Client::setSymbolStringifier(const LanguageServerProtocol::SymbolStringifier &stringifier)
{
    m_symbolStringifier = stringifier;
}

SymbolStringifier Client::symbolStringifier() const
{
    return m_symbolStringifier;
}

void Client::start()
{
    if (m_clientInterface->start())
        LanguageClientManager::clientStarted(this);
    else
        LanguageClientManager::clientFinished(this);
}

bool Client::reset()
{
    if (!m_restartsLeft)
        return false;
    --m_restartsLeft;
    m_state = Uninitialized;
    m_responseHandlers.clear();
    m_clientInterface->resetBuffer();
    updateEditorToolBar(m_openedDocument.keys());
    m_serverCapabilities = ServerCapabilities();
    m_dynamicCapabilities.reset();
    m_diagnosticManager.clearDiagnostics();
    for (auto it = m_openedDocument.cbegin(); it != m_openedDocument.cend(); ++it)
        it.key()->disconnect(this);
    m_openedDocument.clear();
    // temporary container needed since m_resetAssistProvider is changed in resetAssistProviders
    for (TextEditor::TextDocument *document : m_resetAssistProvider.keys())
        resetAssistProviders(document);
    for (TextEditor::IAssistProcessor *processor : qAsConst(m_runningAssistProcessors))
        processor->setAsyncProposalAvailable(nullptr);
    m_runningAssistProcessors.clear();
    qDeleteAll(m_documentHighlightsTimer);
    m_documentHighlightsTimer.clear();
    m_progressManager.reset();
    m_documentVersions.clear();
    return true;
}

void Client::setError(const QString &message)
{
    log(message);
    m_state = Error;
}

void Client::setProgressTitleForToken(const LanguageServerProtocol::ProgressToken &token,
                                      const QString &message)
{
    m_progressManager.setTitleForToken(token, message);
}

void Client::handleMessage(const BaseMessage &message)
{
    LanguageClientManager::logBaseMessage(LspLogMessage::ServerMessage, name(), message);
    if (auto handler = m_contentHandler[message.mimeType]) {
        QString parseError;
        handler(message.content, message.codec, parseError,
                [this](const MessageId &id, const QByteArray &content, QTextCodec *codec){
                    this->handleResponse(id, content, codec);
                },
                [this](const QString &method, const MessageId &id, const IContent *content){
                    this->handleMethod(method, id, content);
                });
        if (!parseError.isEmpty())
            log(parseError);
    } else {
        log(tr("Cannot handle content of type: %1").arg(QLatin1String(message.mimeType)));
    }
}

void Client::log(const QString &message) const
{
    Core::MessageManager::writeFlashing(QString("LanguageClient %1: %2").arg(name(), message));
}

const ServerCapabilities &Client::capabilities() const
{
    return m_serverCapabilities;
}

const DynamicCapabilities &Client::dynamicCapabilities() const
{
    return m_dynamicCapabilities;
}

DocumentSymbolCache *Client::documentSymbolCache()
{
    return &m_documentSymbolCache;
}

HoverHandler *Client::hoverHandler()
{
    return &m_hoverHandler;
}

void Client::log(const ShowMessageParams &message)
{
    log(message.toString());
}

void Client::showMessageBox(const ShowMessageRequestParams &message, const MessageId &id)
{
    auto box = new QMessageBox();
    box->setText(message.toString());
    box->setAttribute(Qt::WA_DeleteOnClose);
    switch (message.type()) {
    case Error: box->setIcon(QMessageBox::Critical); break;
    case Warning: box->setIcon(QMessageBox::Warning); break;
    case Info: box->setIcon(QMessageBox::Information); break;
    case Log: box->setIcon(QMessageBox::NoIcon); break;
    }
    QHash<QAbstractButton *, MessageActionItem> itemForButton;
    if (const Utils::optional<QList<MessageActionItem>> actions = message.actions()) {
        for (const MessageActionItem &action : actions.value())
            itemForButton.insert(box->addButton(action.title(), QMessageBox::InvalidRole), action);
    }
    box->setModal(true);
    connect(box, &QMessageBox::finished, this, [=]{
        ShowMessageRequest::Response response(id);
        const MessageActionItem &item = itemForButton.value(box->clickedButton());
        response.setResult(item.isValid() ? LanguageClientValue<MessageActionItem>(item)
                                          : LanguageClientValue<MessageActionItem>());
        sendContent(response);
    });
    box->show();
}

void Client::resetAssistProviders(TextEditor::TextDocument *document)
{
    const AssistProviders providers = m_resetAssistProvider.take(document);

    if (document->completionAssistProvider() == m_clientProviders.completionAssistProvider)
        document->setCompletionAssistProvider(providers.completionAssistProvider);

    if (document->functionHintAssistProvider() == m_clientProviders.functionHintProvider)
        document->setFunctionHintAssistProvider(providers.functionHintProvider);

    if (document->quickFixAssistProvider() == m_clientProviders.quickFixAssistProvider)
        document->setQuickFixAssistProvider(providers.quickFixAssistProvider);
}

void Client::sendPostponedDocumentUpdates()
{
    m_documentUpdateTimer.stop();
    if (m_documentsToUpdate.isEmpty())
        return;
    TextEditor::TextEditorWidget *currentWidget
        = TextEditor::TextEditorWidget::currentTextEditorWidget();

    struct DocumentUpdate
    {
        TextEditor::TextDocument *document;
        DidChangeTextDocumentNotification notification;
    };

    QList<DocumentUpdate> updates;

    const QList<TextEditor::TextDocument *> documents = m_documentsToUpdate.keys();
    for (auto document : documents) {
        const FilePath &filePath = document->filePath();
        const auto uri = DocumentUri::fromFilePath(filePath);
        m_highlights[uri].clear();
        VersionedTextDocumentIdentifier docId(uri);
        docId.setVersion(++m_documentVersions[filePath]);
        DidChangeTextDocumentParams params;
        params.setTextDocument(docId);
        params.setContentChanges(m_documentsToUpdate.take(document));

        updates.append({document, DidChangeTextDocumentNotification(params)});
    }

    for (const DocumentUpdate &update : qAsConst(updates)) {
        sendContent(update.notification);
        emit documentUpdated(update.document);

        if (currentWidget && currentWidget->textDocument() == update.document)
            cursorPositionChanged(currentWidget);

        m_tokentSupport.updateSemanticTokens(update.document);
    }
}

void Client::handleResponse(const MessageId &id, const QByteArray &content, QTextCodec *codec)
{
    if (auto handler = m_responseHandlers[id])
        handler(content, codec);
}

void Client::handleMethod(const QString &method, const MessageId &id, const IContent *content)
{
    auto logError = [&](const JsonObject &content) {
        log(QJsonDocument(content).toJson(QJsonDocument::Indented) + '\n'
            + tr("Invalid parameter in \"%1\"").arg(method));
    };

    if (method == PublishDiagnosticsNotification::methodName) {
        auto params = dynamic_cast<const PublishDiagnosticsNotification *>(content)->params().value_or(PublishDiagnosticsParams());
        if (params.isValid())
            handleDiagnostics(params);
        else
            logError(params);
    } else if (method == LogMessageNotification::methodName) {
        auto params = dynamic_cast<const LogMessageNotification *>(content)->params().value_or(LogMessageParams());
        if (params.isValid())
            log(params);
        else
            logError(params);
    } else if (method == SemanticHighlightNotification::methodName) {
        auto params = dynamic_cast<const SemanticHighlightNotification *>(content)->params().value_or(SemanticHighlightingParams());
        if (params.isValid())
            handleSemanticHighlight(params);
        else
            logError(params);
    } else if (method == ShowMessageNotification::methodName) {
        auto params = dynamic_cast<const ShowMessageNotification *>(content)->params().value_or(ShowMessageParams());
        if (params.isValid())
            log(params);
        else
            logError(params);
    } else if (method == ShowMessageRequest::methodName) {
        auto request = dynamic_cast<const ShowMessageRequest *>(content);
        auto params = request->params().value_or(ShowMessageRequestParams());
        if (params.isValid()) {
            showMessageBox(params, request->id());
        } else {
            ShowMessageRequest::Response response(request->id());
            ResponseError<std::nullptr_t> error;
            const QString errorMessage =
                    QString("Could not parse ShowMessageRequest parameter of '%1': \"%2\"")
                    .arg(request->id().toString(),
                         QString::fromUtf8(QJsonDocument(params).toJson()));
            error.setMessage(errorMessage);
            response.setError(error);
            sendContent(response);
        }
    } else if (method == RegisterCapabilityRequest::methodName) {
        auto params = dynamic_cast<const RegisterCapabilityRequest *>(content)->params().value_or(RegistrationParams());
        if (params.isValid())
            registerCapabilities(params.registrations());
        else
            logError(params);
    } else if (method == UnregisterCapabilityRequest::methodName) {
        auto params = dynamic_cast<const UnregisterCapabilityRequest *>(content)->params().value_or(UnregistrationParams());
        if (params.isValid())
            unregisterCapabilities(params.unregistrations());
        else
            logError(params);
    } else if (method == ApplyWorkspaceEditRequest::methodName) {
        auto params = dynamic_cast<const ApplyWorkspaceEditRequest *>(content)->params().value_or(ApplyWorkspaceEditParams());
        if (params.isValid())
            applyWorkspaceEdit(this, params.edit());
        else
            logError(params);
    } else if (method == WorkSpaceFolderRequest::methodName) {
        WorkSpaceFolderRequest::Response response(dynamic_cast<const WorkSpaceFolderRequest *>(content)->id());
        const QList<ProjectExplorer::Project *> projects
            = ProjectExplorer::SessionManager::projects();
        WorkSpaceFolderResult result;
        if (projects.isEmpty()) {
            result = nullptr;
        } else {
            result = Utils::transform(projects, [](ProjectExplorer::Project *project) {
                return WorkSpaceFolder(DocumentUri::fromFilePath(project->projectDirectory()),
                                       project->displayName());
            });
        }
        response.setResult(result);
        sendContent(response);
    } else if (method == WorkDoneProgressCreateRequest::methodName) {
        sendContent(WorkDoneProgressCreateRequest::Response(
            dynamic_cast<const WorkDoneProgressCreateRequest *>(content)->id()));
    } else if (method == ProgressNotification::methodName) {
        if (Utils::optional<ProgressParams> params
            = dynamic_cast<const ProgressNotification *>(content)->params()) {
            if (!params->isValid())
                logError(*params);
            m_progressManager.handleProgress(*params);
            if (ProgressManager::isProgressEndMessage(*params))
                emit workDone(params->token());
        }
    } else if (id.isValid()) {
        Response<JsonObject, JsonObject> response(id);
        ResponseError<JsonObject> error;
        error.setCode(ResponseError<JsonObject>::MethodNotFound);
        response.setError(error);
        sendContent(response);
    }
    delete content;
}

void Client::handleDiagnostics(const PublishDiagnosticsParams &params)
{
    const DocumentUri &uri = params.uri();

    const QList<Diagnostic> &diagnostics = params.diagnostics();
    m_diagnosticManager.setDiagnostics(uri, diagnostics, params.version());
    if (LanguageClientManager::clientForUri(uri) == this) {
        m_diagnosticManager.showDiagnostics(uri, m_documentVersions.value(uri.toFilePath()));
        requestCodeActions(uri, diagnostics);
    }
}

void Client::handleSemanticHighlight(const SemanticHighlightingParams &params)
{
    DocumentUri uri;
    LanguageClientValue<int> version;
    auto textDocument = params.textDocument();

    if (Utils::holds_alternative<VersionedTextDocumentIdentifier>(textDocument)) {
        uri = Utils::get<VersionedTextDocumentIdentifier>(textDocument).uri();
        version = Utils::get<VersionedTextDocumentIdentifier>(textDocument).version();
    } else {
        uri = Utils::get<TextDocumentIdentifier>(textDocument).uri();
    }

    m_highlights[uri].clear();
    TextEditor::TextDocument *doc = TextEditor::TextDocument::textDocumentForFilePath(
        uri.toFilePath());

    if (!doc || LanguageClientManager::clientForDocument(doc) != this
        || (!version.isNull() && m_documentVersions.value(uri.toFilePath()) != version.value())) {
        return;
    }

    const TextEditor::HighlightingResults results = SemanticHighligtingSupport::generateResults(
        params.lines());

    m_highlights[uri] = results;

    SemanticHighligtingSupport::applyHighlight(doc, results, capabilities());
}

void Client::rehighlight()
{
    using namespace TextEditor;
    for (auto it = m_highlights.begin(), end = m_highlights.end(); it != end; ++it) {
        if (TextDocument *doc = TextDocument::textDocumentForFilePath(it.key().toFilePath())) {
            if (LanguageClientManager::clientForDocument(doc) == this)
                SemanticHighligtingSupport::applyHighlight(doc, it.value(), capabilities());
        }
    }
}

bool Client::documentUpdatePostponed(const Utils::FilePath &fileName) const
{
    return Utils::contains(m_documentsToUpdate.keys(), [fileName](const TextEditor::TextDocument *doc) {
        return doc->filePath() == fileName;
    });
}

int Client::documentVersion(const Utils::FilePath &filePath) const
{
    return m_documentVersions.value(filePath);
}

void Client::initializeCallback(const InitializeRequest::Response &initResponse)
{
    QTC_ASSERT(m_state == InitializeRequested, return);
    if (optional<ResponseError<InitializeError>> error = initResponse.error()) {
        if (error.value().data().has_value() && error.value().data().value().retry()) {
            const QString title(tr("Language Server \"%1\" Initialize Error").arg(m_displayName));
            auto result = QMessageBox::warning(Core::ICore::dialogParent(),
                                               title,
                                               error.value().message(),
                                               QMessageBox::Retry | QMessageBox::Cancel,
                                               QMessageBox::Retry);
            if (result == QMessageBox::Retry) {
                m_state = Uninitialized;
                initialize();
                return;
            }
        }
        setError(tr("Initialize error: ") + error.value().message());
        emit finished();
        return;
    }
    const optional<InitializeResult> &_result = initResponse.result();
    if (!_result.has_value()) {// continue on ill formed result
        log(tr("No initialize result."));
    } else {
        const InitializeResult &result = _result.value();
        if (!result.isValid()) { // continue on ill formed result
            log(QJsonDocument(result).toJson(QJsonDocument::Indented) + '\n'
                + tr("Initialize result is not valid"));
        }
        const Utils::optional<ServerInfo> serverInfo = result.serverInfo();
        if (serverInfo) {
            if (!serverInfo->isValid()) {
                log(QJsonDocument(result).toJson(QJsonDocument::Indented) + '\n'
                    + tr("Server Info is not valid"));
            } else {
                m_serverName = serverInfo->name();
                if (const Utils::optional<QString> version = serverInfo->version())
                    m_serverVersion = version.value();
            }
        }

        m_serverCapabilities = result.capabilities();
    }

    if (auto completionProvider = qobject_cast<LanguageClientCompletionAssistProvider *>(
            m_clientProviders.completionAssistProvider)) {
        completionProvider->setTriggerCharacters(
            m_serverCapabilities.completionProvider()
                .value_or(ServerCapabilities::CompletionOptions())
                .triggerCharacters());
    }
    if (auto functionHintAssistProvider = qobject_cast<FunctionHintAssistProvider *>(
            m_clientProviders.functionHintProvider)) {
        functionHintAssistProvider->setTriggerCharacters(
            m_serverCapabilities.signatureHelpProvider()
                .value_or(ServerCapabilities::SignatureHelpOptions())
                .triggerCharacters());
    }
    auto tokenProvider = m_serverCapabilities.semanticTokensProvider().value_or(
        SemanticTokensOptions());
    if (tokenProvider.isValid())
        m_tokentSupport.setLegend(tokenProvider.legend());

    qCDebug(LOGLSPCLIENT) << "language server " << m_displayName << " initialized";
    m_state = Initialized;
    sendContent(InitializeNotification(InitializedParams()));
    Utils::optional<Utils::variant<bool, WorkDoneProgressOptions>> documentSymbolProvider
        = capabilities().documentSymbolProvider();
    if (documentSymbolProvider.has_value()) {
        if (!Utils::holds_alternative<bool>(*documentSymbolProvider)
            || Utils::get<bool>(*documentSymbolProvider)) {
            TextEditor::IOutlineWidgetFactory::updateOutline();
        }
    }

    for (auto it = m_openedDocument.cbegin(); it != m_openedDocument.cend(); ++it)
        openDocument(it.key());

    emit initialized(m_serverCapabilities);
}

void Client::shutDownCallback(const ShutdownRequest::Response &shutdownResponse)
{
    QTC_ASSERT(m_state == ShutdownRequested, return);
    QTC_ASSERT(m_clientInterface, return);
    optional<ShutdownRequest::Response::Error> errorValue = shutdownResponse.error();
    if (errorValue.has_value()) {
        ShutdownRequest::Response::Error error = errorValue.value();
        qDebug() << error;
        return;
    }
    // directly send data otherwise the state check would fail;
    m_clientInterface->sendMessage(ExitNotification().toBaseMessage());
    qCDebug(LOGLSPCLIENT) << "language server " << m_displayName << " shutdown";
    m_state = Shutdown;
}

bool Client::sendWorkspceFolderChanges() const
{
    if (!reachable())
        return false;
    if (m_dynamicCapabilities.isRegistered(
                DidChangeWorkspaceFoldersNotification::methodName).value_or(false)) {
        return true;
    }
    if (auto workspace = m_serverCapabilities.workspace()) {
        if (auto folder = workspace.value().workspaceFolders()) {
            if (folder.value().supported().value_or(false)) {
                // holds either the Id for deregistration or whether it is registered
                auto notification = folder.value().changeNotifications().value_or(false);
                return holds_alternative<QString>(notification)
                        || (holds_alternative<bool>(notification) && get<bool>(notification));
            }
        }
    }
    return false;
}

} // namespace LanguageClient