ClangCodeModel: Move quickfix functionality to dedicated set of files

Change-Id: I7cc55afa7aa50ba584593457b6c1393794866c56
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdquickfixes.cpp

@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** 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
+** and conditions see https://www.qt.io/terms-conditions. For further
+** 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.
+**
+****************************************************************************/
+
+#include "clangdquickfixes.h"
+
+#include "clangdclient.h"
+#include "clangmodelmanagersupport.h"
+
+#include <texteditor/codeassist/genericproposal.h>
+
+using namespace LanguageClient;
+using namespace LanguageServerProtocol;
+using namespace TextEditor;
+
+namespace ClangCodeModel {
+namespace Internal {
+
+ClangdQuickFixFactory::ClangdQuickFixFactory() = default;
+
+void ClangdQuickFixFactory::match(const CppEditor::Internal::CppQuickFixInterface &interface,
+                                  QuickFixOperations &result)
+{
+    const auto client = ClangModelManagerSupport::instance()->clientForFile(interface.filePath());
+    if (!client)
+        return;
+
+    const auto uri = DocumentUri::fromFilePath(interface.filePath());
+    QTextCursor cursor(interface.textDocument());
+    cursor.setPosition(interface.position());
+    cursor.select(QTextCursor::LineUnderCursor);
+    const QList<Diagnostic> &diagnostics = client->diagnosticsAt(uri, cursor);
+    for (const Diagnostic &diagnostic : diagnostics) {
+        ClangdDiagnostic clangdDiagnostic(diagnostic);
+        if (const auto actions = clangdDiagnostic.codeActions()) {
+            for (const CodeAction &action : *actions)
+                result << new LanguageClient::CodeActionQuickFixOperation(action, client);
+        }
+    }
+}
+
+class ClangdQuickFixProcessor : public LanguageClientQuickFixAssistProcessor
+{
+public:
+    ClangdQuickFixProcessor(LanguageClient::Client *client)
+        : LanguageClientQuickFixAssistProcessor(client)
+    {
+    }
+
+private:
+    IAssistProposal *perform(const AssistInterface *interface) override
+    {
+        m_interface = interface;
+
+        // Step 1: Collect clangd code actions asynchronously
+        LanguageClientQuickFixAssistProcessor::perform(interface);
+
+        // Step 2: Collect built-in quickfixes synchronously
+        m_builtinOps = CppEditor::quickFixOperations(interface);
+
+        return nullptr;
+    }
+
+    TextEditor::GenericProposal *handleCodeActionResult(const CodeActionResult &result) override
+    {
+        auto toOperation =
+            [=](const Utils::variant<Command, CodeAction> &item) -> QuickFixOperation * {
+            if (auto action = Utils::get_if<CodeAction>(&item)) {
+                const Utils::optional<QList<Diagnostic>> diagnostics = action->diagnostics();
+                if (!diagnostics.has_value() || diagnostics->isEmpty())
+                    return new CodeActionQuickFixOperation(*action, client());
+            }
+            if (auto command = Utils::get_if<Command>(&item))
+                return new CommandQuickFixOperation(*command, client());
+            return nullptr;
+        };
+
+        if (auto list = Utils::get_if<QList<Utils::variant<Command, CodeAction>>>(&result)) {
+            QuickFixOperations ops;
+            for (const Utils::variant<Command, CodeAction> &item : *list) {
+                if (QuickFixOperation *op = toOperation(item)) {
+                    op->setDescription("clangd: " + op->description());
+                    ops << op;
+                }
+            }
+            return GenericProposal::createProposal(m_interface, ops + m_builtinOps);
+        }
+        return nullptr;
+    }
+
+    QuickFixOperations m_builtinOps;
+    const AssistInterface *m_interface = nullptr;
+};
+
+ClangdQuickFixProvider::ClangdQuickFixProvider(ClangdClient *client)
+    : LanguageClientQuickFixProvider(client) {}
+
+IAssistProcessor *ClangdQuickFixProvider::createProcessor(const AssistInterface *) const
+{
+    return new ClangdQuickFixProcessor(client());
+}
+
+} // namespace Internal
+} // namespace ClangCodeModel