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#include "languageclientutils.h"

#include "client.h"

#include <coreplugin/editormanager/documentmodel.h>

#include <texteditor/codeassist/textdocumentmanipulatorinterface.h>
#include <texteditor/refactoringchanges.h>
#include <texteditor/textdocument.h>
#include <texteditor/texteditor.h>
#include <utils/textutils.h>

#include <QFile>
#include <QTextDocument>

using namespace LanguageServerProtocol;
using namespace Utils;
using namespace TextEditor;

namespace LanguageClient {

QTextCursor rangeToTextCursor(const Range &range, QTextDocument *doc)
{
    QTextCursor cursor(doc);
    cursor.setPosition(range.end().toPositionInDocument(doc));
    cursor.setPosition(range.start().toPositionInDocument(doc), QTextCursor::KeepAnchor);
    return cursor;
}

ChangeSet::Range convertRange(const QTextDocument *doc, const Range &range)
{
    return ChangeSet::Range(
        Text::positionInText(doc, range.start().line() + 1, range.start().character() + 1),
        Text::positionInText(doc, range.end().line() + 1, range.end().character()) + 1);
}

ChangeSet editsToChangeSet(const QList<TextEdit> &edits, const QTextDocument *doc)
{
    ChangeSet changeSet;
    for (const TextEdit &edit : edits)
        changeSet.replace(convertRange(doc, edit.range()), edit.newText());
    return changeSet;
}

bool applyTextDocumentEdit(const TextDocumentEdit &edit)
{
    const QList<TextEdit> &edits = edit.edits();
    if (edits.isEmpty())
        return true;
    const DocumentUri &uri = edit.id().uri();
    if (TextDocument* doc = TextDocument::textDocumentForFileName(uri.toFileName())) {
        LanguageClientValue<int> version = edit.id().version();
        if (!version.isNull() && version.value(0) < doc->document()->revision())
            return false;
    }
    return applyTextEdits(uri, edits);
}

bool applyTextEdits(const DocumentUri &uri, const QList<TextEdit> &edits)
{
    if (edits.isEmpty())
        return true;
    RefactoringChanges changes;
    RefactoringFilePtr file;
    file = changes.file(uri.toFileName().toString());
    file->setChangeSet(editsToChangeSet(edits, file->document()));
    return file->apply();
}

void applyTextEdit(TextDocumentManipulatorInterface &manipulator, const TextEdit &edit)
{
    using namespace Utils::Text;
    const Range range = edit.range();
    const QTextDocument *doc = manipulator.textCursorAt(manipulator.currentPosition()).document();
    const int start = positionInText(doc, range.start().line() + 1, range.start().character() + 1);
    const int end = positionInText(doc, range.end().line() + 1, range.end().character() + 1);
    manipulator.replace(start, end - start, edit.newText());
}

bool applyWorkspaceEdit(const WorkspaceEdit &edit)
{
    bool result = true;
    const QList<TextDocumentEdit> &documentChanges
        = edit.documentChanges().value_or(QList<TextDocumentEdit>());
    if (!documentChanges.isEmpty()) {
        for (const TextDocumentEdit &documentChange : documentChanges)
            result |= applyTextDocumentEdit(documentChange);
    } else {
        const WorkspaceEdit::Changes &changes = edit.changes().value_or(WorkspaceEdit::Changes());
        for (const DocumentUri &file : changes.keys())
            result |= applyTextEdits(file, changes.value(file));
        return result;
    }
    return result;
}

QTextCursor endOfLineCursor(const QTextCursor &cursor)
{
    QTextCursor ret = cursor;
    ret.movePosition(QTextCursor::EndOfLine);
    return ret;
}

void updateCodeActionRefactoringMarker(Client *client,
                                       const CodeAction &action,
                                       const DocumentUri &uri)
{
    TextDocument* doc = TextDocument::textDocumentForFileName(uri.toFileName());
    if (!doc)
        return;
    BaseTextEditor *editor = BaseTextEditor::textEditorForDocument(doc);
    if (!editor)
        return;

    TextEditorWidget *editorWidget = editor->editorWidget();

    const QList<Diagnostic> &diagnostics = action.diagnostics().value_or(QList<Diagnostic>());

    RefactorMarkers markers;
    RefactorMarker marker;
    marker.type = client->id();
    if (action.isValid(nullptr))
        marker.tooltip = action.title();
    if (action.edit().has_value()) {
        WorkspaceEdit edit = action.edit().value();
        marker.callback = [edit](const TextEditorWidget *) {
            applyWorkspaceEdit(edit);
        };
        if (diagnostics.isEmpty()) {
            QList<TextEdit> edits;
            if (optional<QList<TextDocumentEdit>> documentChanges = edit.documentChanges()) {
                QList<TextDocumentEdit> changesForUri = Utils::filtered(
                    documentChanges.value(), [uri](const TextDocumentEdit &edit) {
                    return edit.id().uri() == uri;
                });
                for (const TextDocumentEdit &edit : changesForUri)
                    edits << edit.edits();
            } else if (optional<WorkspaceEdit::Changes> localChanges = edit.changes()) {
                edits = localChanges.value()[uri];
            }
            for (const TextEdit &edit : edits) {
                marker.cursor = endOfLineCursor(edit.range().start().toTextCursor(doc->document()));
                markers << marker;
            }
        }
    } else if (action.command().has_value()) {
        const Command command = action.command().value();
        marker.callback = [command, client = QPointer<Client>(client)](const TextEditorWidget *) {
            if (client)
                client->executeCommand(command);
        };
    } else {
        return;
    }
    for (const Diagnostic &diagnostic : diagnostics) {
        marker.cursor = endOfLineCursor(diagnostic.range().start().toTextCursor(doc->document()));
        markers << marker;
    }
    editorWidget->setRefactorMarkers(markers + editorWidget->refactorMarkers());
}

} // namespace LanguageClient