// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include "textdocument.h"

#include "extraencodingsettings.h"
#include "fontsettings.h"
#include "icodestylepreferences.h"
#include "refactoringchanges.h"
#include "storagesettings.h"
#include "syntaxhighlighter.h"
#include "tabsettings.h"
#include "textdocumentlayout.h"
#include "texteditor.h"
#include "texteditorconstants.h"
#include "texteditorsettings.h"
#include "texteditortr.h"
#include "textindenter.h"
#include "typingsettings.h"

#include <coreplugin/coreconstants.h>
#include <coreplugin/diffservice.h>
#include <coreplugin/editormanager/documentmodel.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/documentmanager.h>
#include <coreplugin/icore.h>
#include <coreplugin/progressmanager/progressmanager.h>

#include <extensionsystem/pluginmanager.h>

#include <utils/environment.h>
#include <utils/guard.h>
#include <utils/mimeutils.h>
#include <utils/qtcassert.h>
#include <utils/textutils.h>

#include <QAction>
#include <QApplication>
#include <QFutureInterface>
#include <QScrollBar>
#include <QStringList>

using namespace Core;
using namespace Utils;

/*!
    \class TextEditor::BaseTextDocument
    \brief The BaseTextDocument class is the base class for QTextDocument based documents.

    It is the base class for documents used by implementations of the BaseTextEditor class,
    and contains basic functions for retrieving text content and markers (like bookmarks).

    Subclasses of BaseTextEditor can either use BaseTextDocument as is (and this is the default),
    or created subclasses of BaseTextDocument if they have special requirements.
*/

namespace TextEditor {

class TextDocumentPrivate
{
public:
    TextDocumentPrivate()
        : m_indenter(new PlainTextIndenter(&m_document))
    {
    }

    ~TextDocumentPrivate()
    {
    }

    MultiTextCursor indentOrUnindent(const MultiTextCursor &cursor, bool doIndent, const TabSettings &tabSettings);
    void resetRevisions();
    void updateRevisions();

public:
    FilePath m_defaultPath;
    QString m_suggestedFileName;
    TypingSettingsData m_typingSettings;
    StorageSettingsData m_storageSettings;
    ICodeStylePreferences *m_codeStylePreferences = nullptr;
    TabSettings m_tabSettings;
    ExtraEncodingSettingsData m_extraEncodingSettings;
    FontSettings m_fontSettings;
    bool m_fontSettingsNeedsApply = false; // for applying font settings delayed till an editor becomes visible
    QTextDocument m_document;
    CompletionAssistProvider *m_completionAssistProvider = nullptr;
    CompletionAssistProvider *m_functionHintAssistProvider = nullptr;
    IAssistProvider *m_quickFixProvider = nullptr;
    QScopedPointer<Indenter> m_indenter;
    QScopedPointer<Formatter> m_formatter;
    struct PlainTextCache
    {
        int revision = -1;
        QString plainText;
    };

    PlainTextCache m_plainTextCache;

    int m_autoSaveRevision = -1;
    bool m_silentReload = false;

    TextMarks m_marksCache; // Marks not owned
    Utils::Guard m_modificationChangedGuard;

    SyntaxHighlighter *m_highlighter = nullptr;
    bool m_externalFoldingIndent = false;
};

MultiTextCursor TextDocumentPrivate::indentOrUnindent(const MultiTextCursor &cursors,
                                                      bool doIndent,
                                                      const TabSettings &tabSettings)
{
    MultiTextCursor result;
    bool first = true;
    for (const QTextCursor &textCursor : cursors) {
        QTextCursor cursor = textCursor;
        if (first) {
            cursor.beginEditBlock();
            first = false;
        } else {
            cursor.joinPreviousEditBlock();
        }

        // Indent or unindent the selected lines
        int pos = cursor.position();
        int column = tabSettings.columnAt(cursor.block().text(), cursor.positionInBlock());
        int anchor = cursor.anchor();
        int start = qMin(anchor, pos);
        int end = qMax(anchor, pos);

        QTextBlock startBlock = m_document.findBlock(start);
        QTextBlock endBlock = m_document.findBlock(qMax(end - 1, 0)).next();
        const bool cursorAtBlockStart = (cursor.position() == startBlock.position());
        const bool anchorAtBlockStart = (cursor.anchor() == startBlock.position());
        const bool oneLinePartial = (startBlock.next() == endBlock)
                                    && (start > startBlock.position()
                                        || end < endBlock.position() - 1)
                                    && !cursors.hasMultipleCursors();

        // Make sure one line selection will get processed in "for" loop
        if (startBlock == endBlock)
            endBlock = endBlock.next();

        if (cursor.hasSelection()) {
            if (oneLinePartial) {
                cursor.removeSelectedText();
            } else {
                for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
                    const QString text = block.text();
                    int indentPosition = tabSettings.lineIndentPosition(text);
                    if (!doIndent && !indentPosition)
                        indentPosition = TabSettings::firstNonSpace(text);
                    int targetColumn
                        = tabSettings.indentedColumn(tabSettings.columnAt(text, indentPosition),
                                                     doIndent);
                    cursor.setPosition(block.position() + indentPosition);
                    cursor.insertText(tabSettings.indentationString(0, targetColumn, 0));
                    cursor.setPosition(block.position());
                    cursor.setPosition(block.position() + indentPosition, QTextCursor::KeepAnchor);
                    cursor.removeSelectedText();
                }
                // make sure that selection that begins in first column stays at first column
                // even if we insert text at first column
                cursor = textCursor;
                if (cursorAtBlockStart) {
                    cursor.setPosition(startBlock.position(), QTextCursor::KeepAnchor);
                } else if (anchorAtBlockStart) {
                    cursor.setPosition(startBlock.position(), QTextCursor::MoveAnchor);
                    cursor.setPosition(textCursor.position(), QTextCursor::KeepAnchor);
                }
            }
        } else {
            const QString text = startBlock.text();
            int indentPosition = tabSettings.positionAtColumn(text, column, nullptr, true);
            int spaces = TabSettings::spacesLeftFromPosition(text, indentPosition);
            if (!doIndent && spaces == 0) {
                indentPosition = tabSettings.firstNonSpace(text);
                spaces = TabSettings::spacesLeftFromPosition(text, indentPosition);
            }
            const int startColumn = tabSettings.columnAt(text, indentPosition - spaces);
            const int targetColumn
                = tabSettings.indentedColumn(tabSettings.columnAt(text, indentPosition), doIndent);
            cursor.setPosition(startBlock.position() + indentPosition);
            cursor.setPosition(startBlock.position() + indentPosition - spaces,
                               QTextCursor::KeepAnchor);
            cursor.removeSelectedText();
            cursor.insertText(
                tabSettings.indentationString(startColumn, targetColumn, 0));
        }

        cursor.endEditBlock();
        result.addCursor(cursor);
    }

    return result;
}

void TextDocumentPrivate::resetRevisions()
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    documentLayout->lastSaveRevision = m_document.revision();

    for (QTextBlock block = m_document.begin(); block.isValid(); block = block.next())
        block.setRevision(documentLayout->lastSaveRevision);
}

void TextDocumentPrivate::updateRevisions()
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    int oldLastSaveRevision = documentLayout->lastSaveRevision;
    documentLayout->lastSaveRevision = m_document.revision();

    if (oldLastSaveRevision != documentLayout->lastSaveRevision) {
        for (QTextBlock block = m_document.begin(); block.isValid(); block = block.next()) {
            if (block.revision() < 0 || block.revision() != oldLastSaveRevision)
                block.setRevision(-documentLayout->lastSaveRevision - 1);
            else
                block.setRevision(documentLayout->lastSaveRevision);
        }
    }
}

///////////////////////////////////////////////////////////////////////
//
// BaseTextDocument
//
///////////////////////////////////////////////////////////////////////

TextDocument::TextDocument(Id id)
    : d(new TextDocumentPrivate)
{
    d->m_document.setParent(this);
    connect(&d->m_document, &QTextDocument::modificationChanged,
            this, &TextDocument::modificationChanged);
    connect(&d->m_document, &QTextDocument::contentsChanged,
            this, &Core::IDocument::contentsChanged);
    connect(&d->m_document, &QTextDocument::contentsChange,
            this, &TextDocument::contentsChangedWithPosition);

    // set new document layout
    QTextOption opt = d->m_document.defaultTextOption();
    opt.setTextDirection(Qt::LeftToRight);
    opt.setFlags(opt.flags() | QTextOption::IncludeTrailingSpaces
            | QTextOption::AddSpaceForLineAndParagraphSeparators
            );
    d->m_document.setDefaultTextOption(opt);
    d->m_document.setDocumentLayout(new TextDocumentLayout(&d->m_document));

    if (id.isValid())
        setId(id);

    setSuspendAllowed(true);
}

TextDocument::~TextDocument()
{
    delete d;
}

QMap<FilePath, QString> TextDocument::openedTextDocumentContents()
{
    QMap<FilePath, QString> workingCopy;
    const QList<IDocument *> documents = DocumentModel::openedDocuments();
    for (IDocument *document : documents) {
        auto textEditorDocument = qobject_cast<TextDocument *>(document);
        if (!textEditorDocument)
            continue;
        const FilePath fileName = textEditorDocument->filePath();
        workingCopy[fileName] = textEditorDocument->plainText();
    }
    return workingCopy;
}

QMap<FilePath, TextEncoding> TextDocument::openedTextDocumentEncodings()
{
    QMap<FilePath, TextEncoding> workingCopy;
    const QList<IDocument *> documents = DocumentModel::openedDocuments();
    for (IDocument *document : documents) {
        auto textEditorDocument = qobject_cast<TextDocument *>(document);
        if (!textEditorDocument)
            continue;
        const FilePath fileName = textEditorDocument->filePath();
        workingCopy[fileName] = textEditorDocument->encoding();
    }
    return workingCopy;
}

TextDocument *TextDocument::currentTextDocument()
{
    return qobject_cast<TextDocument *>(EditorManager::currentDocument());
}

TextDocument *TextDocument::textDocumentForFilePath(const Utils::FilePath &filePath)
{
    if (filePath.isEmpty())
        return nullptr;
    return qobject_cast<TextDocument *>(DocumentModel::documentForFilePath(filePath));
}

QString TextDocument::convertToPlainText(const QString &rawText)
{
    // This is basically a copy of QTextDocument::toPlainText but since toRawText returns a
    // text containing formating characters and toPlainText replaces non breaking spaces, we
    // provide our own plain text conversion to be able to save and copy document content
    // containing non breaking spaces.

    QString txt = rawText;
    QChar *uc = txt.data();
    QChar *e = uc + txt.size();

    for (; uc != e; ++uc) {
        switch (uc->unicode()) {
        case 0xfdd0: // QTextBeginningOfFrame
        case 0xfdd1: // QTextEndOfFrame
        case QChar::ParagraphSeparator:
        case QChar::LineSeparator:
            *uc = QLatin1Char('\n');
            break;
        default:;
        }
    }
    return txt;
}

QString TextDocument::plainText() const
{
    if (d->m_plainTextCache.revision != d->m_document.revision()) {
        d->m_plainTextCache.plainText = convertToPlainText(d->m_document.toRawText());
        d->m_plainTextCache.revision = d->m_document.revision();
    }
    return d->m_plainTextCache.plainText;
}

QString TextDocument::textAt(int pos, int length) const
{
    return Utils::Text::textAt(document(), pos, length);
}

QChar TextDocument::characterAt(int pos) const
{
    return document()->characterAt(pos);
}

QString TextDocument::blockText(int blockNumber) const
{
    return document()->findBlockByNumber(blockNumber).text();
}

void TextDocument::setTypingSettings(const TypingSettingsData &typingSettings)
{
    d->m_typingSettings = typingSettings;
}

void TextDocument::setStorageSettings(const StorageSettingsData &storageSettings)
{
    d->m_storageSettings = storageSettings;
}

const TypingSettingsData &TextDocument::typingSettings() const
{
    return d->m_typingSettings;
}

const StorageSettingsData &TextDocument::storageSettings() const
{
    return d->m_storageSettings;
}

void TextDocument::setTabSettings(const TabSettings &tabSettings)
{
    if (const TabSettings candidate = tabSettings.autoDetect(document());
        candidate != d->m_tabSettings) {
        d->m_tabSettings = candidate;
        emit tabSettingsChanged();
    }
}

TabSettings TextDocument::tabSettings() const
{
    return d->m_tabSettings;
}

void TextDocument::setFontSettings(const FontSettings &fontSettings)
{
    if (fontSettings == d->m_fontSettings)
        return;
    bool emitDocumentSizeChanged = fontSettings.lineSpacing() != d->m_fontSettings.lineSpacing();
    d->m_fontSettings = fontSettings;
    d->m_fontSettingsNeedsApply = true;
    emit fontSettingsChanged();
    if (emitDocumentSizeChanged) {
        auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
        QTC_ASSERT(documentLayout, return);
        emit documentLayout->blockSizeChanged(document()->firstBlock());
        documentLayout->emitDocumentSizeChanged();
    }
}

void TextDocument::setFoldingIndentExternallyProvided(bool ext)
{
    d->m_externalFoldingIndent = ext;
    if (d->m_highlighter)
        d->m_highlighter->setIgnoreFolding(ext);
}

bool TextDocument::isFoldingIndentExternallyProvided() const
{
    return d->m_externalFoldingIndent;
}

#ifdef WITH_TESTS
void TextDocument::setSilentReload()
{
    d->m_silentReload = true;
}
#endif

void TextDocument::triggerPendingUpdates()
{
    if (d->m_fontSettingsNeedsApply)
        applyFontSettings();
}

void TextDocument::setCompletionAssistProvider(CompletionAssistProvider *provider)
{
    d->m_completionAssistProvider = provider;
}

CompletionAssistProvider *TextDocument::completionAssistProvider() const
{
    return d->m_completionAssistProvider;
}

void TextDocument::setFunctionHintAssistProvider(CompletionAssistProvider *provider)
{
    d->m_functionHintAssistProvider = provider;
}

CompletionAssistProvider *TextDocument::functionHintAssistProvider() const
{
    return d->m_functionHintAssistProvider;
}

void TextDocument::setQuickFixAssistProvider(IAssistProvider *provider) const
{
    d->m_quickFixProvider = provider;
}

IAssistProvider *TextDocument::quickFixAssistProvider() const
{
    return d->m_quickFixProvider;
}

void TextDocument::setCodeStyle(ICodeStylePreferences *preferences)
{
    indenter()->setCodeStylePreferences(preferences);
    if (d->m_codeStylePreferences) {
        disconnect(d->m_codeStylePreferences, &ICodeStylePreferences::currentTabSettingsChanged,
                   this, &TextDocument::setTabSettings);
        disconnect(d->m_codeStylePreferences, &ICodeStylePreferences::currentValueChanged,
                   this, &TextDocument::slotCodeStyleSettingsChanged);
    }
    d->m_codeStylePreferences = preferences;
    if (d->m_codeStylePreferences) {
        connect(d->m_codeStylePreferences, &ICodeStylePreferences::currentTabSettingsChanged,
                this, &TextDocument::setTabSettings);
        connect(d->m_codeStylePreferences, &ICodeStylePreferences::currentValueChanged,
                this, &TextDocument::slotCodeStyleSettingsChanged);
        setTabSettings(d->m_codeStylePreferences->currentTabSettings());
        slotCodeStyleSettingsChanged();
    }
}

ICodeStylePreferences *TextDocument::codeStyle() const
{
    return d->m_codeStylePreferences;
}

void TextDocument::applyFontSettings()
{
    d->m_fontSettingsNeedsApply = false;
    QTextBlock block = document()->firstBlock();
    while (block.isValid()) {
        TextBlockUserData::updateSuggestionFormats(block, fontSettings());
        block = block.next();
    }
    updateLayout();
    if (d->m_highlighter) {
        d->m_highlighter->setFontSettings(d->m_fontSettings);
        d->m_highlighter->scheduleRehighlight();
    }
}

void TextDocument::slotCodeStyleSettingsChanged() { }

const FontSettings &TextDocument::fontSettings() const
{
    return d->m_fontSettings;
}

void TextDocument::setExtraEncodingSettings(const ExtraEncodingSettingsData &extraEncodingSettings)
{
    d->m_extraEncodingSettings = extraEncodingSettings;
}

void TextDocument::autoIndent(const QTextCursor &cursor, QChar typedChar, int currentCursorPosition)
{
    d->m_indenter->indent(cursor, typedChar, tabSettings(), currentCursorPosition);
}

void TextDocument::autoReindent(const QTextCursor &cursor, int currentCursorPosition)
{
    d->m_indenter->reindent(cursor, tabSettings(), currentCursorPosition);
}

void TextDocument::autoFormatOrIndent(const QTextCursor &cursor)
{
    d->m_indenter->autoIndent(cursor, tabSettings());
}

Utils::MultiTextCursor TextDocument::indent(const Utils::MultiTextCursor &cursor)
{
    return d->indentOrUnindent(cursor, true, tabSettings());
}

Utils::MultiTextCursor TextDocument::unindent(const Utils::MultiTextCursor &cursor)
{
    return d->indentOrUnindent(cursor, false, tabSettings());
}

Formatter *TextDocument::formatter() const
{
    return d->m_formatter.get();
}

void TextDocument::setFormatter(Formatter *formatter)
{
    d->m_formatter.reset(formatter);
}

void TextDocument::setFormatterMode(Formatter::FormatMode mode)
{
    if (d->m_formatter)
        d->m_formatter->setMode(mode);
}

void TextDocument::autoFormat(const QTextCursor &cursor)
{
    using namespace Utils::Text;
    if (!d->m_formatter)
        return;
    d->m_formatter->format(cursor, tabSettings(), [this](const ChangeSet &result) {
        applyChangeSet(result);
    });
}

bool TextDocument::applyChangeSet(const ChangeSet &changeSet)
{
    if (changeSet.isEmpty())
        return true;
    return PlainRefactoringFileFactory().file(filePath())->apply(changeSet);
}

const ExtraEncodingSettingsData &TextDocument::extraEncodingSettings() const
{
    return d->m_extraEncodingSettings;
}

void TextDocument::setIndenter(Indenter *indenter)
{
    // clear out existing code formatter data
    for (QTextBlock it = document()->begin(); it.isValid(); it = it.next())
        TextBlockUserData::setCodeFormatterData(it, nullptr);
    d->m_indenter.reset(indenter);
}

Indenter *TextDocument::indenter() const
{
    return d->m_indenter.data();
}

bool TextDocument::isSaveAsAllowed() const
{
    return true;
}

FilePath TextDocument::fallbackSaveAsPath() const
{
    return d->m_defaultPath;
}

QString TextDocument::fallbackSaveAsFileName() const
{
    return d->m_suggestedFileName;
}

void TextDocument::setFallbackSaveAsPath(const FilePath &defaultPath)
{
    d->m_defaultPath = defaultPath;
}

void TextDocument::setFallbackSaveAsFileName(const QString &suggestedFileName)
{
    d->m_suggestedFileName = suggestedFileName;
}

QTextDocument *TextDocument::document() const
{
    return &d->m_document;
}

/*!
 * Saves the document to the file specified by \a fileName. If errors occur,
 * the return value will be Result::Error that contains their cause.
 * If \a option is \c SaveOption::AutoSave, the cursor will be restored and some signals suppressed
 * and we do not clean up the text file (cleanWhitespace(), ensureFinalNewLine()).
 */
Result<> TextDocument::saveImpl(const FilePath &filePath, SaveOption option)
{
    QTextCursor cursor(&d->m_document);

    // When autosaving, we don't want to modify the document/location under the user's fingers.
    TextEditorWidget *editorWidget = nullptr;
    int savedPosition = 0;
    int savedAnchor = 0;
    int savedVScrollBarValue = 0;
    int savedHScrollBarValue = 0;
    int undos = d->m_document.availableUndoSteps();

    // When saving the current editor, make sure to maintain the cursor and scroll bar
    // positions for undo
    if (BaseTextEditor *editor = BaseTextEditor::currentTextEditor()) {
        if (editor->document() == this) {
            editorWidget = editor->editorWidget();
            QTextCursor cur = editor->textCursor();
            savedPosition = cur.position();
            savedAnchor = cur.anchor();
            savedVScrollBarValue = editorWidget->verticalScrollBar()->value();
            savedHScrollBarValue = editorWidget->horizontalScrollBar()->value();
            cursor.setPosition(cur.position());
        }
    }

    if (option != SaveOption::AutoSave) {
        cursor.beginEditBlock();
        cursor.movePosition(QTextCursor::Start);

        if (d->m_storageSettings.m_cleanWhitespace) {
            cleanWhitespace(cursor,
                            d->m_storageSettings.m_inEntireDocument,
                            d->m_storageSettings.m_cleanIndentation);
        }
        if (d->m_storageSettings.m_addFinalNewLine)
          ensureFinalNewLine(cursor);
        cursor.endEditBlock();
    }

    // check if UTF8-BOM has to be added or removed
    TextFileFormat saveFormat = format();
    if (saveFormat.encoding().isUtf8() && supportsUtf8Bom()) {
        switch (d->m_extraEncodingSettings.m_utf8BomSetting) {
        case ExtraEncodingSettingsData::AlwaysAdd:
            saveFormat.hasUtf8Bom = true;
            break;
        case ExtraEncodingSettingsData::OnlyKeep:
            break;
        case ExtraEncodingSettingsData::AlwaysDelete:
            saveFormat.hasUtf8Bom = false;
            break;
        }
    }

    const Result<> res = write(filePath, saveFormat, plainText());

    // restore text cursor and scroll bar positions
    if (option == SaveOption::AutoSave && undos < d->m_document.availableUndoSteps()) {
        d->m_document.undo();
        if (editorWidget) {
            QTextCursor cur = editorWidget->textCursor();
            cur.setPosition(savedAnchor);
            cur.setPosition(savedPosition, QTextCursor::KeepAnchor);
            editorWidget->verticalScrollBar()->setValue(savedVScrollBarValue);
            editorWidget->horizontalScrollBar()->setValue(savedHScrollBarValue);
            editorWidget->setTextCursor(cur);
        }
    }

    if (!res)
        return res;

    d->m_autoSaveRevision = d->m_document.revision();
    if (option == SaveOption::AutoSave)
        return ResultOk;

    // inform about the new filename
    d->m_document.setModified(false); // also triggers update of the block revisions
    setFilePath(filePath.absoluteFilePath());
    emit changed();
    return ResultOk;
}

QByteArray TextDocument::contents() const
{
    return plainText().toUtf8();
}

Result<> TextDocument::setContents(const QByteArray &contents)
{
    return setPlainText(QString::fromUtf8(contents));
}

void TextDocument::formatContents()
{
    d->m_indenter->format({{document()->firstBlock().blockNumber() + 1,
                            document()->lastBlock().blockNumber() + 1}});
}

bool TextDocument::shouldAutoSave() const
{
    return d->m_autoSaveRevision != d->m_document.revision();
}

void TextDocument::setFilePath(const Utils::FilePath &newName)
{
    if (const FilePath newPath = newName.absoluteFilePath().cleanPath(); newPath != filePath()) {
        if (d->m_indenter)
            d->m_indenter->setFileName(newPath);
        IDocument::setFilePath(newPath);
    }
}

IDocument::ReloadBehavior TextDocument::reloadBehavior(ChangeTrigger state, ChangeType type) const
{
    if (d->m_silentReload)
        return IDocument::BehaviorSilent;
    return BaseTextDocument::reloadBehavior(state, type);
}

bool TextDocument::isModified() const
{
    return d->m_document.isModified();
}

Result<> TextDocument::open(const FilePath &filePath, const FilePath &realFilePath)
{
    emit aboutToOpen(filePath, realFilePath);
    const Result<> result = openImpl(filePath, realFilePath, /*reload =*/ false);
    if (result) {
        setMimeType(Utils::mimeTypeForFile(filePath, MimeMatchMode::MatchDefaultAndRemote).name());
        setTabSettings(d->m_tabSettings);
        emit openFinishedSuccessfully();
    }
    return result;
}

Result<> TextDocument::openImpl(const FilePath &filePath,
                                const FilePath &realFilePath,
                                bool reload)
{
    ReadResult readResult = TextFileFormat::ReadIOError;

    if (!filePath.isEmpty()) {
        readResult = read(realFilePath);

        // Don't call setUndoRedoEnabled(true) when reload is true and filenames are different,
        // since it will reset the undo's clear index
        if (!reload || filePath == realFilePath)
            d->m_document.setUndoRedoEnabled(reload);

        QTextCursor c(&d->m_document);
        c.beginEditBlock();
        if (reload) {
            c.select(QTextCursor::Document);
            c.removeSelectedText();
        } else {
            d->m_document.clear();
        }

        const int textChunkSize = 65536;
        if (readResult.content.size() <= textChunkSize) {
            c.insertText(readResult.content);
        } else {
            const int chunks = readResult.content.size() / textChunkSize;
            QFutureInterface<void> interface;
            interface.setProgressRange(0, chunks);
            ProgressManager::addTask(interface.future(), Tr::tr("Opening File"),
                                     Constants::TASK_OPEN_FILE);
            interface.reportStarted();

            QStringView view(readResult.content);
            for (int i = 0; !view.isEmpty(); ++i, view = view.mid(textChunkSize)) {
                c.insertText(view.left(textChunkSize).toString());
                interface.setProgressValue(i + 1);
                QApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
            }

            interface.reportFinished();
        }

        c.endEditBlock();

        // Don't call setUndoRedoEnabled(true) when reload is true and filenames are different,
        // since it will reset the undo's clear index
        if (!reload || filePath == realFilePath)
            d->m_document.setUndoRedoEnabled(true);

        auto documentLayout =
            qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
        QTC_ASSERT(documentLayout, return ResultError(ResultAssert));
        documentLayout->lastSaveRevision = d->m_autoSaveRevision = d->m_document.revision();
        d->updateRevisions();
        d->m_document.setModified(filePath != realFilePath);
        setFilePath(filePath);
    }
    if (readResult.code == TextFileFormat::ReadIOError)
        return ResultError(readResult.error);
    return ResultOk;
}

Result<> TextDocument::reload(const TextEncoding &encoding)
{
    QTC_ASSERT(encoding.isValid(), return ResultError("No encoding given"));
    setEncoding(encoding);
    return reload();
}

Result<> TextDocument::reload()
{
    return reload(filePath());
}

Result<> TextDocument::reload(const FilePath &realFilePath)
{
    emit aboutToReload();
    auto documentLayout =
        qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    if (documentLayout)
        documentLayout->documentAboutToReload(this); // removes text marks non-permanently

    const Result<> result = openImpl(filePath(), realFilePath, /*reload =*/true);

    if (documentLayout)
        documentLayout->documentReloaded(this); // re-adds text marks
    emit reloadFinished(result.has_value());

    return result;
}

Result<> TextDocument::setPlainText(const QString &text)
{
    if (text.size() > EditorManager::maxTextFileSize()) {
        document()->setPlainText(TextEditorWidget::msgTextTooLarge(text.size()));
        d->resetRevisions();
        document()->setModified(false);
        return ResultError(TextEditorWidget::msgTextTooLarge(text.size()));
    }
    document()->setPlainText(text);
    d->resetRevisions();
    document()->setModified(false);
    return ResultOk;
}

Result<> TextDocument::reload(ReloadFlag flag, ChangeType type)
{
    if (flag == FlagIgnore) {
        if (type != TypeContents)
            return ResultOk;

        const bool wasModified = document()->isModified();
        {
            GuardLocker locker(d->m_modificationChangedGuard);
            // hack to ensure we clean the clear state in QTextDocument
            document()->setModified(false);
            document()->setModified(true);
        }
        if (!wasModified)
            modificationChanged(true);
        return ResultOk;
    }
    return reload();
}

void TextDocument::resetSyntaxHighlighter(const std::function<SyntaxHighlighter *()> &creator)
{
    delete d->m_highlighter;
    d->m_highlighter = creator();
    d->m_highlighter->setParent(this);
    d->m_highlighter->setDocument(this->document());
    d->m_highlighter->setFontSettings(TextEditorSettings::fontSettings());
    d->m_highlighter->setMimeType(mimeType());
    d->m_highlighter->setIgnoreFolding(d->m_externalFoldingIndent);
}

SyntaxHighlighter *TextDocument::syntaxHighlighter() const
{
    return d->m_highlighter;
}

void TextDocument::cleanWhitespace(const QTextCursor &cursor)
{
    bool hasSelection = cursor.hasSelection();
    QTextCursor copyCursor = cursor;
    copyCursor.setVisualNavigation(false);
    copyCursor.beginEditBlock();

    cleanWhitespace(copyCursor, true, true);

    if (!hasSelection)
        ensureFinalNewLine(copyCursor);

    copyCursor.endEditBlock();
}

void TextDocument::cleanWhitespace(QTextCursor &cursor, bool inEntireDocument,
                                   bool cleanIndentation)
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    Q_ASSERT(cursor.visualNavigation() == false);

    QTextBlock block = d->m_document.findBlock(cursor.selectionStart());
    QTextBlock end;
    if (cursor.hasSelection())
        end = d->m_document.findBlock(cursor.selectionEnd()-1).next();

    QList<QTextBlock> blocks;
    while (block.isValid() && block != end) {
        if (inEntireDocument || block.revision() != documentLayout->lastSaveRevision) {
            blocks.append(block);
        }
        block = block.next();
    }
    if (blocks.isEmpty())
        return;

    const TabSettings currentTabSettings = tabSettings();
    const IndentationForBlock &indentations
        = d->m_indenter->indentationForBlocks(blocks, currentTabSettings);

    const bool cleanTrailingWhitespace = d->m_storageSettings.removeTrailingWhitespace(filePath().fileName());
    for (const QTextBlock &block : std::as_const(blocks)) {
        QString blockText = block.text();

        if (cleanTrailingWhitespace)
            removeTrailingWhitespace(block);

        const int indent = indentations[block.blockNumber()];
        if (cleanIndentation && !currentTabSettings.isIndentationClean(block, indent)) {
            cursor.setPosition(block.position());
            const int firstNonSpace = TabSettings::firstNonSpace(blockText);
            if (firstNonSpace == blockText.size()) {
                cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
                cursor.removeSelectedText();
            } else {
                int column = currentTabSettings.columnAt(blockText, firstNonSpace);
                cursor.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, firstNonSpace);
                cursor.insertText(currentTabSettings.indentationString(0, column, column - indent));
            }
        }
    }
}

void TextDocument::ensureFinalNewLine(QTextCursor& cursor)
{
    if (!d->m_storageSettings.m_addFinalNewLine)
        return;

    cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);
    bool emptyFile = !cursor.movePosition(QTextCursor::PreviousCharacter, QTextCursor::KeepAnchor);

    if (!emptyFile && cursor.selectedText().at(0) != QChar::ParagraphSeparator)
    {
        cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);
        cursor.insertText(QLatin1String("\n"));
    }
}

void TextDocument::modificationChanged(bool modified)
{
    if (d->m_modificationChangedGuard.isLocked())
        return;
    // we only want to update the block revisions when going back to the saved version,
    // e.g. with undo
    if (!modified)
        d->updateRevisions();
    emit changed();
}

void TextDocument::removeTrailingWhitespace(const QTextBlock &block)
{
    TabSettings::removeTrailingWhitespace(block);
}

void TextDocument::updateLayout() const
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    documentLayout->requestUpdate();
}

void TextDocument::scheduleUpdateLayout() const
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    documentLayout->scheduleUpdate();
}

TextMarks TextDocument::marks() const
{
    return d->m_marksCache;
}

bool TextDocument::addMark(TextMark *mark)
{
    if (mark->baseTextDocument())
        return false;
    QTC_ASSERT(mark->lineNumber() >= 1, return false);
    int blockNumber = mark->lineNumber() - 1;
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return false);
    QTextBlock block = d->m_document.findBlockByNumber(blockNumber);

    if (block.isValid()) {
        TextBlockUserData *userData = TextBlockUserData::userData(block);
        userData->addMark(mark);
        d->m_marksCache.append(mark);
        mark->updateLineNumber(blockNumber + 1);
        QTC_CHECK(mark->lineNumber() == blockNumber + 1); // Checks that the base class is called
        mark->updateBlock(block);
        mark->setBaseTextDocument(this);
        if (!mark->isVisible())
            return true;
        // Update document layout
        bool fullUpdate = !documentLayout->hasMarks;
        documentLayout->hasMarks = true;
        if (!documentLayout->hasLocationMarker && mark->isLocationMarker()) {
            documentLayout->hasLocationMarker = true;
            fullUpdate = true;
        }
        if (fullUpdate)
            documentLayout->scheduleUpdate();
        else
            documentLayout->requestExtraAreaUpdate();
        return true;
    }
    return false;
}

TextMarks TextDocument::marksAt(int line) const
{
    QTC_ASSERT(line >= 1, return TextMarks());
    int blockNumber = line - 1;
    QTextBlock block = d->m_document.findBlockByNumber(blockNumber);

    if (block.isValid()) {
        if (TextBlockUserData *userData = TextBlockUserData::textUserData(block))
            return userData->marks();
    }
    return TextMarks();
}

void TextDocument::removeMarkFromMarksCache(TextMark *mark)
{
    auto documentLayout = qobject_cast<TextDocumentLayout*>(d->m_document.documentLayout());
    QTC_ASSERT(documentLayout, return);
    d->m_marksCache.removeOne(mark);

    if (mark->isLocationMarker()) {
        documentLayout->hasLocationMarker = false;
        documentLayout->scheduleUpdate();
    }

    if (d->m_marksCache.isEmpty()) {
        documentLayout->hasMarks = false;
        documentLayout->scheduleUpdate();
        return;
    }

    if (!mark->isVisible())
        return;

    documentLayout->requestExtraAreaUpdate();
}

static QSet<Id> &hiddenMarksIds()
{
    static QSet<Id> ids;
    return ids;
}

void TextDocument::temporaryHideMarksAnnotation(const Utils::Id &category)
{
    hiddenMarksIds().insert(category);
    const QList<IDocument *> documents = DocumentModel::openedDocuments();
    for (auto document : documents) {
        if (auto textDocument = qobject_cast<TextDocument*>(document)) {
            const TextMarks marks = textDocument->marks();
            for (const auto mark : marks) {
                if (mark->category().id == category)
                    mark->updateMarker();
            }
        }
    }
}

void TextDocument::showMarksAnnotation(const Utils::Id &category)
{
    hiddenMarksIds().remove(category);
    const QList<IDocument *> documents = DocumentModel::openedDocuments();
    for (auto document : documents) {
        if (auto textDocument = qobject_cast<TextDocument*>(document)) {
            const TextMarks marks = textDocument->marks();
            for (const auto mark : marks) {
                if (mark->category().id == category)
                    mark->updateMarker();
            }
        }
    }
}

bool TextDocument::marksAnnotationHidden(const Utils::Id &category)
{
    return hiddenMarksIds().contains(category);
}

void TextDocument::removeMark(TextMark *mark)
{
    QTextBlock block = d->m_document.findBlockByNumber(mark->lineNumber() - 1);
    if (auto data = static_cast<TextBlockUserData *>(block.userData())) {
        if (!data->removeMark(mark))
            qDebug() << "Could not find mark" << mark << "on line" << mark->lineNumber();
    }

    removeMarkFromMarksCache(mark);
    emit markRemoved(mark);
    mark->setBaseTextDocument(nullptr);
    scheduleUpdateLayout();
}

void TextDocument::updateMark(TextMark *mark)
{
    QTextBlock block = d->m_document.findBlockByNumber(mark->lineNumber() - 1);
    if (block.isValid()) {
        TextBlockUserData *userData = TextBlockUserData::userData(block);
        // re-evaluate priority
        userData->removeMark(mark);
        userData->addMark(mark);
    }
    scheduleUpdateLayout();
}

void TextDocument::moveMark(TextMark *mark, int previousLine)
{
    QTextBlock block = d->m_document.findBlockByNumber(previousLine - 1);
    if (TextBlockUserData *data = TextBlockUserData::textUserData(block)) {
        if (!data->removeMark(mark))
            qDebug() << "Could not find mark" << mark << "on line" << previousLine;
    }
    removeMarkFromMarksCache(mark);
    mark->setBaseTextDocument(nullptr);
    addMark(mark);
}

} // namespace TextEditor
