/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** 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-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QTEXTDOCUMENT_P_H
#define QTEXTDOCUMENT_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtGui/private/qtguiglobal_p.h>
#include "QtCore/qstring.h"
#include "QtCore/qvector.h"
#include "QtCore/qlist.h"
#include "private/qobject_p.h"
#include "private/qfragmentmap_p.h"
#include "QtGui/qtextlayout.h"
#include "QtGui/qtextoption.h"
#include "private/qtextformat_p.h"
#include "QtGui/qtextdocument.h"
#include "QtGui/qtextobject.h"
#include "QtGui/qtextcursor.h"
#include "QtCore/qmap.h"
#include "QtCore/qvariant.h"
#include "QtCore/qurl.h"
#include "private/qcssparser_p.h"

// #define QT_QMAP_DEBUG

#ifdef QT_QMAP_DEBUG
#include <iostream>
#endif

QT_BEGIN_NAMESPACE

class QTextFormatCollection;
class QTextFormat;
class QTextBlockFormat;
class QTextCursorPrivate;
class QAbstractTextDocumentLayout;
class QTextDocument;
class QTextFrame;

#define QTextBeginningOfFrame QChar(0xfdd0)
#define QTextEndOfFrame QChar(0xfdd1)

class QTextFragmentData : public QFragment<>
{
public:
    inline void initialize() {}
    inline void invalidate() const {}
    inline void free() {}
    int stringPosition;
    int format;
};

class QTextBlockData : public QFragment<3>
{
public:
    inline void initialize()
        { layout = 0; userData = 0; userState = -1; revision = 0; hidden = 0; }
    void invalidate() const;
    inline void free()
    { delete layout; layout = 0; delete userData; userData = 0; }

    mutable int format;
    // ##### probably store a QTextEngine * here!
    mutable QTextLayout *layout;
    mutable QTextBlockUserData *userData;
    mutable int userState;
    mutable int revision : 31;
    mutable uint hidden : 1;
};


class QAbstractUndoItem;

class QTextUndoCommand
{
public:
    enum Command {
        Inserted = 0,
        Removed = 1,
        CharFormatChanged = 2,
        BlockFormatChanged = 3,
        BlockInserted = 4,
        BlockRemoved = 5,
        BlockAdded = 6,
        BlockDeleted = 7,
        GroupFormatChange = 8,
        CursorMoved = 9,
        Custom = 256
    };
    enum Operation {
        KeepCursor = 0,
        MoveCursor = 1
    };
    quint16 command;
    uint block_part : 1; // all commands that are part of an undo block (including the first and the last one) have this set to 1
    uint block_end : 1; // the last command in an undo block has this set to 1.
    uint block_padding : 6; // padding since block used to be a quint8
    quint8 operation;
    int format;
    quint32 strPos;
    quint32 pos;
    union {
        int blockFormat;
        quint32 length;
        QAbstractUndoItem *custom;
        int objectIndex;
    };
    quint32 revision;

    bool tryMerge(const QTextUndoCommand &other);
};
Q_DECLARE_TYPEINFO(QTextUndoCommand, Q_PRIMITIVE_TYPE);

class Q_GUI_EXPORT QTextDocumentPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QTextDocument)
public:
    typedef QFragmentMap<QTextFragmentData> FragmentMap;
    typedef FragmentMap::ConstIterator FragmentIterator;
    typedef QFragmentMap<QTextBlockData> BlockMap;

    QTextDocumentPrivate();
    ~QTextDocumentPrivate();

    void init();
    void clear();

    void setLayout(QAbstractTextDocumentLayout *layout);

    void insert(int pos, const QString &text, int format);
    void insert(int pos, int strPos, int strLength, int format);
    int insertBlock(int pos, int blockFormat, int charFormat, QTextUndoCommand::Operation = QTextUndoCommand::MoveCursor);
    int insertBlock(QChar blockSeparator, int pos, int blockFormat, int charFormat,
                     QTextUndoCommand::Operation op = QTextUndoCommand::MoveCursor);

    void move(int from, int to, int length, QTextUndoCommand::Operation = QTextUndoCommand::MoveCursor);
    void remove(int pos, int length, QTextUndoCommand::Operation = QTextUndoCommand::MoveCursor);

    void aboutToRemoveCell(int cursorFrom, int cursorEnd);

    QTextFrame *insertFrame(int start, int end, const QTextFrameFormat &format);
    void removeFrame(QTextFrame *frame);

    enum FormatChangeMode { MergeFormat, SetFormat, SetFormatAndPreserveObjectIndices };

    void setCharFormat(int pos, int length, const QTextCharFormat &newFormat, FormatChangeMode mode = SetFormat);
    void setBlockFormat(const QTextBlock &from, const QTextBlock &to,
                        const QTextBlockFormat &newFormat, FormatChangeMode mode = SetFormat);

    void emitUndoAvailable(bool available);
    void emitRedoAvailable(bool available);

    int undoRedo(bool undo);
    inline void undo() { undoRedo(true); }
    inline void redo() { undoRedo(false); }
    void appendUndoItem(QAbstractUndoItem *);
    inline void beginEditBlock() { if (0 == editBlock++) ++revision; }
    void joinPreviousEditBlock();
    void endEditBlock();
    void finishEdit();
    inline bool isInEditBlock() const { return editBlock; }
    void enableUndoRedo(bool enable);
    inline bool isUndoRedoEnabled() const { return undoEnabled; }

    inline bool isUndoAvailable() const { return undoEnabled && undoState > 0; }
    inline bool isRedoAvailable() const { return undoEnabled && undoState < undoStack.size(); }

    inline int availableUndoSteps() const { return undoEnabled ? undoState : 0; }
    inline int availableRedoSteps() const { return undoEnabled ? qMax(undoStack.size() - undoState - 1, 0) : 0; }

    inline QString buffer() const { return text; }
    QString plainText() const;
    inline int length() const { return fragments.length(); }

    inline QTextFormatCollection *formatCollection() { return &formats; }
    inline const QTextFormatCollection *formatCollection() const { return &formats; }
    inline QAbstractTextDocumentLayout *layout() const { return lout; }

    inline FragmentIterator find(int pos) const { return fragments.find(pos); }
    inline FragmentIterator begin() const { return fragments.begin(); }
    inline FragmentIterator end() const { return fragments.end(); }

    inline QTextBlock blocksBegin() const { return QTextBlock(const_cast<QTextDocumentPrivate *>(this), blocks.firstNode()); }
    inline QTextBlock blocksEnd() const { return QTextBlock(const_cast<QTextDocumentPrivate *>(this), 0); }
    inline QTextBlock blocksFind(int pos) const { return QTextBlock(const_cast<QTextDocumentPrivate *>(this), blocks.findNode(pos)); }
    int blockCharFormatIndex(int node) const;

    inline int numBlocks() const { return blocks.numNodes(); }

    const BlockMap &blockMap() const { return blocks; }
    const FragmentMap &fragmentMap() const { return fragments; }
    BlockMap &blockMap() { return blocks; }
    FragmentMap &fragmentMap() { return fragments; }

    static const QTextBlockData *block(const QTextBlock &it) { return it.p->blocks.fragment(it.n); }

    int nextCursorPosition(int position, QTextLayout::CursorMode mode) const;
    int previousCursorPosition(int position, QTextLayout::CursorMode mode) const;
    int leftCursorPosition(int position) const;
    int rightCursorPosition(int position) const;

    void changeObjectFormat(QTextObject *group, int format);

    void setModified(bool m);
    inline bool isModified() const { return modified; }

    inline QFont defaultFont() const { return formats.defaultFont(); }
    inline void setDefaultFont(const QFont &f) { formats.setDefaultFont(f); }

    void clearUndoRedoStacks(QTextDocument::Stacks stacksToClear, bool emitSignals = false);

private:
    bool split(int pos);
    bool unite(uint f);

    void insert_string(int pos, uint strPos, uint length, int format, QTextUndoCommand::Operation op);
    int insert_block(int pos, uint strPos, int format, int blockformat, QTextUndoCommand::Operation op, int command);
    int remove_string(int pos, uint length, QTextUndoCommand::Operation op);
    int remove_block(int pos, int *blockformat, int command, QTextUndoCommand::Operation op);

    void insert_frame(QTextFrame *f);
    void scan_frames(int pos, int charsRemoved, int charsAdded);
    static void clearFrame(QTextFrame *f);

    void adjustDocumentChangesAndCursors(int from, int addedOrRemoved, QTextUndoCommand::Operation op);

    bool wasUndoAvailable;
    bool wasRedoAvailable;

public:
    void documentChange(int from, int length);

    inline void addCursor(QTextCursorPrivate *c) { cursors.append(c); }
    inline void removeCursor(QTextCursorPrivate *c) { cursors.removeAll(c); }

    QTextFrame *frameAt(int pos) const;
    QTextFrame *rootFrame() const;

    QTextObject *objectForIndex(int objectIndex) const;
    QTextObject *objectForFormat(int formatIndex) const;
    QTextObject *objectForFormat(const QTextFormat &f) const;

    QTextObject *createObject(const QTextFormat &newFormat, int objectIndex = -1);
    void deleteObject(QTextObject *object);

    QTextDocument *document() { return q_func(); }
    const QTextDocument *document() const { return q_func(); }

    bool ensureMaximumBlockCount();

private:
    QTextDocumentPrivate(const QTextDocumentPrivate& m);
    QTextDocumentPrivate& operator= (const QTextDocumentPrivate& m);

    void appendUndoItem(const QTextUndoCommand &c);

    void contentsChanged();

    void compressPieceTable();

    QString text;
    uint unreachableCharacterCount;

    QVector<QTextUndoCommand> undoStack;
    bool undoEnabled;
    int undoState;
    int revision;
    // position in undo stack of the last setModified(false) call
    int modifiedState;
    bool modified;

    int editBlock;
    int editBlockCursorPosition;
    int docChangeFrom;
    int docChangeOldLength;
    int docChangeLength;
    bool framesDirty;

    QTextFormatCollection formats;
    mutable QTextFrame *rtFrame;
    QAbstractTextDocumentLayout *lout;
    FragmentMap fragments;
    BlockMap blocks;
    int initialBlockCharFormatIndex;

    QList<QTextCursorPrivate *> cursors;
    QMap<int, QTextObject *> objects;
    QMap<QUrl, QVariant> resources;
    QMap<QUrl, QVariant> cachedResources;
    QString defaultStyleSheet;

    int lastBlockCount;

public:
    QTextOption defaultTextOption;
    Qt::CursorMoveStyle defaultCursorMoveStyle;
#ifndef QT_NO_CSSPARSER
    QCss::StyleSheet parsedDefaultStyleSheet;
#endif
    int maximumBlockCount;
    uint needsEnsureMaximumBlockCount : 1;
    uint inContentsChange : 1;
    uint blockCursorAdjustment : 1;
    QSizeF pageSize;
    QString title;
    QString url;
    qreal indentWidth;
    qreal documentMargin;
    QUrl baseUrl;

    void mergeCachedResources(const QTextDocumentPrivate *priv);

    friend class QTextHtmlExporter;
    friend class QTextCursor;
};

class QTextTable;
class QTextHtmlExporter
{
public:
    QTextHtmlExporter(const QTextDocument *_doc);

    enum ExportMode {
        ExportEntireDocument,
        ExportFragment
    };

    QString toHtml(const QByteArray &encoding, ExportMode mode = ExportEntireDocument);

private:
    enum StyleMode { EmitStyleTag, OmitStyleTag };
    enum FrameType { TextFrame, TableFrame, RootFrame };

    void emitFrame(const QTextFrame::Iterator &frameIt);
    void emitTextFrame(const QTextFrame *frame);
    void emitBlock(const QTextBlock &block);
    void emitTable(const QTextTable *table);
    void emitFragment(const QTextFragment &fragment);

    void emitBlockAttributes(const QTextBlock &block);
    bool emitCharFormatStyle(const QTextCharFormat &format);
    void emitTextLength(const char *attribute, const QTextLength &length);
    void emitAlignment(Qt::Alignment alignment);
    void emitFloatStyle(QTextFrameFormat::Position pos, StyleMode mode = EmitStyleTag);
    void emitMargins(const QString &top, const QString &bottom, const QString &left, const QString &right);
    void emitAttribute(const char *attribute, const QString &value);
    void emitFrameStyle(const QTextFrameFormat &format, FrameType frameType);
    void emitBorderStyle(QTextFrameFormat::BorderStyle style);
    void emitPageBreakPolicy(QTextFormat::PageBreakFlags policy);

    void emitFontFamily(const QString &family);

    void emitBackgroundAttribute(const QTextFormat &format);
    QString findUrlForImage(const QTextDocument *doc, qint64 cacheKey, bool isPixmap);

    QString html;
    QTextCharFormat defaultCharFormat;
    const QTextDocument *doc;
    bool fragmentMarkers;
};

QT_END_NAMESPACE

#endif // QTEXTDOCUMENT_P_H