/*
  propertyeditordelegate.cpp

  This file is part of GammaRay, the Qt application inspection and
  manipulation tool.

  Copyright (C) 2013-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
  Author: Volker Krause <volker.krause@kdab.com>

  Licensees holding valid commercial KDAB GammaRay licenses may use this file in
  accordance with GammaRay Commercial License Agreement provided with the Software.

  Contact info@kdab.com if any conditions of this licensing are not clear to you.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "propertyeditordelegate.h"
#include "propertyeditorfactory.h"
#include "propertyextendededitor.h"

#include <common/sourcelocation.h>

#include <QApplication>
#include <QDebug>
#include <QMatrix>
#include <QMatrix4x4>
#include <QPainter>
#include <QQuaternion>
#include <QVector2D>
#include <QVector3D>
#include <QVector4D>

using namespace GammaRay;

namespace {
template<typename T> struct matrix_trait {};
template<> struct matrix_trait<QMatrix> {
    static const int rows = 3;
    static const int columns = 2;
    static qreal value(const QMatrix &matrix, int r, int c)
    {
        switch (r << 4 | c) {
        case 0x00:
            return matrix.m11();
        case 0x01:
            return matrix.m12();
        case 0x10:
            return matrix.m21();
        case 0x11:
            return matrix.m22();
        case 0x20:
            return matrix.dx();
        case 0x21:
            return matrix.dy();
        }
        Q_ASSERT(false);
        return 0.0;
    }
};

template<> struct matrix_trait<QMatrix4x4> {
    static const int rows = 4;
    static const int columns = 4;
    static qreal value(const QMatrix4x4 &matrix, int r, int c) { return matrix(r, c); }
};

template<> struct matrix_trait<QTransform> {
    static const int rows = 3;
    static const int columns = 3;
    static qreal value(const QTransform &matrix, int r, int c)
    {
        switch (r << 4 | c) {
        case 0x00:
            return matrix.m11();
        case 0x01:
            return matrix.m12();
        case 0x02:
            return matrix.m13();
        case 0x10:
            return matrix.m21();
        case 0x11:
            return matrix.m22();
        case 0x12:
            return matrix.m23();
        case 0x20:
            return matrix.m31();
        case 0x21:
            return matrix.m32();
        case 0x22:
            return matrix.m33();
        }
        Q_ASSERT(false);
        return 0.0;
    }
};

template<> struct matrix_trait<QVector2D> {
    static const int rows = 2;
    static const int columns = 1;
    static qreal value(const QVector2D &vec, int r, int) { return vec[r]; }
};

template<> struct matrix_trait<QVector3D> {
    static const int rows = 3;
    static const int columns = 1;
    static qreal value(const QVector3D &vec, int r, int) { return vec[r]; }
};

template<> struct matrix_trait<QVector4D> {
    static const int rows = 4;
    static const int columns = 1;
    static qreal value(const QVector4D &vec, int r, int) { return vec[r]; }
};

template<> struct matrix_trait<QQuaternion> {
    static const int rows = 3;
    static const int columns = 1;
    static qreal value(const QQuaternion &quaternion, int r, int)
    {
        float pitch, yaw, roll;
        quaternion.getEulerAngles(&pitch, &yaw, &roll);

        switch (r) {
        case 0:
            return pitch;
        case 1:
            return yaw;
        case 2:
            return roll;
        }
        Q_ASSERT(false);
        return 0.0;
    }
};
}

PropertyEditorDelegate::PropertyEditorDelegate(QObject *parent)
    : QStyledItemDelegate(parent)
{
    setItemEditorFactory(PropertyEditorFactory::instance());
}

PropertyEditorDelegate::~PropertyEditorDelegate() = default;

void PropertyEditorDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
    editor->setProperty("displayString", index.data(Qt::DisplayRole));
    QStyledItemDelegate::setEditorData(editor, index);
}

void PropertyEditorDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
{
    const QVariant value = index.data(Qt::EditRole);
    if (value.canConvert<QMatrix4x4>()) {
        paint(painter, option, index, value.value<QMatrix4x4>());
    } else if (value.canConvert<QMatrix>()) {
        paint(painter, option, index, value.value<QMatrix>());
    } else if (value.type() == QVariant::Transform) {
        paint(painter, option, index, value.value<QTransform>());
    } else if (value.canConvert<QVector2D>()) {
        paint(painter, option, index, value.value<QVector2D>());
    } else if (value.canConvert<QVector3D>()) {
        paint(painter, option, index, value.value<QVector3D>());
    } else if (value.canConvert<QVector4D>()) {
        paint(painter, option, index, value.value<QVector4D>());
    } else if (value.type() == QVariant::Quaternion) {
        paint(painter, option, index, value.value<QQuaternion>());
    } else {
        QStyledItemDelegate::paint(painter, option, index);
    }
}

QSize PropertyEditorDelegate::sizeHint(const QStyleOptionViewItem &option,
                                       const QModelIndex &index) const
{
    const QVariant value = index.data(Qt::EditRole);
    if (value.canConvert<QMatrix4x4>()) {
        return sizeHint(option, index, value.value<QMatrix4x4>());
    } else if (value.canConvert<QMatrix>()) {
        return sizeHint(option, index, value.value<QMatrix>());
    } else if (value.type() == QVariant::Transform) {
        return sizeHint(option, index, value.value<QTransform>());
    } else if (value.canConvert<QVector2D>()) {
        return sizeHint(option, index, value.value<QVector2D>());
    } else if (value.canConvert<QVector3D>()) {
        return sizeHint(option, index, value.value<QVector3D>());
    } else if (value.canConvert<QVector4D>()) {
        return sizeHint(option, index, value.value<QVector4D>());
    } else if (value.type() == QVariant::Quaternion) {
        return sizeHint(option, index, value.value<QQuaternion>());
    }

    // We don't want multiline texts for String values
    if (value.type() == QVariant::String || value.type() == QVariant::ByteArray) {
        QStyleOptionViewItem opt = option;

        QSize sh = QStyledItemDelegate::sizeHint(opt, index);

        initStyleOption(&opt, index);
        return sh.boundedTo(QSize(sh.width(), opt.fontMetrics.height()));
    }

    return QStyledItemDelegate::sizeHint(option, index);
}

template<typename Matrix>
void PropertyEditorDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                                   const QModelIndex &index, const Matrix &matrix) const
{
    QStyleOptionViewItem opt = option;
    initStyleOption(&opt, index);
    opt.text.clear();
    QApplication::style()->drawControl(QStyle::CE_ItemViewItem, &opt, painter, opt.widget);

    QRect textRect = QApplication::style()->subElementRect(QStyle::SE_ItemViewItemText, &opt,
                                                           opt.widget);
    const int textHMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin, nullptr,
                                                               opt.widget) + 1;
    static const int textVMargin = 1;
    textRect = textRect.adjusted(textHMargin, textVMargin, -textHMargin, -textVMargin);

    static const int parenthesisLineWidth = 1;
    const int matrixSpacing = opt.fontMetrics.width(QStringLiteral("x"));
    const int matrixHMargin = matrixSpacing / 2;
    const int parenthesisWidth = qMax(matrixHMargin, 3);

    painter->save();
    painter->setClipRect(textRect);
    painter->translate(textRect.topLeft());
    painter->setPen(opt.palette.color(opt.state
                                      & QStyle::State_Selected ? QPalette::HighlightedText :
                                      QPalette::Text));
    int xOffset = 0;
    painter->drawLine(xOffset, 0, xOffset, textRect.height());
    painter->drawLine(xOffset, 0, xOffset + parenthesisWidth, 0);
    painter->drawLine(xOffset, textRect.height() - 1, xOffset + parenthesisWidth,
                      textRect.height() - 1);
    xOffset += matrixHMargin + parenthesisLineWidth;
    for (int col = 0; col < matrix_trait<Matrix>::columns; ++col) {
        const int colWidth = columnWidth(opt, matrix, col);
        for (int row = 0; row < matrix_trait<Matrix>::rows; ++row) {
            const QRect r(xOffset,
                          row * opt.fontMetrics.lineSpacing(), colWidth,
                          opt.fontMetrics.lineSpacing());
            painter->drawText(r, Qt::AlignHCenter | Qt::AlignRight,
                              QString::number(matrix_trait<Matrix>::value(matrix, row, col)));
        }
        xOffset += colWidth + matrixSpacing;
    }
    xOffset += -matrixSpacing + matrixHMargin;
    painter->drawLine(xOffset, 0, xOffset, textRect.height());
    painter->drawLine(xOffset, 0, xOffset - parenthesisWidth, 0);
    painter->drawLine(xOffset, textRect.height() - 1, xOffset - parenthesisWidth,
                      textRect.height() - 1);
    painter->restore();
}

template<typename Matrix>
QSize PropertyEditorDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index,
                                       const Matrix &matrix) const
{
    QStyleOptionViewItem opt = option;
    initStyleOption(&opt, index);

    static const int parenthesisLineWidth = 1;
    const int textHMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin, nullptr,
                                                               opt.widget) + 1;
    static const int textVMargin = 1;

    int width = 0;
    for (int col = 0; col < matrix_trait<Matrix>::columns; ++col) {
        width += columnWidth(opt, matrix, col);
    }
    width += opt.fontMetrics.width(QStringLiteral("x")) * matrix_trait<Matrix>::columns + 2
             * parenthesisLineWidth + 2 * textHMargin;

    const int height = opt.fontMetrics.lineSpacing() * matrix_trait<Matrix>::rows + 2* textVMargin;

    return {width, height};
}

template<typename Matrix>
int PropertyEditorDelegate::columnWidth(const QStyleOptionViewItem &option, const Matrix &matrix,
                                        int column) const
{
    int width = 0;
    for (int row = 0; row < matrix_trait<Matrix>::rows; ++row) {
        width = qMax(width,
                     option.fontMetrics.width(
                         QString::number(matrix_trait<Matrix>::value(matrix, row, column))));
    }
    return width;
}

bool PropertyEditorDelegate::editorEvent(QEvent* event, QAbstractItemModel* model, const QStyleOptionViewItem& option, const QModelIndex& index)
{
    // if this is a read-only cell containing a complex type we have a suitable editor for, we'll show that in read-only mode
    if (index.isValid() && event->type() == QEvent::MouseButtonDblClick && ((index.flags() & Qt::ItemIsEditable) == 0) && (index.flags() & Qt::ItemIsEnabled)) {
        const auto value = index.data(Qt::EditRole);
        if (value.isNull() || !PropertyEditorFactory::hasExtendedEditor(value.userType()))
            return QStyledItemDelegate::editorEvent(event, model, option, index);

        // special cases for strings, short ones don't benefit from the external editor
        if (value.type() == QVariant::String && !value.toString().contains(QLatin1Char('\n')))
            return QStyledItemDelegate::editorEvent(event, model, option, index);
        else if (value.type() == QVariant::ByteArray && !value.toByteArray().contains('\n'))
            return QStyledItemDelegate::editorEvent(event, model, option, index);

        const auto editor = qobject_cast<PropertyExtendedEditor*>(PropertyEditorFactory::instance()->createEditor(value.userType(), nullptr));
        if (editor) {
            editor->setReadOnly(true);
            editor->setValue(value);
            connect(editor, &PropertyExtendedEditor::editorClosed, editor, &QObject::deleteLater);
            editor->showEditor(const_cast<QWidget*>(option.widget));
        }
    }

    return QStyledItemDelegate::editorEvent(event, model, option, index);
}

QString PropertyEditorDelegate::displayText(const QVariant& value, const QLocale& locale) const
{
    if (value.userType() == qMetaTypeId<SourceLocation>())
        return value.value<SourceLocation>().displayString();
    return QStyledItemDelegate::displayText(value, locale);
}