// Copyright (C) 2024 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qfonticonengine_p.h"

#ifndef QT_NO_ICON

#include <QtCore/qdebug.h>

#include <QtCore/qfile.h>

#include <QtCore/qset.h>

#include <QtGui/qfontdatabase.h>

#include <QtGui/qpainter.h>

#include <QtGui/qpainterpath.h>

#include <QtGui/qpalette.h>

#include <QtGui/qtextlayout.h>

#include <QtGui/private/qfont_p.h>

#include <QtGui/private/qfontengine_p.h>

QT_BEGIN_NAMESPACE

using namespace Qt::StringLiterals;

QFontIconEngine::QFontIconEngine(const QString &iconName, const QFont &font)

    : m_iconName(iconName)

    , m_iconFont(font)

{

    Q_ASSERT_X(font.styleStrategy() & QFont::NoFontMerging, "QFontIconEngine",

                "Icon fonts must not use font merging");

}

QFontIconEngine::~QFontIconEngine() = default;

QIconEngine *QFontIconEngine::clone() const

{

    return new QFontIconEngine(m_iconName, m_iconFont);

}

QString QFontIconEngine::key() const

{

    return u"QFontIconEngine("_s + m_iconFont.key() + u')';

}

QString QFontIconEngine::iconName()

{

    return m_iconName;

}

bool QFontIconEngine::isNull()

{

    const QString text = string();

    if (!text.isEmpty()) {

        const QChar c0 = text.at(0);

        const QFontMetrics fontMetrics(m_iconFont);

        if (c0.isHighSurrogate() && text.size() > 1)

            return !fontMetrics.inFontUcs4(QChar::surrogateToUcs4(c0, text.at(1)));

        return !fontMetrics.inFont(c0);

    }

    return glyph() == 0;

}

QList<QSize> QFontIconEngine::availableSizes(QIcon::Mode, QIcon::State)

{

    return {{16, 16}, {24, 24}, {48, 48}, {128, 128}};

}

QSize QFontIconEngine::actualSize(const QSize &size, QIcon::Mode mode, QIcon::State state)

{

    if (isNull())

        return QIconEngine::actualSize(size, mode, state);

    QFont renderFont(m_iconFont);

    renderFont.setPixelSize(size.height());

    QSizeF result;

    if (const glyph_t glyphIndex = glyph()) {

        QFontEngine *engine = QFontPrivate::get(renderFont)->engineForScript(QChar::Script_Common);

        const glyph_metrics_t gm = engine->boundingBox(glyphIndex);

        const qreal glyph_x = gm.x.toReal();

        const qreal glyph_y = gm.y.toReal();

        const qreal glyph_width = (gm.x + gm.width).toReal() - glyph_x;

        const qreal glyph_height = (gm.y + gm.height).toReal() - glyph_y;

        if (glyph_width > .0 && glyph_height > .0)

            result = {glyph_width, glyph_height};

    } else if (const QString text = string(); !text.isEmpty()) {

        const QFontMetricsF fm(renderFont);

        result = {fm.horizontalAdvance(text), fm.tightBoundingRect(text).height()};

    }

    if (!result.isValid())

        return QIconEngine::actualSize(size, mode, state);

    return result.scaled(size, Qt::KeepAspectRatio).toSize();

}

QPixmap QFontIconEngine::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)

{

    return scaledPixmap(size, mode, state, 1.0);

}

QPixmap QFontIconEngine::scaledPixmap(const QSize &size, QIcon::Mode mode, QIcon::State state, qreal scale)

{

    const quint64 cacheKey = calculateCacheKey(mode, state);

    const QSize fittingSize = actualSize(size, mode, state);

    if (cacheKey != m_pixmapCacheKey || m_pixmap.deviceIndependentSize() != fittingSize

     || m_pixmap.devicePixelRatio() != scale) {

        m_pixmap = QPixmap(fittingSize * scale);

        m_pixmap.fill(Qt::transparent);

        m_pixmap.setDevicePixelRatio(scale);

        if (!m_pixmap.isNull()) {

            QPainter painter(&m_pixmap);

            paint(&painter, QRect(QPoint(), fittingSize), mode, state);

        }

        m_pixmapCacheKey = cacheKey;

    }

    return m_pixmap;

}

void QFontIconEngine::paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state)

{

    Q_UNUSED(state);

    painter->save();

    QFont renderFont(m_iconFont);

    renderFont.setPixelSize(rect.height());

    QColor color = Qt::black;

    QPalette palette;

    switch (mode) {

    case QIcon::Active:

        color = palette.color(QPalette::Active, QPalette::Text);

        break;

    case QIcon::Normal:

        color = palette.color(QPalette::Active, QPalette::Text);

        break;

    case QIcon::Disabled:

        color = palette.color(QPalette::Disabled, QPalette::Text);

        break;

    case QIcon::Selected:

        color = palette.color(QPalette::Active, QPalette::HighlightedText);

        break;

    }

    if (glyph_t glyphIndex = glyph()) {

        QFontEngine *engine = QFontPrivate::get(renderFont)->engineForScript(QChar::Script_Common);

        const glyph_metrics_t gm = engine->boundingBox(glyphIndex);

        const int glyph_x = qFloor(gm.x.toReal());

        const int glyph_y = qFloor(gm.y.toReal());

        const int glyph_width = qCeil((gm.x + gm.width).toReal()) - glyph_x;

        const int glyph_height = qCeil((gm.y + gm.height).toReal()) - glyph_y;

        if (glyph_width > 0 && glyph_height > 0) {

            QFixedPoint pt(QFixed(-glyph_x), QFixed(-glyph_y));

            QPainterPath path;

            path.setFillRule(Qt::WindingFill);

            engine->addGlyphsToPath(&glyphIndex, &pt, 1, &path, {});

            // make the glyph fit tightly into rect

            const QRectF pathBoundingRect = path.boundingRect();

            // center the glyph inside the rect

            const QPointF topLeft = rect.topLeft() - pathBoundingRect.topLeft()

                            + (QPointF(rect.width(), rect.height())

                                - QPointF(pathBoundingRect.width(), pathBoundingRect.height())) / 2;

            painter->translate(topLeft);

            painter->setRenderHint(QPainter::Antialiasing);

            painter->setPen(Qt::NoPen);

            painter->setBrush(color);

            painter->drawPath(path);

        }

    } else if (const QString text = string(); !text.isEmpty()) {

        painter->setFont(renderFont);

        painter->setPen(color);

        painter->drawText(rect, Qt::AlignCenter, text);

    }

    painter->restore();

}

QString QFontIconEngine::string() const

{

    return {};

}

glyph_t QFontIconEngine::glyph() const

{

    if (m_glyph == uninitializedGlyph) {

        QFontEngine *engine = QFontPrivate::get(m_iconFont)->engineForScript(QChar::Script_Common);

        if (engine)

            m_glyph = engine->findGlyph(QLatin1StringView(m_iconName.toLatin1()));

        if (!m_glyph) {

            // May not be a named glyph, but there might be a ligature for the

            // icon name.

            QTextLayout layout(m_iconName, m_iconFont);

            layout.beginLayout();

            layout.createLine();

            layout.endLayout();

            const auto glyphRuns = layout.glyphRuns();

            if (glyphRuns.size() == 1) {

                const auto glyphIndexes = glyphRuns.first().glyphIndexes();

                if (glyphIndexes.size() == 1)

                    m_glyph = glyphIndexes.first();

            }

        }

    }

    return m_glyph;

}

QT_END_NAMESPACE

#endif // QT_NO_ICON