/*
 * Copyright (C) by Hannah von Reth <hannah.vonreth@owncloud.com>
 *
 * 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.
 */

#include "resources/resources.h"

#include "fonticon.h"
#include "resources/qmlresources.h"
#include "resources/template.h"
#include "resources/themewatcher.h"

#include "libsync/common/asserts.h"

#include <QDebug>
#include <QFileInfo>
#include <QImageReader>
#include <QJsonDocument>
#include <QLoggingCategory>
#include <QPalette>

using namespace OCC;
using namespace Resources;

Q_LOGGING_CATEGORY(lcResources, "sync.resoruces", QtInfoMsg)

namespace {
struct IconCache
{
    IconCache()
    {
        auto *watcher = new ThemeWatcher(qApp);
        QObject::connect(watcher, &ThemeWatcher::themeChanged, qApp, [this]() { _cache.clear(); });
    }
    QMap<QString, QIcon> _cache;
    QTemporaryDir tmpDir;
};
Q_GLOBAL_STATIC(IconCache, iconCache)

QString vanillaThemePath()
{
    return QStringLiteral(":/client/QSfera/theme");
}

QString brandThemePath()
{
    return QStringLiteral(":/client/" APPLICATION_SHORTNAME "/theme");
}
}

bool Resources::isVanillaTheme()
{
    return std::string_view(APPLICATION_SHORTNAME).starts_with("QSfera");
}

bool OCC::Resources::isUsingDarkTheme()
{
    return QPalette().base().color().lightnessF() <= 0.5;
}

/*
 * helper to load a icon from either the icon theme the desktop provides or from
 * the apps Qt resources.
 */
QIcon OCC::Resources::loadIcon(const QString &flavor, const QString &name, IconType iconType)
{
    // prevent recusion
    const bool useCoreIcon = (iconType == IconType::VanillaIcon) || isVanillaTheme();
    const QString path = QStringLiteral("%1/%2/%3").arg(useCoreIcon ? vanillaThemePath() : brandThemePath(), flavor, name);
    QIcon &cached = iconCache->_cache[path]; // Take reference, this will also "set" the cache entry
    if (cached.isNull()) {
        const QString svg = QStringLiteral("%1.svg").arg(path);
        if (QFile::exists(svg)) {
            return cached = QIcon(svg);
        }

        const QString png = QStringLiteral("%1.png").arg(path);
        if (QFile::exists(png)) {
            return cached = QIcon(png);
        }

        const QList<int> sizes{16, 22, 32, 48, 64, 128, 256, 512, 1024};
        QString previousIcon;
        for (int size : sizes) {
            QString pixmapName = QStringLiteral("%1-%2.png").arg(path, QString::number(size));
            if (QFile::exists(pixmapName)) {
                previousIcon = pixmapName;
                cached.addFile(pixmapName, {size, size});
            } else if (size >= 128) {
                if (!previousIcon.isEmpty()) {
                    qCWarning(lcResources) << u"Upscaling:" << previousIcon << u"to" << size;
                    cached.addPixmap(QPixmap(previousIcon).scaled({size, size}, Qt::KeepAspectRatio, Qt::SmoothTransformation));
                }
            }
        }
    }
    if (cached.isNull()) {
        if (!useCoreIcon && iconType == IconType::BrandedIconWithFallbackToVanillaIcon) {
            return loadIcon(flavor, name, IconType::VanillaIcon);
        }
        qCWarning(lcResources) << u"Failed to locate the icon" << path;
        Q_ASSERT(false);
    }
    return cached;
}

QColor Resources::tint()
{
    static QColor lilac{"#E2BAFF"};
    static QColor petrol{"#20434F"};
    return isUsingDarkTheme() ? lilac : petrol;
}

QIcon OCC::Resources::themeUniversalIcon(const QString &name, IconType iconType)
{
    return loadIcon(QStringLiteral("universal"), name, iconType);
}

CoreImageProvider::CoreImageProvider()
    : QQuickImageProvider(QQuickImageProvider::Pixmap)
{
}
QPixmap CoreImageProvider::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
{
    const auto qmlIcon = parseIcon(id);
    if (qmlIcon.iconName.isEmpty()) {
        return {};
    }

    QIcon icon;
    if (qmlIcon.theme == QLatin1String("universal")) {
        icon = themeUniversalIcon(qmlIcon.iconName);
    } else if (qmlIcon.theme == QLatin1String("fontawesome")) {
        Q_ASSERT(qmlIcon.iconName.length() == 1);
        icon = FontIcon(qmlIcon.iconName.front(), qmlIcon.size, qmlIcon.color);
    } else if (qmlIcon.theme == QLatin1String("remixicons")) {
        Q_ASSERT(qmlIcon.iconName.length() == 1);
        icon = FontIcon(FontIcon::FontFamily::RemixIcon, qmlIcon.iconName.front(), qmlIcon.size, qmlIcon.color);
    }
    return pixmap(requestedSize, icon, qmlIcon.enabled ? QIcon::Normal : QIcon::Disabled, size);
}

QUrl Resources::iconToFileSystemUrl(const QIcon &icon, QAnyStringView type)
{
    QFileInfo info(QStringLiteral("%1/%2.%3").arg(iconCache->tmpDir.path(), QString::number(icon.cacheKey()), type.toString()));
    if (!info.exists()) {
        if (!icon.pixmap(icon.actualSize({512, 512})).save(info.absoluteFilePath())) {
            qCWarning(lcResources) << u"Failed to save icon to " << info.absoluteFilePath() << info.size();
        }
    }
    return QUrl::fromLocalFile(info.absoluteFilePath());
}
