// This file is part of RSS Guard.
//
// Copyright (C) 2011-2017 by Martin Rotter <rotter.martinos@gmail.com>
//
// RSS Guard 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 3 of the License, or
// (at your option) any later version.
//
// RSS Guard 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 RSS Guard. If not, see <http://www.gnu.org/licenses/>.

#include "miscellaneous/skinfactory.h"

#include "miscellaneous/application.h"

#include <QDir>
#include <QStyleFactory>
#include <QDomDocument>
#include <QDomElement>


SkinFactory::SkinFactory(QObject* parent) : QObject(parent) {
}

SkinFactory::~SkinFactory() {
}

void SkinFactory::loadCurrentSkin() {
	QList<QString> skin_names_to_try;
	skin_names_to_try.append(selectedSkinName());
	skin_names_to_try.append(APP_SKIN_DEFAULT);
	bool skin_parsed;
	Skin skin_data;
	QString skin_name;

	while (!skin_names_to_try.isEmpty()) {
		skin_name = skin_names_to_try.takeFirst();
		skin_data = skinInfo(skin_name, &skin_parsed);

		if (skin_parsed) {
			loadSkinFromData(skin_data);
			// Set this 'Skin' object as active one.
			m_currentSkin = skin_data;
			qDebug("Skin '%s' loaded.", qPrintable(skin_name));
			return;
		}

		else {
			qWarning("Failed to load skin '%s'.", qPrintable(skin_name));
		}
	}

	qCritical("Failed to load selected or default skin. Quitting!");
}

void SkinFactory::loadSkinFromData(const Skin& skin) {
	if (!skin.m_rawData.isEmpty()) {
		qApp->setStyleSheet(skin.m_rawData);
	}

	qApp->setStyle(qApp->settings()->value(GROUP(GUI), SETTING(GUI::Style)).toString());
}

void SkinFactory::setCurrentSkinName(const QString& skin_name) {
	qApp->settings()->setValue(GROUP(GUI), GUI::Skin, skin_name);
}

QString SkinFactory::customSkinBaseFolder() const {
	return qApp->userDataPath() + QDir::separator() + APP_SKIN_USER_FOLDER;
}

QString SkinFactory::selectedSkinName() const {
	return qApp->settings()->value(GROUP(GUI), SETTING(GUI::Skin)).toString();
}

QString SkinFactory::adBlockedPage(const QString& subscription, const QString& rule) {
	const QString& adblocked = currentSkin().m_adblocked.arg(tr("This page was blocked by AdBlock"),
	                                                         tr("Blocked by set: \"%1\"<br/>Blocked by filter: \"%2\"")
	                                                         .arg(subscription,
	                                                                 rule));

	return currentSkin().m_layoutMarkupWrapper.arg(tr("This page was blocked by AdBlock"), adblocked);
}

Skin SkinFactory::skinInfo(const QString& skin_name, bool* ok) const {
	Skin skin;
	QStringList base_skin_folders;
	base_skin_folders.append(APP_SKIN_PATH);
	base_skin_folders.append(customSkinBaseFolder());

	while (!base_skin_folders.isEmpty()) {
		const QString skin_folder = base_skin_folders.takeAt(0) + QDir::separator() + skin_name + QDir::separator();
		const QString metadata_file = skin_folder + APP_SKIN_METADATA_FILE;

		if (QFile::exists(metadata_file)) {
			QFile skin_file(metadata_file);
			QDomDocument dokument;

			if (!skin_file.open(QIODevice::Text | QIODevice::ReadOnly) || !dokument.setContent(&skin_file, true)) {
				if (ok) {
					*ok = false;
				}

				return skin;
			}

			const QDomNode skin_node = dokument.namedItem(QSL("skin"));
			// Obtain visible skin name.
			skin.m_visibleName = skin_name;
			// Obtain author.
			skin.m_author = skin_node.namedItem(QSL("author")).namedItem(QSL("name")).toElement().text();
			// Obtain email.
			skin.m_email = skin_node.namedItem(QSL("author")).namedItem(QSL("email")).toElement().text();
			// Obtain version.
			skin.m_version = skin_node.attributes().namedItem(QSL("version")).toAttr().value();
			// Obtain other information.
			skin.m_baseName = skin_name;
			// Free resources.
			skin_file.close();
			skin_file.deleteLater();
			// Here we use "/" instead of QDir::separator() because CSS2.1 url field
			// accepts '/' as path elements separator.
			//
			// "##" is placeholder for the actual path to skin file. This is needed for using
			// images within the QSS file.
			// So if one uses "##/images/border.png" in QSS then it is
			// replaced by fully absolute path and target file can
			// be safely loaded.
			skin.m_layoutMarkupWrapper = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("html_wrapper.html")));
			skin.m_layoutMarkupWrapper = skin.m_layoutMarkupWrapper.replace(QSL("##"), APP_SKIN_PATH + QL1S("/") + skin_name);
			skin.m_enclosureImageMarkup = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("html_enclosure_image.html")));
			skin.m_enclosureImageMarkup = skin.m_enclosureImageMarkup.replace(QSL("##"), APP_SKIN_PATH + QL1S("/") + skin_name);
			skin.m_layoutMarkup = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("html_single_message.html")));
			skin.m_layoutMarkup = skin.m_layoutMarkup.replace(QSL("##"), APP_SKIN_PATH + QL1S("/") + skin_name);
			skin.m_enclosureMarkup = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("html_enclosure_every.html")));
			skin.m_enclosureMarkup = skin.m_enclosureMarkup.replace(QSL("##"), APP_SKIN_PATH + QL1S("/") + skin_name);
			skin.m_rawData = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("theme.css")));
			skin.m_rawData = skin.m_rawData.replace(QSL("##"), APP_SKIN_PATH + QL1S("/") + skin_name);
			skin.m_adblocked = QString::fromUtf8(IOFactory::readTextFile(skin_folder + QL1S("html_adblocked.html")));

			if (ok != nullptr) {
				*ok = !skin.m_author.isEmpty() && !skin.m_version.isEmpty() &&
				      !skin.m_baseName.isEmpty() && !skin.m_email.isEmpty() &&
				      !skin.m_layoutMarkup.isEmpty();
			}

			break;
		}
	}

	return skin;
}

QList<Skin> SkinFactory::installedSkins() const {
	QList<Skin> skins;
	bool skin_load_ok;
	QStringList skin_directories = QDir(APP_SKIN_PATH).entryList(QDir::Dirs |
	                               QDir::NoDotAndDotDot |
	                               QDir::NoSymLinks |
	                               QDir::Readable);
	skin_directories.append(QDir(customSkinBaseFolder()).entryList(QDir::Dirs |
	                        QDir::NoDotAndDotDot |
	                        QDir::NoSymLinks |
	                        QDir::Readable));

	foreach (const QString& base_directory, skin_directories) {
		const Skin skin_info = skinInfo(base_directory, &skin_load_ok);

		if (skin_load_ok) {
			skins.append(skin_info);
		}
	}

	return skins;
}