/* SPDX-FileCopyrightText: 2026 Project Tick
 * SPDX-FileContributor: Project Tick
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 *   MeshMC - A Custom Launcher for Minecraft
 *   Copyright (C) 2026 Project Tick
 *
 *   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 3 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 <https://www.gnu.org/licenses/>.
 */

#include "CustomTheme.h"
#include <QDir>
#include <Json.h>
#include <FileSystem.h>

const char* themeFile = "theme.json";
const char* styleFile = "themeStyle.css";

static bool readThemeJson(const QString& path, QPalette& palette,
						  double& fadeAmount, QColor& fadeColor, QString& name,
						  QString& widgets)
{
	QFileInfo pathInfo(path);
	if (pathInfo.exists() && pathInfo.isFile()) {
		try {
			auto doc = Json::requireDocument(path, "Theme JSON file");
			const QJsonObject root = doc.object();
			name = Json::requireString(root, "name", "Theme name");
			widgets = Json::requireString(root, "widgets", "Qt widget theme");
			auto colorsRoot =
				Json::requireObject(root, "colors", "colors object");
			auto readColor = [&](QString colorName) -> QColor {
				auto colorValue =
					Json::ensureString(colorsRoot, colorName, QString());
				if (!colorValue.isEmpty()) {
					QColor color(colorValue);
					if (!color.isValid()) {
						qWarning() << "Color value" << colorValue << "for"
								   << colorName << "was not recognized.";
						return QColor();
					}
					return color;
				}
				return QColor();
			};
			auto readAndSetColor = [&](QPalette::ColorRole role,
									   QString colorName) {
				auto color = readColor(colorName);
				if (color.isValid()) {
					palette.setColor(role, color);
				} else {
					qDebug()
						<< "Color value for" << colorName << "was not present.";
				}
			};

			// palette
			readAndSetColor(QPalette::Window, "Window");
			readAndSetColor(QPalette::WindowText, "WindowText");
			readAndSetColor(QPalette::Base, "Base");
			readAndSetColor(QPalette::AlternateBase, "AlternateBase");
			readAndSetColor(QPalette::ToolTipBase, "ToolTipBase");
			readAndSetColor(QPalette::ToolTipText, "ToolTipText");
			readAndSetColor(QPalette::Text, "Text");
			readAndSetColor(QPalette::Button, "Button");
			readAndSetColor(QPalette::ButtonText, "ButtonText");
			readAndSetColor(QPalette::BrightText, "BrightText");
			readAndSetColor(QPalette::Link, "Link");
			readAndSetColor(QPalette::Highlight, "Highlight");
			readAndSetColor(QPalette::HighlightedText, "HighlightedText");

			// fade
			fadeColor = readColor("fadeColor");
			fadeAmount = Json::ensureDouble(colorsRoot, "fadeAmount", 0.5,
											"fade amount");

		} catch (const Exception& e) {
			qWarning() << "Couldn't load theme json: " << e.cause();
			return false;
		}
	} else {
		qDebug() << "No theme json present.";
		return false;
	}
	return true;
}

static bool writeThemeJson(const QString& path, const QPalette& palette,
						   double fadeAmount, QColor fadeColor, QString name,
						   QString widgets)
{
	QJsonObject rootObj;
	rootObj.insert("name", name);
	rootObj.insert("widgets", widgets);

	QJsonObject colorsObj;
	auto insertColor = [&](QPalette::ColorRole role, QString colorName) {
		colorsObj.insert(colorName, palette.color(role).name());
	};

	// palette
	insertColor(QPalette::Window, "Window");
	insertColor(QPalette::WindowText, "WindowText");
	insertColor(QPalette::Base, "Base");
	insertColor(QPalette::AlternateBase, "AlternateBase");
	insertColor(QPalette::ToolTipBase, "ToolTipBase");
	insertColor(QPalette::ToolTipText, "ToolTipText");
	insertColor(QPalette::Text, "Text");
	insertColor(QPalette::Button, "Button");
	insertColor(QPalette::ButtonText, "ButtonText");
	insertColor(QPalette::BrightText, "BrightText");
	insertColor(QPalette::Link, "Link");
	insertColor(QPalette::Highlight, "Highlight");
	insertColor(QPalette::HighlightedText, "HighlightedText");

	// fade
	colorsObj.insert("fadeColor", fadeColor.name());
	colorsObj.insert("fadeAmount", fadeAmount);

	rootObj.insert("colors", colorsObj);
	try {
		Json::write(rootObj, path);
		return true;
	} catch (const Exception& e) {
		qWarning() << "Failed to write theme json to" << path;
		return false;
	}
}

CustomTheme::CustomTheme(ITheme* baseTheme, QString folder)
{
	m_id = folder;
	QString path = FS::PathCombine("themes", m_id);
	QString pathResources = FS::PathCombine("themes", m_id, "resources");

	qDebug() << "Loading theme" << m_id;

	if (!FS::ensureFolderPathExists(path) ||
		!FS::ensureFolderPathExists(pathResources)) {
		qWarning() << "couldn't create folder for theme!";
		m_palette = baseTheme->colorScheme();
		m_styleSheet = baseTheme->appStyleSheet();
		return;
	}

	auto themeFilePath = FS::PathCombine(path, themeFile);

	m_palette = baseTheme->colorScheme();
	if (!readThemeJson(themeFilePath, m_palette, m_fadeAmount, m_fadeColor,
					   m_name, m_widgets)) {
		m_name = "Custom";
		m_palette = baseTheme->colorScheme();
		m_fadeColor = baseTheme->fadeColor();
		m_fadeAmount = baseTheme->fadeAmount();
		m_widgets = baseTheme->qtTheme();

		QFileInfo info(themeFilePath);
		if (!info.exists()) {
			writeThemeJson(themeFilePath, m_palette, m_fadeAmount, m_fadeColor,
						   "Custom", m_widgets);
		}
	} else {
		m_palette = fadeInactive(m_palette, m_fadeAmount, m_fadeColor);
	}

	auto cssFilePath = FS::PathCombine(path, styleFile);
	QFileInfo info(cssFilePath);
	if (info.isFile()) {
		try {
			// TODO: validate css?
			m_styleSheet = QString::fromUtf8(FS::read(cssFilePath));
		} catch (const Exception& e) {
			qWarning() << "Couldn't load css:" << e.cause() << "from"
					   << cssFilePath;
			m_styleSheet = baseTheme->appStyleSheet();
		}
	} else {
		qDebug() << "No theme css present.";
		m_styleSheet = baseTheme->appStyleSheet();
		try {
			FS::write(cssFilePath, m_styleSheet.toUtf8());
		} catch (const Exception& e) {
			qWarning() << "Couldn't write css:" << e.cause() << "to"
					   << cssFilePath;
		}
	}
}

QStringList CustomTheme::searchPaths()
{
	return {FS::PathCombine("themes", m_id, "resources")};
}

QString CustomTheme::id()
{
	return m_id;
}

QString CustomTheme::name()
{
	return m_name;
}

bool CustomTheme::hasColorScheme()
{
	return true;
}

QPalette CustomTheme::colorScheme()
{
	return m_palette;
}

bool CustomTheme::hasStyleSheet()
{
	return true;
}

QString CustomTheme::appStyleSheet()
{
	return m_styleSheet;
}

double CustomTheme::fadeAmount()
{
	return m_fadeAmount;
}

QColor CustomTheme::fadeColor()
{
	return m_fadeColor;
}

QString CustomTheme::qtTheme()
{
	return m_widgets;
}