/* 
 * Mirai. Copyright (C) 2024 Vyn
 * This file is licensed under version 3 of the GNU General Public License (GPL-3.0-only)
 * The license can be found in the LICENSE file or at https://www.gnu.org/licenses/gpl-3.0.txt
 */

#include "Backend.h"
#include "core/TodoMd.h"

Backend::Backend() {
	std::cout << "Backend created" << std::endl;
	QDir().mkdir(QDir::homePath() + "/.config/mirai");
	QFile loadFile(QDir::homePath() + "/.config/mirai/config.json");

	if (!loadFile.open(QIODevice::ReadOnly)) {
		qWarning() << "Couldn't find existing config file";
		exit(1);
	}
	
	QByteArray loadData = loadFile.readAll();
	QJsonDocument json = QJsonDocument::fromJson(loadData);
	loadFile.close();
	if (!json.isObject()) {
		qWarning() << "config.json is not a valid config file";
		exit(1);
	}
	QJsonObject jsonRootObject = json.object();
	
	auto jsonFilesPath = json["files"];
	if (!jsonFilesPath.isArray()) {
		qWarning() << "config.json should contains a 'files' string array";
		exit(1);
	}
	QString filePath = jsonFilesPath.toArray()[0].toString();
	mirai.loadFile(filePath.toStdString());
	view = mirai.getTasks();
	rebuildQMLTasksList();
}

void Backend::addTodo(QString newTodo, QString date) {
	mirai.addTask(newTodo.toStdString(), date.toStdString());
	mirai.save();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::addTodoFromRawFormat(QString text, QString date) {
	mirai.addTask(mirai::TodoMdFormat::StringToTask(text.toStdString(), date.toStdString()));
	mirai.save();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::addTagFilter(QString tag) {
	view.lock()->addTagFilter(tag.toStdString());
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::removeTagFilter(QString tag) {
	view.lock()->removeTagFilter(tag.toStdString());
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::removeFilters() {
	view.lock()->removeFilters();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::updateTodoFromRawFormat(int todoIndex, QString text, QString date) {
	QMLTaskItem& taskItem = QMLTasks[todoIndex];
	*(taskItem.taskItem) = mirai::TodoMdFormat::StringToTask(text.toStdString(), date.toStdString());
	mirai.save();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::updateTodo(int todoIndex, QString state, QString text, QString date) {
	QMLTaskItem& taskItem = QMLTasks[todoIndex];
	taskItem.taskItem->state = state == "TODO" ? mirai::TODO : mirai::DONE;
	if (state == "DONE") {
		taskItem.taskItem->markAsDone();
	} else if (state == "TODO") {
		taskItem.taskItem->markAsUndone();
	}
	taskItem.taskItem->setText(text.toStdString());
	taskItem.taskItem->setDate(date.toStdString());
	mirai.save();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::removeTodo(int todoIndex) {
	QMLTaskItem& taskItem = QMLTasks[todoIndex];
	mirai.removeTask(taskItem.taskItem);
	mirai.save();
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::hideCompletedTasks(bool shouldHide) {
	shouldHideCompletedTasks_ = shouldHide;
	rebuildQMLTasksList();
	emit tasksChanged();
}

void Backend::rebuildQMLTasksList() {
	QMLTasks.clear();
	std::string lastDate = "";
	std::time_t t = std::time(nullptr);
	std::tm tm = *std::localtime(&t);
	std::stringstream currentDate;
	currentDate << std::put_time(&tm, "%Y-%m-%d");
	for (int i = 0; i < view.lock()->count(); ++i) {
		mirai::TaskItem& task = (*view.lock())[i];
		if (shouldHideCompletedTasks_ && task.getState() == mirai::DONE && task.hasDate() && task.getDate() < currentDate.str()) {
			continue;
		}
		bool shouldShowDate = false;
		if (lastDate != task.date) {
			lastDate = task.date;
			shouldShowDate = true;
		}
		QList<QString> qStringTags;
		for (auto& tag : task.getTags()) {
			qStringTags.push_back(QString::fromStdString(tag));
		}
		QMLTasks.push_back({
			.taskItem = &task,
			.shouldShowDate = shouldShowDate,
			.tags = qStringTags
		});
	}


	QMLTags.clear();
	for (auto& tag : mirai.getTags()) {
		QMLTags.push_back(QString::fromStdString(tag));
	}

	QMLActiveTagsFilter.clear();
	for (auto& activeTagFilter: view.lock()->getActiveTagsFilter()) {
		QMLActiveTagsFilter.push_back(QString::fromStdString(activeTagFilter));
	}
}

QVariant Backend::getTasks() {
	return QVariant::fromValue(QMLTasks);
}

QVariant Backend::getTags() {
	return QVariant::fromValue(QMLTags);
}

QVariant Backend::getActiveTagsFilter() {
	return QVariant::fromValue(QMLActiveTagsFilter);
}

bool Backend::shouldHideCompletedTasks() { 
	return shouldHideCompletedTasks_;
}