/* 
 * 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 "TodoMd.h"
#include "TaskItem.h"

namespace mirai {

	TasksFile TodoMdFormat::readFile(const std::string& path) {
		std::ifstream file(path);
		if (!file.is_open()) {
			throw std::runtime_error("todo.txt file not found");
		}
		std::vector<TaskItem> taskItems;
		std::string line;

		if (!std::getline(file, line) || line.substr(0, 2) != "# ") {
			std::cerr << "Couldn't find the task list name" << std::endl;
		}

		std::string name = line.substr(2);
		std::string currentDate = "";

		while (std::getline(file, line)) {
			if (line.substr(0, 3) == "## ") {
				currentDate = line.substr(3);
			} else if (line.substr(0, 5) == "- [ ]" || line.substr(0, 5) == "- [X]") {
				TaskItem taskItem = StringToTask(line, currentDate);
				taskItem.setDate(currentDate);
				taskItems.push_back(taskItem);
			}
		}
		file.close();
		TasksFile tasks({
			.name = name,
			.path = path,
			.tasks = taskItems
		});
		return tasks;
	}

	Tags TodoMdFormat::extractTagsFromMetadata(std::string metadata) {
		Tags tags;

		std::regex regex("(#[a-zA-Z0-1]+)");
		std::smatch matches;

		while (std::regex_search(metadata, matches, regex))
		{
			if (std::find(tags.begin(), tags.end(), matches[0]) == tags.end()) {
				tags.push_back(matches[0]);
			}
			metadata = matches.suffix();
		}
		return tags;
	}

	void TodoMdFormat::writeFile(TasksFile& tasks) {
		std::ofstream file(tasks.getPath());
		if (!file.is_open()) {
			throw std::runtime_error("can't create todo.txt");
		}
		std::string currentDate = "";

		file << "# " << tasks.getName() << "\n";
		for (const auto& task : tasks.getTasks()) {
			if (currentDate != task->date) {
				currentDate = task->date;
				file << "\n## " << (task->date != "" ? task->date : "No date") << "\n\n";
			}
			file << TaskToString(*task) << '\n';
		}
		file.close();
	}

	std::string TodoMdFormat::fieldWithSpace(const std::string& field) {
		if (field.length() == 0)
			return "";
		return (field + " ");
	}

	TaskItem TodoMdFormat::StringToTask(const std::string& str, const std::string& date) {
		std::smatch matches;
			std::regex regex("- \\[(\\s|X)\\] (([0-9]{2}:[0-9]{2})-([0-9]{2}:[0-9]{2}) > )?(.*?)( -- (.*))?");
			std::regex_match(str, matches, regex);

			std::cout << "line " << str << std::endl;
			std::cout << "M 0 " << matches[0] << std::endl;
			std::cout << "M 1 " << matches[1] << std::endl;
			std::cout << "M 2 " << matches[2] << std::endl;
			std::cout << "M 3 " << matches[3] << std::endl;
			std::cout << "M 4 " << matches[4] << std::endl;
			std::cout << "M 5 " << matches[5] << std::endl;
			std::cout << "M 6 " << matches[6] << std::endl;
			std::cout << "M 7 " << matches[7] << std::endl;

			std::string text = matches[5];
			trim(text);

			TaskItem taskItem = {
				.text = text,
				.state = str.substr(0, 5) == "- [X]" ? DONE : TODO,
				.date = date,
				.startTime = matches[3],
				.endTime = matches[4],
				.tags = extractTagsFromMetadata(matches[7])
			};
			return taskItem;
	}

	std::string TodoMdFormat::TaskToString(const TaskItem& task) {
		std::string str = task.getText();
		if (task.getTags().size() > 0) {
			str += " --";
			for (const std::string& tag : task.getTags()) {
				str += " " + tag;
			}
		}
		if (task.getStartTime() != "" && task.getEndTime() != "") {
			str = task.getStartTime() + "-" + task.getEndTime() + " > " + str;
		}
		str = (task.getState() == DONE ? "- [X] " : "- [ ] ") + str;
		return str;
	}
}