const mysql = require("mysql");

const config = require("../config");


let connection = mysql.createConnection(config.dwelling.database);


// This code was taken from https://www.npmjs.com/package/mysql#custom-format
// Only fourth line was changed.
connection.config.queryFormat = function (query, values) {
	if (!values) return query;
	return query.replace(/\:(\w+)/g, function (txt, key) {
		if (values[key] !== undefined)
			return this.escape(values[key]);
		return txt;
	}.bind(this));
};


exports.pageSize = config.dwelling.guestbook.pageSize !== undefined
	? config.dwelling.guestbook.pageSize : 20;


exports.closeConnection = () => connection.end();

exports.getPosts = async (page = 1, page_size = exports.pageSize) => {
	return new Promise((resolve, reject) => {
		let query = "\
			SELECT \
			`guestbook`.`post_id`, \
			`guestbook`.`created`, \
			`guestbook`.`name`, \
			(CASE \
				WHEN `guestbook`.`hide_email` IS false \
				THEN `guestbook`.`email` \
				ELSE NULL \
			END) AS `email`, \
			(CASE \
				WHEN `guestbook`.`hide_website` IS false \
				THEN `guestbook`.`website` \
				ELSE NULL \
			END) AS `website`, \
			`guestbook`.`message`, \
			`guestbook_feedback`.`comment` AS `feedback`, \
			`guestbook_feedback`.`created` AS `feedback_created` \
			FROM `guestbook` \
			LEFT JOIN `guestbook_feedback` ON `guestbook`.`post_id` = `guestbook_feedback`.`post_id` \
			ORDER BY `guestbook`.`created` DESC \
			LIMIT :page_size \
			OFFSET :page_offset;";

		connection.query(query, { page_size: page_size, page_offset: (page-1) * page_size },
			(err, results) => {
				if (err) reject(err);
				resolve(results); });
	});
};

exports.getPostsCount = async () => {
	let promise = new Promise((resolve, reject) => {
		connection.query("SELECT COUNT(`post_id`) AS total FROM `guestbook`;", (err, results, fields) => {
			if (err) reject(err);
			resolve(results[0].total); });
	});

	return promise.then(count => count);
};

exports.addPost = async (post) => {
	return new Promise((resolve, reject) => {
		let query = "INSERT INTO `guestbook` (`name`, `email`, `website`, `message`, `hide_website`, `hide_email`) \
					 VALUES (:name, :email, :website, :message, :hide_website, :hide_email);";

		if (post.message === undefined || post.message === "")
			reject("empty message");
		
		if (post.message.includes("://"))
			reject("spam");

		if (post.name === undefined || post.name === "")
			post.name = "Anonymous";

		post.message = post.message.trim();
		post.message = post.message.replace(/(?:\r\n|\n\r|\r)/g, "\n");
		post.message = post.message.replace(/(?:\n\n|\n \n)/g, "\n");

		connection.query(query, post, (err, results, fields) => {
			if (err) reject(err);
			resolve(true); });
	});
}