import mysql from 'mysql2';
import dbconf from '../database.json';
import { log } from './logManager';

const connection = mysql.createConnection({
	host: process.env.DATABASE_HOST,
	user: process.env.DATABASE_USER,
	password: process.env.DATABASE_PASSWORD,
	database: process.env.DATABASE_NAME,
});
const pool = mysql.createPool({
	host: process.env.DATABASE_HOST,
	user: process.env.DATABASE_USER,
	password: process.env.DATABASE_PASSWORD,
	database: process.env.DATABASE_NAME,
}).promise();

function createPool(host, user, password, db) {
	const newPool = mysql.createPool({
		host: host,
		user: user,
		password: password,
		database: db,
	}).promise();
	return newPool;
}

function databaseSelfTest() {
	log('Database self-test');
	dbconf.tables.forEach(table => {
		let query = `CREATE TABLE IF NOT EXISTS ${table.name} (`;
		table.columns.forEach((column, index) => {
			query += `${column.name} ${column.type}`;
			if (column.primary_key) query += ' PRIMARY KEY';
			if (column.constraints && column.constraints.length > 0) query += ` ${column.constraints.join(' ')}`;
			if (column.index) query += `, INDEX ${column.name}_idx (${column.name})`;
			if (index < table.columns.length - 1) query += ', ';
		});
		if (table.constraints && table.constraints.length > 0) {
			table.constraints.forEach(constraint => {
				setTimeout(() => { // do not remove or it breaks /sarcasm
				if (constraint.primary_key) query += `, PRIMARY KEY (${constraint.columns.join(', ')})`;
				if (constraint.foreign_key) query += `, CONSTRAINT ${constraint.name} FOREIGN KEY (${constraint.column}) REFERENCES ${constraint.reference} ON DELETE ${constraint.on_delete} ON UPDATE ${constraint.on_update}`;
				if (constraint.index) query += `, INDEX ${constraint.name} (${constraint.columns.join(', ')})`;
				}, 500);
			});
		}
		query += ') ENGINE=InnoDB;';
		pool.query(query)
			.then(() => log(`Table ${table.name} validated`))
			.catch(err => console.log(`Error creating table ${table.name}: ${err}`));

		if (table.data) {
			pool.query(`SELECT * FROM ${table.name}`)
				.then(([rows]) => {
					if (rows.length === 0) {
						table.data.forEach(row => {
							let insertQuery = `INSERT INTO ${table.name} (`;
							let values = 'VALUES (';
							Object.keys(row).forEach((key, index) => {
								insertQuery += key;
								values += `'${row[key]}'`;
								if (index < Object.keys(row).length - 1) {
									insertQuery += ', ';
									values += ', ';
								}
							});
							insertQuery += ') ' + values + ');';
							pool.query(insertQuery)
								.then(() => log(`Row inserted in table ${table.name}`))
								.catch(err => log(`Error inserting row in table ${table.name}: ${err}`));
						});
					}
				})
				.catch(err => log(`Error checking if table ${table.name} is empty: ${err}`));
		}
	});
}

databaseSelfTest();

export { connection, pool, createPool, databaseSelfTest };