// fun fact: this migration script is written entirely in the github actions vps using micro editor
//			 so don't expect good code here

const fs = require('fs/promises')
const { Parser } = require('node-sql-parser/build/mariadb');

(async () => {
	const file = (await fs.readFile('./dump_file.sql', 'utf8')).toString();

	console.log('parsing dump file')

	const parser = new Parser()
	const { ast } = parser.parse(file) // this takes the longest (for a production database that has ~650,000 rows)

	console.log('parsed dump file')

	// too lazy to explain this part, i just used the REPL to get what i wanted
	// (an array containing the username and the JSON data)
	const parsed = ast
		.filter(each => each.type === 'insert')
		.map(each => each.values)
		.map(each => each.values)
		.flat()
		.map(each => each.value)
		.map(line => ({
			username: line[0].value
				.replaceAll('\n', '\\n')
				.replaceAll('\b', '\\b')
				.replaceAll('\f', '\\f')
				.replaceAll('\r', '\\r')
				.replaceAll('\t', '\\t'),
			data: JSON.parse(line[1].value.replaceAll('\\"', '"'))
		}))

	console.log('parsed the parsed dump file (into actually readable things you know)')

	let migrated = 'SET GLOBAL max_allowed_packet=107374182400;\n\n'

	migrated += 'DROP TABLE IF EXISTS `players`;\n\n'

	migrated += "CREATE TABLE IF NOT EXISTS players (" +
            "uuid CHAR(36) PRIMARY KEY, " +
            "username VARCHAR(32) NOT NULL, " +
            "lastSeenTime TIMESTAMP," +
            "lastSeenServer VARCHAR(100)" +
            ");\n"

	migrated += "CREATE TABLE IF NOT EXISTS playerIPs (" +
	           "uuid CHAR(36) NOT NULL, " +
	           "server VARCHAR(100) NOT NULL, " +
	           "ip VARCHAR(45) NOT NULL, " +
	           "PRIMARY KEY (uuid, server), " +
	           "INDEX idx_ip_server (ip, server), " +
	           "FOREIGN KEY (uuid) REFERENCES players(uuid) ON DELETE CASCADE" +
	           ");\n\n"
	           
	migrated += 'INSERT IGNORE INTO `players` (uuid, username, lastSeenTime, lastSeenServer) VALUES \n'

	const now = Date.now()

	for (const { username, data } of parsed) {
		// it was very spammy to log players that don't have last seen entries so i commented them out
		
		let lastSeenTime = data.lastSeen?.time
		if (!lastSeenTime) {
			lastSeenTime = now // literally just use the time at migration
			// console.log(`${username} doesn't have lastSeen.time`)
		}

		let lastSeenServer = data.lastSeen?.server
		if (!lastSeenServer) {
			lastSeenServer = 'play.kaboom.pw:25565'
			// console.log(`${username} doesn't have lastSeen.server, i defaulted to ${lastSeenServer}`)
		}

		migrated += `('${data.uuid}', '${username}', FROM_UNIXTIME(FLOOR(${lastSeenTime} / 1000)), '${lastSeenServer}'),\n`
	}

	migrated = migrated.substring(0, migrated.length - 2) + ';\n' // removes trailing comma

	console.log('done processing players table')

	migrated += '\n'
	migrated += 'INSERT IGNORE INTO `playerIPs` (uuid, server, ip) VALUES \n'

	for (const { username, data } of parsed) {
		if (data.ips === undefined) {
			console.log(`${username} doesn't have data.ips`)
			continue
		}

		for (const server of Object.keys(data.ips)) {
			migrated += `('${data.uuid}', '${server}', '${data.ips[server]}'),\n`
		}
	}

	migrated = migrated.substring(0, migrated.length - 2) + ';\n' // removes trailing comma

	console.log('done processing playerIPs table')

	migrated += `\n-- migrated on ${new Date()} using migrator made by chayapak\n`

	await fs.writeFile('migrated.sql', migrated, 'utf8')
	console.log('result SAVED ! thank you.')
})()