#!/usr/bin/env python3

# This script is intended to be called automatically every day (e.g. via cron).
# It only output stuff if new ranks have to be inserted. Therefore the output
# may be redirected to email notifying about manual action to transfer the
# ranks to MySQL.
#
# Configure cron as the user running the DDNet-Server processes
#
#     $ crontab -e
#     30 5 * * * /path/to/this/script/move_sqlite.py --from /path/to/ddnet-server.sqlite
#
# Afterwards configure a MTA (e.g. postfix) and the users email address.

import sqlite3
import argparse
from time import strftime
import os
from datetime import datetime, timedelta

TABLES = ['record_race', 'record_teamrace', 'record_saves']

def sqlite_table_exists(cursor, table):
	cursor.execute(f"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='{table}'")
	return cursor.fetchone()[0] != 0

def sqlite_num_transfer(conn, table, date):
	c = conn.cursor()
	if not sqlite_table_exists(c, table):
		return 0
	query = f'SELECT COUNT(*) FROM {table}'
	if date is not None:
		query += f' WHERE Timestamp < DATETIME("{date}", "utc")'
	c.execute(query)
	num = c.fetchone()[0]
	return num

def transfer(file_from, file_to, date, keep_timestamp_utc):
	conn_to = sqlite3.connect(file_to, isolation_level='EXCLUSIVE')
	cursor_to = conn_to.cursor()

	conn_from = sqlite3.connect(file_from, isolation_level='EXCLUSIVE')
	conn_from.text_factory = lambda b: b.decode(errors = 'ignore').rstrip()
	for line in conn_from.iterdump():
		cursor_to.execute(line)
	for table in TABLES:
		cursor_to.execute(f'INSERT INTO {table} SELECT * FROM {table}_backup WHERE Timestamp < DATETIME("{date}", "utc")')
	cursor_to.close()
	conn_to.commit()

	cursor_from = conn_from.cursor()
	for table in TABLES:
		if sqlite_table_exists(cursor_from, table):
			cursor_from.execute(f'DELETE FROM {table}')
		backup_table = f'{table}_backup'
		if sqlite_table_exists(cursor_from, backup_table):
			cursor_from.execute(f'DELETE FROM {backup_table} WHERE Timestamp < DATETIME("{date}", "utc")')
	cursor_from.close()
	conn_from.commit()
	conn_from.close()

	cursor_to = conn_to.cursor()
	# delete non-moved backup-rows:
	for table in TABLES:
		backup_table = f'{table}_backup'
		if sqlite_table_exists(cursor_to, backup_table):
			cursor_to.execute(f'DELETE FROM {backup_table}')

	if not keep_timestamp_utc:
		# change date from utc to wanted current timezone for mysql https://github.com/ddnet/ddnet/issues/6105
		for table in TABLES:
			cursor_to.execute(f'''
				UPDATE {table}
				SET Timestamp = DATETIME(original.Timestamp, "localtime")
				FROM (
					SELECT rowid, Timestamp FROM {table}
				) as original
				WHERE {table}.rowid = original.rowid''')

	cursor_to.close()
	conn_to.commit()

	for line in conn_to.iterdump():
		print(line.encode('utf-8'))
	conn_to.close()

def main():
	default_output = 'ddnet-server-' + strftime('%Y-%m-%dT%H:%M:%S') + '.sqlite'
	parser = argparse.ArgumentParser(
			description='Move DDNet ranks, teamranks and saves from a possible active SQLite3 to a new one',
			formatter_class=argparse.ArgumentDefaultsHelpFormatter)
	parser.add_argument('--from', '-f', dest='f',
			default='ddnet-server.sqlite',
			help='Input file where ranks are deleted from when moved successfully (default: ddnet-server.sqlite)')
	parser.add_argument('--to', '-t',
			default=default_output,
			help='Output file where ranks are saved adds current date by default')
	parser.add_argument('--backup-timeout',
			default=60,
			type=int,
			help='Time in minutes until when a rank is moved from the _backup tables')
	parser.add_argument('--keep-timestamp-utc',
			default=False,
			action="store_true",
			help='Timestamps are converted to localtime by default. To keep them utc set this config option')
	args = parser.parse_args()

	if not os.path.exists(args.f):
		print(f"Warning: '{args.f}' does not exist (yet). Is the path specified correctly?")
		return

	date = (datetime.now() - timedelta(minutes=args.backup_timeout)).strftime('%Y-%m-%d %H:%M:%S')

	conn = sqlite3.connect(args.f)
	num = {}
	for table in TABLES:
		num[table] = sqlite_num_transfer(conn, table, None)
		num[table] += sqlite_num_transfer(conn, f'{table}_backup', date)
	conn.close()
	if sum(num.values()) == 0:
		return

	print(f'{num} new entries in backup database found ({num["record_race"]} ranks, {num["record_teamrace"]} teamranks, {num["record_saves"]} saves)')
	print(f'Moving entries from {os.path.abspath(args.f)} to {os.path.abspath(args.to)}')
	print("You can use the following commands to import the entries to MySQL (using https://github.com/techouse/sqlite3-to-mysql/):")
	print()
	print(f"sqlite3mysql --sqlite-file {os.path.abspath(args.to)} --ignore-duplicate-keys --mysql-insert-method IGNORE --sqlite-tables record_race record_teamrace record_saves --mysql-password 'PW2' --mysql-host 'host' --mysql-database teeworlds --mysql-user teeworlds")
	print(f"When the ranks are transferred successfully to mysql, {os.path.abspath(args.to)} can be removed")
	print()
	print("Log of the transfer:")
	print()

	transfer(args.f, args.to, date, args.keep_timestamp_utc)

if __name__ == '__main__':
	main()