extends Node2D

var server: TCPServer = null

# Called when the node enters the scene tree for the first time.
func _ready():
	server = TCPServer.new()
	var status = server.listen(25565)
	if status != OK:
		print('статус не ок')

var segment_bits = 0x7F
var continue_bit = 0x80

func read_var_int(conn: StreamPeerTCP):
	var value = 0
	var position = 0
	var byte
	while true:
		byte = conn.get_8()
		value |= (byte & segment_bits) << position
		if (byte & continue_bit) == 0: break
		position += 7
		
		if position >= 32:
			assert(false, 'varint слишком большой')
		
	return value

func shr(value: int, shift: int):
	if value < 0:
		return ((-value) >> shift) | (0x7000 >> shift)
	return value >> shift

func write_var_int_test(value: int):
	var result = 0
	while true:
		if (value & ~segment_bits) == 0:
			result = (result << 8) | value
			return result
		result = (result << 8) | ((value & segment_bits) | continue_bit)
		
		value = shr(value, 7)

func write_var_int(value: int, conn: StreamPeerTCP):
	var result = 0
	while true:
		if (value & ~segment_bits) == 0:
			conn.put_8(value)
			print('%x' % value)
			return
		conn.put_8((value & segment_bits) | continue_bit)
		print('%x' % ((value & segment_bits) | continue_bit))
		
		value = shr(value, 7)
	return result
	
func read_minecraft_string(conn: StreamPeerTCP):
	var character_count = read_var_int(conn)
	var str = ""
	while character_count > 0:
		var byte = conn.get_8()
		character_count -= 1
		if byte < 0x80:
			# 1 byte sequence (ASCII)
			str += char(byte)
		elif byte < 0xE0:
			str += char(((byte & 0x1F) << 6) | (conn.get_8() & 0x3F))
			character_count -= 1
		elif byte < 0xF0:
			# 3 byte sequence
			str += char(((byte & 0x0F) << 12) | ((conn.get_8() & 0x3F) << 6) | (conn.get_8() & 0x3F))
			character_count -= 1
		else:
			# 4 byte sequence (very rare)
			str += char(((byte & 0x07) << 18) | ((conn.get_8() & 0x3F) << 12) | ((conn.get_8() & 0x3F) << 6) | (conn.get_8() & 0x3F))
			character_count -= 1
	return str

func handle(conn: StreamPeerTCP):
	var size = read_var_int(conn)
	print('size %s' % size)
	var packet_id = conn.get_8()
	print('packet_id %s' % packet_id)
	if packet_id != 0x00: return false
	var protocol_version = read_var_int(conn)
	print('Protocol version: ', protocol_version)
	var host = read_minecraft_string(conn)
	print('Host %s' % host)
	var port = conn.get_16()
	print('Port %s' % port)
	var next_state = read_var_int(conn)
	print('Next state %s' % next_state)
	if next_state != 1: return false
	
	size = read_var_int(conn)
	print('size %s' % size)
	packet_id = conn.get_8()
	print('packet_id %s' % packet_id)
	if packet_id != 0x00: return false
	var response = str({
		"version": {
			"name": "1.19.3",
			"protocol": protocol_version
		},
		"players": {
			"max": 100,
			"online": 5,
			"sample": [
				{
					"name": "thinkofdeath",
					"id": "4566e69f-c907-48ee-8d71-d7ba5aa00d20"
				}
			]
		},
		"description": {
			"text": "Hello world"
		},
		"enforcesSecureChat": true
	})
	
	print('отправляем данные')
	conn.put_8(0x00)
	size = write_var_int_test(response.length())
	print('size %s; ' % response.length(), '%x' % size)
	write_var_int(response.length(), conn)
	
	conn.poll()
	print('status %s' % conn.get_status())
	
	conn.put_data(response.to_utf8_buffer())
	print('отправили данные')
	
	print('client sent something')
	return true

var conns: Array[StreamPeerTCP] = []
# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	for i in range(conns.size() - 1, -1, -1):
		var conn = conns[i]
		conn.poll()
		if conn.get_status() != 2:
			print('Connection %s:%s has status %s, killing' % [conn.get_connected_host(), conn.get_connected_port(), conn.get_status()])
			conns.remove_at(i)

	if server.is_connection_available():
		var conn: StreamPeerTCP = server.take_connection()
		conn.big_endian = true
		print('Took connection from %s:%s, status %s' % [conn.get_connected_host(), conn.get_connected_port(), conn.get_status()])
		var status = handle(conn)
		if not status:
			print('Сервер отклонил подключение по причине пошёл нафиг')
			conn.disconnect_from_host()
		print()
		conns.push_back(conn)