server.py

import socket
import sys
import random
import string
import os
from utils import send_all, receive_folders, receive_changes, send_event, readline


# get new id for a new computer
def get_computer_id(map_clients):
	id = ''
	flag = True
	while flag:
		id = ''.join(random.choice(string.digits) for i in range(7))
		flag = False
		for client_changes in map_clients.values():
			if id in client_changes.keys():
				flag = True
				break
	return id


# get new id for a new client
def get_client_id():
	key = ''.join(random.choice(string.ascii_letters + string.digits) for i in range(128))
	while os.path.isdir(key):
		key = ''.join(random.choice(string.ascii_letters + string.digits) for i in range(128))
	return key


if __name__ == "__main__":
	name, port = sys.argv
	server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	server.bind(('', int(port)))
	server.listen(3)
	map_key_of_map_client_and_changes = {}
	computer_id = 0
	key = ''

	while True:
		client_socket, client_address = server.accept()
		try:
			data = client_socket.recv(129).decode()

			# new client
			if data == 'Hi':

				# rand a computer id and client id and send it to the client
				computer_id = get_computer_id(map_key_of_map_client_and_changes)
				key = get_client_id()
				map_key_of_map_client_and_changes[key] = {computer_id: None}
				print(key)
				client_socket.send(computer_id.encode())
				client_socket.send(key.encode())
				os.makedirs(key, exist_ok=True)

				# receive from the client the back-up folder
				try:
					receive_folders(client_socket, key)
				except:
					pass
			else:

				# new computer of an existing client
				if data[0] == 'n':
					if data[1:] not in map_key_of_map_client_and_changes.keys():
						server.close()
						break

					# rand a computer id
					computer_id = get_computer_id(map_key_of_map_client_and_changes)
					map_key_of_map_client_and_changes[data[1:]][computer_id] = None

					# send the computer its new id
					try:
						client_socket.send(computer_id.encode())
						send_all(client_socket, data[1:])
					except:
						pass

				# existing computer
				else:
					computer_id = client_socket.recv(7).decode()
					# send the changes in the back-up folder of the client account
					if map_key_of_map_client_and_changes[data[1:]][computer_id] is not None:
						client_socket.send('updates from another computer'.encode() + b'\n')
						client_socket.send(str(len(map_key_of_map_client_and_changes[data[1:]][computer_id])).encode() + b'\n')
						for event in map_key_of_map_client_and_changes[data[1:]][computer_id]:
							send_event(event[2], client_socket, data[1:], event[0], event[1])
						map_key_of_map_client_and_changes[data[1:]][computer_id] = None
					else:
						client_socket.send('receive changes from client'.encode() + b'\n')

					# receive the changes in the back-up folder of the client
					try:
						size = int(readline(client_socket))
						receive_changes(client_socket, data[1:], size, map_key_of_map_client_and_changes, computer_id)
					except:
						pass
		except:
			pass