import socket
import sys
import threading

class Server:
    def __init__(self, host, port):
        self.host = host
        self.port = port

    def run(self):
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.bind((self.host, self.port))
            s.listen()
            while True:
                conn, addr = s.accept()
                t = threading.Thread(None, Server.process_connection, "conn-"+str(addr), (conn, addr))
                t.start()

    @staticmethod
    def process_connection(connection, address):
        BUFFER_SIZE = 1024
        with connection:
            print('Connected to', address)
            name_len = int.from_bytes(Server._read(connection, 4), 'little')
            name = str(Server._read(connection, name_len), 'utf-8')
            print('Receiving ' + name)
            while True:
                data = connection.recv(BUFFER_SIZE)
                if not data:
                    break
                with open('storage/' + name, 'ab') as f:
                    f.write(data)
            print("Received " + name)

    @staticmethod
    def _read(conn, num):
        data = conn.recv(num)
        if not data:
            raise Exception("Read operation failed")
        return data

if __name__ == "__main__":
    HOST = sys.argv[1] if len(sys.argv) > 1 else '' # any
    PORT = sys.argv[2] if len(sys.argv) > 2 else 65432

    s = Server(HOST, PORT)
    s.run()