import logging
import socket
import threading
import json

LOGGER = logging.getLogger(__name__)


def judge_napt_type_server(port, host="0.0.0.0"):
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    server_socket.bind((host, port))
    while True:
        data, addr = server_socket.recvfrom(1024)
        LOGGER.info("receive data: %s from %s" % (data, addr))
        server_socket.sendto("%s:%d" % addr, addr)

def p2p_server(port, host="0.0.0.0"):
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    server_socket.bind((host, port))

    CLIENTS = {}
    while True:
        data, addr = server_socket.recvfrom(1024)
        request = json.loads(data)
        op = request["op"]

        if op == "register":
            CLIENTS[request["name"]] = addr
            server_socket.sendto(json.dumps({"code": 0}), addr)
        elif op == "unregister":
            ret = 0 if CLIENTS.pop(request["name"], None) else 1
            server_socket.sendto(json.dumps({"code": ret}), addr)
        elif op == "get_peer_by_name":
            peer = CLIENTS.get(request["name"])
            if peer == None:
                server_socket.sendto(json.dumps({"code": 1,
                    "msg": "name is not found"}), addr)
            else:
                server_socket.sendto(json.dumps({"code": 0,
                    "peer": peer}), addr)
        elif op == "prepare":
            name = request["name"]
            LOGGER.info("send prepare to: (%s:%d)" %
                CLIENTS[name])
            server_socket.sendto(json.dumps({"op":
                "prepare", "peer": addr}), CLIENTS[name])
        elif op == "prepare_ok":
            peer = tuple(request["peer"])
            LOGGER.info("send prepare_ok to (%s:%d)" % peer)
            server_socket.sendto(json.dumps({"code": 0,
                "peer": addr}), peer)

if __name__ == "__main__":
    logging.basicConfig(
            level=logging.DEBUG,
            format="%(threadName)s [%(asctime)s] %(message)s",
            datefmt="%F %T")

    for port in [8082, 8083]:
        t = threading.Thread(target=judge_napt_type_server, args=(port, ))
        t.setDaemon(True)
        t.start()

    p2p_server(8081)