import socket
import json

def main():
    SERVER = "timd.cn", 8081
    PEER_NAME = "ClientB"

    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind(("", 0))

    try:
        sock.sendto(json.dumps({"op": "get_peer_by_name",
            "name": PEER_NAME}), SERVER)
        data, addr = sock.recvfrom(1024)
        response = json.loads(data)
        if response["code"] != 0:
            raise RuntimeError("no peer named: %s" % PEER_NAME)

        sock.sendto(json.dumps({"op": "prepare", "name": PEER_NAME}), SERVER)
        data, _ = sock.recvfrom(1024)
        response = json.loads(data)
        if response["code"] != 0:
            raise RuntimeError("prepare for %s failed" % PEER_NAME)
        peer = tuple(response["peer"])
        print("peer is: (%s:%d)" % peer)

        for _ in range(10):
            sock.sendto(json.dumps({"op": "get_data"}), peer)
            print(sock.recvfrom(1024))
    finally:
        sock.close()

if __name__ == "__main__":
    main()