import socket
import struct
import sys
import time

if len(sys.argv) == 1:
    print('''
    Send data from server to 1 or more clients via multicast.

    mtest1.py client
    -> Listen to 225.100.100.100 and display what is received.

    mtest1.py server <text> <repeat_count>
    -> Send <text> repeated <repeat_count> times to 255.100.100.100.
    ''')

elif sys.argv[1] == 'client':
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.bind(('', 6543))
    mreq = struct.pack('4sl', socket.inet_aton('225.100.100.100'), socket.INADDR_ANY)

    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)

    while True:
        print(sock.recv(4096))

elif sys.argv[1] == 'server':
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 10)
    try:
        count = int(sys.argv[3])
    except:
        count = 1
    try:
        text = sys.argv[2]
    except:
        text = "hello"
    for i in range(count):
        sock.sendto(bytes(('%s of %s: ' + text )% (i, count), 'ascii'), 0, ('225.100.100.100', 6543))
        time.sleep(0.001)