client.py

#!/usr/bin/python3
"""
This module allows the user to send arbitrary data to the specified destination.
Accepts a variety of different command line arguments.
"""

import socket, argparse
from protocol_handling import _UDP, _TCP, _MODE_TYPEHINT, _get_connection_mode, CONNECTION_PROTOCOL_DEFAULT

parser = argparse.ArgumentParser(description='Sends arbitrary data to the specified destination.')

# DEFAULT VALUES <THESE MAY BE EDITED TO YOUR HEART'S CONTENT>
# MAY BE CHANGED BY COMMAND LINE ARGUMENTS
PORT_DEFAULT:           int     = 9355
DESTINATION_DEFAULT:    str     = socket.gethostname()
ENCODE_DEFAULT:         str     = 'utf-8'

parser.add_argument('-p', '--port', type=int, metavar='', default=PORT_DEFAULT,
                    help=f"Which port to send to, defaults to {PORT_DEFAULT}")
parser.add_argument('-d', '--destination', type=str, metavar='', default=DESTINATION_DEFAULT,
                    help=f"The IP address of destination. Defaults to {DESTINATION_DEFAULT}")
parser.add_argument('-c', '--connect_mode', type=_get_connection_mode, metavar='', default=CONNECTION_PROTOCOL_DEFAULT,
                    help="Whether to use TCP or UDP when sending and receiving packages. Defaults to 'tcp'. Accepts either 'udp' or 'tcp'")
parser.add_argument('-m', '--message', type=str, metavar='', required=True,  # TODO Kevin: It should be possible to pipe the message from a file (see: sys.stdin).
                    help='Message to send to the specified destination')
parser.add_argument('-e', '--encode', type=lambda value: None if value.lower() in {'none', ''} else value, default=ENCODE_DEFAULT, metavar='',
                    help=f"Determines how the message should be encoded. Defaults to '{ENCODE_DEFAULT}'. May be disabled with: '-e none'")

args = parser.parse_args()

# try:
#     # This provides PyCharm with autocomplete suggestions.
#     # It does, however, raise an unexceptable SyntaxError when running python < 3.
#     args.port: int
#     args.destination: str
#     args.connect_mode: _MODE_TYPEHINT
#     args.message: str
#     args.encode: str
# except SyntaxError:
#     pass  # In such situation, it's necessary to remove this code.


def main():
    # TODO Kevin: Check out socket.sendfile()
    with socket.socket(socket.AF_INET, args.connect_mode) as sock:
        _message = (args.message.encode(args.encode) if args.encode else args.message)

        if args.connect_mode is _UDP:
            sock.sendto(_message, (socket.gethostname(), args.port))
        elif args.connect_mode is _TCP:
            sock.connect((args.destination, args.port))
            sock.sendall(_message)


if __name__ == '__main__':
    main()