import sys, os, time, _thread as thread
from socket import *

blksz = 100
defaultHost = 'localhost'
defaultPort = 50001

helptext = """
Usage...
server => getfile.py -mode server [-port nnn] [-host hhh] [localhost]
client => getfile.py -mode client -file fff [-port nnn] [-host hhh] [localhost]
"""

def now():
    return time.asctime()

def parsecommandline():
	dict = {}
	args = sys.argv[1:]
	while len(args) >= 2:
		dict[args[0]] = args[1]
		args = args[2:]
	return dict

def client(host, port, filename):
	print(filename)
	sock = socket(AF_INET, SOCK_STREAM)
	sock.connect((host, port))
	sock.send((filename + '\n').encode())
	dropdir = os.path.split(filename)[1]
	print(dropdir)
	file = open(dropdir, 'wb')
	while True:
		data = sock.recv(blksz)
		if not data: break
		file.write(data)
	sock.close()
	file.close()
	print('Client got', filename, 'at', now())

def serverthread(clientsock):
	sockfile = clientsock.makefile('r')
	filename = sockfile.readline()[:-1]
	print(filename)
	file = open(filename, 'rb')
	try:
		while True:
			bytes = file.read(blksz)
			if not bytes: break
			sent = clientsock.send(bytes)
			assert sent == len(bytes)
	except:
		print('Error downloading file on server:', filename)
	clientsock.close()

def server(host, port):
	serversock = socket(AF_INET, SOCK_STREAM)
	serversock.bind((host, port))
	serversock.listen(5)
	while True:
		clientsock, clientaddr = serversock.accept()
		print('Server connected by', clientaddr, 'at', now())
		thread.start_new_thread(serverthread, (clientsock,))

def main(args):
	host = args.get('-host', defaultHost)
	port = int(args.get('-port', defaultPort))
	if args.get('-mode') == 'server':
		if host == 'localhost': host = ''
		server(host, port)
	elif args.get('-file'):
		client(host, port, args['-file'])
	else: print(helptext)

if __name__ == '__main__':
	args = parsecommandline()
	main(args)