#!/usr/bin/env python
#
# TP-Link Wi-Fi Smart Plug Protocol Client
# For use with TP-Link HS-100 or HS-110
#
# by Lubomir Stroetmann
# Copyright 2016 softScheck GmbH
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import sys
import socket
import argparse
from struct import pack

version = 0.3

# Check if hostname is valid
def validHostname(hostname):
	try:
		socket.gethostbyname(hostname)
	except socket.error:
		parser.error("Invalid hostname.")
	return hostname

# Check if port is valid
def validPort(port):
	try:
		port = int(port)
	except ValueError:
		parser.error("Invalid port number.")

	if ((port <= 1024) or (port >65535)) :
		parser.error("Invalid port number.")

	return port


# Predefined Smart Plug Commands
# For a full list of commands, consult tplink_commands.txt
commands = {
	'on'       : '{"system":{"set_relay_state":{"state":1}}}',
	'off'      : '{"system":{"set_relay_state":{"state":0}}}',
	'reboot'   : '{"system":{"reboot":{"delay":1}}}'
}

# Encryption and Decryption of TP-Link Smart Home Protocol
# XOR Autokey Cipher with starting key = 171
# Python 3.x Version
if sys.version_info[0] > 2:
	def encrypt(string):
		key = 171
		result = pack('>I', len(string))
		for i in string:
			a = key ^ ord(i)
			key = a
			result += bytes([a])
		return result

	def decrypt(string):
		key = 171
		result = ""
		for i in string:
			a = key ^ i
			key = i
			result += chr(a)
		return result

# Python 2.x Version
else:
	def encrypt(string):
		key = 171
		result = pack('>I', len(string))
		for i in string:
			a = key ^ ord(i)
			key = a
			result += chr(a)
		return result

	def decrypt(string):
		key = 171
		result = ""
		for i in string:
			a = key ^ ord(i)
			key = ord(i)
			result += chr(a)
		return result

# Parse commandline arguments
parser = argparse.ArgumentParser(description="TP-Link Wi-Fi Smart Plug Client v" + str(version))
parser.add_argument("-t", "--target", metavar="<hostname>", required=True, help="Target hostname or IP address", type=validHostname)
parser.add_argument("-p", "--port", metavar="<port>", default=9999, required=False, help="Target port", type=validPort)
parser.add_argument("-q", "--quiet", dest='quiet', action='store_true', help="Only show result")
parser.add_argument("--timeout", default=10, required=False, help="Timeout to establish connection")
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument("-c", "--command", metavar="<command>", help="Preset command to send. Choices are: "+", ".join(commands), choices=commands)
group.add_argument("-j", "--json", metavar="<JSON string>", help="Full JSON string of command to send")
args = parser.parse_args()


# Set target IP, port and command to send
ip = args.target
port = args.port
if args.command is None:
	cmd = args.json
else:
	cmd = commands[args.command]



# Send command and receive reply
try:
	sock_tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	sock_tcp.settimeout(int(args.timeout))
	sock_tcp.connect((ip, port))
	sock_tcp.settimeout(None)
	sock_tcp.send(encrypt(cmd))
	data = sock_tcp.recv(2048)
	sock_tcp.close()

	decrypted = decrypt(data[4:])

	if args.quiet:
		print(decrypted)
	else:
		print("Sent:     ", cmd)
		print("Received: ", decrypted)

except socket.error:
	quit("Could not connect to host " + ip + ":" + str(port))