#!/usr/bin/env python3

import os.path
import socket

from signal import signal, SIGINT
from sys import exit

BUF_SIZE = 1024

DEST_SRV = ('45.141.57.154', 8303) # fokko
DEST_SRV = ('149.202.127.134', 8303)
DEST_SRV = ('127.0.0.1', 8899) # ddnet ++
# DEST_SRV = ('78.135.85.66', 8322) # ddnet turkey muli

_ENV = {}

def senf(key):
    global _ENV
    if not key in _ENV:
        return None
    return _ENV[key]

if os.path.isfile('.env'):
    with open('.env') as f:
        for l in f:
            l = l.rstrip()
            cfg, val = l.split('=', 1)
            _ENV[cfg] = val
            if cfg == 'BIND_PORT':
                _ENV[cfg] = int(val)
            print(f"cfg: {cfg}")
            print(f"val: {val}")

BIND_ADDR = (senf('BIND_IP') or '127.0.0.1', senf('BIND_PORT') or 8303)

print(f"hello world listentin on {BIND_ADDR}")

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(BIND_ADDR)

SRC_CL = None

NET_CTRLMSG_KEEPALIVE = 0x00
NET_CTRLMSG_CLOSE = 0x04

tken_token = None

def disconnect_pck(token):
    return b'\x10\x10\x00\x04' + token

def handler(signal_received, frame):
    global sock
    global tken_token
    print('SIGINT or CTRL-C detected. Exiting gracefully')
    if tken_token:
        print(f"sending disconnect to {DEST_SRV}")
        sock.sendto(disconnect_pck(tken_token), DEST_SRV)
    exit(0)


signal(SIGINT, handler)

while True:
    data, addr = sock.recvfrom(BUF_SIZE)
    target = DEST_SRV
    if addr == DEST_SRV:
        target = SRC_CL
    elif SRC_CL == None:
        print(f"client connected to proxy {addr}")
        SRC_CL = addr
    print(f"got data from {addr} forward to {target}")
    print(data)

    if len(data) > 3:
        # ddnet TKEN
        # b'\x10\x00\x00\x02TKEN\x14S\x17C'
        if len(data) == 12:
            if data[0:8] == b'\x10\x00\x00\x02TKEN':
                tken_token = data[8:]
                print("yoinked token:")
                print(tken_token)
        # control message
        if data[2] == 0:
            # disconnect packet
            # b'\x10\x10\x00\x04\x9a\xcb9\xc9'
            if data[3] == NET_CTRLMSG_CLOSE:
                print("do not send client disconnect")
                SRC_CL = None
                continue
        # b'\x00\x10\x02C\x07\x0c"\x00AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\x00\x01\x00!\xa0\x04\xa3\x04(\x00\x01\x00\x00\x00\x00\x01\x00\x00\x00\xcf\x92\xfbh'

    if target:
        sock.sendto(data, target)
    else:
        print("wanring failed to send no target found")