#!/usr/bin/env python3

import subprocess
import argparse

## a simple utility to generate a pair of mirrored config files

# peers
class Peer:
    def __init__(self):
        self.pubkey = -1
        self.psk = -1
        self.ip = -1
        self.name = ""

    def __repr__(self):
        name = self.name if self.name != "" else "peer"
        haspsk = True if (self.psk != -1) else False
        return f"<Peer ip:{self.ip} pubkey:{self.pubkey} psk: {haspsk}>"

    def __str__(self):
        name = self.name if self.name != "" else "peer"
        haspsk = True if (self.psk != -1) else False
        return f"{name} ({self.ip}): {self.pubkey} psk: {haspsk}"

    def update_ip(self, ip):
        self.ip = ip

    def update_pubkey(self, pubkey):
        self.pubkey = pubkey

    def update_psk(self, psk):
        self.psk = psk

    def update_name(self, name):
        self.name = name

# parser
## Returns 
def read_config(configfile):
   
    config = open(configfile, "r")

    peers = []
    currentPeer = -1
    lastIP = -1
    # skip the interface section
    # TODO modify to parse config for base IP/allowed
    config = config.readlines()[4:]

    for line in config:
        # skip linebreaks and comments
        if line == "\n":
            continue

        line = line.strip()


        if line == "[Peer]":
            peers.append(Peer())
            currentPeer += 1

        if line[0] == "#":
            name = line[1:]
            peers[currentPeer].update_name(name.strip())
        
        if "PublicKey" in line:
            pubkey = line.split("=", 1)
            peers[currentPeer].update_pubkey(pubkey[1].strip())

        if "PresharedKey" in line:
            psk = line.split("=", 1)
            peers[currentPeer].update_psk(psk[1].strip())

        if "AllowedIPs" in line:
            ip = line.split("=", 1)
            peers[currentPeer].update_ip(ip[1].strip())
            peerip = ip[1].split(".")
            peerip = int(peerip[3][0])
            lastIP = peerip if peerip > lastIP else lastIP

    for peer in peers:
       print(peer)

    return lastIP

parser = argparse.ArgumentParser()

parser.add_argument("-i", type=int, help="digit to use for peer ip")
parser.add_argument("-n", required=True, help="name of device")

args = parser.parse_args()

# globals set from args

serverfile = open("backup.conf", "a")
lastIP = read_config("backup.conf") + 1
# exit()

ALLOWED_IP = "192.168.2.1/32"
DOMAIN = "lindoship.com:51820"
PORT = 51280
SERVER_KEY = "X3tEqq9iC6ZD3r4COyTLXWoHw4f8HwlR+WtSH4z4AW4="

preKey = subprocess.run(["wg", "genpsk"], capture_output=True, universal_newlines=True)

privKeyA = subprocess.run(["wg", "genkey"], capture_output=True, universal_newlines=True)
pubKeyA = subprocess.run(["wg", "pubkey"], input=privKeyA.stdout, text=True,  capture_output=True)


peerfile = open("%s.conf" % args.n, "w")

peerfile.write("[Interface]\n")
peerfile.write("ListenPort = %d\n" % PORT)
peerfile.write("Address = 192.168.2.%d/32\n" % lastIP)
peerfile.write("PrivateKey = %s\n\n" % privKeyA.stdout.strip())
peerfile.write("[Peer]\n")
peerfile.write("PublicKey = %s\n" % SERVER_KEY)
peerfile.write("PresharedKey = %s\n" % preKey.stdout.strip())
peerfile.write("AllowedIPs = %s\n" % ALLOWED_IP)
peerfile.write("Endpoint = %s\n" % DOMAIN)


# SERVER
serverfile.write("\n[Peer]\n")
serverfile.write("# %s\n" % args.n)
serverfile.write("PublicKey = %s\n" % pubKeyA.stdout.strip())
serverfile.write("PresharedKey = %s\n" % preKey.stdout.strip())
serverfile.write("AllowedIPs = 192.168.2.%d/32\n" % lastIP)