#!/usr/bin/env python

import subprocess
import argparse
import sys

from pathlib import Path


def main():
    args = parse_args()
    config_file = Path(args.config)
    config = config_file.read_text().strip()

    if args.outfile and args.outfile.exists():
        print("The file {args.outfile} already exists. Do you want to overwrite? y/N ", end="")
        overwrite_input = input()
        overwrite = overwrite_input.strip()[0].lower() == 'y'
        if not overwrite:
            sys.exit(0)

    if not args.quiet:
        print_qr_code(config)

    if args.outfile:
        save_qr_code_image(args.outfile, config)


def print_qr_code(config: str):
    print("### QR Code:")
    print(get_qr_code(config))

def get_qr_code(config: str) -> str:
    process = subprocess.Popen(
        ["qrencode", "-t", "utf8"], stdin=subprocess.PIPE, stdout=subprocess.PIPE
    )
    result = process.communicate(input=config.encode("utf-8"))
    return result[0].decode("utf-8")


def save_qr_code_image(filename: Path, config: str):
    process = subprocess.Popen(
        ["qrencode", "-t", "png", "-o", filename], stdin=subprocess.PIPE
    )
    process.communicate(input=config.encode("utf-8"))


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="WireGuard QR Code Generator")
    parser.add_argument("config", help="The WireGuard config file to generate a qr code for")
    parser.add_argument("-o", "--outfile", type=Path, help="The ouput file for the generated PNG image")
    parser.add_argument("-q", "--quiet", action="store_true", help="Suppress the output of the UTF-8 QR Code")
    return parser.parse_args()


if __name__ == "__main__":
    main()