#!/usr/bin/env nix-shell
#!nix-shell -p nginx-config-formatter python3 -i python3

import os
import re
import shutil
import subprocess
import sys
from tempfile import TemporaryDirectory


def nginx_config() -> str:
    reload_config ="/etc/nginx/nginx.conf"
    if os.path.exists(reload_config):
        return reload_config
    out = subprocess.check_output(["systemctl", "cat", "nginx"])
    match = re.search(r"-c '(\S+-nginx\.conf)", out.decode("utf-8"))
    if not match:
        print("Could not find nginx.conf in nginx.service", file=sys.stderr)
        sys.exit(1)

    return match.group(1)


def main():
    config_path = nginx_config()
    with TemporaryDirectory() as temp_dir:
        temp_path = os.path.join(temp_dir, "nginx.conf")
        with open(temp_path, "wb+") as temp_file, \
                open(config_path, "rb") as config_file:
            shutil.copyfileobj(config_file, temp_file)
            temp_file.flush()
            subprocess.check_call(["nginxfmt", temp_file.name])
            editor = os.environ.get("EDITOR", "cat")
            subprocess.check_call([editor, temp_file.name] + sys.argv[1:])


if __name__ == "__main__":
    main()