#!/usr/bin/env python
from __future__ import unicode_literals
from argparse import ArgumentParser
import idna
import sys

if __name__ == "__main__":
    parser = ArgumentParser(description="dnsmasq-china-list updater")
    parser.add_argument(
        '-a', '--add',
        metavar="DOMAIN",
        nargs="+",
        help='Add one or more new domain(s) (implies -s)',
    )
    parser.add_argument(
        '-d', '--delete',
        metavar="DOMAIN",
        nargs="+",
        help='Remove one or more old domain(s) (implies -s)',
    )
    parser.add_argument(
        '-s', '--sort',
        action='store_true',
        default=True,
        help='Sort the list (default action)',
    )
    parser.add_argument(
        '-f', '--file',
        nargs=1,
        default=["accelerated-domains.china.conf"],
        help="Specify the file to update (accelerated-domains.china.conf by default)",
    )

    options = parser.parse_args()

    with open(options.file[0]) as f:
        lines = list(f)

    changed = False

    if options.add:
        options.sort = True
 
        for domain in options.add:
            new_line = f"server=/{idna.encode(domain).decode()}/114.114.114.114\n"
            if new_line in lines:
                print(f"Domain already exists: {domain}")
            else:
                print(f"New domain added: {domain}")
                lines.append(new_line)
                changed = True

    if options.delete:
        options.sort = True

        for domain in options.delete:
            target_line = f"server=/{idna.encode(domain).decode()}/114.114.114.114\n"
            if target_line not in lines:
                print(f"Failed to remove domain {domain}: not found.")
            else:
                print(f"Domain removed: {domain}")
                lines.remove(target_line)
                changed = True

    if (options.add or options.delete) and not changed:
        sys.exit(1)

    if options.sort:
        lines.sort(key=lambda x: x.lstrip("#"))

    with open(options.file[0], "w") as f:
        f.write(''.join(filter(lambda line: line.strip(), lines)))