#!/usr/bin/env python3

import argparse
import dns.rdataclass
import dns.rdataset
import dns.rdatatype
import dnsmgr
import sys

from time import sleep


def main():
    preparser = argparse.ArgumentParser(add_help=False)
    preparser.add_argument('-b', '--batch', action='store_true')
    preargs, args = preparser.parse_known_args()
    nargs = None if preargs.batch else '?'

    parser = argparse.ArgumentParser(description='Add DNS zones.')
    parser.add_argument('-b', '--batch', help='run in batch mode (no user input)', action='store_true')
    parser.add_argument('-c', '--config', help='path to config file', default=dnsmgr.DEFAULT_CFGFILE)
    parser.add_argument('-t', '--config-template', help='config file/template (overrides value set in ZONE_TEMPLATES config option)', default=None)
    parser.add_argument('-z', '--zone-template', help='zone file/template (overrides value set in ZONE_TEMPLATES config option)', default=None)
    parser.add_argument('zone', metavar='ZONE[@VIEWS]', nargs=nargs, help='DNS zone name and optional list of views (comma separated or asterisk to select all views)', default=None)
    args = parser.parse_args()

    try:
        manager = dnsmgr.DNSManager(cfgfile=args.config)
    except RuntimeError as e:
        dnsmgr.printe(f'config: {e}')
        sys.exit(100)

    managed_views = sorted(manager.config.zones_config.keys())

    try:
        if args.zone is None:
            name = dnsmgr.input_name()
            rows = [[view] for view in managed_views]
            index = dnsmgr.prettyselect(['View'], rows, prompt='Select view', also_valid=['*'])
            views = managed_views if index == '*' else [managed_views[index]]
        else:
            (name, views) = dnsmgr.name_views_from_text(args.zone)
            if views is None:
                if len(managed_views) > 1:
                    raise RuntimeError('multiple managed views configured but none specified')
                elif managed_views[0] != dnsmgr.NAMED_DEFAULT_VIEW:
                    raise RuntimeError('the default view is not managed')
                views = managed_views
            elif views == '*':
                views = managed_views
            else:
                for view in views:
                    if view not in managed_views:
                        raise RuntimeError(f'managed view does not exist -- \'{view}\'')

        existing_views = [zone.view for zone in filter(lambda zone: zone.origin == name and zone.view in views, manager.all_zones)]
        if existing_views:
            views = 'and '.join(existing_views)
            raise RuntimeError(f'zone already exists in view {views}')

    except RuntimeError as e:
        dnsmgr.printe(e)
        sys.exit(150)
    except KeyboardInterrupt:
        sys.exit(0)

    if not args.batch:
        for view in views:
            origin = name.to_text(omit_final_dot=True)
            print(f'View: {view}')
            print(f'\033[32m+ {origin}\033[0m\n')

        if not dnsmgr.input_yes_no():
            sys.exit(0)

    zones = []
    for view in views:
        origin = name.to_text(omit_final_dot=True)
        if len(views) > 1 or view != dnsmgr.NAMED_DEFAULT_VIEW:
            origin = f'{origin}@{view}'
        print(f"Adding zone '{origin}'... ", end='')

        try:
            zone = manager.add_zone(name, view, args.config_template, args.zone_template)
            manager.generate_config(view)
            print('OK')
            if manager.config.zones_config[view].catalog_zone:
                zones.append(zone)
        except RuntimeError as e:
            dnsmgr.printe(e)
            sys.exit(160)

    try:
        print('Reloading named... ', end='')
        manager.named_reload()
        print('OK')
    except RuntimeError as e:
        dnsmgr.printe(e)
        sys.exit(170)

    if zones:
        sleep(2)

    for zone in zones:
        catalog_zone_name = manager.config.zones_config[zone.view].catalog_zone
        try:
            catalog_zones = manager.get_zones(catalog_zone_name, all_zones=True)
        except RuntimeError as e:
            raise RuntimeError(f'catalog zone of view \'{zone.view}\': {e}')

        origin = zone.origin.to_text(omit_final_dot=True)
        if len(zones) > 1 or zone.view != dnsmgr.NAMED_DEFAULT_VIEW:
            origin = f'{origin}@{zone.view}'

        for catalog_zone in catalog_zones:
            rdata = dnsmgr.rdata_from_text(dns.rdatatype.PTR, zone.origin.to_text(), catalog_zone.origin)
            rdataset = dns.rdataset.Rdataset(dns.rdataclass.IN, dns.rdatatype.PTR, ttl=3600)
            rdataset.add(rdata)
            rdname = dns.name.from_text(zone.nfz() + '.zones', catalog_zone.origin)
            catalog_zone_origin = catalog_zone.origin.to_text(omit_final_dot=True)
            if catalog_zone.view != dnsmgr.NAMED_DEFAULT_VIEW:
                catalog_zone_origin += f'@{catalog_zone.view}'

            try:
                print(f'Adding zone \'{origin}\' to catalog zone \'{catalog_zone_origin}\'... ', end='')
                manager.add_zone_record(catalog_zone, rdname, rdataset)
                print('OK')
            except RuntimeError as e:
                dnsmgr.printe(e)


if __name__ == '__main__':
    main()