#!/usr/bin/env python3

import argparse
import dns.rdataclass
import dnsmgr
import sys


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='Delete DNS records.')
    parser.add_argument('-a', '--all-zones', help='allow zones that are not managed', action='store_true')
    parser.add_argument('-A', '--all-types', help='allow unsupported record types', action='store_true')
    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('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)
    parser.add_argument('name', metavar='NAME', nargs=nargs, help='DNS record name', default=None)
    parser.add_argument('type', metavar='TYPE', nargs=nargs, help='DNS record type', default=None)
    parser.add_argument('value', metavar='VALUE', nargs='*', help='DNS record value, multiple values are choined by a space character', 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)

    try:
        if args.zone is None:
            zones = manager.select_zones(args.all_zones)
        else:
            zones = manager.get_zones(args.zone, args.all_zones)

        for zone in zones:
            manager.get_zone_content(zone)

        origin = zones[0].origin

        if args.name is None:
            names = sorted(set([name.to_unicode() for name in zone for zone in zones]))
            rows = [[name] for name in names]
            index = dnsmgr.prettyselect(['Record name'], rows, prompt='Select record name')
            args.name = names[index]

        name = dnsmgr.name_from_text(args.name, origin)

        for zone in zones:
            zone.filter_by_name(name, origin)

        zones = list(filter(lambda zone: zone.nodes, zones))
        if not zones:
            raise RuntimeError(f"No such DNS record -- '{name.to_text(True)}'")

        if args.type is None:
            rdtypes = sorted(set([rdataset.rdtype for rdataset in zone.get_node(name) for zone in zones]))
            if not args.all_types:
                rdtypes = list(filter(lambda rdtype: rdtype in dnsmgr.RECORD_TYPES, rdtypes))
            rdtypes = [rdtype.to_text(rdtype) for rdtype in rdtypes]
            rows = [[rdtype] for rdtype in rdtypes]
            index = dnsmgr.prettyselect(['Record type'], rows, prompt='Select record type')
            args.type = rdtypes[index]

        rdtype = dnsmgr.type_from_text(args.type, args.all_types)

        for zone in zones:
            zone.filter_by_rdtype(rdtype)

        zones = list(filter(lambda zone: zone.nodes, zones))
        if not zones:
            raise RuntimeError(f"No such {rdtype.to_text(rdtype)} record -- '{name.to_text(True)}'")

        rdata = None
        if not args.value and not args.batch and not dnsmgr.input_yes_no(f'Delete all {rdtype.to_text(rdtype)}-records?'):
            values = []
            for zone in zones:
                for rdataset in zone.get_node(name):
                    for rdata in rdataset:
                        values.append(rdata.to_text(origin=zone.origin, relativize=False))
            values = sorted(set(values))
            rows = [[value] for value in values]
            index = dnsmgr.prettyselect(['Record value'], rows, prompt='Select record value', truncate=True)
            args.value = [values[index]]

        if args.value:
            value = ' '.join(args.value)
            rdata = dnsmgr.rdata_from_text(rdtype, value, origin)
            for zone in zones:
                zone.filter_by_rdata(rdata)

            zones = list(filter(lambda zone: zone.nodes, zones))
            if not zones:
                raise RuntimeError(f"No such DNS record found -- {name.to_text(True)} IN {rdtype.to_text(rdtype)} {value}")

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

    zones.sort(key=lambda zone: zone.view)

    if not args.batch:
        for zone in zones:
            print(f'View: {zone.view}')
            node = zone.find_node(name)
            rdataset = node.find_rdataset(dns.rdataclass.IN, rdtype)
            rdclassstr = rdataset.rdclass.to_text(rdataset.rdclass)
            rdtypestr = rdataset.rdtype.to_text(rdataset.rdtype)
            for rdata in rdataset:
                text = rdata.to_text(origin=zone.origin, relativize=False)
                print(f'\033[31m- {name} {rdataset.ttl} {rdclassstr} {rdtypestr} {text}\033[0m\n')

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

    for zone in zones:
        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}'
        print(f"Sending DDNS updates for '{origin}'... ", end='')

        node = zone.find_node(name)
        rdataset = node.find_rdataset(dns.rdataclass.IN, rdtype)

        try:
            manager.delete_zone_record(zone, name, rdataset)
            print('OK')
        except RuntimeError as e:
            dnsmgr.printe(e)
            sys.exit(160)


if __name__ == '__main__':
    main()