# This script requires:
# pip install --upgrade google google-cloud-dns
# Thanks for using this software! DL.

import sys, getopt, time

try:
    import google
    from google.cloud import dns
except ImportError:
    print('\nYou must install google and google-cloud-dns modules to run this script. You may run:\n')
    print('pip install --upgrade google google-cloud-dns\n')
    sys.exit(2)

# Globals
google_client = None
app_subdomains = ['base', 'radius', 'cablemodem', 'ftth', 'dhcp', 'mapas', 'stats', 'grafana', 'geoserver', 'api', 'swagger', 'pma']


def main(argv):

    global google_client
    json_path = action = client = ip_address = domain = opts = args = None

    try:
        opts, args = getopt.getopt(argv, None, ["key=", "action=", "client=", "ip_address=", "domain="])
    except getopt.GetoptError:
        print_usage()
        sys.exit(2)

    for opt, arg in opts:
        if opt in ('--key'):
            json_path = arg
        if opt in ('--action'):
            action = arg
        if opt in ('--client'):
            client = arg
        if opt in ('--ip_address'):
            ip_address = arg
        if opt in ('--domain'):
            domain = arg

    if not json_path:
        print(bcolors.FAIL + bcolors.BOLD +
              '\nERROR: You must provide a path to the JSON Key File! Check documentation for further assistance.'+
              bcolors.ENDC + bcolors.ENDC)
        print_usage()
        sys.exit(2)

    google_client = dns.Client.from_service_account_json(json_path)

    if not google_client:
        print(bcolors.FAIL + bcolors.BOLD +
              '\nERROR: Failed to create Google Client object.\n'+
              bcolors.ENDC + bcolors.ENDC)
        sys.exit(2)

    if action == 'create':

        if not client or not ip_address or not domain:
            print(bcolors.FAIL + bcolors.BOLD +
                '\nERROR: create requires client, ip_address and domain!\n'+
                bcolors.ENDC + bcolors.ENDC)
            print_usage()
            sys.exit(2)

        if create(client=client, ip_address=ip_address, domain=domain):
            print(bcolors.OKGREEN + bcolors.BOLD +
                  '\nEntities have been successfully created!\n' +
                  bcolors.ENDC + bcolors.ENDC)

    elif action == 'delete':

        if not client or not ip_address or not domain:
            print(bcolors.FAIL + bcolors.BOLD +
                '\nERROR: delete requires client and domain!\n'+
                bcolors.ENDC + bcolors.ENDC)
            print_usage()
            sys.exit(2)

        if delete(client=client, domain=domain):
            print(bcolors.OKGREEN + bcolors.BOLD +
                  '\nEntities have been successfully deleted!\n' +
                  bcolors.ENDC + bcolors.ENDC)

    elif action == 'list':
        list()


def list():

    zone = google_client.zone('flowdatnet')
    records = zone.list_resource_record_sets()  # API request

    for record in records:
        print(record.name, record.record_type, record.ttl, record.rrdatas)

    return True


def create(client=None, ip_address=None, domain='flowdat.net'):

    zone = google_client.zone('flowdatnet')
    changes = zone.changes()

    # Add "A" records for domain
    record_set = zone.resource_record_set('{}.{}.'.format(client, domain), 'A', '3600', ip_address)
    changes.add_record_set(record_set)

    # Add "A" records for subdomains
    for subdomain in app_subdomains:
        record_set = zone.resource_record_set('{}.{}.{}.'.format(subdomain, client, domain), 'A', '3600', ip_address)
        changes.add_record_set(record_set)

    try:
        changes.create()
    except google.api_core.exceptions.Conflict as e:
        print(bcolors.FAIL + bcolors.BOLD +
              "\nError: Entity already exist. Please use the delete action to make sure there are no existing records and try again.\n" +
              bcolors.ENDC + bcolors.ENDC)
        print("{}\n".format(e))
        sys.exit(2)

    return True


def delete(client=None, domain='flowdat.net'):

    zone = google_client.zone('flowdatnet')
    changes = zone.changes()

    records = []
    all_records = zone.list_resource_record_sets()

    for record in all_records:

        # Match "A" record for main domain
        if record.name == '{}.{}.'.format(client, domain):
            records.append(record)
            continue

        # Match "A" records for subdomains
        for subdomain in app_subdomains:
            if record.name == '{}.{}.{}.'.format(subdomain, client, domain):
                records.append(record)
                break

    for record in records:
        changes.delete_record_set(record)

    try:
        changes.create()
    except ValueError as e:
        print(bcolors.OKBLUE + bcolors.BOLD +
                  '\nNothing to change.\n' +
                  bcolors.ENDC + bcolors.ENDC)
        return False

    return True


def print_usage():

    print("\n")
    print(bcolors.HEADER + "-- Usage --" + bcolors.ENDC)
    print(
        """
        python googledns.py --key=<Path to JSON Key File> --action=create --client=<Client Name> --ip_address=<IP Address> --domain=<Domain>
        python googledns.py --key=<Path to JSON Key File> --action=delete --client=<Client Name> --domain=<Domain>
        python googledns.py --key=<Path to JSON Key File> --action=list

        """)


class bcolors:

    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'


if __name__ == "__main__":
   main(sys.argv[1:])