#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""API client to core-networks"""

import requests
import os
import json
import urlparse
import configparser
import sys
import logging
import tldextract
import codecs


def setup_logger():
    # seup logging
    logger = logging.getLogger("certbot_dns_corenetworks")
    logging.basicConfig(level=logging.INFO)
    # silence logging from requests module
    logging.getLogger('requests').setLevel(logging.CRITICAL)

    # create console handler
    ch = logging.StreamHandler()
    ch.setLevel(logging.INFO)

    formatter = logging.Formatter(
        '%(asctime)s - %(name)s - %(levelname)s: %(message)s', datefmt='%Y-%m-%d,%H:%M:%S')
    ch.setFormatter(formatter)
    # add handler to logger
    logger.addHandler(ch)
    logger.propagate = False
    return logger


def set_log_level(config):
    try:
        loglevel = str(config.get('LOG', 'LEVEL')).upper()
    except (configparser.NoSectionError, configparser.NoOptionError) as e:
        logger.error("Config error: %s" % (e))
        sys.exit(1)

    if loglevel == 'INFO':
        level = logging.INFO
    elif loglevel == 'ERROR':
        level = logging.ERROR
    elif loglevel == 'DEBUG':
        level = logging.DEBUG
    else:
        level = logging.INFO

    logger = logging.getLogger('certbot_dns_corenetworks')
    logger.setLevel(level)
    for handler in logger.handlers:
        handler.setLevel(level)


def load_config(logger):
    config_path = os.path.join(os.path.expanduser("~"), ".certbot_dns_corenetworks", "config.ini")

    if os.path.isfile(config_path):
        config = configparser.ConfigParser()
        config.read(config_path)
    else:
        logger.error("Configfile " + config_path + " not present.")
        sys.exit(1)

    return config


def get_auth_token(config, logger):
    data = {}

    try:
        data["login"] = config.get('API', 'USER')
        data["password"] = config.get('API', 'PASSWORD')
        json_data = json.dumps(data)

        host = config.get('API', 'HOST')
    except (configparser.NoSectionError, configparser.NoOptionError) as e:
        logger.error("Config error: %s" % (e))
        sys.exit(1)

    url = urlparse.urljoin(host, os.path.join("auth", "token"))

    try:
        r = requests.post(url, data=json_data)
        r.raise_for_status()
    except requests.exceptions.HTTPError as e:
        logger.error(e)
        sys.exit(1)

    return r


def get_record(config, logger):
    filename = '/tmp/CERTBOT_%s.json' % (os.environ['CERTBOT_DOMAIN'])
    if not os.path.isfile(filename):
        logger.error("File '%s' does not exists." % (filename))
        sys.exit(1)

    with open(filename) as f:
        data = json.load(f)

    try:
        host = config.get('API', 'HOST')
        zone = config.get('DNS', 'ZONE')
        token = config.get('API', 'TOKEN')
    except (configparser.NoSectionError, configparser.NoOptionError) as e:
        logger.error("Config error: %s" % (e))
        sys.exit(1)

    url = urlparse.urljoin(
        host, os.path.join("dnszones", zone, "records", "?type=TXT&name=%s&data=%s") %
        (data["name"], data['data'])
    )
    headers = {"Authorization": "Bearer %s" % (token)}

    try:
        r = requests.get(url, headers=headers)
        r.raise_for_status()
    except requests.exceptions.HTTPError, e:
        logger.error(e)
        sys.exit(1)

    return r


def delete_record(config, logger):
    try:
        host = config.get('API', 'HOST')
        zone = config.get('DNS', 'ZONE')
        token = config.get('API', 'TOKEN')
    except (configparser.NoSectionError, configparser.NoOptionError) as e:
        logger.error("Config error: %s" % (e))
        sys.exit(1)

    url = urlparse.urljoin(host, os.path.join("dnszones", zone, "records", "delete"))
    headers = {"Authorization": "Bearer %s" % (token)}

    data = {}
    data["name"] = config.get('DNS', 'RECORD')
    data["data"] = config.get('DNS', 'DATA')
    json_data = json.dumps(data)

    try:
        r = requests.post(url, headers=headers, data=json_data)
        r.raise_for_status()
    except requests.exceptions.HTTPError, e:
        logger.error(e)
        sys.exit(1)

    return r


def dns_commit(config, logger):
    try:
        host = config.get('API', 'HOST')
        zone = config.get('DNS', 'ZONE')
        token = config.get('API', 'TOKEN')
    except (configparser.NoSectionError, configparser.NoOptionError) as e:
        logger.error("Config error: %s" % (e))
        sys.exit(1)

    url = urlparse.urljoin(host, os.path.join("dnszones", zone, "records", "commit"))
    headers = {"Authorization": "Bearer %s" % (token)}

    try:
        r = requests.post(url, headers=headers)
        r.raise_for_status()
    except requests.exceptions.HTTPError, e:
        logger.error(e)
        sys.exit(1)

    return r


def main():
    """Main logic entrypoint"""

    logger = setup_logger()
    config = load_config(logger)
    set_log_level(config)

    # get auth token
    logger.info("Try to get auth token")
    r_token = get_auth_token(config, logger)
    config.set('API', 'TOKEN', r_token.json()["token"])
    logger.info("Authentication successful")

    # get txt record
    logger.info("Verify TXT record")
    z_record = get_record(config, logger)
    records = z_record.json()
    if not records:
        logger.error("No records found")
        sys.exit(1)
    elif len(records) > 1:
        logger.error("Too many records found")
        sys.exit(1)
    else:
        if records[0].get("name") and records[0].get("data"):
            config.set('DNS', 'RECORD', records[0]["name"])
            config.set('DNS', 'DATA', records[0]["data"])
        else:
            logger.error("Not enough data available")
            sys.exit(1)

    # delete record
    logger.info("Try to delete TXT record")
    z_delete = delete_record(config, logger)
    # commit changes
    z_commit = dns_commit(config, logger)
    os.remove('/tmp/CERTBOT_%s.json' % (os.environ['CERTBOT_DOMAIN']))
    logger.info("Delete TXT record successful")


if __name__ == "__main__":
    main()