#!/app/python3/bin/python3

# vplesnila 2019-06-24: creation
# vplesnila 2019-06-25: build self.subdomains_list
# vplesnila 2019-07-01: finalize update subdomains procedure and email sending

import os
import smtplib
from email.message import EmailMessage
from email.mime.text import MIMEText
import socket
import json
import requests
import logging

# LOGGING initialization function
def start_logging(logfile):
        logger = logging.getLogger(__name__)
        logger.setLevel(logging.INFO)

        # create a file handler
        handler = logging.FileHandler(logfile)
        handler.setLevel(logging.INFO)

        # create a logging format
        formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
        handler.setFormatter(formatter)

        # add the handlers to the logger
        logger.addHandler(handler)
        return logger

class DomainUpdater:
  def __init__(self, rootdir):
    self.rootdir = rootdir

    # Load configuration
    with open(self.rootdir + "/" + "DomainUpdater.conf", "r") as f:
    	self.config = json.load(f)    

    # Get current IP
    r = requests.get(self.config["get_current_ip_api_url"])
    self.current_ip = r.json()["ip"]
    logger.info("__BEGIN_BATCH__")
    logger.info("Current IP	is " + self.current_ip)
    
    # Build subdomain list as a ist of (subdomain name, domain_id, subdomain_id)
    self.subdomains_list = []
        
    self.auth = (self.config["dnsmanager_id"], self.config["dnsmanager_key"])
    self.url_base = self.config["dnsmanager_api_url_base"]

    # Get domains dictionary
    url_end = "/user/domains"
    r = requests.get(self.url_base + url_end, auth = self.auth)
    domain_dict = r.json()["results"]

    for domain in domain_dict:
      domain_name = domain["domain"]
      domain_id = domain["id"]
      url_end = "/user/domain/" + str(domain["id"]) + "/records"
      r = requests.get(self.url_base + url_end, auth = self.auth)
      records_dict = r.json()["results"]
      for record_dict in records_dict:
        if record_dict["type"] == "A":
          # Subdomain
          subdomain_id = record_dict["id"]
          subdomain_name = record_dict["name"]
          subdomain_ip = record_dict["content"]
          fqdn = "%s.%s" % (subdomain_name, domain_name)
          record = (fqdn, domain_id, subdomain_id, subdomain_ip)
          self.subdomains_list.append(record)
    return
    
  def send_email_new_ip(self):
    msg = EmailMessage()
    msg["Subject"] = "Your public IP changed"
    msg["From"] = "domain-updater@databasepro.fr"
    msg["To"] = "vplesnila@gmail.com"
    body = """
      Hello,
      You have a new public IP: %s
      Following subdomains has been updated:
      %s
      --------------
      Domain Updater
    """ % (self.current_ip, "\n".join(self.updated_subdomain_list))
    msg.set_content(body)
    s = smtplib.SMTP("localhost")
    s.send_message(msg)
    s.quit()
    logger.info("Email sent to " + msg["To"])
    return

  def check_subdomains(self):
    self.updated_subdomain_list=[]
    for record in self.subdomains_list:
      (fqdn, domain_id, subdomain_id, subdomain_ip) = record
      if (subdomain_ip == self.current_ip):
        logger.info(fqdn + " already set to " + subdomain_ip + ", nothing to do")
      else:  	
        logger.info("Updatting " + fqdn + " with the new IP value " + self.current_ip)
        self.update_subdomain(domain_id, subdomain_id)
        self.updated_subdomain_list.append(fqdn)
        
    logger.info("__END_BATCH__")        
    return

  def update_subdomain(self, domain_id, subdomain_id):
    url_end = "/user/domain/" + str(domain_id) + "/record/" + str(subdomain_id)
    data = json.dumps({"id":subdomain_id, "content":self.current_ip})
    headers = { 'Content-Type': 'application/json'}
    r = requests.put(self.url_base + url_end, auth = self.auth, data = data, headers=headers)   
    return
    
if __name__ == "__main__":
  script_path = os.path.dirname(os.path.abspath(__file__))
  script_name = os.path.basename(__file__)
  logger = start_logging(script_path + '/DomainUpdater.log')
  domainupdater = DomainUpdater(script_path)
  domainupdater.check_subdomains()
  if len(domainupdater.updated_subdomain_list) > 0:
    domainupdater.send_email_new_ip()