#!/usr/bin/env python

import os
import pathlib
import argparse
import sys
import hashlib
import csv
import subprocess
import re
import base64
import sqlite3
from io import StringIO
from datetime import datetime

sys.path.append("/home/pi/pialert/front/plugins")
sys.path.append('/home/pi/pialert/netalertx') 

from plugin_helper import Plugin_Object, Plugin_Objects, decodeBase64
from logger import mylog, append_line_to_file
from helper import timeNowTZ, check_IP_format
from const import logPath, applicationPath, fullDbPath


CUR_PATH = str(pathlib.Path(__file__).parent.resolve())
LOG_FILE = os.path.join(CUR_PATH, 'script.log')
RESULT_FILE = os.path.join(CUR_PATH, 'last_result.log')

pluginName = 'DDNS'

def main():

    mylog('verbose', [f'[{pluginName}] In script'])     
    
    parser = argparse.ArgumentParser(description='Check internet connectivity and IP')
    
    parser.add_argument('prev_ip', action="store", help="Previous IP address to compare against the current IP")    
    parser.add_argument('DDNS_UPDATE_URL', action="store", help="URL for updating Dynamic DNS (DDNS)")
    parser.add_argument('DDNS_USER', action="store", help="Username for Dynamic DNS (DDNS) authentication")
    parser.add_argument('DDNS_PASSWORD', action="store", help="Password for Dynamic DNS (DDNS) authentication")
    parser.add_argument('DDNS_DOMAIN', action="store", help="Dynamic DNS (DDNS) domain name")
    

    values = parser.parse_args()

    PREV_IP         = values.prev_ip.split('=')[1]         
    DDNS_UPDATE_URL = values.DDNS_UPDATE_URL.split('=')[1]
    DDNS_USER       = values.DDNS_USER.split('=')[1]
    DDNS_PASSWORD   = values.DDNS_PASSWORD.split('=')[1]
    DDNS_DOMAIN     = values.DDNS_DOMAIN.split('=')[1]       

    # perform the new IP lookup and DDNS tasks if enabled
    ddns_update( DDNS_UPDATE_URL, DDNS_USER, DDNS_PASSWORD, DDNS_DOMAIN, PREV_IP)   

    mylog('verbose', [f'[{pluginName}] Finished '])   
    
    return 0
  
    
#===============================================================================
# INTERNET IP CHANGE
#===============================================================================
def ddns_update ( DDNS_UPDATE_URL, DDNS_USER, DDNS_PASSWORD, DDNS_DOMAIN, PREV_IP ):   
    
    # Update DDNS record if enabled and IP is different
    # Get Dynamic DNS IP
    
    mylog('verbose', [f'[{pluginName}]    Retrieving Dynamic DNS IP'])
    dns_IP = get_dynamic_DNS_IP(DDNS_DOMAIN)

    # Check Dynamic DNS IP
    if dns_IP == "" or dns_IP == "0.0.0.0" :
        mylog('none', [f'[{pluginName}]     Error retrieving Dynamic DNS IP'])       

    mylog('none', [f'[{pluginName}]    ', dns_IP])

    # Check DNS Change
    if dns_IP != PREV_IP :
        mylog('none', [f'[{pluginName}]     Updating Dynamic DNS IP'])
        message = set_dynamic_DNS_IP (DDNS_UPDATE_URL, DDNS_USER, DDNS_PASSWORD, DDNS_DOMAIN)
        mylog('none', [f'[{pluginName}]        ', message])            

    # plugin_objects = Plugin_Objects(RESULT_FILE)    
    
    # plugin_objects.add_object(
    #     primaryId   = 'Internet',       # MAC (Device Name)
    #     secondaryId = new_internet_IP,  # IP Address 
    #     watched1    = f'Previous IP: {PREV_IP}',
    #     watched2    = '',
    #     watched3    = '',  
    #     watched4    = '',
    #     extra       = f'Previous IP: {PREV_IP}', 
    #     foreignKey  = 'Internet')

    # plugin_objects.write_result_file()    
    

#-------------------------------------------------------------------------------
def get_dynamic_DNS_IP (DDNS_DOMAIN):

    # Using supplied DNS server
    dig_args = ['dig', '+short', DDNS_DOMAIN]

    try:
        # try runnning a subprocess
        dig_output = subprocess.check_output (dig_args, universal_newlines=True)
        mylog('none', [f'[{pluginName}] DIG output :', dig_output])
    except subprocess.CalledProcessError as e:
        # An error occured, handle it
        mylog('none', [f'[{pluginName}] ⚠ ERROR - ', e.output])
        dig_output = '' # probably no internet

    # Check result is an IP
    IP = check_IP_format (dig_output)

    # Handle invalid response
    if IP == '':
        IP = '0.0.0.0'

    return IP

#-------------------------------------------------------------------------------
def set_dynamic_DNS_IP (DDNS_UPDATE_URL, DDNS_USER, DDNS_PASSWORD, DDNS_DOMAIN):
    try:
        # try runnning a subprocess
        # Update Dynamic IP
        curl_output = subprocess.check_output (['curl', 
                                                '-s',
                                                DDNS_UPDATE_URL +
                                                'username='  + DDNS_USER +
                                                '&password=' + DDNS_PASSWORD +
                                                '&hostname=' + DDNS_DOMAIN],
                                                universal_newlines=True)
    except subprocess.CalledProcessError as e:
        # An error occured, handle it
        mylog('none', [f'[{pluginName}] ⚠ ERROR - ',e.output])
        curl_output = ""    
    
    return curl_output


#===============================================================================
# BEGIN
#===============================================================================
if __name__ == '__main__':
    main()