#!/usr/bin/env python
# test script by running:
# /home/pi/pialert/front/plugins/internet_ip/script.py TBD

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/pialert') 

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, pialertPath, 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')

def main():

    mylog('verbose', ['[DDNS] 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', ['[DDNS] 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', ['[DDNS]    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', ['[DDNS]     Error retrieving Dynamic DNS IP'])       

    mylog('none', ['[DDNS]    ', dns_IP])

    # Check DNS Change
    if dns_IP != PREV_IP :
        mylog('none', ['[DDNS]     Updating Dynamic DNS IP'])
        message = set_dynamic_DNS_IP (DDNS_UPDATE_URL, DDNS_USER, DDNS_PASSWORD, DDNS_DOMAIN)
        mylog('none', ['[DDNS]        ', 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)
    except subprocess.CalledProcessError as e:
        # An error occured, handle it
        mylog('none', ['[DDNS] 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', ['[DDNS] ERROR - ',e.output])
        curl_output = ""    
    
    return curl_output


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