#!/usr/bin/python3
# -*- coding: utf-8 -*-

import os
import csv
import sys
import time
import socket
import datetime
import sqlite3
from pathlib import Path

path = Path(__file__).resolve().parent

def update_db(payload):
    conn = None
    try:
        db = (str(path) + "/data/db.sqlite3")
        conn = sqlite3.connect(db)

        c = conn.cursor()
        c.execute(
            '''
            CREATE TABLE IF NOT EXISTS netmonResults  (
              id integer PRIMARY KEY,
              timestamp text,
              status integer
            )
            '''
        )
        c.execute(
            '''
            INSERT OR REPLACE into netmonResults (
              timestamp, status
            )
            VALUES (?, ?)
            ''',
            (payload)
        )
        conn.commit()
        print (f"db update successful")
    except Exception as ex:
        print(ex)
        print (f"db operation failed")    
    finally:
        if conn:
            conn.close()

def internet(dstHost, dstPort, timeout=3):
    """ Generates a new request"""
    try:
        socket.setdefaulttimeout(timeout)
        socket.socket(socket.AF_INET, socket.SOCK_STREAM).connect((dstHost, int(dstPort)))
        return True
    except Exception as ex:
        # print(ex)
        return False


def current_timestamp():
    """ Get Current timestamp string """
    return datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")


def str_to_date(timestamp):
    """ Convert timestamp string to date object """
    return datetime.datetime.strptime(timestamp, "%Y-%m-%d %H:%M:%S")


def secs_to_HMS(secs):
    """ Convert seconds to second and minutes
    Format : HH:MM:SS 
    """
    return str(datetime.timedelta(seconds=secs));


def record_file_exist():
    """ Check if records file exist """
    return os.path.isfile('data/data.csv')


def create_record_file():
    """ Create a new record file """
    with open('data/data.csv', 'a') as csvfile:
        columns = ['timestamp', 'status']
        writer = csv.DictWriter(csvfile, fieldnames=columns)
        writer.writeheader()


def last_record_status():
    """ Get last record """
    result = None
    with open('data/data.csv', 'r') as csvfile:
        reader = csv.DictReader(csvfile)
        for row in reader:
            result = row
    return None if result is None else result['status']


def write_record(status):
    """ Create a new record """
    with open('data/data.csv', 'a') as csvfile:
        columns = ['timestamp', 'status']
        writer = csv.DictWriter(csvfile, fieldnames=columns)
        writer.writerow({'timestamp': str(current_timestamp()), 'status': status})


def get_total_downtime():
    """ Calculate downtime """
    seconds = 0
    down = None
    up = None
    with open('data/data.csv', 'r') as csvfile:
        reader = csv.DictReader(csvfile)
        for record in reader:
            try:
                if record['status'] == '0':
                    print('Went Down at : ', record['timestamp'])
                    down = str_to_date(record['timestamp'])
                    next_record = next(reader)
                    up = str_to_date(next_record['timestamp'])
                    seconds += (up - down).total_seconds()
                    print('Went up at   : ', next_record['timestamp'])
            except Exception as ex:
                print('\nCurrent Status    :  Still Down')
                seconds += (str_to_date(current_timestamp()) - down).total_seconds()
    return secs_to_HMS(seconds);


def monitor_connection(sleep_time):
    try:
        dstHost = os.getenv('dstHost')
        dstPort = os.getenv('dstPort')
        if dstHost is None or dstPort is None:
            raise Exception('vars are fucked')
    except Exception as error:
        print('Caught this error: ' + repr(error))
        print ("""
        pls set vars

        eg;

        for host:
        export dstHost=localhost dstPort=8000
        
        for docker:
        -e dstHost=localhost -e dstPort=8000 

        """)
        sys.exit(1)

    """ Start monitoring """
    print('Monitoring your connection for ' + dstHost)
    while True:
        last_record = last_record_status()
        if not internet(dstHost, dstPort):
            if last_record == '1' or last_record is None:
                print('Internet went down')
                write_record(0)
                update_db((str(current_timestamp()), '0'))
        else:
            if last_record == '0' or last_record is None:
                print('Internet is up')
                write_record(1)
                update_db((str(current_timestamp()), '1'))
        time.sleep(sleep_time)


def args_error():
    print('Please provide an argument\nOptions\n./internet.py monitor\n./internet.py downtime')


args = sys.argv
if not len(args) > 1:
    args_error()
elif args[1] == 'monitor':
    if not record_file_exist():
        create_record_file()
    monitor_connection(1)
elif args[1] == 'downtime':
    print('\nRemained down for : ', get_total_downtime(), ' HH:MM:SS ')