#!/usr/bin/python3

# MIT License

# Copyright (c) 2024 Thomas Williams - https://git.server.wales/thomas

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import config
import psutil
import os
import time
import log
import requests
import threading
import signal
import socket
from functools import partial
from concurrent.futures import ThreadPoolExecutor, as_completed
from bs4 import BeautifulSoup
from log import logsManager 
from datetime import datetime

stop_event = threading.Event()
nonPOSIXCPULoads = []
lock = threading.Lock()

def signal_handler(sig, frame):
    print('SIGINT/SIGTERM aknowledged. Stopping script gracefully, please wait...')
    stop_event.set()

def loadUrl(url):
    
    headers = { 'User-Agent': 'Monutil monitor' }

    response = requests.get(url, timeout=config.urlTimeout, headers=headers)
    return response

def prepareUrl(src, baseUrl):

    if not src.startswith("http://") and not src.startswith("https://"):
        return baseUrl.rstrip("/") + "/" + src.lstrip("/")
    return src

def nonPOSIXCPULoad(stop_event):
    
    global nonPOSIXCPULoads
    nonPOSIXCPULoad = 0

    while not stop_event.is_set():

        nonPOSIXCPULoad = psutil.cpu_percent(interval=1)
        
        with lock:
            
            nonPOSIXCPULoads.append(nonPOSIXCPULoad)
            
            if len(nonPOSIXCPULoads) > 60:
                nonPOSIXCPULoads.pop(0)
        
        time.sleep(0.1)

def getNonPOSIXCPUAverage():

    global nonPOSIXCPULoads
    
    with lock:
        if sum(nonPOSIXCPULoads) > 0:
            avgLoad = sum(nonPOSIXCPULoads) / len(nonPOSIXCPULoads)
        else:
            avgLoad = 0

    return avgLoad

def monitorHost(stop_event):

    while time.strftime("%H:%M:%S") <= config.hostMonitorStartTime:
           time.sleep(1) # This block is important to ensure the thread sleeps until the start time is reached. Else the thread wont start if the script is started before the start time

    nonPOSIXCPUStarted = False

    while not (stop_event.is_set()) and (time.strftime("%H:%M:%S") >= config.hostMonitorStartTime and time.strftime("%H:%M:%S") <= config.hostMonitorEndTime):
        
        if os.name != 'posix' or config.forceNonPOSIXCPU:
            
            if not nonPOSIXCPUStarted:
                
                nonPOSIXCPUMonitor = threading.Thread(target=nonPOSIXCPULoad, args=(stop_event,))
                nonPOSIXCPUMonitor.start()
                nonPOSIXCPUStarted = True

            loadavg = round(getNonPOSIXCPUAverage(), 2)

        else:

            load1, load5, load15 = psutil.getloadavg() # this takes time to warm up if not running script on *nix 
            loadavg = round((load1/os.cpu_count()) * 100, 2)
        
        memory = psutil.virtual_memory().percent
        logHostLog(socket.gethostname(), datetime.now(), loadavg, memory)

        print("CPU %: " + str(loadavg))
        print("Memory %: " + str(memory))
        print() # new line

        time.sleep(config.hostMonitoringPeriod)

def monitorUrls(stop_event):

    while time.strftime("%H:%M:%S") <= config.urlMonitorStartTime:
           time.sleep(1) # This block is important to ensure the thread sleeps until the start time is reached. Else the thread wont start if the script is started before the start time

    while not (stop_event.is_set()) and (time.strftime("%H:%M:%S") >= config.urlMonitorStartTime and time.strftime("%H:%M:%S") <= config.urlMonitorEndTime):
        
        for url in config.urls:
            
            baseUrl = url
            urlFail = False

            startTime = time.time()
            request = loadUrl(url)

            if request.status_code == 200:

                html = BeautifulSoup(request.content, 'html.parser')
                imageUrls = [img['src'] for img in html.find_all('img')]

                with ThreadPoolExecutor(max_workers=config.maxWorkers) as executor:
            
                    responses = [executor.submit(loadUrl, prepareUrl(url, baseUrl)) for url in imageUrls]    
                    responses = [future.result() for future in as_completed(responses)]

                for response in responses:
            
                    if not response.status_code == 200:
                        urlFail = True

                endTime = time.time()
                timeDiff = endTime - startTime
            
                print(baseUrl + " response time: " + str(timeDiff))
                print() # new line
                logURLLog(socket.gethostname(), datetime.now(), baseUrl, timeDiff)
        
            else:
                urlFail = True

        time.sleep(config.urlMonitoringPeriod)

def logHostLog(hostname, logTime, cpu, memory):

    if not config.loggingMode == 'none':
        
        manager = logsManager(config.sqlServer, config.sqlDatabase, config.sqlUsername, config.sqlPassword)
        manager.insertHostLog(hostname, socket.gethostbyname(socket.gethostname()), logTime, cpu, memory)

def logURLLog(hostname, logTime, url, responseTime):

    if not config.loggingMode == 'none':
            
        manager = logsManager(config.sqlServer, config.sqlDatabase, config.sqlUsername, config.sqlPassword)
        manager.insertURLLog(hostname, socket.gethostbyname(socket.gethostname()), logTime, url, responseTime)

def main():

    signal.signal(signal.SIGTERM, signal_handler)
    signal.signal(signal.SIGINT, signal_handler)

    hostMonitorThread = threading.Thread(target=monitorHost, args=(stop_event,))
    urlMonitorThread = threading.Thread(target=monitorUrls, args=(stop_event,))
    
    hostMonitorThread.start() 
    urlMonitorThread.start()

    hostMonitorThread.join()
    urlMonitorThread.join()

if __name__ == "__main__":
    main()