#!/usr/bin/env python3

from distutils.debug import DEBUG
import json, os, smtplib, ssl, logging
from openpyxl.cell.read_only import ReadOnlyCell
from pyvirtualdisplay import Display
from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC
from datetime import datetime
from openpyxl import load_workbook
from email.message import EmailMessage
import time
import sys

def load_settings():
    with open('settings.json') as file:
        return json.load(file)

def fetch_via_browser(newfile):
    disp = Display(backend="xvfb", size=(800,600))
    disp.start()


    options = webdriver.ChromeOptions()
    prefs = {
        "download.default_directory" : set['files'],
        "profile.default_content_settings.popups" : 0,
    }
    logging.info(prefs)
    options.add_experimental_option("prefs", prefs)
    options.add_argument("--headless=new")
    browser = webdriver.Chrome(options=options)
    wait = WebDriverWait(browser, 10)

    
    browser.get(set['oo_url'])

    iframe = wait.until(
        EC.element_to_be_clickable((By.TAG_NAME, 'iframe'))
    )
    browser.switch_to.frame(iframe)

    btn_file = wait.until(
        EC.element_to_be_clickable((By.XPATH, "//a[@data-tab='file']"))
    )
    wait.until(
        EC.invisibility_of_element_located((By.CSS_SELECTOR, 'div.asc-loadmask'))
    )
    btn_file.click()
    
    panel_saveas = wait.until(
        EC.element_to_be_clickable((By.CSS_SELECTOR, "div#panel-saveas"))
    )
   
    btn_download = wait.until(
        EC.element_to_be_clickable((By.CSS_SELECTOR, "div.svg-format-xlsx"))
    )

    btn_download.click()
   
    try:
        timeout = 0

        while not os.path.exists(newfile) and timeout < 20:
            time.sleep(1)
            timeout += 1

        if timeout == 20:
            logging.warning("Timeout beim Dateidownload erreicht.")

        browser.quit()
        disp.stop()

    except:
        logging.error("Exception raised: ",sys.exc_info())

def rotate_file(oldfile, newfile):
    try:
        os.remove(oldfile)
    except Exception as e:
        logging.error("Fehler beim Löschen")
        if hasattr(e, 'message'):
            logging.error(e.message)
        else:
            logging.error(e)

    try:
        os.rename(newfile, oldfile)
    except Exception as e:
        logging.error("Fehler beim Umbenennen")
        if hasattr(e, 'message'):
            logging.error(e.message)
        else:
            logging.error(e)
    
def compare_files(oldfile, newfile):
    results = []

    if os.path.exists(oldfile) and os.path.exists(newfile):
        new_wb = load_workbook(filename=newfile, read_only=True)

        old_wb = load_workbook(filename=oldfile, read_only=True)

        new_sheet = new_wb['BewerberInnen']
        old_sheet = old_wb['BewerberInnen']

        old_sheet.calculate_dimension(force=True)
        new_sheet.calculate_dimension(force=True)

        logging.debug(f'Old-Sheet-Dimensions (mincol/maxcol:minrow/maxrow): {old_sheet.min_column}/{old_sheet.max_column}:{old_sheet.min_row}/{old_sheet.max_row}')
        logging.debug(f'New-Sheet-Dimensions (mincol/maxcolminrow/maxrow): {new_sheet.min_column}/{new_sheet.max_column}:{new_sheet.min_row}/{new_sheet.max_row}')

        global_min_row = min(old_sheet.min_row, new_sheet.min_row)
        global_max_row = max(set.get('max_row', old_sheet.max_row), set.get('max_row', new_sheet.max_row))
        global_min_col = min(old_sheet.min_column, new_sheet.min_column)
        global_max_col = max(set.get('max_col', old_sheet.max_column), set.get('max_col', new_sheet.max_column))

        for row in range(global_min_row, global_max_row + 1):
            for col in range(global_min_col, global_max_col + 1):
                new_cell = new_sheet.cell(row=row, column=col)
                old_cell = old_sheet.cell(row=row, column=col)
                    
                logging.debug(f'Performance Check, Cell: {col}:{row}')

                if new_cell.value != old_cell.value:
                    if type(new_cell) is ReadOnlyCell:
                        coord = new_cell.coordinate                 
                    elif type(old_cell) is ReadOnlyCell:
                        coord = old_cell.coordinate
                    else:
                        coord = f'{col}/{row}'
                    message = f'Veränderung in Zelle {coord}: {old_cell.value} ==> {new_cell.value}'
                    logging.info(message)
                    results.append(message)
        new_wb.close()
        old_wb.close()
                
        if not results:
            logging.info("Keine Änderungen gefunden.")
        else:
            send_email(results, set['email_recipient'])
    
    else: 
        logging.warning('Kann Dateien nicht vergleichen, Dateien nicht vorhanden?')
            
def send_email(results, recipient):

    msg = EmailMessage()
    
    msg['Subject'] = 'ISB-Vermittlung Watchdog'
    msg['From'] = set['smtp_user']
    msg['To'] = recipient
    msg.set_type('text/html')

    msg.set_content('\r\n'.join(results))

    html_msg = f"""\
        <html>
            <body>
                <a href="{set['oo_url']}">Zur Vermittlungsliste des DW</a>
                <br />
                <br />
                {'<br />'.join(results)}
            </body>
        </html>
    """
    msg.add_alternative(html_msg, subtype="html")

    context = ssl.create_default_context()
    with smtplib.SMTP(set['smtp_server'], set['smtp_port']) as server:
        server.starttls(context=context)
        server.login(set['smtp_user'], set['smtp_password'])
        server.send_message(msg)
        server.quit()

def main():
    args = sys.argv[1:]

    oldfile = os.path.join(set['files'], 'vermittlung-old.xlsx')
    newfile = os.path.join(set['files'], 'ISB Vermittlung.xlsx')
    
    if len(args) == 1 and args[0] == '-t':
        send_email("test", "marc-pascal.koenig@outlook.de")

    if len(args) == 1 and args[0] == '-c':
        compare_files(oldfile, newfile)

    else:
        rotate_file(oldfile, newfile)

        fetch_via_browser(newfile)

        compare_files(oldfile, newfile)

set = load_settings()
logging.basicConfig(
    level=set['loglevel'],
    format='[%(asctime)s] %(levelname)s: %(message)s',
    filename=set['logfile']
)

if __name__ == '__main__':
    main()