import os, re, ssl, sys
import subprocess
import logging
import requests
import time
import datetime
from urllib.parse import quote

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support import expected_conditions

import dateparser

from bs4 import BeautifulSoup
from pyvirtualdisplay import Display
from pdfminer.high_level import extract_text

from stem import Signal
from stem.control import Controller

import hashlib
import smtplib
from email.message import EmailMessage

from mastodon import Mastodon

logger = logging.getLogger(__name__)

class RAAspotter:
  class RAA:
    url      = ""
    date     = datetime.datetime(1970, 1, 1)
    date_str = ""
    name     = ""
    filename = ""
    sha256   = ""

    def __init__(self, url, date, name, filename):
      if not url == "":
        self.url = url
      if not date == "":
        self.date = date
        self.date_str = date.strftime("%d/%m/%Y")
      if not name == "":
        self.name = name
      if not filename == "":
        self.filename = filename

    def get_sha256(self):
      if (self.sha256 == ""):
        self.sha256 = hashlib.sha256(self.filename.encode('utf-8')).hexdigest()
      return self.sha256

  def __init__(self, data_dir, user_agent=''):
    logger.debug('Initialisation de RAAspotter')

    self.session          = requests.Session()
    self.data_dir         = data_dir
    self.found            = False
    self.output_file_path = os.path.dirname(os.path.abspath(__file__))+f'/output_{self.short_code}.log'
    self.sleep_time       = 0
    self.tor_enabled      = False
    self.tor_max_requests = 0
    self.tor_requests     = 0
    self.not_before       = datetime.datetime(2024, 1, 1)
    self.smtp_configured  = False
    self.mastodon         = None
    self.mastodon_prefix  = ''
    self.mastodon_suffix  = ''

    self.update_user_agent(user_agent)

    f = open(self.output_file_path,'w')
    f.write('')
    f.close()

  def configure_mastodon(self, access_token, instance, mastodon_prefix, mastodon_suffix):
    if access_token and access_token != "" and instance and instance != "":
      self.mastodon = Mastodon(
        access_token=access_token,
        api_base_url=instance
      )
      self.mastodon_prefix = mastodon_prefix
      self.mastodon_suffix = mastodon_suffix

  def mastodon_toot(self, content):
    if self.mastodon:
      toot = content
      if not self.mastodon_prefix == '':
        toot = f"{self.mastodon_prefix}\n\n{toot}"
      if not self.mastodon_suffix == '':
        toot = f"{toot}\n\n{self.mastodon_suffix}"
      self.mastodon.toot(toot)

  def enable_tor(self, max_requests=0):
    proxies = {
      "http": f"socks5h://127.0.0.1:9050",
      "https": f"socks5h://127.0.0.1:9050",
    }
    self.tor_enabled      = True
    self.tor_max_requests = max_requests
    self.tor_requests     = 0
    self.session.proxies.update(proxies)
    self.tor_get_new_id()

  def disable_tor(self):
    proxies = {}
    self.tor_enabled      = False
    self.tor_max_requests = 0
    self.tor_requests     = 0
    self.session.proxies.update(proxies)

  def tor_get_new_id(self):
    logger.info('Changement d\'identité Tor')
    try:
      controller = Controller.from_port(port = 9051)
      controller.authenticate()
      controller.signal(Signal.NEWNYM)
      time.sleep(5)
      self.tor_requests = 0
    except:
      logger.debug('Impossible de changer d\'identité Tor')

  def get_sub_pages(self, page_content, element, host, recursive_until_pdf):
    soup = BeautifulSoup(page_content, 'html.parser')
    sub_pages = []
    for a in soup.select(element):
      if a.get('href'):
        url = f"{host}{a['href']}"
        if recursive_until_pdf:
          sub_page_content = self.get_page(url, 'get').content
          if not self.has_pdf(sub_page_content):
            logger.info(f'{url} ne contient pas de PDF, on récupère ses sous-pages')
            for sub_sub_page in self.get_sub_pages(sub_page_content, element, host, recursive_until_pdf):
              sub_pages.append(sub_sub_page)
          else:
            sub_page = {
              'url': url,
              'name': a.get_text().strip()
            }
            sub_pages.append(sub_page)
        else:
          sub_page = {
            'url': url,
            'name': a.get_text().strip()
          }
          sub_pages.append(sub_page)
    return sub_pages

  def get_sub_pages_with_pager(self, page, sub_page_element, pager_element, host):
    pages = []
    page_content = self.get_page(page, 'get').content

    # On initialise le parser
    soup = BeautifulSoup(page_content, 'html.parser')
    
    # On recherche les sous-pages
    sub_pages = soup.select(sub_page_element)
    for sub_page in sub_pages:
      if sub_page.get('href'):
        page = {
          'url': f"{host}{sub_page['href']}",
          'name': sub_page.get_text().strip()
        }
        pages.append(page)

    # On recherche un pager, et si on le trouve on le suit
    pager = soup.select(pager_element)
    if pager and pager[0] and pager[0].get('href'):
      for sub_page in self.get_sub_pages_with_pager(f"{host}{pager[0]['href']}", sub_page_element, pager_element, host):
        pages.append(sub_page)

    return pages

  def get_raa_with_pager(self, pages_list, pager_element, host):
    elements = []
    # On parse chaque page passée en paramètre
    for page in pages_list:
      page_content = self.get_page(page, 'get').content

      # Pour chaque page, on récupère les PDF
      for raa in self.get_raa_elements(page_content):
        elements.append(raa)

      # On regarde également s'il n'y aurait pas un pager
      sub_pages = []
      for sub_page in self.get_sub_pages(page_content, pager_element, host, True):
        sub_pages.append(sub_page['url'])
      for sub_raa in self.get_raa_with_pager(sub_pages, pager_element, host):
        elements.append(sub_raa)
    return elements

  def set_sleep_time(self, sleep_time):
    self.sleep_time = sleep_time

  def has_pdf(self, page_content):
    elements = []
    soup = BeautifulSoup(page_content, 'html.parser')
    for a in soup.find_all('a', href=True):
      if a['href'].endswith('.pdf'):
        return True
    return False

  # On démarre le navigateur
  def get_session(self, url, wait_element=""):
    webdriver_options = webdriver.ChromeOptions()
    webdriver_options.add_argument("--no-sandbox")
    webdriver_options.add_argument("--disable-extensions")
    webdriver_options.add_argument("--disable-gpu")
    webdriver_options.add_argument("--disable-dev-shm-usage")
    webdriver_options.add_argument("--use_subprocess")
    webdriver_options.add_argument("--disable-blink-features=AutomationControlled")

    if not self.user_agent == "":
      webdriver_options.add_argument(f"--user-agent={self.user_agent}")

    webdriver_options.add_argument("--headless")
    webdriver_options.add_argument("--window-size=1024,768")
    display = Display(visible=False, size=(1024, 768))
    display.start()

    browser = webdriver.Chrome(options=webdriver_options)

    # Téléchargement de l'URL
    browser.get(url)

    if not wait_element == "":
      # On attend que le navigateur ait passé les tests anti-robots et que le contenu s'affiche
      WebDriverWait(browser, 120).until(expected_conditions.presence_of_element_located((By.ID, wait_element)))
    page_content = browser.page_source

    # On récupère les cookies du navigateur pour les réutiliser plus tard
    for cookie in browser.get_cookies():
      self.session.cookies.set(cookie['name'], cookie['value'])

    # On arrête le navigateur
    browser.quit()
    display.stop()

    return page_content

  def print_output(self, data):
    print(data)
    data = data.replace('\033[92m', '')
    data = data.replace('\033[0m', '')
    data = data.replace('\033[1m', '')
    f = open(self.output_file_path,'a')
    f.write(data+"\n")
    f.close()

  def get_page(self, url, method, data={}):
    try:
      logger.debug(f'Chargement de la page {url}')
      if self.sleep_time > 0:
        time.sleep(self.sleep_time)
      
      page = None
      if method == 'get':
        page = self.session.get(url)
      if method == 'post':
        page = self.session.post(url, data=data)

      if page.status_code == 429:
        logger.info(f'Erreur 429 Too Many Requests reçue, temporisation...')
        self.tor_get_new_id()
        time.sleep(55)
        return self.get_page(url, method, data)
      
      if self.tor_enabled:
        self.tor_requests+=1
        if self.tor_max_requests>0 and self.tor_requests>self.tor_max_requests:
          self.tor_get_new_id()

      return page
    except requests.exceptions.ConnectionError as exc:
      logger.info(f'Erreur de connexion, temporisation...')
      self.tor_get_new_id()
      time.sleep(55)
      return self.get_page(url, method, data)

  def update_user_agent(self, user_agent):
    self.user_agent = user_agent
    self.session.headers.update({'User-Agent': self.user_agent})

  def download_file(self, raa):
    try:
      os.makedirs(os.path.dirname(f'{self.data_dir}{raa.get_sha256()}.pdf'), exist_ok=True)
      file = self.get_page(raa.url, 'get')
      f = open(f'{self.data_dir}{raa.get_sha256()}.pdf','wb')
      f.write(file.content)
      f.close()
    except (requests.exceptions.ConnectionError, requests.exceptions.ChunkedEncodingError):
      logger.warning(f'ATTENTION: la connexion a été interrompue pendant le téléchargement de {raa.url}, nouvelle tentative...')
      self.download_file(raa)
    except Exception as exc:
      logger.warning(f'ATTENTION: Impossible de télécharger le fichier {raa.url}: {exc}')

  def parse_pdf(self, raa, keywords):
    if not os.path.isfile(f'{self.data_dir}{raa.get_sha256()}.pdf'):
      logger.warning(f'ATTENTION: le fichier {raa.get_sha256()}.pdf n\'existe pas')
    else:
      text = extract_text(f'{self.data_dir}{raa.get_sha256()}.pdf')
      found = False
      found_keywords = []
      for keyword in keywords:
        if re.search(keyword, text, re.IGNORECASE|re.MULTILINE):
          if not found:
            url = quote(raa.url, safe='/:')
            self.print_output(f'\033[92m{raa.name}\033[0m ({raa.date_str})')
            self.print_output(f'URL : {url}')
            found = True
            self.found = True
          self.print_output(f'    Le terme \033[1m{keyword}\033[0m a été trouvé.')
          found_keywords.append(keyword)

      # Écrit le texte du PDF dans un fichier texte pour une analyse future, puis supprime le PDF
      f = open(f'{self.data_dir}{raa.get_sha256()}.txt','w')
      f.write(text)
      f.close()
      os.remove(f'{self.data_dir}{raa.get_sha256()}.pdf')
      if found:
        self.print_output('')
        url = quote(raa.url, safe='/:')
        found_keywords_str = ', '.join([str(x) for x in found_keywords])
        self.mastodon_toot(f"{raa.name} ({raa.date_str})\n\nLes termes suivants ont été trouvés : {found_keywords_str}.\n\nURL : {url}")


  def ocr(self, raa, retry_on_failure=True):
    cmd = [
      'ocrmypdf',
      '-l', 'eng+fra',
      '--output-type', 'pdfa',
      '--redo-ocr',
      '--skip-big', '500',
      '--invalidate-digital-signatures',
      f'{self.data_dir}{raa.get_sha256()}.pdf',
      f'{self.data_dir}{raa.get_sha256()}.pdf'
    ]
    logger.debug(f'Lancement de ocrmypdf: {cmd}')
    try:
      output = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
    except subprocess.CalledProcessError as exc:
      if exc.returncode == 2 and retry_on_failure:
        logger.warning('ATTENTION : Le fichier n\'est pas un PDF correct, nouvelle tentative de le télécharger')
        if self.tor_enabled:
          self.tor_get_new_id()
        self.download_file(raa)
        self.ocr(raa,False)
      elif (not exc.returncode == 6) and (not exc.returncode == 10):
        logger.warning('ATTENTION : Impossible d\'OCRiser le document', exc.returncode, exc.output)

  def parse_raa(self, elements, keywords):
    for raa in elements:
      # Si le fichier n'a pas déjà été parsé et qu'il est postérieur à la date maximale d'analyse,
      # on le télécharge et on le parse
      if (raa.date >= self.not_before) and (not os.path.isfile(f'{self.data_dir}{raa.get_sha256()}.txt')):
        url = quote(raa.url, safe='/:')
        logger.info(f'Nouveau fichier : {raa.name} ({raa.date_str}). URL : {url}')
        self.download_file(raa)
        self.ocr(raa, True)
        self.parse_pdf(raa, keywords)

  def get_raa(self, page_content):
    logger.error('Cette fonction doit être surchargée')

  def configure_mailer(self, smtp_host, smtp_username, smtp_password,
                       smtp_port, smtp_starttls, smtp_ssl, email_from,
                       email_to, email_object):
    self.smtp_host     = smtp_host
    self.smtp_username = smtp_username
    self.smtp_password = smtp_password
    if smtp_port <= 0:
      self.smtp_port   = 587
    else:
      self.smtp_port   = int(smtp_port)
    self.smtp_starttls = smtp_starttls
    self.smtp_ssl      = smtp_ssl
    self.email_from    = email_from
    self.email_to      = email_to
    self.email_object  = email_object

    if smtp_host and smtp_username and smtp_password and email_from and email_to and email_object:
      self.smtp_configured = True

  def mailer(self):
    if self.smtp_configured and self.found:
      try:
        message = EmailMessage()
        message.set_content(open(self.output_file_path).read())

        message['Subject'] = self.email_object
        message['From'] = self.email_from

        context = ssl.create_default_context()

        if self.smtp_ssl == True:
          for address in self.email_to.split(','):
            del message['To']
            message['To'] = address
            smtp = smtplib.SMTP_SSL(self.smtp_host, port, context=context)
            if self.smtp_username:
              smtp.login(self.smtp_username, self.smtp_password)
            smtp.send_message(message)
            smtp.quit()
        elif self.smtp_starttls == True:
          for address in self.email_to.split(','):
            del message['To']
            message['To'] = address
            smtp = smtplib.SMTP(self.smtp_host)
            smtp.starttls(context=context)
            if self.smtp_username:
              smtp.login(self.smtp_username, self.smtp_password)
            smtp.send_message(message)
            smtp.quit()
        else:
          for address in self.email_to.split(','):
            del message['To']
            message['To'] = address
            smtp = smtplib.SMTP(self.smtp_host)
            if self.smtp_username:
              smtp.login(self.smtp_username, self.smtp_password)
            smtp.send_message(message)
            smtp.quit()
      except Exception as exc:
        logger.warning(f'Impossible d\'envoyer le courrier électronique : {exc}')

  # Fonction qui essaie de deviner la date d'un RAA à partir de son nom.
  # Utile pour limiter les requêtes lors de l'obtention des RAA à scanner.
  def guess_date(string, regex):
    try:
      search = re.search(regex, string, re.IGNORECASE)
      guessed_date = dateparser.parse(search.group(1))
      if guessed_date == None:
        raise Exception('La date est un objet None')
      else:
        return guessed_date
    except Exception as exc:
      logger.warning(f"Impossible de deviner la date du terme {string} : {exc}")
      return datetime.datetime(9999, 1, 1)