import requests, time, re, os, configparser, sys, argparse, shutil
from bs4 import BeautifulSoup

def main(args: dict) -> None:
  print(f"Fetching PDFs.")
  if not os.path.isdir("pdfs"):
    print("Setting up PDFs directory.")
    os.mkdir("pdfs")
  if args.save_pages and not os.path.isdir("html"):
    print("Setting up HTML directory.")
    os.mkdir("html")
    
  config = configparser.ConfigParser(interpolation=None)
  if not os.path.isfile('config.ini'):
    print("config.ini is missing!")
    sys.exit(0)
  config.read('config.ini')

  if "username" not in config["DEFAULT"] or "password" not in config["DEFAULT"] or config["DEFAULT"]["username"] == "" or config["DEFAULT"]["password"] == "":
    print("username and password must be present in config.ini.")
    sys.exit(0)

  INFOVAYA_ROOT = "https://events.infovaya.com/"

  info = { "username": config["DEFAULT"]["username"],
          "password": config["DEFAULT"]["password"],
          "action": "login"
          }

  infovaya_session = requests.Session()
  infovaya_creds_request = infovaya_session.post(f"{INFOVAYA_ROOT}login", data=info)
  infovaya_creds_request.raise_for_status()

  root_event = 88 if not args.event else args.event
  caching = not args.no_cache
  cache_list = []
  if caching:
    if not os.path.isfile(f"{root_event}_cache.txt"):
      cache_file = open(f"{root_event}_cache.txt", "w")
    else:
      cache_file = open(f"{root_event}_cache.txt", "a")
      cache_list = cache_file.readlines()

  skip_until = False if not args.start_with else True
  start_with = args.start_with

  sessions_request = infovaya_session.get(f"{INFOVAYA_ROOT}event?id={root_event}&actionMenu=sessions")
  sessions_request.raise_for_status()
  sessions_page_soup = BeautifulSoup(sessions_request.text, "html.parser")
  if args.save_pages:
    with open("html/main.html", "w+", encoding="utf-8") as file:
      file.write(sessions_page_soup.prettify())
  print("Starting to search for PDFs. This may take a while...")
  for session_link in sessions_page_soup.find_all("a", href=re.compile("session\?id")):
    session_href = session_link["href"][1:]
    page_id = session_href.split("=")[-1]
    page_name = f"session_{page_id}.html"
    if caching and page_id not in cache_list:
      cache_file.write(f"{page_id}\n")
    if skip_until and page_id != start_with:
      continue
    skip_until = False
    if not caching or page_id not in cache_list:
      time.sleep(1)
      print(f"Fetching {session_href} ... ", end="")
      page_request = infovaya_session.get(f"{INFOVAYA_ROOT}{session_href}")
      page_request.raise_for_status()
      print("Success! Finding presentations... ", end="")
      page_soup = BeautifulSoup(page_request.text, "html.parser")
      if args.save_pages:
        with open(f"html/{page_name}", "w+", encoding="utf-8") as file:
          file.write(page_soup.prettify())
        print(f"Wrote to file html/{page_name}.")
      else:
        print()
        # import pdb; pdb.set_trace()
      for presentation_link in page_soup.find_all("a", href=re.compile("presentation\?id")):
        presentation_href = presentation_link["href"][1:]
        presentation_id = presentation_href.split('=')[-1]
        pres_page_name = f"pres_{presentation_id}.html"
        if not caching or presentation_id not in cache_list:
          print(f"  Fetching {presentation_href} ...", end="")
          pres_request = infovaya_session.get(f"{INFOVAYA_ROOT}{presentation_href}")
          pres_request.raise_for_status()
          print("Success! ", end="")
          pres_page_soup = BeautifulSoup(pres_request.text, "html.parser")
          if args.save_pages:
            with open(f"html/{pres_page_name}", "w+", encoding="utf-8") as file:
              file.write(pres_page_soup.prettify())
          pres_page_title = pres_page_soup.h1.string
          print(f"Found '{pres_page_title}'. Finding PDF...")
          for pdf_tag in pres_page_soup.find_all("a", href=re.compile("pdfviewer")):
            pdf_name = pdf_tag["href"].split("/")[-1]
            file_name = f"{pres_page_title.replace(' ', '_').replace('/', '-')}-{pdf_name}"
            pdf_request = infovaya_session.get(f"{INFOVAYA_ROOT}{pdf_tag['href'][1:]}")
            pdf_request.raise_for_status()
            if b"Download Quota Exceeded" in pdf_request.content:
              print("""ATTENTION
              Infovaya is reporting that you've exceeded your download limit.
              If you're caching, you can start over from this point tomorrow.
              If you haven't been caching, you can use the --start-with flag to enter the last SESSION ID above and start from there.""")
              sys.exit(0)
            if caching and presentation_id not in cache_list:
              cache_file.write(f"{presentation_id}\n")
            print(f"Fetching PDF for '{pres_page_title}'...")
            if not os.path.isfile(f"pdfs/{file_name}"):
              with open(f"pdfs/{file_name}", "wb") as file:
                file.write(pdf_request.content)
                print(f"Saved as pdfs/{file_name}")
              time.sleep(2)
  if caching:
    cache_file.close()
  

if __name__ == "__main__":
  parser = argparse.ArgumentParser()
  parser.add_argument("-s", "--save-pages", action="store_true", help="Save HTML of the scanned pages")
  parser.add_argument("-e", "--event", action="store_true", help="Choose which event ID to scan")
  parser.add_argument("-c", "--no-cache", action="store_true", help="Don't cache previously-seen pages; re-download everything")
  parser.add_argument("-w", "--start-with", action="store", help="Start with the given session ID")
  args = parser.parse_args()
  print(args)
  main(args)