import string

import requests
from bs4 import BeautifulSoup


BASE_URL = "https://www.cnrtl.fr"
PER_FIRST_LETTER_URL = BASE_URL + "/portailindex/LEXI/TLFI/"


def main():
    for letter in string.ascii_uppercase:
        try:
            with open(f"lexical_forms_{letter}.txt", "wt") as letter_file:
                process_letter(letter, letter_file)
        except OSError as exc:
            exit(f"FUCK {exc}")


def process_letter(letter, letter_file):
    next_url = PER_FIRST_LETTER_URL + letter
    while True:
        print(f"Processing {next_url}")
        response = requests.get(next_url)
        if response.status_code != 200:
            exit(f"ERROR {response.status_code} at {next_url}")
        next_page = process_page(response.text, letter_file)
        if not next_page:
            break
        next_url = BASE_URL + next_page


def process_page(page, output):
    soup = BeautifulSoup(page, "html.parser")
    hometab = soup.find("table", class_="hometab")
    lexical_forms = [td.string for td in hometab("td")]
    for form in lexical_forms:
        if form:
            output.write(str(form) + "\n")
    nav_table = hometab.find_next_sibling("table")
    if not nav_table:
        return None
    nav_table_cells = nav_table("td")
    if not nav_table_cells or len(nav_table_cells) < 2:
        return None
    second_cell = nav_table_cells[1]
    next_page_link = second_cell.find("a")
    if not next_page_link:
        return None
    try:
        return next_page_link["href"]
    except KeyError:
        return None


if __name__ == "__main__":
    main()