import re
import time
from urllib.parse import urljoin
import requests
from requests.structures import CaseInsensitiveDict
from bs4 import BeautifulSoup

BASE_URL = "https://www.vstu.ru/"
RASP_PREFIX = "https://www.vstu.ru/student/raspisaniya/zanyatiy/index.php?dep="


def parse_links(facultets):
    session = requests.Session()
    session.headers = CaseInsensitiveDict(
        {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:132.0) Gecko/20100101 Firefox/132.0",
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
            "Accept-Language: ru-RU,ru;q=0.8,en-US;q=0.5,en;q=0.3",
            "Accept-Encoding": "gzip, deflate",
            "Connection": "keep-alive",
            "Referer": "http://dump.vstu.ru/",
            "Upgrade-Insecure-Requests": "1",
            "Priority": "u=0, i",
            "Pragma": "no-cache",
            "Cache-Control": "no-cach",
        }
    )

    EXCEL_LINKS = {}
    for facultet in facultets:
        url = RASP_PREFIX + facultet
        r = session.get(url)
        print(f"GET {url}")
        soup = BeautifulSoup(r.text, 'html.parser')
        excel_pattern = re.compile(r'\.xlsx?$')

        # Ищем все теги <a>, у которых атрибут href соответствует нашему паттерну
        excel_tags = soup.find_all('a', href=excel_pattern)
        excel_links = [tag.get('href') for tag in excel_tags]

        # Предположим, вы уже получили excel_links из одного из методов выше
        # excel_links = ['../../../upload/raspisanie/z/ОН_ХТФ_1 курс.xlsx', ...]

        absolute_links = [urljoin(BASE_URL, relative_link) for relative_link in excel_links]

        if facultet not in EXCEL_LINKS.keys():
            EXCEL_LINKS[facultet] = set()

        for excel_url in absolute_links:
            EXCEL_LINKS[facultet].add(excel_url)
            print(f"+url {excel_url}")
    
    return EXCEL_LINKS