import requests

from urllib.parse import urlparse, parse_qs
import re

from bs4 import BeautifulSoup, NavigableString
import random


session = requests.Session()

session.headers.update({
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:130.0) Gecko/20100101 Firefox/130.0'
})


class LVA:
    def __init__(self, id: str, name: str, ects: float, curricula: list[str], type: str):
        self.id = id
        self.name = name
        self.ects = ects
        self.curricula = curricula
        self.type = type

    def id_pretty(self):
        # format 123123 -> 123.123
        return f'{self.id[:3]}.{self.id[3:]}'

    def __str__(self):
        return f'{self.name} ({self.id}) - {self.ects} ECTS'

    def __repr__(self):
        return f'{self.name} ({self.id})'

def get_direct_text_clean(element):
    text = ''.join(child for child in element.children if isinstance(child, NavigableString))
    return re.sub(r'\s+', ' ', text).strip()


def gen_request_tokens():
    request_token = str(random.randint(0, 999))
    window_id = str(random.randint(0, 999))

    session.cookies.set(f"dsrwid-{request_token}", window_id)
    return (request_token, window_id)


class TISS:
    @staticmethod
    def get_anonymous_tiss_link(code: str):
        return f"https://tiss.tuwien.ac.at/course/courseDetails.xhtml?courseNr={code}"

    @staticmethod
    def get_lva(code: str):
        tokens = gen_request_tokens()

        res = session.get(f"https://tiss.tuwien.ac.at/course/courseDetails.xhtml?courseNr={code}&dsrid={tokens[0]}&dswid={tokens[1]}")
        soup = BeautifulSoup(res.text, 'html.parser')

        course_name = get_direct_text_clean(soup.select('#contentInner > h1')[0])
        
        subheader = soup.select('#subHeader')[0].text
        ects = float(re.search(r'(\d+\.\d+)EC', subheader).group(1))
        # extract "VU" from "2024W, VU, 2.0h, 3.0EC"
        type = subheader.split(",")[1].strip()

        
        table = soup.select('th[aria-label="Studienkennzahl"]')[0].parent.parent.parent
        curricula = [re.sub("\D", "", tr.find("td").text) for tr in table.find("tbody").find_all("tr")]

        lva = LVA(code, course_name, ects, curricula, type)

        return lva
    

    @staticmethod
    def get_code_from_any(any: str):
        # Example: https://tiss.tuwien.ac.at/course/courseDetails.xhtml?dswid=5304&dsrid=381&courseNr=180771&semester=2024W
        any = any.strip()
        url = urlparse(any)

        if all([url.scheme, url.netloc]):
            # Yes, this was an URL
            params = parse_qs(url.query)

            course_nr = params.get('courseNr', [None])[0]
            return course_nr
        else:
            if len(any) == 6:
                return any

            match = re.search(r'\w{3}\.\w{3}', any)

            if match:
                return match.group(0).replace(".", "")
            else:
                return None