import requests
import pandas as pd
import numpy as np
from lxml import etree
from typing import Union


def get_responses(url: str) -> Union[str, pd.DataFrame]:
    r = requests.get(url)
    r.raise_for_status()
    tree = etree.HTML(r.content)

    name_raw: str = tree.xpath('//div[@class="main-info-pnl"]//td[.="Candidate Name"]/following-sibling::td/text()')[0]
    name = name_raw.split()[0].strip().lower()

    questions = []
    for panel in tree.xpath('//div[@class="question-pnl"]'):
        qno_raw = panel.xpath('.//td[@class="bold" and starts-with(text(), "Q.")]/text()')[0].split()[-1]
        qno = int(qno_raw.split(".")[1].strip())
        menu_tbl = panel.xpath('.//table[@class="menu-tbl"]')[0]
        
        qid = int(menu_tbl.xpath('.//td[.="Question ID :"]/following-sibling::td/text()')[0])
        ono_raw = menu_tbl.xpath('.//td[.="Chosen Option :"]/following-sibling::td/text()')[0].strip()
        
        if ono_raw == "--":
            ono = None
            oid = None
        else:
            ono = float(ono_raw)
            oid = float(menu_tbl.xpath(f'.//td[.="Option {ono_raw} ID :"]/following-sibling::td/text()')[0].strip())
        
        questions.append({
            "QNO": qno,
            "QID": qid,
            "ONO": ono,
            "OID": oid,
        })

    return name, pd.DataFrame(questions)


def check_result(your_df: pd.DataFrame, master_df: pd.DataFrame) -> pd.DataFrame:
    df = pd.merge(your_df, master_df, how='left', on='QID')
    
    df['TOID'] = df['TOID'].astype(float)
    df['Score'] = np.where(df['OID'].isna(), 0, np.where(df['OID'] == df['TOID'], 4, -1))

    print(f'Score: {df["Score"].sum()}')
    print(f'Correct: {len(df[df['Score'] == 4]['QNO'].tolist())}, Incorrect: {len(df[df['Score'] == -1]['QNO'].tolist())}, Unattempted: {len(df[df['Score'] == 0]['QNO'].tolist())}')

    print(df[df['Score'] == -1]['QNO'].tolist())

    return df


if __name__ == '__main__':
    response_url = '<your-response-sheet-url>'

    master = pd.read_csv('master.csv')
    stdn_name, stdn = get_responses(response_url)

    stdn_df = check_result(stdn, master)
    stdn_df.to_csv(f'{stdn_name}-scorecard.csv', index=False)