import os
import csv
import uuid
from datetime import datetime
import streamlit as st
from settings import BASE_DIR, NUMBER_OF_TECHNICAL_QUESTIONS, NUMBER_OF_COMMON_QUESTIONS
from core.slack_notifier import SlackNotifier
from core.questions_loader_local import QuestionLoaderLocal
from presentation.layout import Layout

# Slack Webhook
SLACK_WEBHOOK_URL = os.environ["SLACK_WEBHOOK_URL"]
layout = Layout()

def call(candidate_id):
    # Check if questions are already loaded
    if 'questions' not in st.session_state:
        # Define questions
        questions = QuestionLoaderLocal(
            os.path.join(BASE_DIR, "data/questions", st.session_state['technology'].lower(), "questions.csv"),
            NUMBER_OF_TECHNICAL_QUESTIONS
        ).fetch_questions()
        
        if not questions:
            st.markdown("Work in progress!!")
            return

        common_questions = QuestionLoaderLocal(
            os.path.join(BASE_DIR, "data/questions", "common", "questions.csv"),
            NUMBER_OF_COMMON_QUESTIONS
        ).fetch_questions()
        questions.extend(common_questions)
        
        # Store questions in session state to persist across interactions
        st.session_state['questions'] = questions

    # Retrieve the questions from session state
    questions = st.session_state['questions']
    score = 0
    total_questions = len(questions)
    answered_all = True

    for idx, question in enumerate(questions):
        # Section for each question with styling
        selected_option = layout.render_test_question(question, idx)
        if not selected_option:
            answered_all = False
        # Checking for correct answer and assigning points based on difficulty
        if selected_option == question['answer']:
            score += 1

    if st.button("Submit Test", use_container_width=True, type="primary"):
        if answered_all:
            st.session_state['test_started'] = False
            layout.render_completion_message(score, total_questions)
            result = (score / total_questions) * 100
            update_candidate_status(candidate_id, result)
            SlackNotifier(SLACK_WEBHOOK_URL).send_candidate_info(
                st.session_state['name'], 
                st.session_state['email'], 
                st.session_state['experience'], 
                st.session_state['technology'], 
                f"{result:.2f}%"
            )
        else:
            # Show a message asking the user to answer all questions
            st.warning("Please answer all questions before submitting.")

def generate_url():
    id = uuid.uuid4().hex  # Generate a UUID and convert it to a hex string
    return f'http://localhost:8501/?candidate_id={id}', id

def add_candidate_id_to_csv(candidate_id):
    with open(os.path.join(BASE_DIR, "data", "candidates.csv"), 'a') as file:
        csv.writer(file).writerow([candidate_id,"","","","","","","In Progress"])        

def read_candidate_csv():
    with open(os.path.join(BASE_DIR, "data", "candidates.csv"), 'r') as file:
        reader = csv.DictReader(file)
        return list(reader)

def is_candidate_test_completed(candidate_id, candidates):
    for row in candidates:
        if row["id"].lower() == candidate_id.lower() and row["status"] == "Test Completed":
            return True
    return False

def is_valid_candidate_id(candidate_id, candidates):
    for row in candidates:
        if row["id"].lower() == candidate_id:
            return True
    return False

def update_candidate_status(candidate_id, result):
    with open(os.path.join(BASE_DIR, "data", "candidates.csv"), 'r') as file:
        reader = csv.reader(file)
        header = next(reader)  # Save the header
        rows = []
        for row in reader:
            if row[0] == candidate_id:
                row[1] = st.session_state['name']
                row[2] = st.session_state['email']
                row[3] = st.session_state['experience']
                row[4] = st.session_state['technology'] 
                row[5] = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
                row[6] = result
                row[7] = "Test Completed"
            rows.append(row)
    with open(os.path.join(BASE_DIR, "data", "candidates.csv"), 'w') as file:

        writer = csv.writer(file)
        writer.writerow(header)  # Write the header
        writer.writerows(rows)

def main():
    query_params = st.query_params
    if not query_params:
        st.markdown("Invalid URL")
        return
    
    candidate_id = query_params.get("candidate_id", None)
    internal = query_params.get("internal", None)
    # Set page config with custom title and layout
    st.set_page_config(page_title="Candidate MCQ Platform", layout="wide")
    layout.render_header()
    if internal:
        if st.button('Generate URL'):
            url, candidate_id = generate_url()
            st.write(f"Generated URL: {url}")
            add_candidate_id_to_csv(candidate_id)

    elif candidate_id:
        candidates = read_candidate_csv()
        if not is_valid_candidate_id(candidate_id, candidates):
            st.markdown("Invalid URL")
            return
        print("Candidate ID:", candidate_id)
        if is_candidate_test_completed(candidate_id, candidates):
            st.markdown("Test has been completed! Great job on completing it. Thank you for your effort and dedication.")
            return
        
        if 'test_started' not in st.session_state:
            st.session_state['test_started'] = False

        if not st.session_state['test_started']:
            st.title("Welcome to the Candidate Assessment Platform")
            name, email, experience, technology, submit = layout.render_signup_form()
            if name and email:
                st.session_state['name'] = name
                st.session_state['email'] = email
                st.session_state['experience'] = experience
                st.session_state['technology'] = technology
                st.session_state['test_wip'] = True
            if submit:
                st.session_state['test_started'] = True
                st.rerun()
            layout.render_instructions()
        else:
            call(candidate_id)
    else:
        st.markdown("Invalid URL")
if __name__ == "__main__":
    main()