from flask import Blueprint, render_template, request, flash, redirect, url_for, current_app
from flask_mail import Message
from itsdangerous import URLSafeTimedSerializer, SignatureExpired, BadSignature
from app.extensions import db, mail
from app.models import Participant

bp = Blueprint('main', __name__)

def get_confirmed_count():
    return Participant.query.filter_by(confirmed=True).count()

def add_user(name, email, looking_for_team, on_waitlist = False):
    new_user = Participant(name=name, email=email, looking_for_team=looking_for_team)
    if on_waitlist:
        new_user.on_waitlist = on_waitlist
    db.session.add(new_user)
    db.session.commit()
    return new_user

def send_verification_email(user):
    s = URLSafeTimedSerializer(current_app.config['SECRET_KEY'])
    token = s.dumps(user.email, salt='email-confirm-h4tum-ctf-2025')
    link = url_for('main.verify_email', token=token, _external=True)
    logo = url_for('static', filename='h4tum_white.png', _external=True)
    
    msg = Message('Verify your CTF Registration', recipients=[user.email])
    msg.html = render_template("email.html", user_name=user.name, link=link, logo_url=logo)
    mail.send(msg)
    user.num_emails_sent += 1
    db.session.commit()
    return True

def send_waitlist_email(user):
    msg = Message('h4tum CTF 2026 Registration', recipients=[user.email])
    logo = url_for('static', filename='h4tum_white.png', _external=True)
    msg.html = render_template("waitlist_email.html", logo_url=logo, user_name=user.name)
    mail.send(msg)

@bp.route('/', methods=['GET', 'POST'])
def index():
    confirmed_count = get_confirmed_count()
    max_spots = current_app.config['MAX_SPOTS']
    spots_left = max_spots - confirmed_count

    if request.method == 'POST':
        name = request.form['name']
        email = request.form['email'].lower().strip()
        looking_for_team = True if request.form.get('looking_for_team') else False
        
        tum_domain = current_app.config['TUM_DOMAIN']
        if not email.endswith(f"@{tum_domain}"):
            flash(f"Error: You must use a @{tum_domain} email address.", "error")
            return redirect(url_for('main.index'))

        existing_user = Participant.query.filter_by(email=email).first()

        if existing_user:
            if existing_user.confirmed:
                flash("You are already registered and confirmed!", "info")
            elif existing_user.on_waitlist:
                flash("You are already on the waitlist", "info")
            else:
                if existing_user.num_emails_sent < 5:
                    flash("Confirmation email resent. Please check your inbox.", "info")
                    send_verification_email(existing_user)
                else:
                    flash("Email limit reached", "error")
            return redirect(url_for('main.index'))
        else:
            new_user = add_user(name, email, looking_for_team) 

            if confirmed_count < max_spots:
                send_verification_email(new_user)
                flash("Registration started! Check your email to confirm your spot.", "success")
            else:
                new_user.on_waitlist = True
                db.session.commit()
                send_waitlist_email(new_user)
                flash("The event is already full!\nYou have been placed on the waitlist", "info")
            return redirect(url_for('main.index'))

    return render_template('index.html', spots_left=spots_left, max_spots=max_spots)

@bp.route('/verify/<token>')
def verify_email(token):
    s = URLSafeTimedSerializer(current_app.config['SECRET_KEY'])
    try:
        email = s.loads(token, salt='email-confirm-h4tum-ctf-2025', max_age=3600)
    except SignatureExpired:
        return '<h1>Token expired. Please register again.</h1>'
    except BadSignature:
        return '<h1>Invalid token.</h1>'

    user = Participant.query.filter_by(email=email).first_or_404()

    if get_confirmed_count() >= current_app.config['MAX_SPOTS']:
        return '<h1>Sorry! The event filled up while you were verifying.</h1>'

    user.confirmed = True
    db.session.commit()

    discord_link = current_app.config['DISCORD_LINK']
    discord_token = user.discord_token
    msg = "You are confirmed!"
    if user.looking_for_team:
        msg += " Since you need a team, please join the #looking-for-group channel."
    
    return render_template('success.html', message=msg, discord_link=discord_link, discord_token=discord_token)

@bp.route('/dsgvo')
def dsgvo():
    return render_template('dsgvo.html')

@bp.route('/impressum')
def impressum():
    return render_template('impressum.html')

@bp.route('/rules')
def rules():
    return render_template('rules.html')