from flask import Blueprint, render_template, request, redirect, url_for, flash, session
from flask_login import login_user, login_required, logout_user, current_user
from werkzeug.security import generate_password_hash, check_password_hash
from sqlalchemy.exc import IntegrityError
from web.db import db, User
from web.helpers import is_safe_url
from core import config

auth_bp = Blueprint('auth', __name__)


@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        user = User.query.filter_by(username=username).first()
        if user and check_password_hash(user.password, password):
            login_user(user)
            next_page = request.args.get('next')
            if not next_page or not is_safe_url(next_page):
                next_page = url_for('project.index')
            return redirect(next_page)
        if user and user.is_admin:
            print(f"⚠️ System: Admin login failed for '{username}'. Password hash mismatch.")
        flash('Invalid credentials')
    return render_template('login.html')


@auth_bp.route('/register', methods=['GET', 'POST'])
def register():
    if request.method == 'POST':
        username = request.form.get('username')
        password = request.form.get('password')
        if User.query.filter_by(username=username).first():
            flash('Username exists')
            return redirect(url_for('auth.register'))

        new_user = User(username=username, password=generate_password_hash(password, method='pbkdf2:sha256'))
        if config.ADMIN_USER and username == config.ADMIN_USER:
            new_user.is_admin = True
        try:
            db.session.add(new_user)
            db.session.commit()
            login_user(new_user)
            return redirect(url_for('project.index'))
        except IntegrityError:
            db.session.rollback()
            flash('Username exists')
            return redirect(url_for('auth.register'))
    return render_template('register.html')


@auth_bp.route('/logout')
def logout():
    logout_user()
    return redirect(url_for('auth.login'))