"""
Authentication Blueprint - Login, Logout, Register
"""
from flask import Blueprint, render_template, request, redirect, url_for, flash
from flask_login import login_user, logout_user, login_required, current_user
from app.extensions import db, bcrypt, login_manager
from app.models import User
from app.utils.logger import log_action
from typing import Optional

auth_bp = Blueprint('auth', __name__)


@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    """User login"""
    # Redirect if already logged in
    if current_user.is_authenticated:
        return redirect(url_for('main.dashboard'))
    
    if request.method == 'POST':
        username = request.form.get('username', '').strip()
        password = request.form.get('password', '')
        remember = request.form.get('remember', False)
        
        # Validate input
        if not username or not password:
            flash('Please provide both username and password.', 'danger')
            return render_template('auth/login.html')
        
        # Find user
        user = User.query.filter_by(username=username).first()
        
        # Verify credentials
        if user and bcrypt.check_password_hash(user.password, password):
            login_user(user, remember=remember)
            log_action('info', f'User {username} logged in')
            
            # Redirect to next page or dashboard
            next_page = request.args.get('next')
            if next_page:
                return redirect(next_page)
            return redirect(url_for('main.dashboard'))
        else:
            flash('Invalid username or password.', 'danger')
            log_action('warning', f'Failed login attempt for username: {username}')
    
    # Check for logo
    import os
    login_picture_exists = os.path.exists(
        os.path.join(auth_bp.root_path or '.', 'static/resurse/login_picture.png')
    )
    
    return render_template('auth/login.html', login_picture_exists=login_picture_exists)


@auth_bp.route('/logout')
@login_required
def logout():
    """User logout"""
    username = current_user.username
    logout_user()
    log_action('info', f'User {username} logged out')
    flash('You have been logged out.', 'info')
    return redirect(url_for('auth.login'))


@auth_bp.route('/register', methods=['GET', 'POST'])
def register():
    """User registration"""
    # Redirect if already logged in
    if current_user.is_authenticated:
        return redirect(url_for('main.dashboard'))
    
    if request.method == 'POST':
        username = request.form.get('username', '').strip()
        password = request.form.get('password', '')
        confirm_password = request.form.get('confirm_password', '')
        
        # Validate input
        if not username or not password:
            flash('Username and password are required.', 'danger')
            return render_template('auth/register.html')
        
        if password != confirm_password:
            flash('Passwords do not match.', 'danger')
            return render_template('auth/register.html')
        
        if len(password) < 6:
            flash('Password must be at least 6 characters long.', 'danger')
            return render_template('auth/register.html')
        
        # Check if user already exists
        if User.query.filter_by(username=username).first():
            flash('Username already exists.', 'danger')
            return render_template('auth/register.html')
        
        # Create new user
        hashed_password = bcrypt.generate_password_hash(password).decode('utf-8')
        new_user = User(
            username=username,
            password=hashed_password,
            role='viewer'  # Default role
        )
        
        db.session.add(new_user)
        db.session.commit()
        
        log_user_created(username, 'viewer')
        flash('Registration successful! Please log in.', 'success')
        return redirect(url_for('auth.login'))
    
    return render_template('auth/register.html')


@auth_bp.route('/change-password', methods=['GET', 'POST'])
@login_required
def change_password():
    """Change user password"""
    if request.method == 'POST':
        current_password = request.form.get('current_password', '')
        new_password = request.form.get('new_password', '')
        confirm_password = request.form.get('confirm_password', '')
        
        # Verify current password
        if not bcrypt.check_password_hash(current_user.password, current_password):
            flash('Current password is incorrect.', 'danger')
            return render_template('auth/change_password.html')
        
        # Validate new password
        if new_password != confirm_password:
            flash('New passwords do not match.', 'danger')
            return render_template('auth/change_password.html')
        
        if len(new_password) < 6:
            flash('Password must be at least 6 characters long.', 'danger')
            return render_template('auth/change_password.html')
        
        # Update password
        current_user.password = bcrypt.generate_password_hash(new_password).decode('utf-8')
        db.session.commit()
        
        log_action('info', f'User {current_user.username} changed password')
        flash('Password changed successfully.', 'success')
        return redirect(url_for('main.dashboard'))
    
    return render_template('auth/change_password.html')