from flask import Blueprint, render_template, redirect, url_for, flash, request, session
from flask_login import login_user, logout_user, login_required, current_user
from app import db
from app.models.user import User
from app.forms.auth import LoginForm
from datetime import datetime

auth_bp = Blueprint('auth', __name__)

@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    """Handle user login"""
    if current_user.is_authenticated:
        return redirect(url_for('main.dashboard'))
    
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
        
        if user and user.check_password(form.password.data):
            if not user.is_active:
                flash('Your account has been deactivated. Please contact administrator.', 'error')
                return render_template('auth/login.html', form=form)
            
            login_user(user, remember=form.remember_me.data)
            user.update_last_login()
            
            # Si el usuario tiene idioma configurado en su perfil, sobrescribe el navegador en toda la sesión
            if user.preferred_language and user.preferred_language in ['es', 'en']:
                session['language'] = user.preferred_language
            
            next_page = request.args.get('next')
            if not next_page or not next_page.startswith('/'):
                next_page = url_for('main.dashboard')
            
            flash(f'Welcome back, {user.first_name} {user.last_name}!', 'success')
            return redirect(next_page)
        else:
            flash('Invalid email or password.', 'error')
    
    return render_template('auth/login.html', form=form)

@auth_bp.route('/logout')
@login_required
def logout():
    """Handle user logout"""
    logout_user()
    # Al cerrar sesión, se limpia el idioma para que el login use el del navegador por defecto
    session.pop('language', None)
    flash('You have been logged out successfully.', 'info')
    return redirect(url_for('auth.login'))

@auth_bp.route('/profile', methods=['GET', 'POST'])
@login_required
def profile():
    """User profile page"""
    if request.method == 'POST':
        lang = request.form.get('preferred_language')
        if lang in ['es', 'en']:
            current_user.preferred_language = lang
            session['language'] = lang
            db.session.commit()
            flash('Idioma de preferencia actualizado correctamente.', 'success')
        return redirect(url_for('auth.profile'))
    return render_template('auth/profile.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')
        
        if not current_user.check_password(current_password):
            flash('Current password is incorrect.', 'error')
            return redirect(url_for('auth.change_password'))
        
        if new_password != confirm_password:
            flash('New passwords do not match.', 'error')
            return redirect(url_for('auth.change_password'))
        
        if len(new_password) < 6:
            flash('Password must be at least 6 characters long.', 'error')
            return redirect(url_for('auth.change_password'))
        
        current_user.set_password(new_password)
        db.session.commit()
        
        flash('Password changed successfully!', 'success')
        return redirect(url_for('auth.profile'))
    
    return render_template('auth/change_password.html')