from flask import Blueprint, render_template, redirect, url_for, flash, request, session, jsonify
from flask_login import login_user, logout_user, login_required, current_user
from flask_babel import gettext as _
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__)

from sqlalchemy import func

@auth_bp.route('/login', methods=['GET', 'POST'])
def login():
    """Handle user login with case-insensitive email lookup and whitespace trimming"""
    if current_user.is_authenticated:
        return redirect(url_for('main.dashboard'))
    
    form = LoginForm()
    if form.validate_on_submit():
        clean_email = (form.email.data or '').strip().lower()
        user = User.query.filter(func.lower(User.email) == clean_email).first()
        
        if user and user.check_password(form.password.data):
            if not user.is_active:
                flash(_('Tu cuenta ha sido desactivada. Por favor contacta al administrador.'), 'error')
                return render_template('auth/login.html', form=form)
            
            login_user(user, remember=form.remember_me.data)
            user.update_last_login()

            # Registrar en bitácora de auditoría
            try:
                from app.services.audit_service import AuditService
                AuditService.log(
                    action='LOGIN',
                    module='auth',
                    user_id=user.id,
                    user_email=user.email,
                    details=f"Inicio de sesión exitoso ({user.role})"
                )
            except Exception:
                pass
            
            # 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
            else:
                session.pop('language', None)
            
            session.pop('login_lang_explicit', None)
            
            next_page = request.args.get('next')
            if not next_page or not next_page.startswith('/'):
                next_page = url_for('main.dashboard')
            
            user_full_name = f'{user.first_name} {user.last_name}'.strip() or user.name
            flash(_('¡Bienvenido de nuevo, %(name)s!', name=user_full_name), 'success')
            return redirect(next_page)
        else:
            try:
                from app.services.audit_service import AuditService
                AuditService.log(
                    action='LOGIN_FAILED',
                    module='auth',
                    details=f"Intento fallido de login con email: {clean_email}"
                )
            except Exception:
                pass
            flash(_('Correo electrónico o contraseña inválidos.'), '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 limpian las cookies de idioma para que el login detecte el navegador o use español
    session.pop('language', None)
    session.pop('login_lang_explicit', None)
    flash(_('Has cerrado sesión correctamente.'), 'info')
    return redirect(url_for('auth.login'))

@auth_bp.route('/profile', methods=['GET', 'POST'])
@login_required
def profile():
    """User profile page with language and theme settings"""
    if request.method == 'POST':
        lang = request.form.get('preferred_language')
        if lang in ['es', 'en']:
            current_user.preferred_language = lang
            session['language'] = lang
        else:
            # Cadena vacía o None restablece la detección automática del navegador
            current_user.preferred_language = None
            session.pop('language', None)
            
        theme = request.form.get('theme_preference')
        if theme in ['auto', 'light', 'dark']:
            current_user.theme_preference = theme
            
        db.session.commit()
        flash(_('Preferencias de usuario actualizadas correctamente.'), 'success')
        return redirect(url_for('auth.profile'))
    return render_template('auth/profile.html')

@auth_bp.route('/api/user/theme', methods=['POST'])
@login_required
def update_theme_api():
    """Update user theme preference via fetch/AJAX from navbar toggle"""
    data = request.get_json(silent=True) or request.form
    theme = data.get('theme') if data else None
    if theme in ['auto', 'light', 'dark']:
        current_user.theme_preference = theme
        db.session.commit()
        return jsonify({'status': 'success', 'theme': theme})
    return jsonify({'status': 'error', 'message': 'Invalid theme'}), 400



@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')