"""
Application factory and initialization.
"""
import os
from flask import Flask
from flask_login import LoginManager
from flask_bcrypt import Bcrypt

from app.config import config
from app.models import db

bcrypt = Bcrypt()
login_manager = LoginManager()


def create_app(config_name='development'):
    """
    Create and configure the Flask application.
    
    Args:
        config_name: Configuration environment (development, production, testing)
        
    Returns:
        Flask application instance
    """
    # Get the parent directory of the app package (project root)
    basedir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
    
    app = Flask(__name__, 
                static_folder=os.path.join(basedir, 'static'),
                template_folder=os.path.join(basedir, 'templates'))
    
    # Load configuration
    app.config.from_object(config[config_name])
    
    # Initialize extensions
    db.init_app(app)
    bcrypt.init_app(app)
    login_manager.init_app(app)
    login_manager.login_view = 'auth.login'
    login_manager.login_message = 'Please log in to access this page.'
    login_manager.login_message_category = 'info'
    
    # Register user loader
    from app.models import User
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))
    
    # Context processor to inject cart count globally
    @app.context_processor
    def inject_cart_count():
        from flask_login import current_user
        from app.models import CartItem
        
        cart_count = 0
        if current_user.is_authenticated:
            cart_count = CartItem.query.filter_by(user_id=current_user.id).count()
        return dict(cart_count=cart_count)
    
    # Register blueprints
    from app.routes import main_bp, auth_bp, admin_bp
    app.register_blueprint(main_bp)
    app.register_blueprint(auth_bp)
    app.register_blueprint(admin_bp)
    
    # Create database tables
    with app.app_context():
        db.create_all()
    
    return app