from flask import Flask
from flask_session import Session
import os

# Initialize Flask-Session
sess = Session()

def create_app(config_name=None):
    """Application factory pattern."""
    app = Flask(__name__)
    
    # Load configuration
    if config_name is None:
        config_name = os.environ.get('FLASK_ENV', 'development')
    
    from config import config
    app.config.from_object(config.get(config_name, config['default']))
    
    # Initialize extensions
    sess.init_app(app)
    
    # Register blueprints
    from app.routes import health, auth, views, webdav_proxy, admin
    app.register_blueprint(health.bp)
    app.register_blueprint(auth.bp)
    app.register_blueprint(views.bp)
    app.register_blueprint(webdav_proxy.bp)
    app.register_blueprint(admin.bp)
    
    return app