from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from config import config
from app.models import db, Base, User
from flask_migrate import Migrate

# Initialize Flask-Login
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.login_message = 'Please log in to access this page.'
login_manager.login_message_category = 'warning'

from flask import Flask, request, make_response
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from config import config
from app.models import db, Base, User
from flask_migrate import Migrate

# Initialize Flask-Login
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
login_manager.login_message = 'Please log in to access this page.'
login_manager.login_message_category = 'warning'


def create_app(config_name='default'):
    app = Flask(__name__, static_folder='static', static_url_path='/static')
    app.config.from_object(config[config_name])
    
    # Add middleware to simulate 500 errors
    @app.before_request
    def check_for_simulate_500():
        # Check if the X-Simulate-500 header is present
        if request.headers.get('X-Simulate-500'):
            response = make_response({'error': 'Simulated server error'}, 500)
            response.headers['Content-Type'] = 'application/json'
            return response
    
    # Initialize extensions
    db.init_app(app)
    migrate = Migrate(app, db)
    login_manager.init_app(app)
    
    # Register blueprints
    from app.routes import main
    from app.auth import auth
    app.register_blueprint(main)
    app.register_blueprint(auth, url_prefix='/auth')
    
    # User loader for Flask-Login
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))
    
    return app