from flask import Flask, g, redirect, url_for, render_template
import datetime
import os

def create_app(config_name='development'):
    app = Flask(__name__, 
                static_folder='static',
                template_folder='templates')
    
    # Load configuration
    if config_name == 'production':
        app.config.from_object('config.ProductionConfig')
    elif config_name == 'testing':
        app.config.from_object('config.TestingConfig')
    else:
        app.config.from_object('config.DevelopmentConfig')
    
    # Initialize extensions
    from app.core.extensions import db, migrate, login_manager, bcrypt, limiter, csrf
    db.init_app(app)
    migrate.init_app(app, db)
    login_manager.init_app(app)
    bcrypt.init_app(app)
    csrf.init_app(app)
    limiter.init_app(app)
    
    # Initialize login manager
    from app.core.auth import User
    
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))
    
    login_manager.login_view = 'auth.login'
    login_manager.login_message = 'Please log in to access this page.'
    login_manager.login_message_category = 'info'
    
    # Register template filters
    from app.core.template_filters import bp as filters_bp
    app.register_blueprint(filters_bp)
    
    # Create database tables without seeding any data
    with app.app_context():
        try:
            db.create_all()
            print("Database tables created successfully")
        except Exception as e:
            print(f"Error with database setup: {e}")
    
    # Register blueprints
    from app.routes.auth import bp as auth_bp
    app.register_blueprint(auth_bp)
    
    from app.routes.dashboard import bp as dashboard_bp
    app.register_blueprint(dashboard_bp)
    
    from app.routes.ipam import bp as ipam_bp
    app.register_blueprint(ipam_bp)
    
    from app.routes.api import bp as api_bp
    app.register_blueprint(api_bp)
    
    # Add error handlers
    @app.errorhandler(404)
    def page_not_found(e):
        return render_template('errors/404.html', title='Page Not Found'), 404

    @app.errorhandler(500)
    def internal_server_error(e):
        return render_template('errors/500.html', title='Server Error'), 500

    @app.errorhandler(403)
    def forbidden(e):
        return render_template('errors/403.html', title='Forbidden'), 403
    
    return app