"""
Flask Application Factory

Creates and configures the Flask application with SocketIO support for real-time
updates of the Markov economics simulation.
"""

import os
from flask import Flask
from flask_socketio import SocketIO
from config import config
from app.models import SimulationManager

# Initialize SocketIO with enhanced proxy support
socketio = SocketIO(
    cors_allowed_origins="*",
    async_mode='threading',
    logger=True,
    engineio_logger=True
)

# Global simulation manager instance
simulation_manager = SimulationManager()


def create_app(config_name=None):
    """
    Create and configure the Flask application.
    
    Args:
        config_name: Configuration profile to use
        
    Returns:
        Configured Flask application instance
    """
    if config_name is None:
        config_name = os.getenv('FLASK_CONFIG', os.getenv('FLASK_ENV', 'development'))
        
    app = Flask(__name__)
    app.config.from_object(config[config_name])
    
    # Initialize extensions with proxy-friendly settings
    socketio.init_app(
        app, 
        async_mode='threading',
        cors_allowed_origins="*",
        allow_upgrades=True,
        transports=['websocket', 'polling']
    )
    
    # Register blueprints
    from .routes.main import main_bp
    from .routes.api import api_bp
    
    app.register_blueprint(main_bp)
    app.register_blueprint(api_bp, url_prefix='/api')
    
    return app