app.py

import os
import tempfile
import importlib.util
from flask import Flask

def load_app():
    code = os.getenv("MAIN_CODE")
    if not code:
        raise RuntimeError("No application code found")
    
    # Create temporary file with the Flask app code
    with tempfile.NamedTemporaryFile(suffix=".py", delete=False, mode='w', encoding='utf-8') as f:
        f.write(code)
        tmp_name = f.name
    
    try:
        # Load the module
        spec = importlib.util.spec_from_file_location("flask_app", tmp_name)
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
        
        # Look for Flask app instances
        app = None
        
        # Method 1: Look for a variable named 'app'
        if hasattr(module, 'app') and isinstance(module.app, Flask):
            app = module.app
        # Method 2: Look for a function that returns a Flask app
        elif hasattr(module, 'create_app'):
            app = module.create_app()
        # Method 3: Look for any Flask instance in the module
        else:
            for attr_name in dir(module):
                attr = getattr(module, attr_name)
                if isinstance(attr, Flask):
                    app = attr
                    break
        
        if app is None:
            raise RuntimeError("No Flask application found in the code")
        
        return app
        
    finally:
        # Clean up temporary file
        try:
            os.unlink(tmp_name)
        except:
            pass

if __name__ == "__main__":
    app = load_app()
    # Run the Flask app with common defaults
    port = 7860
    app.run(host='0.0.0.0', port=port, debug=False)