"""
Main application entry point for CAE Mesh Generator
"""
from flask import Flask, request, jsonify
from config import FLASK_CONFIG
import os

def create_app():
    """Create and configure Flask application"""
    app = Flask(__name__, 
                static_folder='frontend/static',
                template_folder='frontend')
    
    # Load configuration
    app.config.update(FLASK_CONFIG)
    
    # Register API blueprint
    from backend.api.routes import api_bp
    app.register_blueprint(api_bp, url_prefix='/api')
    
    # Basic route for serving frontend
    @app.route('/')
    def index():
        from flask import render_template
        return render_template('index.html')
    
    # Favicon route
    @app.route('/favicon.ico')
    def favicon():
        return app.send_static_file('favicon.ico')
    
    # Error handlers
    @app.errorhandler(413)
    def too_large(e):
        return jsonify({
            'success': False,
            'error': 'File too large. Maximum size is 100MB.'
        }), 413
    
    @app.errorhandler(404)
    def not_found(e):
        if request.path.startswith('/api/'):
            return jsonify({
                'success': False,
                'error': 'API endpoint not found'
            }), 404
        # Don't redirect favicon or other static file requests to index.html
        if request.path.startswith('/favicon.ico') or request.path.startswith('/static/'):
            return jsonify({
                'success': False,
                'error': 'File not found'
            }), 404
        # For other routes, serve the SPA
        from flask import render_template
        return render_template('index.html')
    
    @app.errorhandler(500)
    def internal_error(e):
        return jsonify({
            'success': False,
            'error': 'Internal server error'
        }), 500
    
    # Register cleanup on app teardown
    @app.teardown_appcontext
    def cleanup_resources(error):
        """Clean up resources when app context is torn down"""
        try:
            from backend.utils.resource_manager import resource_manager
            resource_manager.cleanup_temp_files()
        except Exception as e:
            app.logger.warning(f"Resource cleanup warning: {e}")
    
    return app

if __name__ == '__main__':
    app = create_app()
    app.run(host='0.0.0.0', port=5000, debug=True)