import json
import function_a
import function_b


def lambda_handler(event, context):
    """
    AWS Lambda handler that routes to function_a or function_b
    
    Expected event structure:
    {
        "function_name": "function_a" or "function_b",
        "text_parameter": "your string here"
    }
    """
    try:
        # DEBUG: Log the entire event
        print(f"Received event: {json.dumps(event)}")
        
        # Handle different event sources
        body = None
        
        # Check if body exists and is a string (API Gateway)
        if 'body' in event:
            if event['body'] is None:
                return {
                    'statusCode': 400,
                    'body': json.dumps({'error': 'Request body is empty'})
                }
            
            if isinstance(event['body'], str):
                # Try to parse JSON
                try:
                    body = json.loads(event['body'])
                except json.JSONDecodeError as e:
                    return {
                        'statusCode': 400,
                        'body': json.dumps({
                            'error': 'Invalid JSON in request body',
                            'details': str(e),
                            'received': event['body'][:100]  # First 100 chars
                        })
                    }
            else:
                body = event['body']
        else:
            # Direct invocation (no body wrapper)
            body = event
        
        print(f"Parsed body: {json.dumps(body)}")
        
        # Get parameters
        function_name = body.get('function_name')
        text_parameter = body.get('text_parameter')
        
        # Validate inputs
        if not function_name:
            return {
                'statusCode': 400,
                'body': json.dumps({'error': 'function_name is required'})
            }
        
        if not text_parameter:
            return {
                'statusCode': 400,
                'body': json.dumps({'error': 'text_parameter is required'})
            }
        
        # Route to the appropriate function
        if function_name == 'function_a':
            result = function_a.execute(text_parameter)
        elif function_name == 'function_b':
            result = function_b.execute(text_parameter)
        else:
            return {
                'statusCode': 400,
                'body': json.dumps({'error': f'Unknown function: {function_name}. Use "function_a" or "function_b"'})
            }
        
        # Return success response
        return {
            'statusCode': 200,
            'body': json.dumps({
                'message': 'Success',
                'result': result
            })
        }
        
    except Exception as e:
        print(f"Error: {str(e)}")
        import traceback
        print(traceback.format_exc())
        return {
            'statusCode': 500,
            'body': json.dumps({
                'error': str(e),
                'type': type(e).__name__
            })
        }


# For local testing
if __name__ == "__main__":
    # Test event
    test_event = {
        'function_name': 'function_a',
        'text_parameter': 'Hello from Lambda!'
    }
    
    result = lambda_handler(test_event, None)
    print(json.dumps(result, indent=2))