app/api/controllers.py

"""API controllers for request handling and validation."""

import asyncio
from fastapi import HTTPException

from app.core.logging import logger
from app.services.base import InferenceService
from app.api.models import ImageRequest, PredictionResponse


class PredictionController:
    """Controller for prediction endpoints."""

    @staticmethod
    async def predict(
        request: ImageRequest,
        service: InferenceService
    ) -> PredictionResponse:
        """Run inference using the configured service."""
        try:
            if not service or not service.is_loaded:
                raise HTTPException(503, "Service not available")

            if not request.image.mediaType.startswith('image/'):
                raise HTTPException(400, f"Invalid media type: {request.image.mediaType}")

            return await asyncio.to_thread(service.predict, request)

        except HTTPException:
            raise
        except ValueError as e:
            logger.error(f"Invalid input: {e}")
            raise HTTPException(400, str(e))
        except Exception as e:
            logger.error(f"Prediction failed: {e}")
            raise HTTPException(500, "Internal server error")