from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Any

from PIL import Image

from ..image_io import DownloadedImage


class UpscaleEngineUnavailable(RuntimeError):
    pass


@dataclass(frozen=True)
class UpscaleResult:
    image: Image.Image
    metadata: dict[str, Any]


@dataclass(frozen=True)
class EngineHealth:
    status: str
    engine: str
    device: str
    models_loaded: bool
    details: dict[str, Any] = field(default_factory=dict)


class UpscaleEngine(ABC):
    @abstractmethod
    def health(self) -> EngineHealth:
        raise NotImplementedError

    def available(self) -> bool:
        health = self.health()

        return health.status == "ok" and health.models_loaded

    @abstractmethod
    def upscale(self, downloaded: DownloadedImage, scale: int, mode: str, output_format: str) -> UpscaleResult:
        raise NotImplementedError