internal

var EncodeImage ImageEncoder = png.Encode

var GetImageOfTheDay ImageOfTheDayGetter = func(apiKey, date string) (string, error) {
	url := fmt.Sprintf("https://api.nasa.gov/planetary/apod?api_key=%s&thumbs=true&date=%s", apiKey, date)
	res, err := HttpGet(url)
	if err != nil {
		return "", fmt.Errorf("failed to query image of the day (%s): %w", url, err)
	}

	if res.StatusCode != http.StatusOK {
		return "", fmt.Errorf("failed to request image of the day: %s: %w", http.StatusText(res.StatusCode), err)
	}

	body, err := io.ReadAll(res.Body)
	if err != nil {
		return "", fmt.Errorf("failed to read image of the day response: %w", err)
	}

	var response APODResponse
	err = json.Unmarshal(body, &response)
	if err != nil {
		return "", fmt.Errorf("failed to decode image of the day response: %w", err)
	}

	if response.Type == "image" {
		return response.URL, nil
	} else if response.Type == "video" {
		return response.Thumbnail, nil
	}

	return "", fmt.Errorf("unexpected image type %s", response.Type)
}

var ProcessImage ImageProcessor = func(url string, width, height int) (image.Image, error) {
	imageConfig := &imageConf.Config{
		Source: url,
		Scale:  imageConf.ScaleCover,
	}
	return imageConfig.GenerateImage(width, height)
}

var WriteImage ImageWriter = func(file string, i image.Image) error {
	f, err := os.Create(file)
	if err != nil {
		return err
	}
	err = EncodeImage(f, i)
	if err != nil {
		return err
	}
	return f.Close()
}