package util

import (
	"bytes"
	"encoding/base64"
	"image"
	"image/jpeg"
	"image/png"
)

// EncodePNG encodes img as PNG bytes.
func EncodePNG(img image.Image) ([]byte, error) {
	var buf bytes.Buffer
	if err := png.Encode(&buf, img); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}

// EncodeImageToBase64PNG encodes img as a base64-encoded PNG string.
func EncodeImageToBase64PNG(img image.Image) (string, error) {
	data, err := EncodePNG(img)
	if err != nil {
		return "", err
	}
	return base64.StdEncoding.EncodeToString(data), nil
}

// DecodeBase64PNG decodes a base64-encoded PNG string to an image.Image.
func DecodeBase64PNG(b64 string) (image.Image, error) {
	data, err := base64.StdEncoding.DecodeString(b64)
	if err != nil {
		return nil, err
	}
	return png.Decode(bytes.NewReader(data))
}

// EncodeJPEG encodes img as JPEG bytes with quality 90.
func EncodeJPEG(img image.Image) ([]byte, error) {
	var buf bytes.Buffer
	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: 90}); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}