feat: image variants engine

internal/infrastructure/imaging/variantEncoders.go

@@ -0,0 +1,60 @@
+package imaging
+
+import (
+	domain "RenewCMS/internal/domain/image"
+	"bytes"
+	"image"
+	"image/jpeg"
+	"image/png"
+
+	"github.com/gen2brain/webp"
+)
+
+type encoder interface {
+	contentType() string
+	flattensTransparency() bool
+	encode(output *bytes.Buffer, source image.Image, quality int) error
+}
+
+type jpegEncoder struct{}
+
+func (jpegEncoder) contentType() string { return "image/jpeg" }
+
+func (jpegEncoder) flattensTransparency() bool { return true }
+
+func (jpegEncoder) encode(output *bytes.Buffer, source image.Image, quality int) error {
+	return jpeg.Encode(output, source, &jpeg.Options{Quality: quality})
+}
+
+type pngEncoder struct{}
+
+func (pngEncoder) contentType() string { return "image/png" }
+
+func (pngEncoder) flattensTransparency() bool { return false }
+
+func (pngEncoder) encode(output *bytes.Buffer, source image.Image, _ int) error {
+	return png.Encode(output, source)
+}
+
+type webpEncoder struct{}
+
+func (webpEncoder) contentType() string { return "image/webp" }
+
+func (webpEncoder) flattensTransparency() bool { return false }
+
+func (webpEncoder) encode(output *bytes.Buffer, source image.Image, quality int) error {
+	return webp.Encode(output, source, webp.Options{Quality: quality})
+}
+
+var knownEncoders = map[domain.VariantFormat]encoder{
+	domain.FormatJPEG: jpegEncoder{},
+	domain.FormatPNG:  pngEncoder{},
+	domain.FormatWebP: webpEncoder{},
+}
+
+var sourceFormats = map[string]domain.VariantFormat{
+	"jpeg": domain.FormatJPEG,
+	"png":  domain.FormatPNG,
+	"webp": domain.FormatWebP,
+	"gif":  domain.FormatPNG,
+}