feat(API): media library

internal/infrastructure/useCases/CreateImage.go

@@ -2,8 +2,26 @@ package useCases
 
 import (
 	"RenewCMS/internal/domain/image"
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/xml"
+	stdimage "image"
+	"io"
+
+	_ "golang.org/x/image/webp"
+	_ "image/jpeg"
+	_ "image/png"
 )
 
+const svgRootElement = "svg"
+
+var rasterFormats = map[string]string{
+	"image/png":  "png",
+	"image/jpeg": "jpeg",
+	"image/webp": "webp",
+}
+
 type CreateImageUseCase struct {
 	imageRepository image.Repository
 }
@@ -16,8 +34,68 @@ func (g *CreateImageUseCase) CreateImage(input image.ImageInput) (image.Image, e
 	if !image.IsAllowedContentType(input.ContentType) {
 		return image.Image{}, image.ErrImageTypeNotAllowed
 	}
-	if input.Size > image.MaxImageSize {
-		return image.Image{}, image.ErrImageTooLarge
+
+	data, err := readWithinLimit(input.Content)
+	if err != nil {
+		return image.Image{}, err
+	}
+
+	width, height, err := measure(data, input.ContentType)
+	if err != nil {
+		return image.Image{}, err
+	}
+
+	checksum := sha256.Sum256(data)
+	return g.imageRepository.Create(image.ImageInput{
+		Content:      bytes.NewReader(data),
+		Filename:     image.NormalizeUploadFilename(input.Filename, input.ContentType),
+		Size:         int64(len(data)),
+		ContentType:  input.ContentType,
+		Width:        width,
+		Height:       height,
+		SHA256:       hex.EncodeToString(checksum[:]),
+		UploadedByID: input.UploadedByID,
+	})
+}
+
+func readWithinLimit(content io.Reader) ([]byte, error) {
+	if content == nil {
+		return nil, image.ErrImageUnreadable
+	}
+	data, err := io.ReadAll(io.LimitReader(content, image.MaxImageSize+1))
+	if err != nil {
+		return nil, err
+	}
+	if int64(len(data)) > image.MaxImageSize {
+		return nil, image.ErrImageTooLarge
+	}
+	return data, nil
+}
+
+func measure(data []byte, contentType string) (int, int, error) {
+	if contentType == "image/svg+xml" {
+		if !hasSvgRoot(data) {
+			return 0, 0, image.ErrImageUnreadable
+		}
+		return 0, 0, nil
+	}
+
+	config, format, err := stdimage.DecodeConfig(bytes.NewReader(data))
+	if err != nil || format != rasterFormats[contentType] {
+		return 0, 0, image.ErrImageUnreadable
+	}
+	return config.Width, config.Height, nil
+}
+
+func hasSvgRoot(data []byte) bool {
+	decoder := xml.NewDecoder(bytes.NewReader(data))
+	for {
+		token, err := decoder.Token()
+		if err != nil {
+			return false
+		}
+		if start, ok := token.(xml.StartElement); ok {
+			return start.Name.Local == svgRootElement
+		}
 	}
-	return g.imageRepository.Create(input)
 }