refac: decouple persistence and image storage behind driver registries

internal/infrastructure/useCases/BackfillImageMetadata.go

@@ -0,0 +1,90 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/image"
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	stdimage "image"
+	"io"
+	"path"
+
+	_ "golang.org/x/image/webp"
+	_ "image/jpeg"
+	_ "image/png"
+)
+
+var extensionContentTypes = map[string]string{
+	".png":  "image/png",
+	".jpg":  "image/jpeg",
+	".jpeg": "image/jpeg",
+	".webp": "image/webp",
+	".svg":  "image/svg+xml",
+}
+
+type BackfillImageMetadataUseCase struct {
+	imageRepository image.Repository
+	storage         image.Storage
+}
+
+func NewBackfillImageMetadataUseCase(imageRepository image.Repository, storage image.Storage) *BackfillImageMetadataUseCase {
+	return &BackfillImageMetadataUseCase{imageRepository, storage}
+}
+
+func (u *BackfillImageMetadataUseCase) Run() error {
+	pending, err := u.imageRepository.ListMissingMetadata()
+	if err != nil {
+		return err
+	}
+	for _, row := range pending {
+		metadata, ok := u.readStoredImage(row.Path)
+		if !ok {
+			continue
+		}
+		if err := u.imageRepository.UpdateMetadata(row.ID, metadata); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (u *BackfillImageMetadataUseCase) readStoredImage(storedPath string) (image.Metadata, bool) {
+	fileName := image.StoredName(storedPath)
+	contentType, known := extensionContentTypes[path.Ext(fileName)]
+	if !known {
+		return image.Metadata{}, false
+	}
+
+	data, err := u.read(fileName)
+	if err != nil {
+		return image.Metadata{}, false
+	}
+
+	width, height := 0, 0
+	if contentType != "image/svg+xml" {
+		config, _, err := stdimage.DecodeConfig(bytes.NewReader(data))
+		if err != nil {
+			return image.Metadata{}, false
+		}
+		width, height = config.Width, config.Height
+	}
+
+	checksum := sha256.Sum256(data)
+	return image.Metadata{
+		Filename:    fileName,
+		Size:        int64(len(data)),
+		ContentType: contentType,
+		Width:       width,
+		Height:      height,
+		SHA256:      hex.EncodeToString(checksum[:]),
+	}, true
+}
+
+func (u *BackfillImageMetadataUseCase) read(storedName string) ([]byte, error) {
+	blob, err := u.storage.Open(storedName)
+	if err != nil {
+		return nil, err
+	}
+	defer blob.Content.Close()
+	return io.ReadAll(blob.Content)
+}