Initial commit: Open sourcing all of the Maple Open Technologies code.

cloud/maplefile-backend/internal/usecase/filemetadata/get.go

@@ -0,0 +1,63 @@
+// monorepo/cloud/backend/internal/maplefile/usecase/filemetadata/get.go
+package filemetadata
+
+import (
+	"go.uber.org/zap"
+
+	"github.com/gocql/gocql"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/config"
+	dom_file "codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/domain/file"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/httperror"
+)
+
+type GetFileMetadataUseCase interface {
+	Execute(id gocql.UUID) (*dom_file.File, error)
+}
+
+type getFileMetadataUseCaseImpl struct {
+	config *config.Configuration
+	logger *zap.Logger
+	repo   dom_file.FileMetadataRepository
+}
+
+func NewGetFileMetadataUseCase(
+	config *config.Configuration,
+	logger *zap.Logger,
+	repo dom_file.FileMetadataRepository,
+) GetFileMetadataUseCase {
+	logger = logger.Named("GetFileMetadataUseCase")
+	return &getFileMetadataUseCaseImpl{config, logger, repo}
+}
+
+func (uc *getFileMetadataUseCaseImpl) Execute(id gocql.UUID) (*dom_file.File, error) {
+	//
+	// STEP 1: Validation.
+	//
+
+	e := make(map[string]string)
+	if id.String() == "" {
+		e["id"] = "File ID is required"
+	}
+	if len(e) != 0 {
+		uc.logger.Warn("Failed validating file metadata retrieval",
+			zap.Any("error", e))
+		return nil, httperror.NewForBadRequest(&e)
+	}
+
+	//
+	// STEP 2: Get from database.
+	//
+
+	file, err := uc.repo.Get(id)
+	if err != nil {
+		return nil, err
+	}
+
+	if file == nil {
+		uc.logger.Debug("File metadata not found",
+			zap.Any("id", id))
+		return nil, httperror.NewForNotFoundWithSingleField("message", "File not found")
+	}
+
+	return file, nil
+}