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

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

@@ -0,0 +1,52 @@
+// monorepo/cloud/backend/internal/maplefile/usecase/filemetadata/check_exists.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 CheckFileExistsUseCase interface {
+	Execute(id gocql.UUID) (bool, error)
+}
+
+type checkFileExistsUseCaseImpl struct {
+	config *config.Configuration
+	logger *zap.Logger
+	repo   dom_file.FileMetadataRepository
+}
+
+func NewCheckFileExistsUseCase(
+	config *config.Configuration,
+	logger *zap.Logger,
+	repo dom_file.FileMetadataRepository,
+) CheckFileExistsUseCase {
+	logger = logger.Named("CheckFileExistsUseCase")
+	return &checkFileExistsUseCaseImpl{config, logger, repo}
+}
+
+func (uc *checkFileExistsUseCaseImpl) Execute(id gocql.UUID) (bool, 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 existence check",
+			zap.Any("error", e))
+		return false, httperror.NewForBadRequest(&e)
+	}
+
+	//
+	// STEP 2: Check existence in database.
+	//
+
+	return uc.repo.CheckIfExistsByID(id)
+}