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

cloud/maplefile-backend/internal/service/file/update.go

@@ -0,0 +1,178 @@
+// monorepo/cloud/backend/internal/maplefile/service/file/update.go
+package file
+
+import (
+	"context"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/gocql/gocql"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/config"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/config/constants"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/domain/crypto"
+	dom_collection "codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/domain/collection"
+	uc_filemetadata "codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/usecase/filemetadata"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/httperror"
+)
+
+type UpdateFileRequestDTO struct {
+	ID                gocql.UUID            `json:"id"`
+	EncryptedMetadata string                `json:"encrypted_metadata,omitempty"`
+	EncryptedFileKey  crypto.EncryptedFileKey `json:"encrypted_file_key,omitempty"`
+	EncryptionVersion string                `json:"encryption_version,omitempty"`
+	EncryptedHash     string                `json:"encrypted_hash,omitempty"`
+	Version           uint64                `json:"version,omitempty"`
+}
+
+type UpdateFileService interface {
+	Execute(ctx context.Context, req *UpdateFileRequestDTO) (*FileResponseDTO, error)
+}
+
+type updateFileServiceImpl struct {
+	config                *config.Configuration
+	logger                *zap.Logger
+	collectionRepo        dom_collection.CollectionRepository
+	getMetadataUseCase    uc_filemetadata.GetFileMetadataUseCase
+	updateMetadataUseCase uc_filemetadata.UpdateFileMetadataUseCase
+}
+
+func NewUpdateFileService(
+	config *config.Configuration,
+	logger *zap.Logger,
+	collectionRepo dom_collection.CollectionRepository,
+	getMetadataUseCase uc_filemetadata.GetFileMetadataUseCase,
+	updateMetadataUseCase uc_filemetadata.UpdateFileMetadataUseCase,
+) UpdateFileService {
+	logger = logger.Named("UpdateFileService")
+	return &updateFileServiceImpl{
+		config:                config,
+		logger:                logger,
+		collectionRepo:        collectionRepo,
+		getMetadataUseCase:    getMetadataUseCase,
+		updateMetadataUseCase: updateMetadataUseCase,
+	}
+}
+
+func (svc *updateFileServiceImpl) Execute(ctx context.Context, req *UpdateFileRequestDTO) (*FileResponseDTO, error) {
+	//
+	// STEP 1: Validation
+	//
+	if req == nil {
+		svc.logger.Warn("Failed validation with nil request")
+		return nil, httperror.NewForBadRequestWithSingleField("non_field_error", "File update details are required")
+	}
+
+	if req.ID.String() == "" {
+		svc.logger.Warn("Empty file ID provided")
+		return nil, httperror.NewForBadRequestWithSingleField("id", "File ID is required")
+	}
+
+	//
+	// STEP 2: Get user ID from context
+	//
+	userID, ok := ctx.Value(constants.SessionUserID).(gocql.UUID)
+	if !ok {
+		svc.logger.Error("Failed getting user ID from context")
+		return nil, httperror.NewForInternalServerErrorWithSingleField("message", "Authentication context error")
+	}
+
+	//
+	// STEP 3: Get existing file metadata
+	//
+	file, err := svc.getMetadataUseCase.Execute(req.ID)
+	if err != nil {
+		svc.logger.Error("Failed to get file metadata",
+			zap.Any("error", err),
+			zap.Any("file_id", req.ID))
+		return nil, err
+	}
+
+	//
+	// STEP 4: Check if user has write access to the file's collection
+	//
+	hasAccess, err := svc.collectionRepo.CheckAccess(ctx, file.CollectionID, userID, dom_collection.CollectionPermissionReadWrite)
+	if err != nil {
+		svc.logger.Error("Failed to check collection access",
+			zap.Any("error", err),
+			zap.Any("collection_id", file.CollectionID),
+			zap.Any("user_id", userID))
+		return nil, err
+	}
+
+	if !hasAccess {
+		svc.logger.Warn("Unauthorized file update attempt",
+			zap.Any("user_id", userID),
+			zap.Any("file_id", req.ID),
+			zap.Any("collection_id", file.CollectionID))
+		return nil, httperror.NewForForbiddenWithSingleField("message", "You don't have permission to update this file")
+	}
+
+	//
+	// STEP 5: Check if submitted collection request is in-sync with our backend's collection copy.
+	//
+
+	// Developers note:
+	// What is the purpose of this check?
+	// Our server has multiple clients sharing data and hence our backend needs to ensure that the file being updated is the most recent version.
+	if file.Version != req.Version {
+		svc.logger.Warn("Outdated collection update attempt",
+			zap.Any("user_id", userID),
+			zap.Any("collection_id", req.ID),
+			zap.Any("submitted_version", req.Version),
+			zap.Any("current_version", file.Version))
+		return nil, httperror.NewForBadRequestWithSingleField("message", "Collection has been updated since you last fetched it")
+	}
+
+	//
+	// STEP 6: Update file metadata
+	//
+	updated := false
+
+	if req.EncryptedMetadata != "" {
+		file.EncryptedMetadata = req.EncryptedMetadata
+		updated = true
+	}
+	if req.EncryptedFileKey.Ciphertext != nil && len(req.EncryptedFileKey.Ciphertext) > 0 {
+		file.EncryptedFileKey = req.EncryptedFileKey
+		updated = true
+	}
+	if req.EncryptionVersion != "" {
+		file.EncryptionVersion = req.EncryptionVersion
+		updated = true
+	}
+	if req.EncryptedHash != "" {
+		file.EncryptedHash = req.EncryptedHash
+		updated = true
+	}
+
+	if !updated {
+		svc.logger.Warn("No fields to update provided")
+		return nil, httperror.NewForBadRequestWithSingleField("non_field_error", "At least one field must be provided for update")
+	}
+
+	file.Version++ // Mutation means we increment version.
+	file.ModifiedAt = time.Now()
+	file.ModifiedByUserID = userID
+
+	//
+	// STEP 6: Save updated file
+	//
+	err = svc.updateMetadataUseCase.Execute(ctx, file)
+	if err != nil {
+		svc.logger.Error("Failed to update file metadata",
+			zap.Any("error", err),
+			zap.Any("file_id", file.ID))
+		return nil, err
+	}
+
+	//
+	// STEP 7: Map domain model to response DTO
+	//
+	response := mapFileToDTO(file)
+
+	svc.logger.Debug("File updated successfully",
+		zap.Any("file_id", file.ID))
+
+	return response, nil
+}