add revision number

internal/contract/letter_outgoing_contract.go

@@ -107,6 +107,7 @@ type OutgoingLetterResponse struct {
 	IssueDate             time.Time                          `json:"issue_date"`
 	Status                string                             `json:"status"`
 	ApprovalFlowID        *uuid.UUID                         `json:"approval_flow_id,omitempty"`
+	RevisionNumber        int                                `json:"revision_number"`
 	CreatedBy             uuid.UUID                          `json:"created_by"`
 	CreatedAt             time.Time                          `json:"created_at"`
 	UpdatedAt             time.Time                          `json:"updated_at"`
@@ -157,6 +158,12 @@ type RejectLetterRequest struct {
 	Reason string `json:"reason" validate:"required"`
 }
 
+type ReviseLetterRequest struct {
+	FileURL  string `json:"file_url" validate:"required"`
+	FileName string `json:"file_name" validate:"required"`
+	FileType string `json:"file_type" validate:"required"`
+}
+
 type AddRecipientsRequest struct {
 	Recipients []CreateOutgoingLetterRecipient `json:"recipients" validate:"required,dive"`
 }

internal/entities/approval_flow.go

@@ -52,6 +52,7 @@ type LetterOutgoingApproval struct {
 	ID             uuid.UUID      `gorm:"type:uuid;primary_key;default:gen_random_uuid()" json:"id"`
 	LetterID       uuid.UUID      `gorm:"type:uuid;not null" json:"letter_id"`
 	StepID         uuid.UUID      `gorm:"type:uuid;not null" json:"step_id"`
+	RevisionNumber int            `gorm:"not null;default:0" json:"revision_number"`
 	StepOrder      int            `gorm:"not null" json:"step_order"`
 	ParallelGroup  int            `gorm:"default:1" json:"parallel_group"`
 	IsRequired     bool           `gorm:"default:true" json:"is_required"`

internal/entities/letter_outgoing.go

@@ -28,6 +28,7 @@ type LetterOutgoing struct {
 	IssueDate             time.Time            `json:"issue_date"`
 	Status                LetterOutgoingStatus `gorm:"not null;default:'draft'" json:"status"`
 	ApprovalFlowID        *uuid.UUID           `json:"approval_flow_id,omitempty"`
+	RevisionNumber        int                  `gorm:"not null;default:0" json:"revision_number"`
 	CreatedBy             uuid.UUID            `gorm:"not null" json:"created_by"`
 	IsArchived            bool                 `gorm:"not null;default:false" json:"is_archived"`
 	ArchivedAt            *time.Time           `json:"archived_at,omitempty"`
@@ -69,6 +70,7 @@ func (LetterOutgoingRecipient) TableName() string { return "letter_outgoing_reci
 type LetterOutgoingAttachment struct {
 	ID             uuid.UUID  `gorm:"type:uuid;primary_key;default:gen_random_uuid()" json:"id"`
 	LetterID       uuid.UUID  `gorm:"type:uuid;not null" json:"letter_id"`
+	RevisionNumber int        `gorm:"not null;default:0" json:"revision_number"`
 	FileURL        string     `gorm:"not null" json:"file_url"`
 	FileName       string     `gorm:"not null" json:"file_name"`
 	FileType       string     `gorm:"not null" json:"file_type"`

internal/entities/letter_outgoing_activity_log.go

@@ -36,6 +36,7 @@ const (
 	LetterOutgoingActionSubmittedApproval = "submitted_for_approval"
 	LetterOutgoingActionApproved         = "approved"
 	LetterOutgoingActionRejected         = "rejected"
+	LetterOutgoingActionRevised          = "revised"
 	LetterOutgoingActionSent             = "sent"
 	LetterOutgoingActionArchived         = "archived"
 	LetterOutgoingActionAttachmentAdded  = "attachment_added"

internal/handler/letter_outgoing_handler.go

@@ -23,6 +23,7 @@ type LetterOutgoingService interface {
 	SubmitForApproval(ctx context.Context, letterID uuid.UUID) error
 	ApproveOutgoingLetter(ctx context.Context, letterID uuid.UUID, req *contract.ApproveLetterRequest) error
 	RejectOutgoingLetter(ctx context.Context, letterID uuid.UUID, req *contract.RejectLetterRequest) error
+	ReviseOutgoingLetter(ctx context.Context, letterID uuid.UUID, req *contract.ReviseLetterRequest) error
 	SendOutgoingLetter(ctx context.Context, letterID uuid.UUID) error
 	ArchiveOutgoingLetter(ctx context.Context, letterID uuid.UUID) error
 
@@ -217,6 +218,27 @@ func (h *LetterOutgoingHandler) RejectOutgoingLetter(c *gin.Context) {
 	c.JSON(http.StatusOK, contract.BuildSuccessResponse(&contract.SuccessResponse{Message: "rejected"}))
 }
 
+func (h *LetterOutgoingHandler) ReviseOutgoingLetter(c *gin.Context) {
+	id, err := uuid.Parse(c.Param("id"))
+	if err != nil {
+		c.JSON(http.StatusBadRequest, &contract.ErrorResponse{Error: "invalid id", Code: http.StatusBadRequest})
+		return
+	}
+
+	var req contract.ReviseLetterRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, &contract.ErrorResponse{Error: "invalid body", Code: http.StatusBadRequest})
+		return
+	}
+
+	if err := h.svc.ReviseOutgoingLetter(c.Request.Context(), id, &req); err != nil {
+		c.JSON(http.StatusInternalServerError, &contract.ErrorResponse{Error: err.Error(), Code: http.StatusInternalServerError})
+		return
+	}
+
+	c.JSON(http.StatusOK, contract.BuildSuccessResponse(&contract.SuccessResponse{Message: "revised"}))
+}
+
 func (h *LetterOutgoingHandler) SendOutgoingLetter(c *gin.Context) {
 	id, err := uuid.Parse(c.Param("id"))
 	if err != nil {

internal/processor/letter_outgoing_processor.go

@@ -24,8 +24,9 @@ type LetterOutgoingProcessor interface {
 	ArchiveOutgoingLetter(ctx context.Context, letterID uuid.UUID, userID uuid.UUID) error
 
 	ProcessApprovalSubmission(ctx context.Context, letterID uuid.UUID, approvalFlowID uuid.UUID, userID uuid.UUID) error
-	ProcessApproval(ctx context.Context, letterID uuid.UUID, approval *entities.LetterOutgoingApproval, userID uuid.UUID, allApproved bool) error
+	ProcessApproval(ctx context.Context, letterID uuid.UUID, approval *entities.LetterOutgoingApproval, userID uuid.UUID) error
 	ProcessRejection(ctx context.Context, letterID uuid.UUID, approval *entities.LetterOutgoingApproval, userID uuid.UUID) error
+	ProcessRevision(ctx context.Context, letterID uuid.UUID, attachment entities.LetterOutgoingAttachment, userID uuid.UUID) error
 
 	AddRecipients(ctx context.Context, letterID uuid.UUID, recipients []entities.LetterOutgoingRecipient, userID uuid.UUID) error
 	UpdateRecipient(ctx context.Context, recipient *entities.LetterOutgoingRecipient) error
@@ -40,6 +41,7 @@ type LetterOutgoingProcessor interface {
 	DeleteDiscussion(ctx context.Context, id uuid.UUID) error
 
 	GetApprovalsByLetter(ctx context.Context, letterID uuid.UUID) ([]entities.LetterOutgoingApproval, error)
+	GetApprovalsByLetterAndRevision(ctx context.Context, letterID uuid.UUID, revisionNumber int) ([]entities.LetterOutgoingApproval, error)
 	GetApprovalFlow(ctx context.Context, flowID uuid.UUID) (*entities.ApprovalFlow, error)
 
 	// GetOutgoingLetterWithDetails fetches letter with all related data
@@ -397,6 +399,12 @@ func (p *LetterOutgoingProcessorImpl) ProcessApprovalSubmission(ctx context.Cont
 	}
 
 	return p.txManager.WithTransaction(ctx, func(txCtx context.Context) error {
+		// Get the letter to get the current revision number
+		letter, err := p.letterRepo.Get(txCtx, letterID)
+		if err != nil {
+			return err
+		}
+		
 		// Find the minimum step order (first step)
 		minStepOrder := flow.Steps[0].StepOrder
 		for _, step := range flow.Steps {
@@ -410,6 +418,7 @@ func (p *LetterOutgoingProcessorImpl) ProcessApprovalSubmission(ctx context.Cont
 			approvals[i] = entities.LetterOutgoingApproval{
 				LetterID:       letterID,
 				StepID:         step.ID,
+				RevisionNumber: letter.RevisionNumber,
 				StepOrder:      step.StepOrder,
 				ParallelGroup:  step.ParallelGroup,
 				IsRequired:     step.Required,
@@ -483,15 +492,15 @@ func (p *LetterOutgoingProcessorImpl) ProcessApprovalSubmission(ctx context.Cont
 	})
 }
 
-func (p *LetterOutgoingProcessorImpl) ProcessApproval(ctx context.Context, letterID uuid.UUID, approval *entities.LetterOutgoingApproval, userID uuid.UUID, allApproved bool) error {
+func (p *LetterOutgoingProcessorImpl) ProcessApproval(ctx context.Context, letterID uuid.UUID, approval *entities.LetterOutgoingApproval, userID uuid.UUID) error {
 	return p.txManager.WithTransaction(ctx, func(txCtx context.Context) error {
 		// Step 1: Update the approval record
 		if err := p.updateApprovalRecord(txCtx, approval, userID); err != nil {
 			return err
 		}
 
-		// Step 2: Get all approvals and organize by step
-		approvalsByStep, err := p.getApprovalsByStep(txCtx, letterID)
+		// Step 2: Get all approvals FOR THE SAME REVISION and organize by step
+		approvalsByStep, err := p.getApprovalsByStepForRevision(txCtx, letterID, approval.RevisionNumber)
 		if err != nil {
 			return err
 		}
@@ -499,12 +508,12 @@ func (p *LetterOutgoingProcessorImpl) ProcessApproval(ctx context.Context, lette
 		// Step 3: Check if current step is completed
 		if p.isStepCompleted(approvalsByStep[approval.StepOrder]) {
 			// Step 4: Activate next step if exists
-			if err := p.activateNextStep(txCtx, letterID, approval.StepOrder, approvalsByStep); err != nil {
+			if err := p.activateNextStepForRevision(txCtx, letterID, approval.StepOrder, approval.RevisionNumber, approvalsByStep); err != nil {
 				return err
 			}
 		}
 
-		// Step 5: Check if all required approvals are completed
+		// Step 5: Check if all required approvals are completed FOR THIS REVISION
 		if p.areAllRequiredApprovalsCompleted(approvalsByStep) {
 			// Step 6: Update letter status to approved
 			if err := p.letterRepo.UpdateStatus(txCtx, letterID, entities.LetterOutgoingStatusApproved); err != nil {
@@ -542,6 +551,24 @@ func (p *LetterOutgoingProcessorImpl) getApprovalsByStep(ctx context.Context, le
 	return approvalsByStep, nil
 }
 
+// getApprovalsByStepForRevision fetches approvals for a specific revision and organizes them by step order
+func (p *LetterOutgoingProcessorImpl) getApprovalsByStepForRevision(ctx context.Context, letterID uuid.UUID, revisionNumber int) (map[int][]entities.LetterOutgoingApproval, error) {
+	allApprovals, err := p.approvalRepo.ListByLetter(ctx, letterID)
+	if err != nil {
+		return nil, err
+	}
+
+	approvalsByStep := make(map[int][]entities.LetterOutgoingApproval)
+	for _, approval := range allApprovals {
+		// Only include approvals from the same revision
+		if approval.RevisionNumber == revisionNumber {
+			approvalsByStep[approval.StepOrder] = append(approvalsByStep[approval.StepOrder], approval)
+		}
+	}
+
+	return approvalsByStep, nil
+}
+
 // isStepCompleted checks if all required approvals in a step are approved
 func (p *LetterOutgoingProcessorImpl) isStepCompleted(stepApprovals []entities.LetterOutgoingApproval) bool {
 	for _, approval := range stepApprovals {
@@ -582,6 +609,39 @@ func (p *LetterOutgoingProcessorImpl) activateNextStep(ctx context.Context, lett
 	return nil
 }
 
+// activateNextStepForRevision activates the next approval step for a specific revision
+func (p *LetterOutgoingProcessorImpl) activateNextStepForRevision(ctx context.Context, letterID uuid.UUID, currentStepOrder int, revisionNumber int, approvalsByStep map[int][]entities.LetterOutgoingApproval) error {
+	nextStepOrder := currentStepOrder + 1
+	nextStepApprovals, exists := approvalsByStep[nextStepOrder]
+	if !exists {
+		return nil // No next step
+	}
+
+	// Get existing recipients to avoid duplicates
+	existingUserIDs, err := p.getExistingRecipientUserIDs(ctx, letterID)
+	if err != nil {
+		return err
+	}
+
+	// Process each approval in the next step (already filtered by revision in approvalsByStep)
+	for _, nextApproval := range nextStepApprovals {
+		// Only process if it's the same revision
+		if nextApproval.RevisionNumber == revisionNumber {
+			// Activate approval if not started
+			if err := p.activateApprovalIfNotStarted(ctx, &nextApproval); err != nil {
+				return err
+			}
+
+			// Add approver as recipient if not already exists
+			if err := p.addApproverAsRecipientIfNeeded(ctx, letterID, nextApproval.ApproverID, existingUserIDs); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 // getExistingRecipientUserIDs gets a set of existing recipient user IDs
 func (p *LetterOutgoingProcessorImpl) getExistingRecipientUserIDs(ctx context.Context, letterID uuid.UUID) (map[uuid.UUID]bool, error) {
 	currentRecipients, err := p.recipientRepo.ListByLetter(ctx, letterID)
@@ -665,12 +725,39 @@ func (p *LetterOutgoingProcessorImpl) ProcessRejection(ctx context.Context, lett
 			return err
 		}
 
+		// Mark all other pending approvals in the same revision as rejected
+		allApprovals, err := p.approvalRepo.ListByLetter(txCtx, letterID)
+		if err != nil {
+			return err
+		}
+
+		for i := range allApprovals {
+			// Only update other pending approvals from the same revision
+			if allApprovals[i].RevisionNumber == approval.RevisionNumber && 
+			   allApprovals[i].ID != approval.ID && 
+			   allApprovals[i].Status == entities.ApprovalStatusPending {
+				allApprovals[i].Status = entities.ApprovalStatusRejected
+				if err := p.approvalRepo.Update(txCtx, &allApprovals[i]); err != nil {
+					return err
+				}
+			}
+		}
+
 		if err := p.letterRepo.UpdateStatus(txCtx, letterID, entities.LetterOutgoingStatusRejected); err != nil {
 			return err
 		}
 
 		fromStatus := string(entities.LetterOutgoingStatusPendingApproval)
 		toStatus := string(entities.LetterOutgoingStatusRejected)
+
+		// Include rejection remarks in activity log context
+		var context entities.JSONB
+		if approval.Remarks != nil && *approval.Remarks != "" {
+			context = entities.JSONB{"remarks": *approval.Remarks, "revision_number": approval.RevisionNumber}
+		} else {
+			context = entities.JSONB{"revision_number": approval.RevisionNumber}
+		}
+
 		activityLog := &entities.LetterOutgoingActivityLog{
 			LetterID:    letterID,
 			ActionType:  entities.LetterOutgoingActionRejected,
@@ -678,6 +765,79 @@ func (p *LetterOutgoingProcessorImpl) ProcessRejection(ctx context.Context, lett
 			TargetID:    &approval.ID,
 			FromStatus:  &fromStatus,
 			ToStatus:    &toStatus,
+			Context:     context,
+		}
+		if err := p.activityLogRepo.Create(txCtx, activityLog); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
+func (p *LetterOutgoingProcessorImpl) ProcessRevision(ctx context.Context, letterID uuid.UUID, attachment entities.LetterOutgoingAttachment, userID uuid.UUID) error {
+	return p.txManager.WithTransaction(ctx, func(txCtx context.Context) error {
+		// Get the current letter
+		letter, err := p.letterRepo.Get(txCtx, letterID)
+		if err != nil {
+			return err
+		}
+
+		// Increment revision number
+		letter.RevisionNumber++
+		
+		// Set revision number on the new attachment
+		attachment.RevisionNumber = letter.RevisionNumber
+		
+		// Add the new attachment
+		if err := p.attachmentRepo.Create(txCtx, &attachment); err != nil {
+			return err
+		}
+
+		// Update letter with new revision number
+		if err := p.letterRepo.Update(txCtx, letter); err != nil {
+			return err
+		}
+
+		// Update status to pending approval (ready for re-submission)
+		if err := p.letterRepo.UpdateStatus(txCtx, letterID, entities.LetterOutgoingStatusPendingApproval); err != nil {
+			return err
+		}
+
+		// Get existing approvals for the current revision
+		approvals, err := p.approvalRepo.ListByLetter(txCtx, letterID)
+		if err != nil {
+			return err
+		}
+
+		// Create new approval records for the new revision
+		for _, approval := range approvals {
+			// Create a new approval for the new revision
+			newApproval := entities.LetterOutgoingApproval{
+				LetterID:       approval.LetterID,
+				StepID:         approval.StepID,
+				RevisionNumber: letter.RevisionNumber,
+				StepOrder:      approval.StepOrder,
+				ParallelGroup:  approval.ParallelGroup,
+				IsRequired:     approval.IsRequired,
+				Status:         entities.ApprovalStatusPending,
+			}
+			if err := p.approvalRepo.Create(txCtx, &newApproval); err != nil {
+				return err
+			}
+		}
+
+		// Log activity
+		fromStatus := string(entities.LetterOutgoingStatusRejected)
+		toStatus := string(entities.LetterOutgoingStatusPendingApproval)
+		activityLog := &entities.LetterOutgoingActivityLog{
+			LetterID:    letterID,
+			ActionType:  entities.LetterOutgoingActionRevised,
+			ActorUserID: &userID,
+			TargetID:    &attachment.ID,
+			FromStatus:  &fromStatus,
+			ToStatus:    &toStatus,
+			Context:     entities.JSONB{"attachment": attachment.FileName, "revision_number": letter.RevisionNumber},
 		}
 		if err := p.activityLogRepo.Create(txCtx, activityLog); err != nil {
 			return err
@@ -732,6 +892,17 @@ func (p *LetterOutgoingProcessorImpl) RemoveRecipient(ctx context.Context, lette
 
 func (p *LetterOutgoingProcessorImpl) AddAttachments(ctx context.Context, letterID uuid.UUID, attachments []entities.LetterOutgoingAttachment, userID uuid.UUID) error {
 	return p.txManager.WithTransaction(ctx, func(txCtx context.Context) error {
+		// Get the letter to get the current revision number
+		letter, err := p.letterRepo.Get(txCtx, letterID)
+		if err != nil {
+			return err
+		}
+		
+		// Set revision number on all attachments
+		for i := range attachments {
+			attachments[i].RevisionNumber = letter.RevisionNumber
+		}
+		
 		if err := p.attachmentRepo.CreateBulk(txCtx, attachments); err != nil {
 			return err
 		}
@@ -808,7 +979,31 @@ func (p *LetterOutgoingProcessorImpl) DeleteDiscussion(ctx context.Context, id u
 }
 
 func (p *LetterOutgoingProcessorImpl) GetApprovalsByLetter(ctx context.Context, letterID uuid.UUID) ([]entities.LetterOutgoingApproval, error) {
-	return p.approvalRepo.ListByLetter(ctx, letterID)
+	// Get the letter first to know the current revision
+	letter, err := p.letterRepo.Get(ctx, letterID)
+	if err != nil {
+		return nil, err
+	}
+	
+	return p.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
+}
+
+func (p *LetterOutgoingProcessorImpl) GetApprovalsByLetterAndRevision(ctx context.Context, letterID uuid.UUID, revisionNumber int) ([]entities.LetterOutgoingApproval, error) {
+	// Get all approvals for this letter
+	approvals, err := p.approvalRepo.ListByLetter(ctx, letterID)
+	if err != nil {
+		return nil, err
+	}
+	
+	// Filter to only return approvals for the specified revision
+	var currentRevisionApprovals []entities.LetterOutgoingApproval
+	for _, approval := range approvals {
+		if approval.RevisionNumber == revisionNumber {
+			currentRevisionApprovals = append(currentRevisionApprovals, approval)
+		}
+	}
+	
+	return currentRevisionApprovals, nil
 }
 
 func (p *LetterOutgoingProcessorImpl) GetApprovalFlow(ctx context.Context, flowID uuid.UUID) (*entities.ApprovalFlow, error) {

internal/router/health_handler.go

@@ -106,6 +106,7 @@ type LetterOutgoingHandler interface {
 	SubmitForApproval(c *gin.Context)
 	ApproveOutgoingLetter(c *gin.Context)
 	RejectOutgoingLetter(c *gin.Context)
+	ReviseOutgoingLetter(c *gin.Context)
 	SendOutgoingLetter(c *gin.Context)
 	ArchiveOutgoingLetter(c *gin.Context)
 	GetLetterApprovalInfo(c *gin.Context)

internal/router/router.go

@@ -193,6 +193,7 @@ func (r *Router) addAppRoutes(rg *gin.Engine) {
 			lettersch.POST("/outgoing/:id/submit", r.letterOutgoingHandler.SubmitForApproval)
 			lettersch.POST("/outgoing/:id/approve", r.letterOutgoingHandler.ApproveOutgoingLetter)
 			lettersch.POST("/outgoing/:id/reject", r.letterOutgoingHandler.RejectOutgoingLetter)
+			lettersch.POST("/outgoing/:id/revise", r.letterOutgoingHandler.ReviseOutgoingLetter)
 			lettersch.POST("/outgoing/:id/send", r.letterOutgoingHandler.SendOutgoingLetter)
 			lettersch.POST("/outgoing/:id/archive", r.letterOutgoingHandler.ArchiveOutgoingLetter)
 			lettersch.POST("/outgoing/archive", r.letterOutgoingHandler.BulkArchiveOutgoingLetters)

internal/service/letter_outgoing_service.go

@@ -628,7 +628,8 @@ func (s *LetterOutgoingServiceImpl) ApproveOutgoingLetter(ctx context.Context, l
 		return gorm.ErrInvalidData
 	}
 
-	approvals, err := s.processor.GetApprovalsByLetter(ctx, letterID)
+	// Get approvals for the current revision only
+	approvals, err := s.processor.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
 	if err != nil {
 		return err
 	}
@@ -651,15 +652,7 @@ func (s *LetterOutgoingServiceImpl) ApproveOutgoingLetter(ctx context.Context, l
 
 	currentApproval.Remarks = req.Remarks
 
-	allApproved := true
-	for _, approval := range approvals {
-		if approval.ID != currentApproval.ID && approval.Status == entities.ApprovalStatusPending {
-			allApproved = false
-			break
-		}
-	}
-
-	err = s.processor.ProcessApproval(ctx, letterID, currentApproval, userID, allApproved)
+	err = s.processor.ProcessApproval(ctx, letterID, currentApproval, userID)
 	if err != nil {
 		return err
 	}
@@ -691,7 +684,8 @@ func (s *LetterOutgoingServiceImpl) RejectOutgoingLetter(ctx context.Context, le
 		return gorm.ErrInvalidData
 	}
 
-	approvals, err := s.processor.GetApprovalsByLetter(ctx, letterID)
+	// Get approvals for the current revision only
+	approvals, err := s.processor.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
 	if err != nil {
 		return err
 	}
@@ -728,6 +722,35 @@ func (s *LetterOutgoingServiceImpl) RejectOutgoingLetter(ctx context.Context, le
 	return nil
 }
 
+func (s *LetterOutgoingServiceImpl) ReviseOutgoingLetter(ctx context.Context, letterID uuid.UUID, req *contract.ReviseLetterRequest) error {
+	userID := getUserIDFromContext(ctx)
+
+	letter, err := s.processor.GetOutgoingLetterByID(ctx, letterID)
+	if err != nil {
+		return err
+	}
+
+	// Can only revise rejected letters
+	if letter.Status != entities.LetterOutgoingStatusRejected {
+		return gorm.ErrInvalidData
+	}
+
+	attachment := entities.LetterOutgoingAttachment{
+		LetterID:   letterID,
+		FileURL:    req.FileURL,
+		FileName:   req.FileName,
+		FileType:   req.FileType,
+		UploadedBy: &userID,
+	}
+
+	err = s.processor.ProcessRevision(ctx, letterID, attachment, userID)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (s *LetterOutgoingServiceImpl) SendOutgoingLetter(ctx context.Context, letterID uuid.UUID) error {
 	userID := getUserIDFromContext(ctx)
 
@@ -968,8 +991,8 @@ func (s *LetterOutgoingServiceImpl) GetLetterApprovalInfo(ctx context.Context, l
 		return nil, err
 	}
 
-	// Get all approvals for this letter
-	approvals, err := s.processor.GetApprovalsByLetter(ctx, letterID)
+	// Get all approvals for this letter's current revision
+	approvals, err := s.processor.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
 	if err != nil {
 		return nil, err
 	}
@@ -1030,6 +1053,15 @@ func (s *LetterOutgoingServiceImpl) GetLetterApprovalInfo(ctx context.Context, l
 		}
 	}
 
+	// Add REVISE action if letter is rejected and user is the creator
+	if letter.Status == entities.LetterOutgoingStatusRejected && letter.CreatedBy == userID {
+		actions = append(actions, contract.ApprovalAction{
+			Type:   "REVISE",
+			Href:   fmt.Sprintf("/api/v1/letters/outgoing/%s/revise", letterID),
+			Method: "POST",
+		})
+	}
+
 	// Determine overall decision status
 	decisionStatus := "PENDING"
 
@@ -1080,8 +1112,8 @@ func (s *LetterOutgoingServiceImpl) GetLetterApprovals(ctx context.Context, lett
 		return nil, err
 	}
 
-	// Get all approvals for this letter
-	approvals, err := s.processor.GetApprovalsByLetter(ctx, letterID)
+	// Get all approvals for this letter's current revision
+	approvals, err := s.processor.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
 	if err != nil {
 		return nil, err
 	}
@@ -1435,6 +1467,7 @@ func transformLetterToResponse(letter *entities.LetterOutgoing) *contract.Outgoi
 		IssueDate:             letter.IssueDate,
 		Status:                string(letter.Status),
 		ApprovalFlowID:        letter.ApprovalFlowID,
+		RevisionNumber:        letter.RevisionNumber,
 		CreatedBy:             letter.CreatedBy,
 		CreatedAt:             letter.CreatedAt,
 		UpdatedAt:             letter.UpdatedAt,
@@ -1778,7 +1811,15 @@ func (s *LetterOutgoingServiceImpl) BulkArchiveOutgoingLetters(ctx context.Conte
 func (s *LetterOutgoingServiceImpl) sendStepApprovalNotifications(ctx context.Context, letterID uuid.UUID, subject string, stepOrder int) {
 	log.Printf("[DEBUG] sendStepApprovalNotifications START - LetterID: %s, StepOrder: %d", letterID.String(), stepOrder)
 
-	approvals, err := s.processor.GetApprovalsByLetter(ctx, letterID)
+	// Get the letter to know the current revision
+	letter, err := s.processor.GetOutgoingLetterByID(ctx, letterID)
+	if err != nil {
+		log.Printf("[ERROR] Failed to get letter: %v", err)
+		return
+	}
+
+	// Get approvals for the current revision only
+	approvals, err := s.processor.GetApprovalsByLetterAndRevision(ctx, letterID, letter.RevisionNumber)
 	if err != nil {
 		log.Printf("[ERROR] Failed to get approvals: %v", err)
 		return

migrations/000042_add_revision_number_to_letter_outgoing.down.sql

@@ -0,0 +1,8 @@
+BEGIN;
+
+DROP INDEX IF EXISTS idx_letters_outgoing_revision_number;
+
+ALTER TABLE letters_outgoing
+DROP COLUMN IF EXISTS revision_number;
+
+COMMIT;

migrations/000042_add_revision_number_to_letter_outgoing.up.sql

@@ -0,0 +1,8 @@
+BEGIN;
+
+ALTER TABLE letters_outgoing 
+ADD COLUMN IF NOT EXISTS revision_number INTEGER NOT NULL DEFAULT 0;
+
+CREATE INDEX IF NOT EXISTS idx_letters_outgoing_revision_number ON letters_outgoing(revision_number);
+
+COMMIT;

migrations/000043_add_revision_number_to_attachments_and_approvals.down.sql

@@ -0,0 +1,14 @@
+BEGIN;
+
+-- Drop indexes
+DROP INDEX IF EXISTS idx_letter_outgoing_attachments_revision;
+DROP INDEX IF EXISTS idx_letter_outgoing_approvals_revision;
+
+-- Remove revision_number from tables
+ALTER TABLE letter_outgoing_attachments
+DROP COLUMN IF EXISTS revision_number;
+
+ALTER TABLE letter_outgoing_approvals
+DROP COLUMN IF EXISTS revision_number;
+
+COMMIT;

migrations/000043_add_revision_number_to_attachments_and_approvals.up.sql

@@ -0,0 +1,15 @@
+BEGIN;
+
+-- Add revision_number to letter_outgoing_attachments
+ALTER TABLE letter_outgoing_attachments 
+ADD COLUMN IF NOT EXISTS revision_number INTEGER NOT NULL DEFAULT 0;
+
+-- Add revision_number to letter_outgoing_approvals
+ALTER TABLE letter_outgoing_approvals 
+ADD COLUMN IF NOT EXISTS revision_number INTEGER NOT NULL DEFAULT 0;
+
+-- Create indexes for better query performance
+CREATE INDEX IF NOT EXISTS idx_letter_outgoing_attachments_revision ON letter_outgoing_attachments(letter_id, revision_number);
+CREATE INDEX IF NOT EXISTS idx_letter_outgoing_approvals_revision ON letter_outgoing_approvals(letter_id, revision_number);
+
+COMMIT;