hybrid pagination

internal/tender/handler.go

@@ -177,11 +177,15 @@ func (h *TenderHandler) Search(c echo.Context) error {
 		return response.ValidationError(c, "Validation failed", err.Error())
 	}
 
-	// Call service
-	tenders, err := h.service.Search(c.Request().Context(), form, response.NewPagination(c))
+	pagination, err := response.NewPagination(c)
 	if err != nil {
-		if isInvalidPaginationCursor(err) {
-			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		return response.PaginationBadRequest(c, err)
+	}
+
+	tenders, err := h.service.Search(c.Request().Context(), form, pagination)
+	if err != nil {
+		if response.IsListPaginationError(err) {
+			return response.PaginationBadRequest(c, err)
 		}
 		return response.InternalServerError(c, "Failed to list tenders")
 	}
@@ -259,10 +263,15 @@ func (h *TenderHandler) GetPublicTenders(c echo.Context) error {
 	}
 	form.CustomerID = customerID
 
-	result, err := h.service.Search(c.Request().Context(), form, response.NewPagination(c))
+	pagination, err := response.NewPagination(c)
 	if err != nil {
-		if isInvalidPaginationCursor(err) {
-			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		return response.PaginationBadRequest(c, err)
+	}
+
+	result, err := h.service.Search(c.Request().Context(), form, pagination)
+	if err != nil {
+		if response.IsListPaginationError(err) {
+			return response.PaginationBadRequest(c, err)
 		}
 		return response.InternalServerError(c, "Failed to retrieve tenders")
 	}
@@ -335,10 +344,15 @@ func (h *TenderHandler) RecommendTenders(c echo.Context) error {
 	}
 	form.CustomerID = customerID
 
-	result, err := h.service.Recommend(c.Request().Context(), form, response.NewPagination(c))
+	pagination, err := response.NewPagination(c)
 	if err != nil {
-		if isInvalidPaginationCursor(err) {
-			return response.ValidationError(c, "Invalid pagination cursor", err.Error())
+		return response.PaginationBadRequest(c, err)
+	}
+
+	result, err := h.service.Recommend(c.Request().Context(), form, pagination)
+	if err != nil {
+		if response.IsListPaginationError(err) {
+			return response.PaginationBadRequest(c, err)
 		}
 		return response.InternalServerError(c, "Failed to retrieve tenders")
 	}
@@ -664,6 +678,3 @@ func (h *TenderHandler) GetAllAISummaries(c echo.Context) error {
 	return response.Success(c, summaries, "AI summaries retrieved successfully")
 }
 
-func isInvalidPaginationCursor(err error) bool {
-	return errors.Is(err, orm.ErrInvalidCursor)
-}

internal/tender/repository.go

@@ -40,8 +40,6 @@ func collectionName() string {
 	return "tenders"
 }
 
-// deepOffsetSkipCountThreshold skips CountDocuments when offset pagination goes this deep.
-const deepOffsetSkipCountThreshold = 1000
 
 // SearchPageResult is the paginated outcome of a tender search/list query.
 type SearchPageResult struct {
@@ -49,6 +47,7 @@ type SearchPageResult struct {
 	TotalCount int64 // -1 when count was skipped
 	NextCursor string
 	HasMore    bool
+	PageOffset int
 }
 
 // tenderSearchListProjection excludes large fields not needed for list/search API payloads.
@@ -370,21 +369,20 @@ func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, paginat
 		sortOrder = pagination.SortOrder
 	}
 
-	skipCount := pagination.Cursor != "" || pagination.Offset >= deepOffsetSkipCountThreshold
-
-	paginationBuilder := orm.NewPaginationBuilder().
-		Limit(pagination.Limit).
-		SortBy(sort, sortOrder).
-		Projection(tenderSearchListProjection()).
-		SkipCount(skipCount)
-
-	if pagination.Cursor != "" {
-		paginationBuilder.Cursor(pagination.Cursor)
-	} else {
-		paginationBuilder.Skip(pagination.Offset)
+	mongoPagination, err := orm.BuildListPagination(
+		pagination.Limit,
+		pagination.Offset,
+		pagination.Cursor,
+		sort,
+		sortOrder,
+		filter,
+		orm.ListPaginationOptions{Projection: tenderSearchListProjection()},
+	)
+	if err != nil {
+		return nil, err
 	}
 
-	result, err := r.ormRepo.FindAll(ctx, filter, paginationBuilder.Build())
+	result, err := r.ormRepo.FindAll(ctx, filter, mongoPagination)
 	if err != nil {
 		r.logger.Error("Failed to search tenders", map[string]interface{}{
 			"error": err.Error(),
@@ -397,6 +395,7 @@ func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, paginat
 		TotalCount: result.TotalCount,
 		NextCursor: result.NextCursor,
 		HasMore:    result.HasMore,
+		PageOffset: result.PageOffset,
 	}, nil
 }
 

internal/tender/service.go

@@ -648,7 +648,7 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 
 		return &SearchResponse{
 			Tenders:  tenderResponses,
-			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
+			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore, page.PageOffset),
 		}, nil
 	}
 
@@ -667,7 +667,7 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 
 		return &SearchResponse{
 				Tenders:  tenderResponses,
-				Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
+				Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore, page.PageOffset),
 			},
 			nil
 	}
@@ -690,7 +690,7 @@ func (s *tenderService) Search(ctx context.Context, form *SearchForm, pagination
 
 	return &SearchResponse{
 			Tenders:  tenderResponses,
-			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
+			Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore, page.PageOffset),
 		},
 		nil
 }
@@ -757,7 +757,7 @@ func (s *tenderService) Recommend(ctx context.Context, form *SearchForm, paginat
 
 	return &SearchResponse{
 		Tenders:  tenderResponses,
-		Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore),
+		Metadata: pagination.ListMeta(page.TotalCount, page.NextCursor, page.HasMore, page.PageOffset),
 	}, nil
 }