cursor pagination

internal/tender/repository.go

@@ -26,7 +26,7 @@ type TenderRepository interface {
 	GetTenderCountByCountry(ctx context.Context) (map[string]int64, error)
 	GetTenderCountByType(ctx context.Context) (map[string]int64, error)
 	GetTenderCountByClassification(ctx context.Context) (map[string]int64, error)
-	Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) ([]Tender, int64, error)
+	Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) (*SearchPageResult, error)
 	GetExpiredTenders(ctx context.Context, beforeDate int64) ([]Tender, error)
 	GetUnScrapedTenders(ctx context.Context, limit, skip int) ([]Tender, int64, error)
 	GetUnSummarizedTenders(ctx context.Context, limit, skip int) ([]Tender, int64, error)
@@ -40,11 +40,27 @@ 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 {
+	Items      []Tender
+	TotalCount int64 // -1 when count was skipped
+	NextCursor string
+	HasMore    bool
+}
+
 // tenderSearchListProjection excludes large fields not needed for list/search API payloads.
 func tenderSearchListProjection() bson.M {
 	return bson.M{
-		"content_xml":        0,
-		"document_summaries": 0,
+		"content_xml":         0,
+		"document_summaries":  0,
+		"scraped_documents":   0,
+		"selection_criteria":  0,
+		"modifications":       0,
+		"source_file_url":     0,
+		"source_file_name":    0,
 	}
 }
 
@@ -85,6 +101,26 @@ func NewRepository(mongoManager *orm.ConnectionManager, logger logger.Logger) Te
 		*orm.NewIndex("tender_deadline_idx", bson.D{{Key: "tender_deadline", Value: 1}}),
 		*orm.NewIndex("estimated_value_idx", bson.D{{Key: "estimated_value", Value: -1}}),
 		*orm.NewIndex("created_at_idx", bson.D{{Key: "created_at", Value: -1}}),
+		// Stable keyset pagination for default admin list (created_at desc).
+		*orm.NewIndex("created_at_id_idx", bson.D{
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("status_created_at_id_idx", bson.D{
+			{Key: "status", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("country_code_created_at_id_idx", bson.D{
+			{Key: "country_code", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
+		*orm.NewIndex("notice_type_code_created_at_id_idx", bson.D{
+			{Key: "notice_type_code", Value: 1},
+			{Key: "created_at", Value: -1},
+			{Key: "_id", Value: -1},
+		}),
 		*orm.NewIndex("updated_at_idx", bson.D{{Key: "updated_at", Value: -1}}),
 		// Compound indexes for common queries
 		*orm.NewIndex("status_country_idx", bson.D{
@@ -321,10 +357,9 @@ func (r *tenderRepository) Delete(ctx context.Context, id string) error {
 }
 
 // Search searches tenders based on criteria
-func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) ([]Tender, int64, error) {
+func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, pagination *response.Pagination) (*SearchPageResult, error) {
 	filter := r.buildSearchFilter(form)
 
-	// Build sort
 	sort := "created_at"
 	if pagination.SortBy != "" {
 		sort = pagination.SortBy
@@ -335,23 +370,34 @@ func (r *tenderRepository) Search(ctx context.Context, form *SearchForm, paginat
 		sortOrder = pagination.SortOrder
 	}
 
-	// Build pagination
+	skipCount := pagination.Cursor != "" || pagination.Offset >= deepOffsetSkipCountThreshold
+
 	paginationBuilder := orm.NewPaginationBuilder().
 		Limit(pagination.Limit).
-		Skip(pagination.Offset).
 		SortBy(sort, sortOrder).
 		Projection(tenderSearchListProjection()).
-		Build()
+		SkipCount(skipCount)
 
-	result, err := r.ormRepo.FindAll(ctx, filter, paginationBuilder)
+	if pagination.Cursor != "" {
+		paginationBuilder.Cursor(pagination.Cursor)
+	} else {
+		paginationBuilder.Skip(pagination.Offset)
+	}
+
+	result, err := r.ormRepo.FindAll(ctx, filter, paginationBuilder.Build())
 	if err != nil {
 		r.logger.Error("Failed to search tenders", map[string]interface{}{
 			"error": err.Error(),
 		})
-		return nil, 0, err
+		return nil, err
 	}
 
-	return result.Items, result.TotalCount, nil
+	return &SearchPageResult{
+		Items:      result.Items,
+		TotalCount: result.TotalCount,
+		NextCursor: result.NextCursor,
+		HasMore:    result.HasMore,
+	}, nil
 }
 
 // GetExpiredTenders retrieves tenders that are expired