refactor(backend): move pagination calculation to crud package

- Move pagination logic to a shared crud interface
- Update managers to use shared pagination struct

Author: maniac-en

internal/collections/manager.go

@@ -127,22 +127,12 @@ func (c *CollectionsManager) ListPaginated(ctx context.Context, limit, offset in
 		entities[i] = CollectionEntity{Collection: collection}
 	}
 
-	// Calculate pagination metadata
-	totalPages := int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
-	currentPage := (offset / limit) + 1
-	hasNext := (offset + limit) < int(total)
-	hasPrev := offset > 0
+	pagination := crud.CalculatePagination(total, limit, offset)
 
 	result := &PaginatedCollections{
-		Collections: entities,
-		Total:       total,
-		Offset:      offset,
-		Limit:       limit,
-		HasNext:     hasNext,
-		HasPrev:     hasPrev,
-		TotalPages:  totalPages,
-		CurrentPage: currentPage,
+		Collections:        entities,
+		PaginationMetadata: pagination,
 	}
-	log.Info("retrieved collections", "count", len(entities), "total", total, "page", currentPage, "total_pages", totalPages)
+	log.Info("retrieved collections", "count", len(entities), "total", pagination.Total, "page", pagination.CurrentPage, "total_pages", pagination.TotalPages)
 	return result, nil
 }

internal/collections/models.go

@@ -3,6 +3,7 @@ package collections
 import (
 	"time"
 
+	"github.com/maniac-en/req/internal/crud"
 	"github.com/maniac-en/req/internal/database"
 	"github.com/maniac-en/req/internal/log"
 )
@@ -43,11 +44,5 @@ type CollectionsManager struct {
 
 type PaginatedCollections struct {
 	Collections []CollectionEntity `json:"collections"`
-	Total       int64              `json:"total"`
-	HasNext     bool               `json:"has_next"`
-	HasPrev     bool               `json:"has_prev"`
-	Limit       int                `json:"limit"`
-	Offset      int                `json:"offset"`
-	TotalPages  int                `json:"total_pages"`
-	CurrentPage int                `json:"current_page"`
+	crud.PaginationMetadata
 }

internal/crud/interfaces.go

@@ -26,3 +26,30 @@ type Manager[T Entity] interface {
 	Delete(ctx context.Context, id int64) error
 	List(ctx context.Context) ([]T, error)
 }
+
+type PaginationMetadata struct {
+	Total       int64 `json:"total"`
+	HasNext     bool  `json:"has_next"`
+	HasPrev     bool  `json:"has_prev"`
+	Limit       int   `json:"limit"`
+	Offset      int   `json:"offset"`
+	TotalPages  int   `json:"total_pages"`
+	CurrentPage int   `json:"current_page"`
+}
+
+func CalculatePagination(total int64, limit, offset int) PaginationMetadata {
+	totalPages := int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
+	currentPage := (offset / limit) + 1
+	hasNext := (offset + limit) < int(total)
+	hasPrev := offset > 0
+
+	return PaginationMetadata{
+		Total:       total,
+		HasNext:     hasNext,
+		HasPrev:     hasPrev,
+		Limit:       limit,
+		Offset:      offset,
+		TotalPages:  totalPages,
+		CurrentPage: currentPage,
+	}
+}

internal/endpoints/manager.go

@@ -93,23 +93,13 @@ func (e *EndpointsManager) ListByCollection(ctx context.Context, collectionID in
 		entities[i] = EndpointEntity{Endpoint: endpoint}
 	}
 
-	// Calculate pagination metadata
-	totalPages := int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
-	currentPage := (offset / limit) + 1
-	hasNext := (offset + limit) < int(total)
-	hasPrev := offset > 0
+	pagination := crud.CalculatePagination(total, limit, offset)
 
 	result := &PaginatedEndpoints{
-		Endpoints:   entities,
-		Total:       total,
-		Offset:      offset,
-		Limit:       limit,
-		HasNext:     hasNext,
-		HasPrev:     hasPrev,
-		TotalPages:  totalPages,
-		CurrentPage: currentPage,
-	}
-	log.Info("retrieved endpoints", "collection_id", collectionID, "count", len(entities), "total", total, "page", currentPage, "total_pages", totalPages)
+		Endpoints:          entities,
+		PaginationMetadata: pagination,
+	}
+	log.Info("retrieved endpoints", "collection_id", collectionID, "count", len(entities), "total", pagination.Total, "page", pagination.CurrentPage, "total_pages", pagination.TotalPages)
 	return result, nil
 }
 

internal/endpoints/models.go

@@ -3,6 +3,7 @@ package endpoints
 import (
 	"time"
 
+	"github.com/maniac-en/req/internal/crud"
 	"github.com/maniac-en/req/internal/database"
 	"github.com/maniac-en/req/internal/log"
 )
@@ -42,14 +43,8 @@ type EndpointsManager struct {
 }
 
 type PaginatedEndpoints struct {
-	Endpoints   []EndpointEntity `json:"endpoints"`
-	Total       int64            `json:"total"`
-	Offset      int              `json:"offset"`
-	Limit       int              `json:"limit"`
-	HasNext     bool             `json:"has_next"`
-	HasPrev     bool             `json:"has_prev"`
-	TotalPages  int              `json:"total_pages"`
-	CurrentPage int              `json:"current_page"`
+	Endpoints []EndpointEntity `json:"endpoints"`
+	crud.PaginationMetadata
 }
 
 type EndpointData struct {

internal/history/manager.go

@@ -94,24 +94,14 @@ func (h *HistoryManager) ListByCollection(ctx context.Context, collectionID int6
 		}}
 	}
 
-	// Calculate pagination metadata
-	totalPages := int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
-	currentPage := (offset / limit) + 1
-	hasNext := (offset + limit) < int(total)
-	hasPrev := offset > 0
+	pagination := crud.CalculatePagination(total, limit, offset)
 
 	result := PaginatedHistory{
-		Items:       entities,
-		Total:       total,
-		HasNext:     hasNext,
-		HasPrev:     hasPrev,
-		Limit:       limit,
-		Offset:      offset,
-		TotalPages:  totalPages,
-		CurrentPage: currentPage,
+		Items:              entities,
+		PaginationMetadata: pagination,
 	}
 
-	log.Info("listed history by collection", "collection_id", collectionID, "count", len(entities), "total", total, "page", currentPage, "total_pages", totalPages)
+	log.Info("listed history by collection", "collection_id", collectionID, "count", len(entities), "total", pagination.Total, "page", pagination.CurrentPage, "total_pages", pagination.TotalPages)
 	return result, nil
 }
 

internal/history/models.go

@@ -4,6 +4,7 @@ package history
 import (
 	"time"
 
+	"github.com/maniac-en/req/internal/crud"
 	"github.com/maniac-en/req/internal/database"
 	"github.com/maniac-en/req/internal/log"
 )
@@ -39,14 +40,8 @@ func (h HistoryEntity) GetUpdatedAt() time.Time {
 }
 
 type PaginatedHistory struct {
-	Items       []HistoryEntity `json:"items"`
-	Total       int64           `json:"total"`
-	HasNext     bool            `json:"has_next"`
-	HasPrev     bool            `json:"has_prev"`
-	Limit       int             `json:"limit"`
-	Offset      int             `json:"offset"`
-	TotalPages  int             `json:"total_pages"`
-	CurrentPage int             `json:"current_page"`
+	Items []HistoryEntity `json:"items"`
+	crud.PaginationMetadata
 }
 
 type ExecutionData struct {