initial commit

backend/internal/utils/paging_util.go

@@ -0,0 +1,45 @@
+package utils
+
+import (
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+	"strconv"
+)
+
+type PaginationResponse struct {
+	TotalPages  int64 `json:"totalPages"`
+	TotalItems  int64 `json:"totalItems"`
+	CurrentPage int   `json:"currentPage"`
+}
+
+func Paginate(c *gin.Context, db *gorm.DB, result interface{}) (PaginationResponse, error) {
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("limit", "10"))
+
+	if page < 1 {
+		page = 1
+	}
+
+	if pageSize < 1 {
+		pageSize = 10
+	} else if pageSize > 100 {
+		pageSize = 100
+	}
+
+	offset := (page - 1) * pageSize
+
+	var totalItems int64
+	if err := db.Count(&totalItems).Error; err != nil {
+		return PaginationResponse{}, err
+	}
+
+	if err := db.Offset(offset).Limit(pageSize).Find(result).Error; err != nil {
+		return PaginationResponse{}, err
+	}
+
+	return PaginationResponse{
+		TotalPages:  (totalItems + int64(pageSize) - 1) / int64(pageSize),
+		TotalItems:  totalItems,
+		CurrentPage: page,
+	}, nil
+}