feat: init repo

backend/app/requests/pagination.go

@@ -0,0 +1,30 @@
+package requests
+
+import "github.com/samber/lo"
+
+type Pager struct {
+	Pagination `json:",inline"`
+	Total      int64       `json:"total"`
+	Items      interface{} `json:"items"`
+}
+
+type Pagination struct {
+	Page  int `json:"page" form:"page" query:"page"`
+	Limit int `json:"limit" form:"limit" query:"limit"`
+}
+
+func (filter *Pagination) Offset() int {
+	return (filter.Page - 1) * filter.Limit
+}
+
+func (filter *Pagination) Format() *Pagination {
+	if filter.Page <= 0 {
+		filter.Page = 1
+	}
+
+	if !lo.Contains([]int{10, 20, 50, 100}, filter.Limit) {
+		filter.Limit = 10
+	}
+
+	return filter
+}