feat(media): pagination

api/handlers/media/mediaHandler.go

@@ -70,9 +70,23 @@ type countsResponse struct {
 }
 
 type listResponse struct {
-	Items      []mediaItemResponse `json:"items"`
-	NextCursor *string             `json:"next_cursor"`
-	Counts     countsResponse      `json:"counts"`
+	Items  []mediaItemResponse `json:"items"`
+	Total  int                 `json:"total"`
+	Page   int                 `json:"page"`
+	Size   int                 `json:"size"`
+	Counts countsResponse      `json:"counts"`
+}
+
+type pagingQuery struct {
+	Page int `validate:"gte=1"`
+	Size int `validate:"oneof=5 25 50 100"`
+}
+
+func intQueryParam(values url.Values, name string, fallback int) (int, error) {
+	if !values.Has(name) {
+		return fallback, nil
+	}
+	return strconv.Atoi(values.Get(name))
 }
 
 type usageResponse struct {
@@ -173,7 +187,6 @@ func parseListQuery(r *http.Request) (domainImage.ListQuery, error) {
 	query := domainImage.NewListQuery()
 	query.Search = values.Get("q")
 	query.Hash = strings.ToLower(values.Get("hash"))
-	query.Cursor = values.Get("cursor")
 	if values.Has("filter") {
 		query.Filter = domainImage.Filter(values.Get("filter"))
 	}
@@ -186,13 +199,19 @@ func parseListQuery(r *http.Request) (domainImage.ListQuery, error) {
 	if values.Has("sort") {
 		query.Sort = domainImage.Sort(values.Get("sort"))
 	}
-	if values.Has("limit") {
-		limit, err := strconv.Atoi(values.Get("limit"))
-		if err != nil {
-			return domainImage.ListQuery{}, domainImage.ErrInvalidQuery
-		}
-		query.Limit = limit
+	page, err := intQueryParam(values, "page", domainImage.DefaultListPage)
+	if err != nil {
+		return domainImage.ListQuery{}, domainImage.ErrInvalidQuery
 	}
+	size, err := intQueryParam(values, "size", domainImage.DefaultListSize)
+	if err != nil {
+		return domainImage.ListQuery{}, domainImage.ErrInvalidQuery
+	}
+	if validator.Validate.Struct(pagingQuery{Page: page, Size: size}) != nil {
+		return domainImage.ListQuery{}, domainImage.ErrInvalidQuery
+	}
+	query.Page = page
+	query.Size = size
 	return query, nil
 }
 
@@ -219,11 +238,11 @@ func (h *Handler) List(w http.ResponseWriter, r *http.Request) {
 	}
 	response := listResponse{
 		Items:  items,
+		Total:  page.Total,
+		Page:   page.Page,
+		Size:   page.Size,
 		Counts: countsResponse{All: page.Counts.All, Unused: page.Counts.Unused, Duplicates: page.Counts.Duplicates},
 	}
-	if page.NextCursor != "" {
-		response.NextCursor = &page.NextCursor
-	}
 	writeJSON(w, http.StatusOK, response)
 }