api: refactor pagination (WIP)

api/elections.go

@@ -29,9 +29,21 @@ const (
 	MaxOffchainFileSize = 1024 * 1024 * 1 // 1MB
 )
 
+const (
+	ParamPage = "page"
+)
+
 func (a *API) enableElectionHandlers() error {
 	if err := a.Endpoint.RegisterMethod(
-		"/elections/page/{page}",
+		"/elections/page/{page}", // legacy endpoint
+		"GET",
+		apirest.MethodAccessTypePublic,
+		a.electionFullListByPageHandler,
+	); err != nil {
+		return err
+	}
+	if err := a.Endpoint.RegisterMethod(
+		"/elections",
 		"GET",
 		apirest.MethodAccessTypePublic,
 		a.electionFullListHandler,
@@ -124,17 +136,17 @@ func (a *API) enableElectionHandlers() error {
 	return nil
 }
 
-// electionFullListHandler
+// electionFullListByPageHandler
 //
-//	@Summary		List elections
+//	@Summary		List elections (legacy params design)
 //	@Description	Get a list of elections summaries.
 //	@Tags			Elections
 //	@Accept			json
 //	@Produce		json
 //	@Param			page	path		number	true	"Page "
 //	@Success		200		{object}	ElectionSummary
 //	@Router			/elections/page/{page} [get]
-func (a *API) electionFullListHandler(_ *apirest.APIdata, ctx *httprouter.HTTPContext) error {
+func (a *API) electionFullListByPageHandler(_ *apirest.APIdata, ctx *httprouter.HTTPContext) error {
 	page := 0
 	if ctx.URLParam("page") != "" {
 		var err error
@@ -143,6 +155,32 @@ func (a *API) electionFullListHandler(_ *apirest.APIdata, ctx *httprouter.HTTPCo
 			return ErrCantParsePageNumber.With(ctx.URLParam("page"))
 		}
 	}
+	return a.electionFullListByPage(ctx, page)
+}
+
+// electionFullListHandler
+//
+//	@Summary		List elections
+//	@Description	Get a list of elections summaries.
+//	@Tags			Elections
+//	@Accept			json
+//	@Produce		json
+//	@Param			page	query		number	false	"Page "
+//	@Success		200		{object}	ElectionSummary
+//	@Router			/elections [get]
+func (a *API) electionFullListHandler(_ *apirest.APIdata, ctx *httprouter.HTTPContext) error {
+	page := 0
+	if p := ctx.QueryParam(ParamPage); p != "" {
+		var err error
+		page, err = strconv.Atoi(p)
+		if err != nil {
+			return ErrCantParsePageNumber.With(p)
+		}
+	}
+	return a.electionFullListByPage(ctx, page)
+}
+
+func (a *API) electionFullListByPage(ctx *httprouter.HTTPContext, page int) error {
 	elections, err := a.indexer.ProcessList(nil, page*MaxPageSize, MaxPageSize, "", 0, 0, "", false)
 	if err != nil {
 		return ErrCantFetchElectionList.WithErr(err)

httprouter/message.go

@@ -44,6 +44,12 @@ func (h *HTTPContext) URLParam(key string) string {
 	return chi.URLParam(h.Request, key)
 }
 
+// QueryParam is a wrapper around go-chi to get the value of a query string parameter (like "?key=value").
+// If key is not present, returns the empty string.
+func (h *HTTPContext) QueryParam(key string) string {
+	return h.Request.URL.Query().Get(key)
+}
+
 // Send replies the request with the provided message.
 func (h *HTTPContext) Send(msg []byte, httpStatusCode int) error {
 	defer func() {