From eb1a29640f2d7c7d3daca0626b2beb623903c9cd Mon Sep 17 00:00:00 2001
From: Tusooa Zhu <tusooa@kazv.moe>
Date: Tue, 8 Mar 2022 21:26:05 -0500
Subject: [PATCH] Add pagination to AdminAPI.AnnouncementController.index

---
 lib/pleroma/announcement.ex                   |  7 +++
 .../controllers/announcement_controller.ex    |  9 +++-
 .../admin/announcement_operation.ex           | 16 +++++++
 .../announcement_controller_test.exs          | 48 +++++++++++++++++++
 4 files changed, 78 insertions(+), 2 deletions(-)

diff --git a/lib/pleroma/announcement.ex b/lib/pleroma/announcement.ex
index 8c15d5bdf..6c11eff7e 100644
--- a/lib/pleroma/announcement.ex
+++ b/lib/pleroma/announcement.ex
@@ -61,6 +61,13 @@ defmodule Pleroma.Announcement do
     |> Repo.all()
   end
 
+  def list_paginated(%{limit: limited_number, offset: offset_number}) do
+    __MODULE__
+    |> limit(^limited_number)
+    |> offset(^offset_number)
+    |> Repo.all()
+  end
+
   def get_by_id(id) do
     Repo.get_by(__MODULE__, id: id)
   end
diff --git a/lib/pleroma/web/admin_api/controllers/announcement_controller.ex b/lib/pleroma/web/admin_api/controllers/announcement_controller.ex
index 6195e582a..6ad5fc12c 100644
--- a/lib/pleroma/web/admin_api/controllers/announcement_controller.ex
+++ b/lib/pleroma/web/admin_api/controllers/announcement_controller.ex
@@ -16,8 +16,13 @@ defmodule Pleroma.Web.AdminAPI.AnnouncementController do
 
   defdelegate open_api_operation(action), to: Pleroma.Web.ApiSpec.Admin.AnnouncementOperation
 
-  def index(conn, _params) do
-    announcements = Announcement.list_all()
+  defp default_limit, do: 20
+
+  def index(conn, params) do
+    limit = Map.get(params, :limit, default_limit())
+    offset = Map.get(params, :offset, 0)
+
+    announcements = Announcement.list_paginated(%{limit: limit, offset: offset})
 
     render(conn, "index.json", announcements: announcements)
   end
diff --git a/lib/pleroma/web/api_spec/operations/admin/announcement_operation.ex b/lib/pleroma/web/api_spec/operations/admin/announcement_operation.ex
index cdf04d357..58a039e72 100644
--- a/lib/pleroma/web/api_spec/operations/admin/announcement_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/admin/announcement_operation.ex
@@ -21,8 +21,24 @@ defmodule Pleroma.Web.ApiSpec.Admin.AnnouncementOperation do
       summary: "Retrieve a list of announcements",
       operationId: "AdminAPI.AnnouncementController.index",
       security: [%{"oAuth" => ["admin:read"]}],
+      parameters: [
+        Operation.parameter(
+          :limit,
+          :query,
+          %Schema{type: :integer, minimum: 1},
+          "the maximum number of announcements to return"
+        ),
+        Operation.parameter(
+          :offset,
+          :query,
+          %Schema{type: :integer, minimum: 0},
+          "the offset of the first announcement to return"
+        )
+        | admin_api_params()
+      ],
       responses: %{
         200 => Operation.response("Response", "application/json", list_of_announcements()),
+        400 => Operation.response("Forbidden", "application/json", ApiError),
         403 => Operation.response("Forbidden", "application/json", ApiError)
       }
     }
diff --git a/test/pleroma/web/admin_api/controllers/announcement_controller_test.exs b/test/pleroma/web/admin_api/controllers/announcement_controller_test.exs
index c6b2163d0..56da1c6aa 100644
--- a/test/pleroma/web/admin_api/controllers/announcement_controller_test.exs
+++ b/test/pleroma/web/admin_api/controllers/announcement_controller_test.exs
@@ -30,6 +30,54 @@ defmodule Pleroma.Web.AdminAPI.AnnouncementControllerTest do
 
       assert [%{"id" => ^id}] = response
     end
+
+    test "it paginates announcements", %{conn: conn} do
+      _announcements = Enum.map(0..20, fn _ -> insert(:announcement) end)
+
+      response =
+        conn
+        |> get("/api/v1/pleroma/admin/announcements")
+        |> json_response_and_validate_schema(:ok)
+
+      assert length(response) == 20
+    end
+
+    test "it paginates announcements with custom params", %{conn: conn} do
+      announcements = Enum.map(0..20, fn _ -> insert(:announcement) end)
+
+      response =
+        conn
+        |> get("/api/v1/pleroma/admin/announcements", limit: 5, offset: 7)
+        |> json_response_and_validate_schema(:ok)
+
+      assert length(response) == 5
+      assert Enum.at(response, 0)["id"] == Enum.at(announcements, 7).id
+    end
+
+    test "it returns empty list with out-of-bounds offset", %{conn: conn} do
+      _announcements = Enum.map(0..20, fn _ -> insert(:announcement) end)
+
+      response =
+        conn
+        |> get("/api/v1/pleroma/admin/announcements", offset: 21)
+        |> json_response_and_validate_schema(:ok)
+
+      assert [] = response
+    end
+
+    test "it rejects invalid pagination params", %{conn: conn} do
+      conn
+      |> get("/api/v1/pleroma/admin/announcements", limit: 0)
+      |> json_response_and_validate_schema(400)
+
+      conn
+      |> get("/api/v1/pleroma/admin/announcements", limit: -1)
+      |> json_response_and_validate_schema(400)
+
+      conn
+      |> get("/api/v1/pleroma/admin/announcements", offset: -1)
+      |> json_response_and_validate_schema(400)
+    end
   end
 
   describe "GET /api/v1/pleroma/admin/announcements/:id" do