From 60cbea5bb2e70d6a843d6f595a3c1cfe9cc78d1e Mon Sep 17 00:00:00 2001
From: Maxim Filippov <colixer@gmail.com>
Date: Wed, 25 Sep 2019 01:25:42 +0300
Subject: [PATCH] Allow activities pagination via limit/offset

---
 lib/pleroma/pagination.ex                       |  1 +
 lib/pleroma/web/activity_pub/activity_pub.ex    | 17 +++++++++++------
 .../web/admin_api/admin_api_controller.ex       |  6 +++++-
 test/web/activity_pub/activity_pub_test.exs     | 15 +++++++++++++++
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/lib/pleroma/pagination.ex b/lib/pleroma/pagination.ex
index b55379c4a..9d279fba7 100644
--- a/lib/pleroma/pagination.ex
+++ b/lib/pleroma/pagination.ex
@@ -64,6 +64,7 @@ defmodule Pleroma.Pagination do
 
   def paginate(query, options, :offset) do
     query
+    |> restrict(:order, options)
     |> restrict(:offset, options)
     |> restrict(:limit, options)
   end
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 1cf8b6151..bb0a5ca73 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -519,13 +519,13 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> Repo.one()
   end
 
-  def fetch_public_activities(opts \\ %{}) do
+  def fetch_public_activities(opts \\ %{}, pagination \\ :keyset) do
     opts = Map.drop(opts, ["user"])
 
     [Pleroma.Constants.as_public()]
     |> fetch_activities_query(opts)
     |> restrict_unlisted()
-    |> Pagination.fetch_paginated(opts)
+    |> Pagination.fetch_paginated(opts, pagination)
     |> Enum.reverse()
   end
 
@@ -918,11 +918,11 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> exclude_poll_votes(opts)
   end
 
-  def fetch_activities(recipients, opts \\ %{}) do
+  def fetch_activities(recipients, opts \\ %{}, pagination \\ :keyset) do
     list_memberships = Pleroma.List.memberships(opts["user"])
 
     fetch_activities_query(recipients ++ list_memberships, opts)
-    |> Pagination.fetch_paginated(opts)
+    |> Pagination.fetch_paginated(opts, pagination)
     |> Enum.reverse()
     |> maybe_update_cc(list_memberships, opts["user"])
   end
@@ -953,10 +953,15 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     )
   end
 
-  def fetch_activities_bounded(recipients, recipients_with_public, opts \\ %{}) do
+  def fetch_activities_bounded(
+        recipients,
+        recipients_with_public,
+        opts \\ %{},
+        pagination \\ :keyset
+      ) do
     fetch_activities_query([], opts)
     |> fetch_activities_bounded_query(recipients, recipients_with_public)
-    |> Pagination.fetch_paginated(opts)
+    |> Pagination.fetch_paginated(opts, pagination)
     |> Enum.reverse()
   end
 
diff --git a/lib/pleroma/web/admin_api/admin_api_controller.ex b/lib/pleroma/web/admin_api/admin_api_controller.ex
index 0d1db8fa0..6761c32b9 100644
--- a/lib/pleroma/web/admin_api/admin_api_controller.ex
+++ b/lib/pleroma/web/admin_api/admin_api_controller.ex
@@ -463,13 +463,17 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
   end
 
   def list_reports(conn, params) do
+    {page, page_size} = page_params(params)
+
     params =
       params
       |> Map.put("type", "Flag")
       |> Map.put("skip_preload", true)
       |> Map.put("total", true)
+      |> Map.put("limit", page_size)
+      |> Map.put("offset", (page - 1) * page_size)
 
-    reports = ActivityPub.fetch_activities([], params)
+    reports = ActivityPub.fetch_activities([], params, :offset)
 
     conn
     |> put_view(ReportView)
diff --git a/test/web/activity_pub/activity_pub_test.exs b/test/web/activity_pub/activity_pub_test.exs
index 4100108a5..f28fd6871 100644
--- a/test/web/activity_pub/activity_pub_test.exs
+++ b/test/web/activity_pub/activity_pub_test.exs
@@ -647,6 +647,21 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubTest do
       assert last == last_expected
     end
 
+    test "paginates via offset/limit" do
+      _first_activities = ActivityBuilder.insert_list(10)
+      activities = ActivityBuilder.insert_list(10)
+      _later_activities = ActivityBuilder.insert_list(10)
+      first_expected = List.first(activities)
+
+      activities =
+        ActivityPub.fetch_public_activities(%{"page" => "2", "page_size" => "20"}, :offset)
+
+      first = List.first(activities)
+
+      assert length(activities) == 20
+      assert first == first_expected
+    end
+
     test "doesn't return reblogs for users for whom reblogs have been muted" do
       activity = insert(:note_activity)
       user = insert(:user)