From 5237a2df9f123f661de30a53193b7d9fec69ecae Mon Sep 17 00:00:00 2001
From: Ivan Tashkinov <ivantashkinov@gmail.com>
Date: Fri, 19 Jun 2020 16:14:06 +0300
Subject: [PATCH] [#1873] Fixes missing :offset pagination param support. Added
 pagination support for hashtags search.

---
 lib/pleroma/pagination.ex                     |  6 ++++
 lib/pleroma/web/api_spec/helpers.ex           |  6 ++++
 .../controllers/search_controller.ex          | 31 ++++++++++++-------
 .../controllers/search_controller_test.exs    | 16 ++++++++++
 .../controllers/status_controller_test.exs    |  2 +-
 5 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/lib/pleroma/pagination.ex b/lib/pleroma/pagination.ex
index 1b99e44f9..9a3795769 100644
--- a/lib/pleroma/pagination.ex
+++ b/lib/pleroma/pagination.ex
@@ -64,6 +64,12 @@ defmodule Pleroma.Pagination do
   @spec paginate(Ecto.Query.t(), map(), type(), atom() | nil) :: [Ecto.Schema.t()]
   def paginate(query, options, method \\ :keyset, table_binding \\ nil)
 
+  def paginate(list, options, _method, _table_binding) when is_list(list) do
+    offset = options[:offset] || 0
+    limit = options[:limit] || 0
+    Enum.slice(list, offset, limit)
+  end
+
   def paginate(query, options, :keyset, table_binding) do
     query
     |> restrict(:min_id, options, table_binding)
diff --git a/lib/pleroma/web/api_spec/helpers.ex b/lib/pleroma/web/api_spec/helpers.ex
index a9cfe0fed..a258e8421 100644
--- a/lib/pleroma/web/api_spec/helpers.ex
+++ b/lib/pleroma/web/api_spec/helpers.ex
@@ -39,6 +39,12 @@ defmodule Pleroma.Web.ApiSpec.Helpers do
         :string,
         "Return the newest items newer than this ID"
       ),
+      Operation.parameter(
+        :offset,
+        :query,
+        %Schema{type: :integer, default: 0},
+        "Return items past this number of items"
+      ),
       Operation.parameter(
         :limit,
         :query,
diff --git a/lib/pleroma/web/mastodon_api/controllers/search_controller.ex b/lib/pleroma/web/mastodon_api/controllers/search_controller.ex
index 3be0ca095..e50980122 100644
--- a/lib/pleroma/web/mastodon_api/controllers/search_controller.ex
+++ b/lib/pleroma/web/mastodon_api/controllers/search_controller.ex
@@ -107,21 +107,21 @@ defmodule Pleroma.Web.MastodonAPI.SearchController do
     )
   end
 
-  defp resource_search(:v2, "hashtags", query, _options) do
+  defp resource_search(:v2, "hashtags", query, options) do
     tags_path = Web.base_url() <> "/tag/"
 
     query
-    |> prepare_tags()
+    |> prepare_tags(options)
     |> Enum.map(fn tag ->
       %{name: tag, url: tags_path <> tag}
     end)
   end
 
-  defp resource_search(:v1, "hashtags", query, _options) do
-    prepare_tags(query)
+  defp resource_search(:v1, "hashtags", query, options) do
+    prepare_tags(query, options)
   end
 
-  defp prepare_tags(query, add_joined_tag \\ true) do
+  defp prepare_tags(query, options) do
     tags =
       query
       |> preprocess_uri_query()
@@ -139,13 +139,20 @@ defmodule Pleroma.Web.MastodonAPI.SearchController do
 
     tags = Enum.map(tags, fn tag -> String.trim_leading(tag, "#") end)
 
-    if Enum.empty?(explicit_tags) && add_joined_tag do
-      tags
-      |> Kernel.++([joined_tag(tags)])
-      |> Enum.uniq_by(&String.downcase/1)
-    else
-      tags
-    end
+    tags =
+      if Enum.empty?(explicit_tags) && !options[:skip_joined_tag] do
+        add_joined_tag(tags)
+      else
+        tags
+      end
+
+    Pleroma.Pagination.paginate(tags, options)
+  end
+
+  defp add_joined_tag(tags) do
+    tags
+    |> Kernel.++([joined_tag(tags)])
+    |> Enum.uniq_by(&String.downcase/1)
   end
 
   # If `query` is a URI, returns last component of its path, otherwise returns `query`
diff --git a/test/web/mastodon_api/controllers/search_controller_test.exs b/test/web/mastodon_api/controllers/search_controller_test.exs
index c605957b1..826f37fbc 100644
--- a/test/web/mastodon_api/controllers/search_controller_test.exs
+++ b/test/web/mastodon_api/controllers/search_controller_test.exs
@@ -151,6 +151,22 @@ defmodule Pleroma.Web.MastodonAPI.SearchControllerTest do
              ]
     end
 
+    test "supports pagination of hashtags search results", %{conn: conn} do
+      results =
+        conn
+        |> get(
+          "/api/v2/search?#{
+            URI.encode_query(%{q: "#some #text #with #hashtags", limit: 2, offset: 1})
+          }"
+        )
+        |> json_response_and_validate_schema(200)
+
+      assert results["hashtags"] == [
+               %{"name" => "text", "url" => "#{Web.base_url()}/tag/text"},
+               %{"name" => "with", "url" => "#{Web.base_url()}/tag/with"}
+             ]
+    end
+
     test "excludes a blocked users from search results", %{conn: conn} do
       user = insert(:user)
       user_smith = insert(:user, %{nickname: "Agent", name: "I love 2hu"})
diff --git a/test/web/mastodon_api/controllers/status_controller_test.exs b/test/web/mastodon_api/controllers/status_controller_test.exs
index 648e6f2ce..a98e939e8 100644
--- a/test/web/mastodon_api/controllers/status_controller_test.exs
+++ b/test/web/mastodon_api/controllers/status_controller_test.exs
@@ -1561,7 +1561,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusControllerTest do
 
     # Using the header for pagination works correctly
     [next, _] = get_resp_header(result, "link") |> hd() |> String.split(", ")
-    [_, max_id] = Regex.run(~r/max_id=(.*)>;/, next)
+    [_, max_id] = Regex.run(~r/max_id=([^&]+)/, next)
 
     assert max_id == third_favorite.id