From 3c7585614971849035011ede6c0d5d2d5621df81 Mon Sep 17 00:00:00 2001
From: Thomas Citharel <tcit@tcit.fr>
Date: Wed, 20 Dec 2023 09:26:28 +0100
Subject: [PATCH] fix(feeds): make sure posts for feeds are ordered by
 publication date desc

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
---
 lib/mobilizon/posts/posts.ex | 15 +++++++++++++--
 lib/service/export/common.ex |  2 +-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/mobilizon/posts/posts.ex b/lib/mobilizon/posts/posts.ex
index 5fe60b433..97387b709 100644
--- a/lib/mobilizon/posts/posts.ex
+++ b/lib/mobilizon/posts/posts.ex
@@ -22,11 +22,13 @@ defmodule Mobilizon.Posts do
     :private
   ])
 
-  @spec list_public_local_posts(integer | nil, integer | nil) :: Page.t(Post.t())
-  def list_public_local_posts(page \\ nil, limit \\ nil) do
+  @spec list_public_local_posts(integer | nil, integer | nil, atom | nil, atom | nil) ::
+          Page.t(Post.t())
+  def list_public_local_posts(page \\ nil, limit \\ nil, sort \\ nil, direction \\ nil) do
     Post
     |> filter_public()
     |> filter_local()
+    |> order_posts(sort, direction)
     |> preload_post_associations()
     |> Page.build_page(page, limit)
   end
@@ -171,4 +173,13 @@ defmodule Mobilizon.Posts do
   defp preload_post_associations(query, associations \\ @post_preloads) do
     preload(query, ^associations)
   end
+
+  @spec order_posts(Ecto.Queryable.t(), atom | nil, atom | nil) :: Ecto.Queryable.t()
+  def order_posts(query, nil, _direction), do: query
+  def order_posts(query, _sort, nil), do: query
+
+  def order_posts(query, sort, direction) do
+    order_by_param = Keyword.new([{direction, sort}])
+    order_by(query, ^order_by_param)
+  end
 end
diff --git a/lib/service/export/common.ex b/lib/service/export/common.ex
index 9f3175642..149055e31 100644
--- a/lib/service/export/common.ex
+++ b/lib/service/export/common.ex
@@ -97,7 +97,7 @@ defmodule Mobilizon.Service.Export.Common do
   @spec fetch_instance_public_content(integer()) :: {:ok, list(Event.t()), list(Post.t())}
   def fetch_instance_public_content(limit) do
     %Page{elements: events} = Events.list_public_local_events(1, limit, :begins_on, :desc)
-    %Page{elements: posts} = Posts.list_public_local_posts(1, limit)
+    %Page{elements: posts} = Posts.list_public_local_posts(1, limit, :publish_at, :desc)
     {:ok, events, posts}
   end