Refacotr posting into separate module

This will make it easier to keep in sync creating posts from multiple
places (e.g. MastoAPI).

lib/clacks/activitypub.ex

@@ -89,6 +89,7 @@ defmodule Clacks.ActivityPub do
 
   @spec synthesized_create(object :: map()) :: map()
   def synthesized_create(object) do
+    # todo: does this need to have an id field?
     %{
       "@context" => @context,
       "type" => "Create",

lib/clacks/user_actions_helper.ex

@@ -0,0 +1,60 @@
+defmodule Clacks.UserActionsHelper do
+  alias Clacks.{User, Repo, Activity, Object, ActivityPub}
+
+  @public "https://www.w3.org/ns/activitystreams#Public"
+
+  @spec post_status(
+          author :: User.t(),
+          content :: String.t(),
+          in_reply_to :: String.t() | Activity.t() | nil
+        ) :: {:ok, Activity.t()} | {:error, any()}
+
+  def post_status(author, content, in_reply_to_ap_id) when is_binary(in_reply_to_ap_id) do
+    case Activity.get_by_ap_id(in_reply_to_ap_id) do
+      nil ->
+        {:error, "Could find post to reply to with AP ID '#{in_reply_to_ap_id}'"}
+
+      in_reply_to ->
+        post_status(author, content, in_reply_to)
+    end
+  end
+
+  def post_status(author, content, in_reply_to) do
+    note = note_for_posting(author, content, in_reply_to)
+    note_changeset = Object.changeset_for_creating(note)
+    {:ok, _object} = Repo.insert(note_changeset)
+
+    %{"id" => ap_id} = create = ActivityPub.create(note)
+
+    case ActivityPub.Helper.save_and_federate(create, author.actor) do
+      {:ok, activity} ->
+        {:ok, activity}
+
+      :error ->
+        {:error, "Unable to save and federate activity with ID '#{ap_id}'"}
+    end
+  end
+
+  defp note_for_posting(author, content, %Activity{
+         data: %{"id" => in_reply_to_ap_id, "context" => context, "actor" => in_reply_to_actor}
+       }) do
+    to = [in_reply_to_actor, @public]
+    # todo: followers
+    cc = []
+
+    ActivityPub.note(
+      author.actor.ap_id,
+      content,
+      context,
+      in_reply_to_ap_id,
+      nil,
+      DateTime.utc_now(),
+      to,
+      cc
+    )
+  end
+
+  defp note_for_posting(author, content, _in_reply_to) do
+    ActivityPub.note(author.actor.ap_id, content)
+  end
+end

lib/clacks_web/controllers/frontend_controller.ex

@@ -1,6 +1,6 @@
 defmodule ClacksWeb.FrontendController do
   use ClacksWeb, :controller
-  alias Clacks.{Actor, User, Timeline, Repo, ActivityPub, Activity, Object}
+  alias Clacks.{Actor, User, Timeline, Repo, ActivityPub, Activity, Object, UserActionsHelper}
   alias ClacksWeb.Router.Helpers, as: Routes
   alias ClacksWeb.Endpoint
   import Ecto.Query
@@ -251,47 +251,22 @@ defmodule ClacksWeb.FrontendController do
     })
   end
 
-  def post_status(conn, %{"content" => _content} = params) do
+  def post_status(conn, %{"content" => content} = params) do
     current_user = conn.assigns[:user] |> Repo.preload(:actor)
 
-    note = note_for_posting(current_user, params)
-    note_changeset = Object.changeset_for_creating(note)
-    {:ok, _object} = Repo.insert(note_changeset)
-
-    create = ActivityPub.create(note)
-    {:ok, activity} = ActivityPub.Helper.save_and_federate(create, current_user.actor)
-
+    UserActionsHelper.post_status(current_user, content, Map.get(params, "in_reply_to"))
+    |> case do
+      {:ok, activity} ->
         path = Map.get(params, "continue", Routes.frontend_path(Endpoint, :status, activity.id))
         redirect(conn, to: path)
-  end
 
-  defp note_for_posting(current_user, %{"content" => content, "in_reply_to" => in_reply_to_ap_id}) do
-    with %Activity{data: %{"context" => context, "actor" => in_reply_to_actor}} <-
-           Activity.get_by_ap_id(in_reply_to_ap_id) do
-      to = [in_reply_to_actor, @public]
-      # todo: followers
-      cc = []
-
-      ActivityPub.note(
-        current_user.actor.ap_id,
-        content,
-        context,
-        in_reply_to_ap_id,
-        nil,
-        DateTime.utc_now(),
-        to,
-        cc
-      )
-    else
-      _ ->
-        ActivityPub.note(current_user.actor.ap_id, content)
+      {:error, reason} ->
+        conn
+        |> put_flash(:error, "Unable to post status: #{inspect(reason)}")
+        |> redirect(to: Map.get(params, "continue", Routes.frontend_path(Endpoint, :index)))
     end
   end
 
-  defp note_for_posting(current_user, %{"content" => content}) do
-    ActivityPub.note(current_user.actor.ap_id, content)
-  end
-
   @spec follow_activity(follower :: Actor.t(), followee :: Actor.t()) :: map()
   def follow_activity(follower, followee) do
     # todo: get latest