From a12ba25f189eaa995c8e845eec95b2435211c196 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Wed, 2 Oct 2019 19:13:52 -0400
Subject: [PATCH] Add user outboxes

---
 lib/clacks/paginator.ex                       | 26 +++++++
 .../controllers/outbox_controller.ex          | 76 +++++++++++++++++++
 lib/clacks_web/router.ex                      |  1 +
 3 files changed, 103 insertions(+)
 create mode 100644 lib/clacks/paginator.ex
 create mode 100644 lib/clacks_web/controllers/outbox_controller.ex

diff --git a/lib/clacks/paginator.ex b/lib/clacks/paginator.ex
new file mode 100644
index 0000000..b83b597
--- /dev/null
+++ b/lib/clacks/paginator.ex
@@ -0,0 +1,26 @@
+defmodule Clacks.Paginator do
+  import Ecto.Query
+
+  def paginate(query, %{"max_id" => max_id}) do
+    query
+    |> where([a], a.id < ^max_id)
+    |> order_by(desc: :id)
+  end
+
+  def paginate(query, %{"since_id" => since_id}) do
+    query
+    |> where([a], a.id > ^since_id)
+    |> order_by(desc: :id)
+  end
+
+  def paginate(query, %{"min_id" => min_id}) do
+    query
+    |> where([a], a.id > ^min_id)
+    |> order_by(asc: :id)
+  end
+
+  def paginate(query, _params) do
+    query
+    |> order_by(desc: :id)
+  end
+end
diff --git a/lib/clacks_web/controllers/outbox_controller.ex b/lib/clacks_web/controllers/outbox_controller.ex
new file mode 100644
index 0000000..b95838d
--- /dev/null
+++ b/lib/clacks_web/controllers/outbox_controller.ex
@@ -0,0 +1,76 @@
+defmodule ClacksWeb.OutboxController do
+  use ClacksWeb, :controller
+  alias Clacks.{Repo, Actor, Activity}
+  import Ecto.Query
+
+  @context "https://www.w3.org/ns/activitystreams"
+  @outbox_types ["Create", "Announce"]
+
+  plug :get_actor
+
+  defp get_actor(%Plug.Conn{path_params: %{"nickname" => nickname}} = conn, _opts) do
+    case Actor.get_by_nickname(nickname) do
+      nil ->
+        conn
+        |> put_status(404)
+
+      %Actor{local: false} ->
+        conn
+        |> put_status(404)
+
+      actor ->
+        assign(conn, :actor, actor)
+    end
+  end
+
+  def outbox(conn, params) when params == %{} do
+    actor = conn.assigns[:actor]
+
+    activities = Repo.all(outbox_query(params, actor))
+
+    data = %{
+      "@context" => @context,
+      "type" => "OrderedCollection",
+      "id" => current_url(conn, %{}),
+      "first" => outbox_page(conn, params, activities)
+    }
+
+    conn
+    |> put_resp_header("content-type", "application/activity+json")
+    |> json(data)
+  end
+
+  def outbox(conn, params) do
+    actor = conn.assigns[:actor]
+
+    activities = Repo.all(outbox_query(params, actor))
+
+    data =
+      outbox_page(conn, params, activities)
+      |> Map.put("@context", @context)
+
+    conn
+    |> put_resp_header("content-type", "application/activity+json")
+    |> json(data)
+  end
+
+  defp outbox_query(params, %Actor{ap_id: ap_id}) do
+    Activity
+    |> where([a], a.actor == ^ap_id)
+    |> where([a], fragment("?->>'type'", a.data) in @outbox_types)
+    |> Clacks.Paginator.paginate(params)
+    |> limit(^Map.get(params, "limit", 20))
+  end
+
+  defp outbox_page(conn, pagination_params, activities) do
+    last_id = List.last(activities).id
+
+    %{
+      "type" => "OrderedColletionPage",
+      "partOf" => current_url(conn, %{}),
+      "id" => current_url(conn, pagination_params),
+      "next" => current_url(conn, %{max_id: last_id}),
+      "orderedItems" => Enum.map(activities, & &1.data)
+    }
+  end
+end
diff --git a/lib/clacks_web/router.ex b/lib/clacks_web/router.ex
index dd0a8e1..be08e25 100644
--- a/lib/clacks_web/router.ex
+++ b/lib/clacks_web/router.ex
@@ -39,6 +39,7 @@ defmodule ClacksWeb.Router do
     get "/users/:nickname", ActorController, :get
     get "/users/:nickname/followers", ActorController, :followers
     get "/users/:nickname/following", ActorController, :following
+    get "/users/:nickname/outbox", OutboxController, :outbox
 
     post "/inbox", InboxController, :shared
     post "/users/:nickname/inbox", InboxController, :user_specific