Update outbox

lib/nulla/activitypub.ex

@@ -316,4 +316,44 @@ defmodule Nulla.ActivityPub do
       last: "https://#{domain}/@#{username}/outbox?min_id=0&page=true"
     )
   end
+
+  @spec outbox(String.t(), Integer.t(), Integer.t(), String.t(), List.t()) ::
+          Jason.OrderedObject.t()
+  def outbox(domain, username, max_id, min_id, items) do
+    Jason.OrderedObject.new(
+      "@context": [
+        "https://www.w3.org/ns/activitystreams",
+        Jason.OrderedObject.new(
+          sensitive: "as:sensitive",
+          Hashtag: "as:Hashtag"
+        )
+      ],
+      id: "https://#{domain}/@#{username}/outbox?page=true",
+      type: "OrderedCollectionPage",
+      next: "https://#{domain}/@#{username}/outbox?max_id=#{max_id}&page=true",
+      prev: "https://#{domain}/@#{username}/outbox?min_id=#{min_id}&page=true",
+      partOf: "https://#{domain}/@#{username}/outbox",
+      orderedItems: items
+    )
+  end
+
+  @spec render_activity(String.t(), Note.t()) :: Jason.OrderedObject.t()
+  def render_activity(domain, note) do
+    Jason.OrderedObject.new(
+      id: "https://#{domain}/@#{note.user.username}/#{note.id}/activity",
+      type: "Create",
+      actor: "https://#{domain}/@#{note.user.username}",
+      published: note.inserted_at |> DateTime.to_iso8601(),
+      to: ["https://www.w3.org/ns/activitystreams#Public"],
+      object:
+        Jason.OrderedObject.new(
+          id: "https://#{domain}/@#{note.user.username}/#{note.id}",
+          type: "Note",
+          content: note.content,
+          published: note.inserted_at |> DateTime.to_iso8601(),
+          attributedTo: "https://#{domain}/@#{note.user.username}",
+          to: ["https://www.w3.org/ns/activitystreams#Public"]
+        )
+    )
+  end
 end

lib/nulla/models/note.ex

@@ -32,7 +32,23 @@ defmodule Nulla.Models.Note do
 
   def get_note!(id), do: Repo.get!(Note, id)
 
-  def get_all_notes!(user_id), do: Repo.all(from n in Note, where: n.user_id == ^user_id)
+  def get_latest_notes(user_id, limit \\ 20) do
+    from(n in Note,
+      where: n.user_id == ^user_id,
+      order_by: [desc: n.inserted_at],
+      limit: ^limit
+    )
+    |> Repo.all()
+  end
+
+  def get_before_notes(user_id, max_id, limit \\ 20) do
+    from(n in Note,
+      where: n.user_id == ^user_id and n.id < ^max_id,
+      order_by: [desc: n.inserted_at],
+      limit: ^limit
+    )
+    |> Nulla.Repo.all()
+  end
 
   def get_total_notes_count(user_id) do
     from(n in Note, where: n.user_id == ^user_id)

lib/nulla_web/controllers/outbox_controller.ex

@@ -5,7 +5,43 @@ defmodule NullaWeb.OutboxController do
   alias Nulla.Models.Note
   alias Nulla.Models.InstanceSettings
 
-  def show(conn, %{"username" => username}) do
+  def show(conn, %{"username" => username} = params) do
+    case Map.get(params, "page") do
+      "true" ->
+        instance_settings = InstanceSettings.get_instance_settings!()
+        domain = instance_settings.domain
+        user = User.get_user_by_username!(username)
+        max_id = params["max_id"] && String.to_integer(params["max_id"])
+
+        notes =
+          if max_id do
+            Note.get_before_notes(user.id, max_id)
+          else
+            Note.get_latest_notes(user.id)
+          end
+
+        items = Enum.map(notes, &ActivityPub.render_activity(&1, domain))
+
+        next_max_id =
+          case List.last(notes) do
+            nil -> 0
+            last -> last.id
+          end
+
+        min_id =
+          case List.first(notes) do
+            nil -> 0
+            first -> first.id
+          end
+
+        conn
+        |> put_resp_content_type("application/activity+json")
+        |> send_resp(
+          200,
+          Jason.encode!(ActivityPub.outbox(domain, username, next_max_id, min_id || 0, items))
+        )
+
+      _ ->
         instance_settings = InstanceSettings.get_instance_settings!()
         domain = instance_settings.domain
         user = User.get_user_by_username!(username)
@@ -16,3 +52,4 @@ defmodule NullaWeb.OutboxController do
         |> send_resp(200, Jason.encode!(ActivityPub.outbox(domain, username, total)))
     end
   end
+end

lib/nulla_web/controllers/user_controller.ex

@@ -11,7 +11,7 @@ defmodule NullaWeb.UserController do
     instance_settings = InstanceSettings.get_instance_settings!()
     domain = instance_settings.domain
     user = User.get_user_by_username!(username)
-    notes = Note.get_all_notes!(user.id)
+    notes = Note.get_notes(user.id)
 
     if accept in ["application/activity+json", "application/ld+json"] do
       conn