Add basic mastodon notification support.

lib/pleroma/notification.ex

@@ -0,0 +1,38 @@
+defmodule Pleroma.Notification do
+  use Ecto.Schema
+  alias Pleroma.{User, Activity, Notification, Repo}
+  import Ecto.Query
+
+  schema "notifications" do
+    field :seen, :boolean, default: false
+    belongs_to :user, Pleroma.User
+    belongs_to :activity, Pleroma.Activity
+
+    timestamps()
+  end
+
+  def for_user(user, opts \\ %{}) do
+    query = from n in Notification,
+      where: n.user_id == ^user.id,
+      order_by: [desc: n.id],
+      preload: [:activity],
+      limit: 20
+    Repo.all(query)
+  end
+
+  def create_notifications(%Activity{id: id, data: %{"to" => to, "type" => type}} = activity) when type in ["Create"] do
+    users = User.get_notified_from_activity(activity)
+
+    notifications = Enum.map(users, fn (user) -> create_notification(activity, user) end)
+    {:ok, notifications}
+  end
+  def create_notifications(_), do: {:ok, []}
+
+  # TODO move to sql, too.
+  def create_notification(%Activity{} = activity, %User{} = user) do
+    notification = %Notification{user_id: user.id, activity_id: activity.id}
+    {:ok, notification} = Repo.insert(notification)
+    notification
+  end
+end
+