Update

lib/nulla/models/relation.ex

@@ -0,0 +1,30 @@
+defmodule Nulla.Models.Relation do
+  use Ecto.Schema
+  import Ecto.Changeset
+  alias Nulla.Models.Actor
+  alias Nulla.Models.Activity
+
+  @primary_key {:id, :integer, autogenerate: false}
+  schema "relations" do
+    field :type, :string
+    field :status, :string
+
+    belongs_to :source, Actor, foreign_key: :source_id, type: :integer
+    belongs_to :target, Actor, foreign_key: :target_id, type: :integer
+    belongs_to :activity, Activity, foreign_key: :activity_id, type: :integer
+
+    timestamps()
+  end
+
+  def changeset(relation, attrs) do
+    relation
+    |> cast(attrs, [:id, :source_id, :target_id, :type, :status, :activity_id])
+    |> validate_required([:id, :source_id, :target_id, :type])
+    |> validate_inclusion(:type, ~w(follow block mute friend_request))
+    |> validate_inclusion(:status, ~w(pending accepted rejected active))
+    |> foreign_key_constraint(:source_id)
+    |> foreign_key_constraint(:target_id)
+    |> foreign_key_constraint(:activity_id)
+    |> unique_constraint([:source_id, :target_id, :type])
+  end
+end