Adding likes to tweets

lib/mixer/posts/tweet_like.ex

@@ -0,0 +1,65 @@
+defmodule Mixer.Posts.TweetLike do
+  use Ash.Resource,
+    otp_app: :mixer,
+    domain: Mixer.Posts,
+    data_layer: AshPostgres.DataLayer,
+    authorizers: [Ash.Policy.Authorizer]
+
+  postgres do
+    table "tweet_likes"
+    repo Mixer.Repo
+  end
+
+  actions do
+    defaults [:read, :destroy]
+
+    create :create do
+      accept [:tweet_id]
+      change relate_actor(:user)
+    end
+  end
+
+  attributes do
+    uuid_primary_key :id
+
+    attribute :tweet_id, :uuid do
+      allow_nil? false
+    end
+
+    attribute :user_id, :uuid do
+      allow_nil? false
+    end
+  end
+
+  relationships do
+    belongs_to :tweet, Mixer.Posts.Tweet do
+      attribute_type :uuid
+      attribute_writable? true
+      allow_nil? false
+    end
+
+    belongs_to :user, Mixer.Accounts.User do
+      attribute_type :uuid
+      attribute_writable? true
+      allow_nil? false
+    end
+  end
+
+  identities do
+    identity :unique_user_tweet, [:tweet_id, :user_id]
+  end
+
+  policies do
+    policy action_type(:read) do
+      authorize_if always()
+    end
+
+    policy action(:create) do
+      authorize_if actor_present()
+    end
+
+    policy action_type(:destroy) do
+      authorize_if relates_to_actor_via(:user)
+    end
+  end
+end