Update

lib/nulla_web/controllers/inbox_controller.ex

@@ -1,25 +1,23 @@
 defmodule NullaWeb.InboxController do
   use NullaWeb, :controller
+  alias Nulla.Models.Follow
+  alias Nulla.Utils
 
-  def receive(conn, %{"type" => "Follow"} = activity) do
-    # Check signature
-    # Verify actor and object
-    # Save follow to db
-    # Send Accept or Reject
-    json(conn, %{"status" => "Follow received"})
-  end
-
-  def receive(conn, %{"type" => "Like"} = activity) do
-    # Process Like
-    json(conn, %{"status" => "Like received"})
-  end
-
-  def receive(conn, %{"type" => "Create"} = activity) do
-    # Create object and save
-    json(conn, %{"status" => "Object created"})
-  end
-
-  def receive(conn, _params) do
-    json(conn, %{"status" => "Unhandled type"})
+  def inbox(
+        conn,
+        %{"type" => "Follow", "actor" => actor_uri, "object" => target_uri} = activity
+      ) do
+    with {:ok, target_user} <- Utils.resolve_local_actor(target_uri),
+         {:ok, remote_actor} <- Utils.fetch_remote_actor(actor_uri),
+         :ok <- HTTPSignature.verify(conn, remote_actor),
+         remote_user <- Follow.create_remote_user(remote_actor),
+         follow <- Follow.create_follow(%{user: remote_user, target: target_user}),
+         :ok <- Utils.send_accept_activity(remote_actor, target_user, follow, activity) do
+      json(conn, %{"status" => "Follow accepted"})
+    else
+      error ->
+        IO.inspect(error, label: "Follow error")
+        json(conn, %{"error" => "Failed to process Follow"})
+    end
   end
 end