unfollow

lib/vonbraun/activity_pub/handler/accept.ex

@@ -23,12 +23,12 @@ defmodule Vonbraun.ActivityPub.Handler.Accept do
       {:ok, actor_id}
     else
       _ ->
-        {:error, :notfound}
+        {:error, :not_found}
     end
   end
 
   def extract_follow_object_actor(_) do
-    {:error, :notfound}
+    {:error, :not_found}
   end
 
   # Lots of kinds of things can be accepted but for right now only follows.

lib/vonbraun/activity_pub/object.ex

@@ -51,12 +51,16 @@ defmodule Vonbraun.ActivityPub.Object do
     }
   end
 
-  def my_follow_activity_id(to_follow_id) when is_binary(to_follow_id),
-    do:
-      "https://#{Application.fetch_env!(:vonbraun, :domain)}/id/follow:#{URI.encode(to_follow_id)}"
+  @spec create_actor_activity_id(String.t(), String.t()) :: String.t()
+  def create_actor_activity_id(actor_id, verb) when is_binary(actor_id) and is_binary(verb) do
+    "https://#{Application.fetch_env!(:vonbraun, :domain)}/id/#{URI.encode(verb)}:#{URI.encode(actor_id)}"
+  end
 
   def follow_activity(to_follow_id) when is_binary(to_follow_id),
-    do: activity("Follow", my_follow_activity_id(to_follow_id), to_follow_id, to: to_follow_id)
+    do:
+      activity("Follow", create_actor_activity_id(to_follow_id, "follow"), to_follow_id,
+        to: to_follow_id
+      )
 
   def accept_follow_activity(followee_id, activity_id, type \\ :accept)
       when is_binary(followee_id) and is_binary(activity_id) and type in [:accept, :reject] do
@@ -74,7 +78,7 @@ defmodule Vonbraun.ActivityPub.Object do
     }
 
     accept_activity_id =
-      "https://#{Application.fetch_env!(:vonbraun, :domain)}/id/follow-reply:#{URI.encode(followee_id)}"
+      create_actor_activity_id(followee_id, "follow-reply")
 
     activity(activity_type, accept_activity_id, object, to: followee_id)
   end

lib/vonbraun/activitypub_req.ex

@@ -86,6 +86,6 @@ defmodule Vonbraun.ActivityPubReq do
   end
 
   def extract_actor_inbox(%{}) do
-    {:error, :notfound}
+    {:error, :not_found}
   end
 end

lib/vonbraun/control.ex

@@ -58,7 +58,49 @@ defmodule Vonbraun.Control do
     end
   end
 
-  def unfollow(id) when is_binary(id) do
+  def unfollow(followee_actor_id) when is_binary(followee_actor_id) do
+    with {:actor, {:ok, actor}} <- {:actor, ActivityPubReq.get_cached_actor(followee_actor_id)},
+         {:inbox, {:ok, raw_inbox}} <- {:inbox, ActivityPubReq.extract_actor_inbox(actor)},
+         {:parse_inbox, inbox = %URI{}} <- {:parse_inbox, URI.parse(raw_inbox)},
+         {:state, {:ok, %Actor{}}} <-
+           {:state, Actor.remove_followee(followee_actor_id)} do
+      object = Object.follow_activity(followee_actor_id)
+      activity_id = Object.create_actor_activity_id(followee_actor_id, "unfollow")
+      activity = Object.activity("Undo", activity_id, object)
+      payload = Jason.encode!(activity)
+
+      case ActivityPubReq.post(inbox, payload) do
+        {:ok, %{:status => status, :body => body}} when status >= 200 and status <= 299 ->
+          Logger.debug(inspect(body))
+          Logger.info("Unfollow request sent successfully, now it's up to the remote server.")
+          :ok
+
+        {:ok, %{:status => status, :body => body}} ->
+          Logger.debug(inspect(body))
+          Logger.warning("Got a status of: #{status}, probably not good.")
+          {:error, {:status, status}}
+
+        {:error, error} ->
+          Logger.error("Failed to send unfollow request: #{inspect(error)}")
+          {:error, {:post, error}}
+      end
+    else
+      {:inbox, {:error, _}} ->
+        Logger.warning("Actor had an invalid inbox.")
+        {:error, :invalid_inbox}
+
+      {:actor, {:error, error}} ->
+        Logger.warning("Failed to query remote actor: #{inspect(error)}")
+        {:error, {:actor, error}}
+
+      {:state, error = {:error, :not_following}} ->
+        Logger.warning("Not following user.")
+        error
+
+      {:state, {:error, error}} ->
+        Logger.error("Unexpected error: #{inspect(error)}")
+        {:error, error}
+    end
   end
 
   def post_note(content, public?, to \\ [])

lib/vonbraun/ecto/schema/actor.ex

@@ -181,6 +181,28 @@ defmodule Vonbraun.Ecto.Schema.Actor do
     end
   end
 
+  @spec remove_followee(String.t()) :: {:ok, __MODULE__.t()} | {:error, any()}
+  @doc """
+  Mark a remote actor as no longer being followed.
+  """
+  def remove_followee(id) when is_binary(id) do
+    case Repo.get(__MODULE__, id) do
+      nil ->
+        {:error, :not_following}
+
+      actor = %__MODULE__{:following_state => following_state}
+      when following_state in ["accepted", "pending"] ->
+        now = DateTime.now!("Etc/UTC")
+
+        changeset(actor, %{following_state: nil, following_ts: now})
+        |> Repo.update()
+
+      %__MODULE__{:following_state => following_state}
+      when following_state == "rejected" or is_nil(following_state) ->
+        {:error, :not_following}
+    end
+  end
+
   @spec get_my_followers() :: list(String.t())
   def get_my_followers() do
     query =