3 files changed, 122 insertions, 8 deletions
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 24b4f045a..8485a8009 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -192,12 +192,11 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  def unfollow(follower, followed, local \\ true) do
+  def unfollow(follower, followed, activity_id \\ nil, local \\ true) do
     with %Activity{} = follow_activity <- fetch_latest_follow(follower, followed),
-         unfollow_data <- make_unfollow_data(follower, followed, follow_activity),
+         unfollow_data <- make_unfollow_data(follower, followed, follow_activity, activity_id),
          {:ok, activity} <- insert(unfollow_data, local),
-         :ok,
-         maybe_federate(activity) do
+         :ok <- maybe_federate(activity) do
       {:ok, activity}
     end
   end
@@ -221,6 +220,29 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
+  def block(blocker, blocked, activity_id \\ nil, local \\ true) do
+    follow_activity = fetch_latest_follow(blocker, blocked)
+
+    if follow_activity do
+      unfollow(blocker, blocked, nil, local)
+    end
+
+    with block_data <- make_block_data(blocker, blocked, activity_id),
+         {:ok, activity} <- insert(block_data, local),
+         :ok <- maybe_federate(activity) do
+      {:ok, activity}
+    end
+  end
+
+  def unblock(blocker, blocked, activity_id \\ nil, local \\ true) do
+    with %Activity{} = block_activity <- fetch_latest_block(blocker, blocked),
+         unblock_data <- make_unblock_data(blocker, blocked, block_activity, activity_id),
+         {:ok, activity} <- insert(unblock_data, local),
+         :ok <- maybe_federate(activity) do
+      {:ok, activity}
+    end
+  end
+
   def fetch_activities_for_context(context, opts \\ %{}) do
     public = ["https://www.w3.org/ns/activitystreams#Public"]
 
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 7d6fd8632..803445011 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -244,6 +244,56 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   def handle_incoming(
         %{
           "type" => "Undo",
+          "object" => %{"type" => "Follow", "object" => followed},
+          "actor" => follower,
+          "id" => id
+        } = _data
+      ) do
+    with %User{local: true} = followed <- User.get_cached_by_ap_id(followed),
+         %User{} = follower <- User.get_or_fetch_by_ap_id(follower),
+         {:ok, activity} <- ActivityPub.unfollow(follower, followed, id, false) do
+      User.unfollow(follower, followed)
+      {:ok, activity}
+    else
+      e -> :error
+    end
+  end
+
+  def handle_incoming(
+        %{
+          "type" => "Undo",
+          "object" => %{"type" => "Block", "object" => blocked},
+          "actor" => blocker,
+          "id" => id
+        } = _data
+      ) do
+    with %User{local: true} = blocked <- User.get_cached_by_ap_id(blocked),
+         %User{} = blocker <- User.get_or_fetch_by_ap_id(blocker),
+         {:ok, activity} <- ActivityPub.unblock(blocker, blocked, id, false) do
+      User.unblock(blocker, blocked)
+      {:ok, activity}
+    else
+      e -> :error
+    end
+  end
+
+  def handle_incoming(
+        %{"type" => "Block", "object" => blocked, "actor" => blocker, "id" => id} = data
+      ) do
+    with %User{local: true} = blocked = User.get_cached_by_ap_id(blocked),
+         %User{} = blocker = User.get_or_fetch_by_ap_id(blocker),
+         {:ok, activity} <- ActivityPub.block(blocker, blocked, id, false) do
+      User.unfollow(blocker, blocked)
+      User.block(blocker, blocked)
+      {:ok, activity}
+    else
+      e -> :error
+    end
+  end
+
+  def handle_incoming(
+        %{
+          "type" => "Undo",
           "object" => %{"type" => "Like", "object" => object_id},
           "actor" => actor,
           "id" => id
@@ -261,7 +311,6 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
 
   # TODO
   # Accept
-  # Undo for non-Announce
 
   def handle_incoming(_), do: :error
 
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index a3feca480..831e13b7e 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -347,13 +347,56 @@ defmodule Pleroma.Web.ActivityPub.Utils do
 
   #### Unfollow-related helpers
 
-  def make_unfollow_data(follower, followed, follow_activity) do
-    %{
+  def make_unfollow_data(follower, followed, follow_activity, activity_id) do
+    data = %{
       "type" => "Undo",
       "actor" => follower.ap_id,
       "to" => [followed.ap_id],
-      "object" => follow_activity.data["id"]
+      "object" => follow_activity.data
+    }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
+  end
+
+  #### Block-related helpers
+  def fetch_latest_block(%User{ap_id: blocker_id}, %User{ap_id: blocked_id}) do
+    query =
+      from(
+        activity in Activity,
+        where:
+          fragment(
+            "? @> ?",
+            activity.data,
+            ^%{type: "Block", object: blocked_id}
+          ),
+        where: activity.actor == ^blocker_id,
+        order_by: [desc: :id],
+        limit: 1
+      )
+
+    Repo.one(query)
+  end
+
+  def make_block_data(blocker, blocked, activity_id) do
+    data = %{
+      "type" => "Block",
+      "actor" => blocker.ap_id,
+      "to" => [blocked.ap_id],
+      "object" => blocked.ap_id
+    }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
+  end
+
+  def make_unblock_data(blocker, blocked, block_activity, activity_id) do
+    data = %{
+      "type" => "Undo",
+      "actor" => blocker.ap_id,
+      "to" => [blocked.ap_id],
+      "object" => block_activity.data
     }
+
+    if activity_id, do: Map.put(data, "id", activity_id), else: data
   end
 
   #### Create-related helpers