Conversations: Create or bump on inserting a dm.

lib/conversation.ex

@@ -5,10 +5,12 @@
 defmodule Pleroma.Conversation do
   alias Pleroma.Repo
   alias Pleroma.Conversation.Participation
+  alias Pleroma.User
   use Ecto.Schema
   import Ecto.Changeset
 
   schema "conversations" do
+    # This is the context ap id.
     field(:ap_id, :string)
     has_many(:participations, Participation)
 
@@ -25,6 +27,44 @@ defmodule Pleroma.Conversation do
   def create_for_ap_id(ap_id) do
     %__MODULE__{}
     |> creation_cng(%{ap_id: ap_id})
-    |> Repo.insert()
+    |> Repo.insert(
+      on_conflict: [set: [updated_at: NaiveDateTime.utc_now()]],
+      returning: true,
+      conflict_target: :ap_id
+    )
+  end
+
+  def get_for_ap_id(ap_id) do
+    Repo.get_by(__MODULE__, ap_id: ap_id)
+  end
+
+  @doc """
+  This will
+  1. Create a conversation if there isn't one already
+  2. Create a participation for all the people involved who don't have one already
+  3. Bump all relevant participations to 'unread'
+  """
+  def create_or_bump_for(activity) do
+    with true <- Pleroma.Web.ActivityPub.Visibility.is_direct?(activity),
+         "Create" <- activity.data["type"],
+         "Note" <- activity.data["object"]["type"],
+         ap_id when is_binary(ap_id) <- activity.data["object"]["context"] do
+      {:ok, conversation} = create_for_ap_id(ap_id)
+
+      local_users = User.get_users_from_set(activity.recipients, true)
+
+      participations =
+        Enum.map(local_users, fn user ->
+          {:ok, participation} =
+            Participation.create_for_user_and_conversation(user, conversation)
+
+          participation
+        end)
+
+      %{
+        conversation
+        | participations: participations
+      }
+    end
   end
 end

lib/conversation/participation.ex

@@ -26,7 +26,11 @@ defmodule Pleroma.Conversation.Participation do
   def create_for_user_and_conversation(user, conversation) do
     %__MODULE__{}
     |> creation_cng(%{user_id: user.id, conversation_id: conversation.id})
-    |> Repo.insert()
+    |> Repo.insert(
+      on_conflict: [set: [read: false, updated_at: NaiveDateTime.utc_now()]],
+      returning: true,
+      conflict_target: [:user_id, :conversation_id]
+    )
   end
 
   def read_cng(struct, params) do

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.ActivityPub.ActivityPub do
   alias Pleroma.Activity
+  alias Pleroma.Conversation
   alias Pleroma.Instances
   alias Pleroma.Notification
   alias Pleroma.Object
@@ -143,6 +144,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       end)
 
       Notification.create_notifications(activity)
+      Conversation.create_or_bump_for(activity)
       stream_out(activity)
       {:ok, activity}
     else