Fix software design suggestions

lib/service/activity_pub/converter/comment.ex

@@ -0,0 +1,104 @@
+defmodule Mobilizon.Service.ActivityPub.Converter.Comment do
+  @moduledoc """
+  Comment converter.
+
+  This module allows to convert events from ActivityStream format to our own
+  internal one, and back.
+  """
+
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Events.Comment, as: CommentModel
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Service.ActivityPub
+  alias Mobilizon.Service.ActivityPub.{Converter, Convertible}
+
+  require Logger
+
+  @behaviour Converter
+
+  defimpl Convertible, for: CommentModel do
+    alias Mobilizon.Service.ActivityPub.Converter.Comment, as: CommentConverter
+
+    defdelegate model_to_as(comment), to: CommentConverter
+  end
+
+  @doc """
+  Converts an AP object data to our internal data structure.
+  """
+  @impl Converter
+  @spec as_to_model_data(map) :: map
+  def as_to_model_data(object) do
+    {:ok, %Actor{id: actor_id}} = ActivityPub.get_or_fetch_by_url(object["actor"])
+
+    Logger.debug("Inserting full comment")
+    Logger.debug(inspect(object))
+
+    data = %{
+      "text" => object["content"],
+      "url" => object["id"],
+      "actor_id" => actor_id,
+      "in_reply_to_comment_id" => nil,
+      "event_id" => nil,
+      "uuid" => object["uuid"]
+    }
+
+    # We fetch the parent object
+    Logger.debug("We're fetching the parent object")
+
+    data =
+      if Map.has_key?(object, "inReplyTo") && object["inReplyTo"] != nil &&
+           object["inReplyTo"] != "" do
+        Logger.debug(fn -> "Object has inReplyTo #{object["inReplyTo"]}" end)
+
+        case ActivityPub.fetch_object_from_url(object["inReplyTo"]) do
+          # Reply to an event (Event)
+          {:ok, %Event{id: id}} ->
+            Logger.debug("Parent object is an event")
+            data |> Map.put("event_id", id)
+
+          # Reply to a comment (Comment)
+          {:ok, %CommentModel{id: id} = comment} ->
+            Logger.debug("Parent object is another comment")
+
+            data
+            |> Map.put("in_reply_to_comment_id", id)
+            |> Map.put("origin_comment_id", comment |> CommentModel.get_thread_id())
+
+          # Anything else is kind of a MP
+          {:error, parent} ->
+            Logger.debug("Parent object is something we don't handle")
+            Logger.debug(inspect(parent))
+            data
+        end
+      else
+        Logger.debug("No parent object for this comment")
+
+        data
+      end
+
+    data
+  end
+
+  @doc """
+  Make an AS comment object from an existing `Comment` structure.
+  """
+  @impl Converter
+  @spec model_to_as(CommentModel.t()) :: map
+  def model_to_as(%CommentModel{} = comment) do
+    object = %{
+      "type" => "Note",
+      "to" => ["https://www.w3.org/ns/activitystreams#Public"],
+      "content" => comment.text,
+      "actor" => comment.actor.url,
+      "attributedTo" => comment.actor.url,
+      "uuid" => comment.uuid,
+      "id" => comment.url
+    }
+
+    if comment.in_reply_to_comment do
+      object |> Map.put("inReplyTo", comment.in_reply_to_comment.url || comment.event.url)
+    else
+      object
+    end
+  end
+end