Unify the logic of updating objects

6 files changed, 183 insertions, 101 deletions

diff --git a/lib/pleroma/object.ex b/lib/pleroma/object.ex
index 670ab8743..fe264b5e0 100644
--- a/lib/pleroma/object.ex
+++ b/lib/pleroma/object.ex
@@ -425,46 +425,4 @@ defmodule Pleroma.Object do
   end
 
   def object_data_hashtags(_), do: []
-
-  def history_for(object) do
-    with history <- Map.get(object, "formerRepresentations"),
-         true <- is_map(history),
-         "OrderedCollection" <- Map.get(history, "type"),
-         true <- is_list(Map.get(history, "orderedItems")),
-         true <- is_integer(Map.get(history, "totalItems")) do
-      history
-    else
-      _ -> history_skeleton()
-    end
-  end
-
-  defp history_skeleton do
-    %{
-      "type" => "OrderedCollection",
-      "totalItems" => 0,
-      "orderedItems" => []
-    }
-  end
-
-  def maybe_update_history(updated_object, orig_object_data, updated) do
-    if not updated do
-      updated_object
-    else
-      # Put edit history
-      # Note that we may have got the edit history by first fetching the object
-      history = Object.history_for(orig_object_data)
-
-      latest_history_item =
-        orig_object_data
-        |> Map.drop(["id", "formerRepresentations"])
-
-      new_history =
-        history
-        |> Map.put("orderedItems", [latest_history_item | history["orderedItems"]])
-        |> Map.put("totalItems", history["totalItems"] + 1)
-
-      updated_object
-      |> Map.put("formerRepresentations", new_history)
-    end
-  end
 end
diff --git a/lib/pleroma/object/fetcher.ex b/lib/pleroma/object/fetcher.ex
index ce816c1fc..d81fdcf24 100644
--- a/lib/pleroma/object/fetcher.ex
+++ b/lib/pleroma/object/fetcher.ex
@@ -50,7 +50,14 @@ defmodule Pleroma.Object.Fetcher do
           Pleroma.Constants.status_updatable_fields()
           |> Enum.any?(fn field -> Map.get(old_data, field) != Map.get(new_data, field) end)
 
-        new_data |> Object.maybe_update_history(old_data, changed?)
+        %{updated_object: updated_object} =
+          new_data
+          |> Object.Updater.maybe_update_history(old_data,
+            updated: changed?,
+            use_history_in_new_object?: false
+          )
+
+        updated_object
       else
         new_data
       end
diff --git a/lib/pleroma/object/updater.ex b/lib/pleroma/object/updater.ex
new file mode 100644
index 000000000..03136c38e
--- /dev/null
+++ b/lib/pleroma/object/updater.ex
@@ -0,0 +1,157 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Object.Updater do
+  require Pleroma.Constants
+
+  def update_content_fields(orig_object_data, updated_object) do
+    Pleroma.Constants.status_updatable_fields()
+    |> Enum.reduce(
+      %{data: orig_object_data, updated: false},
+      fn field, %{data: data, updated: updated} ->
+        updated = updated or Map.get(updated_object, field) != Map.get(orig_object_data, field)
+
+        data =
+          if Map.has_key?(updated_object, field) do
+            Map.put(data, field, updated_object[field])
+          else
+            Map.drop(data, [field])
+          end
+
+        %{data: data, updated: updated}
+      end
+    )
+  end
+
+  def maybe_history(object) do
+    with history <- Map.get(object, "formerRepresentations"),
+         true <- is_map(history),
+         "OrderedCollection" <- Map.get(history, "type"),
+         true <- is_list(Map.get(history, "orderedItems")),
+         true <- is_integer(Map.get(history, "totalItems")) do
+      history
+    else
+      _ -> nil
+    end
+  end
+
+  def history_for(object) do
+    with history when not is_nil(history) <- maybe_history(object) do
+      history
+    else
+      _ -> history_skeleton()
+    end
+  end
+
+  defp history_skeleton do
+    %{
+      "type" => "OrderedCollection",
+      "totalItems" => 0,
+      "orderedItems" => []
+    }
+  end
+
+  def maybe_update_history(
+        updated_object,
+        orig_object_data,
+        opts
+      ) do
+    updated = opts[:updated]
+    use_history_in_new_object? = opts[:use_history_in_new_object?]
+
+    if not updated do
+      %{updated_object: updated_object, used_history_in_new_object?: false}
+    else
+      # Put edit history
+      # Note that we may have got the edit history by first fetching the object
+      {new_history, used_history_in_new_object?} =
+        with true <- use_history_in_new_object?,
+             updated_history when not is_nil(updated_history) <- maybe_history(updated_object) do
+          {updated_history, true}
+        else
+          _ ->
+            history = history_for(orig_object_data)
+
+            latest_history_item =
+              orig_object_data
+              |> Map.drop(["id", "formerRepresentations"])
+
+            updated_history =
+              history
+              |> Map.put("orderedItems", [latest_history_item | history["orderedItems"]])
+              |> Map.put("totalItems", history["totalItems"] + 1)
+
+            {updated_history, false}
+        end
+
+      updated_object =
+        updated_object
+        |> Map.put("formerRepresentations", new_history)
+
+      %{updated_object: updated_object, used_history_in_new_object?: used_history_in_new_object?}
+    end
+  end
+
+  defp maybe_update_poll(to_be_updated, updated_object) do
+    choice_key = fn data ->
+      if Map.has_key?(data, "anyOf"), do: "anyOf", else: "oneOf"
+    end
+
+    with true <- to_be_updated["type"] == "Question",
+         key <- choice_key.(updated_object),
+         true <- key == choice_key.(to_be_updated),
+         orig_choices <- to_be_updated[key] |> Enum.map(&Map.drop(&1, ["replies"])),
+         new_choices <- updated_object[key] |> Enum.map(&Map.drop(&1, ["replies"])),
+         true <- orig_choices == new_choices do
+      # Choices are the same, but counts are different
+      to_be_updated
+      |> Map.put(key, updated_object[key])
+    else
+      # Choices (or vote type) have changed, do not allow this
+      _ -> to_be_updated
+    end
+  end
+
+  # This calculates the data to be sent as the object of an Update.
+  # new_data's formerRepresentations is not considered.
+  # formerRepresentations is added to the returned data.
+  def make_update_object_data(original_data, new_data, date) do
+    %{data: updated_data, updated: updated} =
+      original_data
+      |> update_content_fields(new_data)
+
+    if not updated do
+      updated_data
+    else
+      %{updated_object: updated_data} =
+        updated_data
+        |> maybe_update_history(original_data, updated: updated, use_history_in_new_object?: false)
+
+      updated_data
+      |> Map.put("updated", date)
+    end
+  end
+
+  # This calculates the data of the new Object from an Update.
+  # new_data's formerRepresentations is considered.
+  def make_new_object_data_from_update_object(original_data, new_data) do
+    %{data: updated_data, updated: updated} =
+      original_data
+      |> update_content_fields(new_data)
+
+    %{updated_object: updated_data, used_history_in_new_object?: used_history_in_new_object?} =
+      updated_data
+      |> maybe_update_history(original_data, updated: updated, use_history_in_new_object?: false)
+
+    updated_data =
+      updated_data
+      |> maybe_update_poll(new_data)
+
+    %{
+      updated_data: updated_data,
+      updated: updated,
+      used_history_in_new_object?: used_history_in_new_object?
+    }
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/side_effects.ex b/lib/pleroma/web/activity_pub/side_effects.ex
index aa4183bf6..7345a6904 100644
--- a/lib/pleroma/web/activity_pub/side_effects.ex
+++ b/lib/pleroma/web/activity_pub/side_effects.ex
@@ -412,45 +412,6 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   end
 
   @updatable_object_types ["Note", "Question"]
-  defp update_content_fields(orig_object_data, updated_object) do
-    Pleroma.Constants.status_updatable_fields()
-    |> Enum.reduce(
-      %{data: orig_object_data, updated: false},
-      fn field, %{data: data, updated: updated} ->
-        updated = updated or Map.get(updated_object, field) != Map.get(orig_object_data, field)
-
-        data =
-          if Map.has_key?(updated_object, field) do
-            Map.put(data, field, updated_object[field])
-          else
-            Map.drop(data, [field])
-          end
-
-        %{data: data, updated: updated}
-      end
-    )
-  end
-
-  defp maybe_update_poll(to_be_updated, updated_object) do
-    choice_key = fn data ->
-      if Map.has_key?(data, "anyOf"), do: "anyOf", else: "oneOf"
-    end
-
-    with true <- to_be_updated["type"] == "Question",
-         key <- choice_key.(updated_object),
-         true <- key == choice_key.(to_be_updated),
-         orig_choices <- to_be_updated[key] |> Enum.map(&Map.drop(&1, ["replies"])),
-         new_choices <- updated_object[key] |> Enum.map(&Map.drop(&1, ["replies"])),
-         true <- orig_choices == new_choices do
-      # Choices are the same, but counts are different
-      to_be_updated
-      |> Map.put(key, updated_object[key])
-    else
-      # Choices (or vote type) have changed, do not allow this
-      _ -> to_be_updated
-    end
-  end
-
   defp handle_update_object(
          %{data: %{"type" => "Update", "object" => updated_object}} = object,
          meta
@@ -462,14 +423,11 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
     updated_object = meta[:object_data]
 
     if orig_object_data["type"] in @updatable_object_types do
-      %{data: updated_object_data, updated: updated} =
-        orig_object_data
-        |> update_content_fields(updated_object)
-
-      updated_object_data =
-        updated_object_data
-        |> Object.maybe_update_history(orig_object_data, updated)
-        |> maybe_update_poll(updated_object)
+      %{
+        updated_data: updated_object_data,
+        updated: updated,
+        used_history_in_new_object?: used_history_in_new_object?
+      } = Object.Updater.make_new_object_data_from_update_object(orig_object_data, updated_object)
 
       changeset =
         orig_object
@@ -481,6 +439,16 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
            {:ok, _} <- Object.set_cache(new_object),
            # The metadata/utils.ex uses the object id for the cache.
            {:ok, _} <- Pleroma.Activity.HTML.invalidate_cache_for(new_object.id) do
+        if used_history_in_new_object? do
+          with create_activity when not is_nil(create_activity) <-
+                 Pleroma.Activity.get_create_by_object_ap_id(orig_object_ap_id),
+               {:ok, _} <- Pleroma.Activity.HTML.invalidate_cache_for(create_activity.id) do
+            nil
+          else
+            _ -> nil
+          end
+        end
+
         if updated do
           object
           |> Activity.normalize()
diff --git a/lib/pleroma/web/common_api.ex b/lib/pleroma/web/common_api.ex
index e60c26053..e5a78c102 100644
--- a/lib/pleroma/web/common_api.ex
+++ b/lib/pleroma/web/common_api.ex
@@ -422,15 +422,7 @@ defmodule Pleroma.Web.CommonAPI do
 
     with {:ok, draft} <- ActivityDraft.create(user, params) do
       change =
-        Pleroma.Constants.status_updatable_fields()
-        |> Enum.reduce(orig_object.data, fn key, acc ->
-          if Map.has_key?(draft.object, key) do
-            acc |> Map.put(key, Map.get(draft.object, key))
-          else
-            acc |> Map.drop([key])
-          end
-        end)
-        |> Map.put("updated", Utils.make_date())
+        Object.Updater.make_update_object_data(orig_object.data, draft.object, Utils.make_date())
 
       {:ok, change}
     else
diff --git a/lib/pleroma/web/mastodon_api/views/status_view.ex b/lib/pleroma/web/mastodon_api/views/status_view.ex
index 8439431eb..54e025aae 100644
--- a/lib/pleroma/web/mastodon_api/views/status_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/status_view.ex
@@ -274,7 +274,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
 
     history_len =
       1 +
-        (Object.history_for(object.data)
+        (Object.Updater.history_for(object.data)
          |> Map.get("orderedItems")
          |> length())
 
@@ -413,7 +413,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
     user = CommonAPI.get_user(activity.data["actor"])
 
     past_history =
-      Object.history_for(object.data)
+      Object.Updater.history_for(object.data)
       |> Map.get("orderedItems")
       |> Enum.map(&Map.put(&1, "id", object.data["id"]))
       |> Enum.map(&%Object{data: &1, id: object.id})