Update Publisher to sync only a new non-local data.

lib/decentralised_book_index/metadata.ex

@@ -149,6 +149,7 @@ defmodule DecentralisedBookIndex.Metadata do
       define :get_publisher_by_id, args: [:id], action: :by_id
       define :search_publisher, action: :search, args: [:name]
       define :update_publisher, action: :update
+      define :assign_publisher_dbi_server, args: [:dbi_server_id], action: :assign_dbi_server_id
       define :destroy_publisher, action: :destroy
     end
   end

lib/decentralised_book_index/metadata/publisher.ex

@@ -56,6 +56,10 @@ defmodule DecentralisedBookIndex.Metadata.Publisher do
       accept [:name]
     end
 
+    update :assign_dbi_server_id do
+      accept [:dbi_server_id]
+    end
+
     update :sync do
       accept [:name, :inserted_at, :updated_at, :dbi_server_id]
     end

lib/decentralised_book_index/sync/sync/publisher_sync.ex

@@ -5,21 +5,23 @@ defmodule DecentralisedBookIndex.Sync.PublisherSync do
   def create_update(attrs, server_id) do
     case Metadata.get_publisher_by_id(attrs.id) do
       {:ok, publisher} ->
+        if not is_local(publisher) and is_new(attrs, publisher) do
           attrs =
             attrs
             |> Map.delete(:id)
-          |> Map.put(:dbi_server_id, server_id)
+            |> Map.put_new(:dbi_server_id, server_id)
 
           publisher
           |> Ash.Changeset.for_update(:sync, attrs)
           |> Ash.update!(authorize?: false)
+        end
 
         :ok
 
       {:error, %Ash.Error.Query.NotFound{}} ->
         attrs =
           attrs
-          |> Map.put(:dbi_server_id, server_id)
+          |> Map.put_new(:dbi_server_id, server_id)
 
         Publisher
         |> Ash.Changeset.for_create(:sync_create, attrs)
@@ -28,4 +30,17 @@ defmodule DecentralisedBookIndex.Sync.PublisherSync do
         :ok
     end
   end
+
+  defp is_local(publisher) do
+    is_nil(publisher.dbi_server_id)
+  end
+
+  defp is_new(new_publisher, publisher) do
+    with {:ok, datetime, _offset} <- DateTime.from_iso8601(new_publisher[:updated_at]) do
+      DateTime.after?(datetime, publisher.updated_at)
+    else
+      {:error, reason} ->
+        false
+    end
+  end
 end

test/decentralised_book_index/sync/sync/publisher_sync_test.exs

@@ -29,12 +29,9 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.PublisherSyncTest do
       assert :ok = PublisherSync.create_update(publisher, server.id)
       assert {:ok, saved_publisher} = Metadata.get_publisher_by_id(publisher.id)
 
-      publisher =
+      publisher = datetime_from_iso8601_for_map(publisher)
-        publisher
-        |> Map.replace(:inserted_at, inserted_at)
-        |> Map.replace(:updated_at, updated_at)
 
-      assert publisher = saved_publisher
+      assert get_submap(saved_publisher, publisher) == publisher
       assert server.id == saved_publisher.dbi_server_id
     end
 
@@ -42,19 +39,64 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.PublisherSyncTest do
       server = generate(dbi_server(url: @test_server_endpoint))
 
       {:ok, publisher} = Metadata.create_publisher("Publisher", actor: user)
+      {:ok, publisher} = Metadata.assign_publisher_dbi_server(publisher, server.id, actor: user)
 
       publisher_attrs = %{
         id: publisher.id,
         name: "Publisher",
         inserted_at: "2025-03-21T09:20:48.791539Z",
-        updated_at: "2025-03-21T09:20:48.791539Z"
+        updated_at: datetime_add_second_as_string(publisher.updated_at, 10),
+        dbi_server_id: server.id
       }
 
       assert :ok = PublisherSync.create_update(publisher_attrs, server.id)
       assert {:ok, saved_publisher} = Metadata.get_publisher_by_id(publisher.id)
 
-      assert publisher_attrs = saved_publisher
+      publisher_attrs = datetime_from_iso8601_for_map(publisher_attrs)
+
+      assert get_submap(saved_publisher, publisher_attrs) == publisher_attrs
       assert server.id == saved_publisher.dbi_server_id
     end
+
+    test "the local existing publisher wouldn't updated", %{user: user} do
+      server = generate(dbi_server(url: @test_server_endpoint))
+
+      {:ok, publisher} = Metadata.create_publisher("Publisher", actor: user)
+
+      publisher_attrs = %{
+        id: publisher.id,
+        name: "Updated Publisher",
+        inserted_at: "2025-03-21T09:20:48.791539Z",
+        updated_at: "2025-03-21T09:20:48.791539Z"
+      }
+
+      assert :ok = PublisherSync.create_update(publisher_attrs, server.id)
+      assert {:ok, saved_publisher} = Metadata.get_publisher_by_id(publisher.id)
+
+      assert get_submap(saved_publisher, publisher_attrs) != publisher_attrs
+      assert saved_publisher.name == "Publisher"
+      assert saved_publisher.dbi_server_id == nil
+    end
+
+    test "old publisher wouldn't be sync", %{user: user} do
+      server = generate(dbi_server(url: @test_server_endpoint))
+
+      {:ok, publisher} = Metadata.create_publisher("Publisher", actor: user)
+      {:ok, publisher} = Metadata.assign_publisher_dbi_server(publisher, server.id, actor: user)
+
+      publisher_attrs = %{
+        id: publisher.id,
+        name: "Old Publisher",
+        inserted_at: "2022-03-21T09:20:48.791539Z",
+        updated_at: "2022-03-21T09:20:48.791539Z",
+        dbi_server_id: server.id
+      }
+
+      assert :ok = PublisherSync.create_update(publisher_attrs, server.id)
+      assert {:ok, saved_publisher} = Metadata.get_publisher_by_id(publisher.id)
+
+      assert get_submap(saved_publisher, publisher_attrs) != publisher_attrs
+      assert saved_publisher.name == "Publisher"
+    end
   end
 end