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

lib/decentralised_book_index/metadata.ex

@@ -74,6 +74,7 @@ defmodule DecentralisedBookIndex.Metadata do
       define :search_book_by_bid, action: :search_by_bid, args: [:type, :bid]
       define :update_book, action: :update
       define :assign_book_cover_image, args: [:cover_image_url], action: :assign_cover_image
+      define :assign_book_dbi_server, args: [:dbi_server_id], action: :assign_dbi_server_id
       define :destroy_book, action: :destroy
     end
 

lib/decentralised_book_index/metadata/book.ex

@@ -40,7 +40,8 @@ defmodule DecentralisedBookIndex.Metadata.Book do
         :published,
         :publisher_id,
         :cover_image_url,
-        :book_editions_registry_id
+        :book_editions_registry_id,
+        :dbi_server_id
       ]
 
       argument :bids, {:array, :map}
@@ -276,6 +277,10 @@ defmodule DecentralisedBookIndex.Metadata.Book do
     update :assign_cover_image do
       accept [:cover_image_url]
     end
+
+    update :assign_dbi_server_id do
+      accept [:dbi_server_id]
+    end
   end
 
   policies do

lib/decentralised_book_index/sync/sync/book_sync.ex

@@ -8,15 +8,18 @@ defmodule DecentralisedBookIndex.Sync.BookSync do
 
     case Metadata.get_book_by_id(attrs.id) do
       {:ok, book} ->
+
+        if not is_local(book) and is_new(attrs, book) do
           attrs =
             attrs
             |> Map.delete(:id)
             |> update_registry(registry_info)
-          |> Map.put(:dbi_server_id, server_id)
+            |> Map.put_new(:dbi_server_id, server_id)
 
           book
           |> Ash.Changeset.for_update(:sync, attrs)
           |> Ash.update!(authorize?: false)
+        end
 
         :ok
 
@@ -24,7 +27,7 @@ defmodule DecentralisedBookIndex.Sync.BookSync do
         attrs =
           attrs
           |> update_registry(registry_info)
-          |> Map.put(:dbi_server_id, server_id)
+          |> Map.put_new(:dbi_server_id, server_id)
 
         Book
         |> Ash.Changeset.for_create(:sync_create, attrs)
@@ -58,4 +61,17 @@ defmodule DecentralisedBookIndex.Sync.BookSync do
         |> Map.delete(:book_editions_registry_id)
     end
   end
+
+  defp is_local(book) do
+    is_nil(book.dbi_server_id)
+  end
+
+  defp is_new(new_book, book) do
+    with {:ok, datetime, _offset} <- DateTime.from_iso8601(new_book[:updated_at]) do
+      DateTime.after?(datetime, book.updated_at)
+    else
+      {:error, reason} ->
+        false
+    end
+  end
 end

test/decentralised_book_index/sync/sync/book_sync_test.exs

@@ -7,6 +7,11 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.BookSyncTest do
   alias DecentralisedBookIndex.TestEndpoints
   @test_server_endpoint TestEndpoints.test_api_endpoint()
 
+  setup do
+    user = generate(user(role: :moderator))
+    %{user: user}
+  end
+
   describe "sync book transformations" do
     test "a new book will be created" do
       server = generate(dbi_server(url: @test_server_endpoint))
@@ -164,11 +169,62 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.BookSyncTest do
       assert {:ok, saved_book} = Metadata.get_book_by_id(book.id)
     end
 
-    test "update book's relationship for an existing book" do
+    test "the local existing book wouldn't updated", %{user: user} do
+      server = generate(dbi_server(url: @test_server_endpoint))
+
+      book = generate(book())
+
+      book_attrs = %{
+        id: book.id,
+        cover_image_url: "/images/book_cover2.png",
+        description: "A cool book 2.",
+        format: "Ebook",
+        inserted_at: "2025-01-20T14:44:36.162986Z",
+        language: "English",
+        page_count: 1001,
+        published: "2025-03-05",
+        title: "New Book2",
+        updated_at: "2025-02-01T18:14:25.754055Z"
+      }
+
+      assert :ok = BookSync.create_update(book_attrs, server.id)
+      assert {:ok, saved_book} = Metadata.get_book_by_id(book.id)
+
+      assert get_submap(saved_book, book_attrs) != book_attrs
+      assert saved_book.title != "New Book2"
+      assert saved_book.dbi_server_id == nil
+    end
+
+    test "old book wouldn't be sync", %{user: user} do
       server = generate(dbi_server(url: @test_server_endpoint))
 
       book = generate(book())
 
+      book_attrs = %{
+        id: book.id,
+        cover_image_url: "/images/book_cover2.png",
+        description: "A cool book 2.",
+        format: "Ebook",
+        inserted_at: "2025-01-20T14:44:36.162986Z",
+        language: "English",
+        page_count: 1001,
+        published: "2025-03-05",
+        title: "New Book2",
+        updated_at: "2025-02-01T18:14:25.754055Z"
+      }
+
+      assert :ok = BookSync.create_update(book_attrs, server.id)
+      assert {:ok, saved_book} = Metadata.get_book_by_id(book.id)
+
+      assert get_submap(saved_book, book_attrs) != book_attrs
+      assert saved_book.title != "New Book2"
+    end
+
+    test "update book's relationship for an existing book" do
+      server = generate(dbi_server(url: @test_server_endpoint))
+
+      book = generate(book(dbi_server_id: server.id))
+
       author1 = generate(author())
       author2 = generate(author())
       publisher = generate(publisher())
@@ -212,7 +268,8 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.BookSyncTest do
         published: "2025-03-04",
         publisher_id: publisher.id,
         title: "Book 6",
-        updated_at: "2025-04-08T07:02:42.778095Z"
+        updated_at: datetime_add_second_as_string(book.updated_at, 10),
+        dbi_server_id: server.id
       }
 
       assert :ok = BookSync.create_update(book_attrs, server.id)
@@ -228,7 +285,7 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.BookSyncTest do
     test "olds bids and roles are destroyed after update" do
       server = generate(dbi_server(url: @test_server_endpoint))
 
-      book = generate(book())
+      book = generate(book(dbi_server_id: server.id))
 
       author1 = generate(author())
       author2 = generate(author())
@@ -273,7 +330,8 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.BookSyncTest do
         published: "2025-03-04",
         publisher_id: publisher.id,
         title: "Book 6",
-        updated_at: "2025-04-08T07:02:42.778095Z"
+        updated_at: datetime_add_second_as_string(book.updated_at, 10),
+        dbi_server_id: server.id
       }
 
       old_bids = get_ids(Metadata.list_book_ids!())

test/support/generators.ex

@@ -179,6 +179,8 @@ defmodule DecentralisedBookIndex.Generators do
 
     related_book = opts[:related_book] || nil
 
+    dbi_server_id = opts[:dbi_server_id] || nil
+
     book_editions_registry_id =
       if related_book do
         related_book.book_editions_registry_id
@@ -199,7 +201,8 @@ defmodule DecentralisedBookIndex.Generators do
         bids: bids,
         author_roles: author_roles,
         publisher_id: publisher_id,
-        book_editions_registry_id: book_editions_registry_id
+        book_editions_registry_id: book_editions_registry_id,
+        dbi_server_id: dbi_server_id
       ],
       overrides: opts,
       actor: actor