fix: issue #7 rebuild media links to get gallery working again

test/bds/media/link_restore_fresh_test.exs

@@ -0,0 +1,62 @@
+defmodule BDS.Media.LinkRestoreFreshTest do
+  use ExUnit.Case, async: false
+
+  import Ecto.Query
+
+  alias BDS.Media
+  alias BDS.Media.Media, as: MediaRecord
+  alias BDS.Posts.PostMedia
+  alias BDS.Repo
+
+  setup do
+    :ok = Ecto.Adapters.SQL.Sandbox.checkout(Repo)
+    Ecto.Adapters.SQL.Sandbox.mode(Repo, {:shared, self()})
+    temp_dir = Path.join(System.tmp_dir!(), "bds-freshlink-#{System.unique_integer([:positive])}")
+    File.mkdir_p!(temp_dir)
+    on_exit(fn -> File.rm_rf(temp_dir) end)
+
+    {:ok, project} = BDS.Projects.create_project(%{name: "Fresh", data_path: temp_dir})
+    {:ok, _} = BDS.Metadata.update_project_metadata(project.id, %{main_language: "en"})
+
+    {:ok, post} =
+      BDS.Posts.create_post(%{
+        project_id: project.id,
+        title: "Gallery Post",
+        content: "[[gallery]]",
+        language: "en"
+      })
+
+    source = Path.join(temp_dir, "fresh.jpg")
+    File.write!(source, "fake jpeg")
+    {:ok, media} = Media.import_media(%{project_id: project.id, source_path: source})
+    {:ok, _} = Media.link_media_to_post(media.id, post.id)
+
+    %{project: project, post: post, media: media}
+  end
+
+  test "fresh media rebuild (media record gone, only files on disk) restores links", %{
+    project: project,
+    post: post,
+    media: media
+  } do
+    # Sidecar on disk should carry the link.
+    sidecar_path = Path.join(project.data_path, media.sidecar_path)
+    assert File.exists?(sidecar_path)
+    contents = File.read!(sidecar_path)
+    assert contents =~ "linkedPostIds"
+    assert contents =~ post.id
+
+    # Simulate a fresh DB: drop the media record AND its links entirely.
+    Repo.delete_all(from pm in PostMedia, where: pm.media_id == ^media.id)
+    Repo.delete_all(from m in MediaRecord, where: m.id == ^media.id)
+    assert Repo.aggregate(from(m in MediaRecord, where: m.id == ^media.id), :count) == 0
+
+    assert {:ok, _} = BDS.Media.rebuild_media_from_files(project.id)
+
+    # Media re-inserted from sidecar.
+    assert Repo.aggregate(from(m in MediaRecord, where: m.project_id == ^project.id), :count) == 1
+
+    # Link restored so the post's media list is populated again.
+    assert Repo.aggregate(from(pm in PostMedia, where: pm.post_id == ^post.id), :count) == 1
+  end
+end

test/bds/media/link_restore_test.exs

@@ -69,4 +69,51 @@ defmodule BDS.Media.LinkRestoreTest do
     assert {:ok, _} = BDS.Media.rebuild_media_from_files(project.id)
     assert link_count(post.id, media.id) == 1
   end
+
+  test "rebuild_media_links rebuilds gallery links from sidecars", %{
+    project: project,
+    post: post,
+    media: media
+  } do
+    # Simulate a project whose junction table was never populated even though
+    # the media sidecar references the post (the reported gallery regression).
+    Repo.delete_all(from pm in PostMedia, where: pm.media_id == ^media.id)
+    assert link_count(post.id, media.id) == 0
+
+    assert {:ok, %{media: 1, links: 1}} = BDS.Media.rebuild_media_links(project.id)
+
+    assert link_count(post.id, media.id) == 1
+  end
+
+  test "rebuild_media_links drops stale junction links not present in sidecars", %{
+    project: project,
+    post: post,
+    media: media
+  } do
+    {:ok, other_post} =
+      BDS.Posts.create_post(%{
+        project_id: project.id,
+        title: "Unrelated Post",
+        content: "no gallery here",
+        language: "en"
+      })
+
+    # A junction row that drifted from the sidecar: the media is linked to a
+    # post its sidecar does not reference. The sidecar is the source of truth,
+    # so rebuild must drop this link.
+    Repo.insert!(%PostMedia{
+      id: Ecto.UUID.generate(),
+      project_id: project.id,
+      post_id: other_post.id,
+      media_id: media.id,
+      sort_order: 5,
+      created_at: 0
+    })
+
+    assert {:ok, %{links: 1}} = BDS.Media.rebuild_media_links(project.id)
+
+    # The real (sidecar-backed) link survives, the drifted link is gone.
+    assert link_count(post.id, media.id) == 1
+    assert link_count(other_post.id, media.id) == 0
+  end
 end