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

lib/bds/desktop/shell_commands.ex

@@ -196,6 +196,14 @@ defmodule BDS.Desktop.ShellCommands do
     end)
   end
 
+  defp dispatch("rebuild_media_links", project, _params) do
+    queue_task(project, "rebuild_media_links", "Rebuild Media Links", "Maintenance", fn report ->
+      {:ok, result} = BDS.Media.rebuild_media_links(project.id, on_progress: report)
+      report.(1.0, "Media links rebuilt")
+      %{project_id: project.id, counts: %{media_links: result.links}}
+    end)
+  end
+
   defp dispatch("regenerate_missing_thumbnails", project, _params) do
     queue_task(
       project,

lib/bds/desktop/shell_live/settings_editor_html/settings_editor.html.heex

@@ -375,7 +375,8 @@
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_media_from_files"><%= dgettext("ui", "Rebuild Media From Files") %></button>
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_scripts_from_files"><%= dgettext("ui", "Rebuild Scripts From Files") %></button>
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_templates_from_files"><%= dgettext("ui", "Rebuild Templates From Files") %></button>
-            <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_post_links"><%= dgettext("ui", "Rebuild Links") %></button>
+            <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_post_links"><%= dgettext("ui", "Rebuild Post Links") %></button>
+            <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_media_links"><%= dgettext("ui", "Rebuild Media Links") %></button>
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="regenerate_missing_thumbnails"><%= dgettext("ui", "Regenerate Missing Thumbnails") %></button>
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="rebuild_embedding_index"><%= dgettext("ui", "Rebuild Embedding Index") %></button>
             <button class="secondary ui-button ui-button-secondary" type="button" phx-click="settings_shell_command" phx-value-action="open_data_folder"><%= dgettext("ui", "Open Data Folder") %></button>

lib/bds/media.ex

@@ -66,6 +66,12 @@ defmodule BDS.Media do
   defdelegate link_media_to_post(media_id, post_id), to: BDS.Media.Linking
   defdelegate unlink_media_from_post(media_id, post_id), to: BDS.Media.Linking
 
+  defdelegate rebuild_media_links(project_id), to: BDS.Media.Linking,
+    as: :rebuild_links_from_sidecars
+
+  defdelegate rebuild_media_links(project_id, opts), to: BDS.Media.Linking,
+    as: :rebuild_links_from_sidecars
+
   defdelegate rebuild_media_from_files(project_id), to: BDS.Media.Rebuilder
   defdelegate rebuild_media_from_files(project_id, opts), to: BDS.Media.Rebuilder
 

lib/bds/media/linking.ex

@@ -5,6 +5,13 @@ defmodule BDS.Media.Linking do
 
   import Ecto.Query
 
+  import BDS.Media.FileOps,
+    only: [
+      progress_callback: 1,
+      report_rebuild_progress: 4,
+      report_rebuild_started: 3
+    ]
+
   alias BDS.Media.Media
   alias BDS.Media.Sidecars
   alias BDS.Persistence
@@ -134,6 +141,45 @@ defmodule BDS.Media.Linking do
 
   def restore_post_links(_project_id, _media_id, _post_ids), do: :ok
 
+  @doc """
+  Rebuild the `post_media` junction for a project from every media sidecar's
+  `linkedPostIds`.
+
+  Media sidecars are the source of truth for gallery associations (matching the
+  old bDS `rebuildFromSidecars`). Existing project links are cleared and then
+  re-created from the on-disk sidecars, so galleries reflect the project's
+  metadata even if the junction table drifted or was never populated. Links to
+  posts that are not present in the database are skipped.
+  """
+  @spec rebuild_links_from_sidecars(String.t(), keyword()) ::
+          {:ok, %{media: non_neg_integer(), links: non_neg_integer()}}
+  def rebuild_links_from_sidecars(project_id, opts \\ []) when is_binary(project_id) do
+    project = Projects.get_project!(project_id)
+    on_progress = progress_callback(opts)
+
+    media_list =
+      Repo.all(from m in Media, where: m.project_id == ^project_id, order_by: [asc: m.id])
+
+    total = length(media_list)
+    :ok = report_rebuild_started(on_progress, total, "media links")
+
+    {_cleared, _} =
+      Repo.delete_all(from pm in PostMedia, where: pm.project_id == ^project_id)
+
+    media_list
+    |> Enum.with_index(1)
+    |> Enum.each(fn {media, index} ->
+      post_ids = Sidecars.read_linked_post_ids(project, media)
+      restore_post_links(project_id, media.id, post_ids)
+      :ok = report_rebuild_progress(on_progress, index, total, "media links")
+    end)
+
+    links =
+      Repo.aggregate(from(pm in PostMedia, where: pm.project_id == ^project_id), :count)
+
+    {:ok, %{media: total, links: links}}
+  end
+
   defp ensure_link(project_id, media_id, post_id) do
     already_linked? =
       Repo.exists?(

lib/bds/media/sidecars.ex

@@ -349,6 +349,29 @@ defmodule BDS.Media.Sidecars do
     |> File.exists?()
   end
 
+  @doc """
+  Read the `linkedPostIds` list persisted in a media item's canonical sidecar.
+
+  The media sidecar is the source of truth for gallery associations (matching
+  the old bDS `linkedPostIds` field). Returns `[]` when the sidecar is missing
+  or has no linked posts.
+  """
+  @spec read_linked_post_ids(BDS.Projects.Project.t(), Media.t()) :: [String.t()]
+  def read_linked_post_ids(project, %Media{} = media) do
+    sidecar_path = Path.join(Projects.project_data_dir(project), media.sidecar_path)
+
+    case parse_existing_canonical_sidecar(project, sidecar_path) do
+      {:ok, sidecar} ->
+        sidecar.fields
+        |> DocumentFields.get("linkedPostIds", [])
+        |> List.wrap()
+        |> Enum.filter(&is_binary/1)
+
+      {:error, _reason} ->
+        []
+    end
+  end
+
   defp parse_existing_canonical_sidecar(project, sidecar_path) do
     if File.exists?(sidecar_path) do
       parse_canonical_sidecar(project, sidecar_path)