Extract metadata from a PDF file using pdfinfo.

Parameters

• pdf_path - Path to the PDF file

Returns

• {:ok, metadata} - Map with extracted metadata
• {:ok, %{}} - Empty map on failure (graceful degradation)

@spec file_attrs(map() | nil, map()) :: %{metadata: map()}

Turn extract_metadata/1's result into attrs for PhoenixKit.Modules.Storage.File.changeset/2.

The pdfinfo fields ("page_count", "title", "author", "creator", "creation_date") are string-keyed and are not columns on the file row — they belong inside its :metadata map. Returning them at the top level next to the atom-keyed :status the job adds gives Ecto a mixed-key map, which cast/3 rejects with Ecto.CastError — that crashed every PDF job on a host with poppler.

They only fill keys the map doesn't already hold. "title" is also the user-editable title the media detail page saves into the same map, so a pdfinfo value merged over it would replace the user's title each time the file is processed again.

Convert the first page of a PDF to a JPEG image.

Uses pdftoppm to render the first page at the specified DPI.

Parameters

• pdf_path - Path to the input PDF file
• output_prefix - Prefix for the output JPEG file (e.g., "/tmp/my_pdf")
• opts - Options
  • :dpi - Resolution in DPI (default: 150)

Returns

• {:ok, jpeg_path} - Path to the generated JPEG file
• {:error, reason} - If conversion fails