src/lib/pdf_export/__init__.py

"""TTS / screen-reader-friendly PDF builders.

Two flavors, both keyed by `book_id` and both backed by PyMuPDF:

    make_text_pdf(book_id) -> bytes
        A fresh PDF where each page contains only the cleaned Arabic text,
        rendered RTL via `insert_htmlbox`. Small file, no images. Best for
        TTS / screen readers / copy-paste.

    make_searchable_pdf(book_id) -> bytes
        The original PDF with an *invisible* text layer added to every
        page (PDF render-mode 3). Visual fidelity is preserved; Cmd+F and
        TTS extract the cleaned Arabic Unicode. CAVEAT: this ADDS a layer
        without removing the page's existing text — for a PDF that already
        ships a (garbage) text layer the two blend. Use make_clean_ocr_pdf
        for those.

    make_clean_ocr_pdf(book_id) -> bytes
        Like make_searchable_pdf, but on any page that has an embedded text
        layer it first rasterizes the page to an image — destroying the
        original (often garbage) text — so the inserted OCR text is the
        *single source of truth*. Pure-scan pages pass through untouched.
        This is the "download to read aloud" build. Tunable via the
        `pdf_export` config section.

Source text precedence: cleaned text from `data/clean/{book_id}/page_NNNN.json`
if present (statuses 'clean' / 'indexed'); else raw OCR text from
`data/ocr/{book_id}/page_NNNN.json`. Pages with no JSON at all are emitted
as blank text — never crash the build.

Font note: PyMuPDF's `insert_htmlbox` falls back through HarfBuzz / system
fonts to find an Arabic-capable face. On Windows / typical desktop Linux
this Just Works. If the runtime has no Arabic font installed, text-only
PDFs may render glyph boxes — but the Unicode in the content stream
remains extractable, so TTS still works. Bundling a TTF (e.g. Amiri OFL)
is the obvious next step if cloud deploys turn out to lack Arabic fonts.
"""

from __future__ import annotations

from .builder import make_clean_ocr_pdf, make_searchable_pdf, make_text_pdf

__all__ = ["make_text_pdf", "make_searchable_pdf", "make_clean_ocr_pdf"]