"""Optional OCR for cropped image/table regions."""

from __future__ import annotations

import io
from pathlib import Path

import fitz


def ocr_pixmap(pix: fitz.Pixmap) -> str:
    """Run OCR on a pixmap; returns empty string when OCR is unavailable."""
    try:
        import pytesseract
        from PIL import Image
    except ImportError:
        return ""

    try:
        image = Image.open(io.BytesIO(pix.tobytes("png")))
        return _ocr_pil(image)
    except Exception:
        return ""


def ocr_image_file(path: Path) -> str:
    try:
        import pytesseract  # noqa: F401
        from PIL import Image
    except ImportError:
        return ""

    try:
        return _ocr_pil(Image.open(path))
    except Exception:
        return ""


def _ocr_pil(image) -> str:
    import pytesseract

    for lang in ("chi_tra+eng", "chi_sim+eng", "eng"):
        try:
            text = pytesseract.image_to_string(image, lang=lang)
            cleaned = " ".join(text.split())
            if cleaned:
                return cleaned
        except Exception:
            continue
    return ""


def describe_visual(ocr_text: str, kind: str, label: str) -> str:
    """Lightweight image/table description without an external vision model."""
    if ocr_text:
        return f"{kind}：{ocr_text[:300]}"
    return f"{kind}：{label}"