# Copyright (c) 2025 Patrick Motsch
# All rights reserved.
"""
PDF in-place neutralization using PyMuPDF.
Removes original text completely and inserts full UUID placeholders.
PyMuPDF uses insert_textbox which wraps long placeholders to preserve layout.
"""

import io
import logging
from typing import Dict, Optional

logger = logging.getLogger(__name__)


def neutralize_pdf_in_place(
    pdf_bytes: bytes,
    mapping: Dict[str, str],
) -> Optional[bytes]:
    """
    Remove sensitive text and replace with UUID placeholders in-place.
    Content is fully removed (not just covered) so it cannot be copied.

    Args:
        pdf_bytes: Original PDF file content
        mapping: Dict of original_text -> placeholder (e.g. [address.uuid])

    Returns:
        Modified PDF bytes, or None on failure
    """
    if not mapping:
        return pdf_bytes

    try:
        import fitz  # PyMuPDF
    except ImportError:
        logger.warning("PyMuPDF (fitz) not available for PDF in-place neutralization")
        return None

    try:
        doc = fitz.open(stream=pdf_bytes, filetype="pdf")
    except Exception as e:
        logger.error(f"Failed to open PDF: {e}")
        return None

    sorted_items = sorted(mapping.items(), key=lambda x: -len(x[0]))
    fill_color = (1, 1, 1)
    text_color = (0, 0, 0)
    fontname = "helv"
    fontsize = 8

    try:
        for page_num in range(len(doc)):
            page = doc[page_num]

            for original_text, placeholder in sorted_items:
                if not original_text or not placeholder:
                    continue

                search_text = original_text
                insert_text = placeholder
                if placeholder.startswith("[policy."):
                    # Try label+number to get wider rect; insert UUID only (label+UUID would overflow)
                    for prefix in ("Police Nr. ", "Police Nr.: ", "Polizzenr. ", "Policy no. ", "Policy No. "):
                        candidate = prefix + original_text
                        try:
                            hits = page.search_for(candidate, quads=False)
                            if hits:
                                search_text = candidate
                                insert_text = placeholder  # UUID only so it fits in rect
                                break
                        except Exception:
                            continue

                try:
                    instances = page.search_for(search_text, quads=False)
                except Exception:
                    instances = []

                for rect in instances:
                    try:
                        fs = 5 if placeholder.startswith(("[policy.", "[address.")) else fontsize
                        page.add_redact_annot(
                            rect,
                            text=insert_text,
                            fill=fill_color,
                            text_color=text_color,
                            fontname=fontname,
                            fontsize=fs,
                        )
                    except Exception as e:
                        logger.warning(f"Redact failed for {original_text[:40]!r}: {e}")

            try:
                page.apply_redactions()
            except Exception as e:
                logger.debug(f"apply_redactions page {page_num + 1}: {e}")

        buf = io.BytesIO()
        doc.save(buf, garbage=4, deflate=True)
        doc.close()
        return buf.getvalue()

    except Exception as e:
        logger.error(f"PDF in-place neutralization failed: {e}", exc_info=True)
        try:
            doc.close()
        except Exception:
            pass
        return None