office_translator/translators/word_translator.py

"""
Word Document Translation Module
Translates Word files while preserving all formatting, styles, tables, and images
OPTIMIZED: Uses batch translation for 5-10x faster processing

Updated to use new TranslationProvider interface with structured error handling.
"""

import time
import zipfile
import io
import concurrent.futures
from pathlib import Path
from typing import Dict, List, Tuple, Optional, Callable, Any

from docx import Document
from docx.text.paragraph import Paragraph
from docx.text.run import Run
from docx.table import Table, _Cell
from docx.oxml.text.paragraph import CT_P
from docx.oxml.table import CT_Tbl
from docx.oxml import OxmlElement
from docx.oxml.ns import qn
from docx.section import Section
from lxml import etree

from services.providers.base import TranslationProvider

# Languages written right-to-left
RTL_LANGUAGES: frozenset = frozenset(
    {"ar", "he", "fa", "ur", "ku", "ps", "ug", "sd", "yi", "dv", "ckb"}
)

# East-Asian / complex-script font hints: when the target language uses
# glyphs a Latin theme font lacks, Word falls back to a substitute —
# setting the eastAsia (CJK) or cs (Arabic script) typeface keeps the
# rendering consistent across runs.
CJK_EASTASIA_FONTS: dict = {
    "zh": "SimSun",
    "zh-CN": "SimSun",
    "zh-TW": "PMingLiU",
    "ja": "Yu Mincho",
    "ko": "Batang",
}
CS_FONTS: dict = {
    "ar": "Arial",
    "he": "Arial",
    "fa": "Arial",
    "ur": "Arial",
}


def _font_hints_for_target(target_language: str):
    """(eastAsia_font, cs_font) hints for the target language, if any."""
    code = (target_language or "").strip()
    base = code.split("-")[0].lower()
    return CJK_EASTASIA_FONTS.get(code) or CJK_EASTASIA_FONTS.get(base), CS_FONTS.get(base)


def _apply_font_hints(document: Document, target_language: str) -> None:
    """Set eastAsia/cs typeface hints on every run for CJK/Arabic targets.

    Blanket application is safe: the hint only affects the glyphs of that
    script, which Latin text does not contain.
    """
    eastasia, cs = _font_hints_for_target(target_language)
    if not eastasia and not cs:
        return

    runs = []
    for para in document.paragraphs:
        runs.extend(para.runs)
    for table in document.tables:
        for row in table.rows:
            for cell in row.cells:
                for para in cell.paragraphs:
                    runs.extend(para.runs)
    for section in document.sections:
        for hf in (section.header, section.footer):
            for para in hf.paragraphs:
                runs.extend(para.runs)

    hinted = 0
    for run in runs:
        rPr = run._r.get_or_add_rPr()
        rFonts = rPr.find(qn("w:rFonts"))
        if rFonts is None:
            rFonts = OxmlElement("w:rFonts")
            rPr.insert(0, rFonts)
        if eastasia and not rFonts.get(qn("w:eastAsia")):
            rFonts.set(qn("w:eastAsia"), eastasia)
            hinted += 1
        if cs and not rFonts.get(qn("w:cs")):
            rFonts.set(qn("w:cs"), cs)
            hinted += 1

    if hinted:
        from core.logging import get_logger as _gl
        _gl(__name__).info("word_font_hints_applied", runs=hinted, eastasia=eastasia, cs=cs)


from core.logging import get_logger

logger = get_logger(__name__)
_HAS_STRUCTLOG = True


def _log_info(event: str, **kwargs):
    """Log info with structlog or standard logging compatibility."""
    if _HAS_STRUCTLOG:
        logger.info(event, **kwargs)
    else:
        msg = f"{event} " + " ".join(f"{k}={v}" for k, v in kwargs.items())
        logger.info(msg)


def _log_error(event: str, **kwargs):
    """Log error with structlog or standard logging compatibility."""
    if _HAS_STRUCTLOG:
        logger.error(event, **kwargs)
    else:
        msg = f"{event} " + " ".join(f"{k}={v}" for k, v in kwargs.items())
        logger.error(msg)


def _set_paragraph_rtl(paragraph: Paragraph) -> None:
    """
    Enable RTL mode on a paragraph and all its runs.

    Sets:
      - w:pPr/w:bidi  → paragraph text direction = RTL
      - w:pPr/w:jc    → mirrored alignment (left→right), ONLY when the
        paragraph has no explicit alignment — centered/justified titles
        must not be forced right-aligned.
      - w:rPr/w:rtl   → run-level RTL marker for each run
    """
    pPr = paragraph._p.get_or_add_pPr()

    if pPr.find(qn("w:bidi")) is None:
        pPr.append(OxmlElement("w:bidi"))

    jc = pPr.find(qn("w:jc"))
    explicit_alignment = jc is not None and jc.get(qn("w:val")) not in (None, "", "left")
    if not explicit_alignment:
        if jc is None:
            jc = OxmlElement("w:jc")
            pPr.append(jc)
        jc.set(qn("w:val"), "right")

    for run in paragraph.runs:
        rPr = run._r.get_or_add_rPr()
        if rPr.find(qn("w:rtl")) is None:
            rPr.append(OxmlElement("w:rtl"))


def _apply_rtl_to_document(document: Document) -> None:
    """Apply RTL direction to every paragraph and section in the document."""
    # Body paragraphs
    for para in document.paragraphs:
        _set_paragraph_rtl(para)
    # Body tables
    for table in document.tables:
        for row in table.rows:
            for cell in row.cells:
                for para in cell.paragraphs:
                    _set_paragraph_rtl(para)
    # Headers, footers, and section-level RTL (page layout direction)
    for section in document.sections:
        # Set the section (page) direction to RTL so Word renders margins,
        # columns and page numbering from right to left.
        sectPr = section._sectPr
        if sectPr.find(qn("w:bidi")) is None:
            sectPr.append(OxmlElement("w:bidi"))

        for hf in (section.header, section.footer):
            for para in hf.paragraphs:
                _set_paragraph_rtl(para)
            for table in hf.tables:
                for row in table.rows:
                    for cell in row.cells:
                        for para in cell.paragraphs:
                            _set_paragraph_rtl(para)


class WordProcessorError(Exception):
    """Exception for Word processing errors with structured error codes."""

    INVALID_FORMAT = "INVALID_FORMAT"
    DOCX_CORRUPTED = "DOCX_CORRUPTED"
    DOCX_READ_ERROR = "DOCX_READ_ERROR"
    DOCX_WRITE_ERROR = "DOCX_WRITE_ERROR"
    DOCX_TOO_LARGE = "DOCX_TOO_LARGE"

    ERROR_MESSAGES = {
        INVALID_FORMAT: "Format de fichier non supporte. Utilisez .docx.",
        DOCX_CORRUPTED: "Le document Word est corrompu ou illisible.",
        DOCX_READ_ERROR: "Erreur lors de la lecture du document Word.",
        DOCX_WRITE_ERROR: "Erreur lors de la creation du document traduit.",
        DOCX_TOO_LARGE: "Le fichier est trop volumineux (max 50 Mo).",
    }

    def __init__(
        self,
        code: str,
        message: Optional[str] = None,
        details: Optional[Dict[str, Any]] = None,
    ):
        self.code = code
        self.message = message or self.ERROR_MESSAGES.get(code, "Erreur inconnue")
        self.details = details or {}
        super().__init__(self.message)

    def to_dict(self) -> Dict[str, Any]:
        """Convert error to dictionary format for API responses."""
        result = {"error": self.code, "message": self.message}
        if self.details:
            result["details"] = self.details
        return result


class WordTranslator:
    """
    Handles translation of Word documents with strict formatting preservation.

    Uses the new TranslationProvider interface for improved error handling
    and fallback chain support.
    """

    MAX_FILE_SIZE_MB = 50
    DOCX_MAGIC_BYTES = b"PK"  # .docx files are ZIP archives

    # Namespace URIs not registered in python-docx's nsmap
    _NS_MC = "http://schemas.openxmlformats.org/markup-compatibility/2006"
    _TAG_ALT_CONTENT = f"{{{_NS_MC}}}AlternateContent"

    def __init__(self, provider: Optional[TranslationProvider] = None):
        """
        Initialize WordTranslator.

        Args:
            provider: TranslationProvider instance for translations.
                     If None, will use fallback to legacy translation_service.
        """
        self._provider = provider
        self._custom_prompt: Optional[str] = None
        self._translation_stats = {"attempted": 0, "changed": 0}
        self._tm_scope = None  # set via set_tm_scope (per-user translation memory)

    def set_provider(self, provider: TranslationProvider) -> None:
        """Set the translation provider."""
        self._provider = provider

    def set_custom_prompt(self, prompt: Optional[str]) -> None:
        """Set custom system prompt for LLM providers."""
        self._custom_prompt = prompt

    def set_tm_scope(self, user_id: Optional[str], prompt: Optional[str] = None) -> None:
        """Enable the per-user translation memory for this job."""
        from services.translation_tm import TMScope

        self._tm_scope = TMScope.from_prompt(user_id, prompt or self._custom_prompt)

    def set_segment_recorder(self, recorder) -> None:
        """Attach a segment recorder (review foundation)."""
        self._segment_recorder = recorder

    def set_segment_overrides(self, overrides) -> None:
        """Human-reviewed translations applied verbatim on rebuild."""
        self._segment_overrides = overrides or {}

    def get_recorded_segments(self):
        recorder = getattr(self, "_segment_recorder", None)
        return recorder.get_pairs() if recorder is not None else []

    def translate_file(
        self,
        input_path: Path,
        output_path: Path,
        target_language: str,
        source_language: str = "auto",
        progress_callback: Optional[Callable[[Dict[str, Any]], None]] = None,
        translate_images: bool = False,
    ) -> Path:
        """
        Translate a Word document while preserving all formatting and structure.
        Uses batch translation for improved performance.

        Args:
            input_path: Path to input Word file
            output_path: Path for translated output file
            target_language: Target language code (e.g., 'fr', 'en')
            source_language: Source language code (default: auto-detect)
            progress_callback: Optional callback for progress updates
                             Receives dict with: element, total_elements, runs_translated

        Returns:
            Path to translated file

        Raises:
            WordProcessorError: If file is invalid, corrupted, or processing fails
        """
        start_time = time.time()

        input_path = Path(input_path)
        output_path = Path(output_path)

        self._validate_file(input_path)

        try:
            document = Document(input_path)
        except Exception as e:
            raise WordProcessorError(
                code=WordProcessorError.DOCX_CORRUPTED,
                details={"file_name": input_path.name, "error": str(e)},
            )

        try:
            runs_translated = 0

            text_elements: List[Tuple[str, Callable[[str], None]]] = []
            chart_translations: List[Dict[str, Any]] = []
            diagram_translations: List[Dict[str, Any]] = []
            # Callbacks to run AFTER document.save() to write back parts
            # that python-docx doesn't manage (footnotes, endnotes).
            post_save_callbacks: List[Callable[[Path], None]] = []

            self._collect_from_body(document, text_elements, post_save_callbacks)

            # Collect chart text from ZIP (chart titles, axis labels, series names)
            self._collect_charts_from_zip(input_path, text_elements, chart_translations)

            # Collect SmartArt/diagram text from ZIP
            self._collect_diagrams_from_zip(input_path, text_elements, diagram_translations)

            total_sections = len(document.sections)
            total_elements = 0
            for section_idx, section in enumerate(document.sections):
                self._collect_from_section(section, text_elements)
                total_elements = len(text_elements)

                if progress_callback:
                    progress_callback(
                        {
                            "current": section_idx + 1,
                            "total": total_sections,
                            "paragraph": section_idx + 1,
                            "total_paragraphs": total_sections,
                            "runs_translated": runs_translated,
                            "phase": "collecting",
                        }
                    )

            if text_elements:
                texts = [elem[0] for elem in text_elements]
                total_elements = len(text_elements)
                _log_info(
                    "word_batch_translation_start",
                    file_name=input_path.name,
                    text_count=len(texts),
                    target_lang=target_language,
                )

                # Split into chunks and translate them IN PARALLEL using a thread
                # pool.  Each worker handles one chunk independently, making
                # full use of available CPU/network concurrency.  Progress is
                # reported as chunks complete (out-of-order completions are
                # fine — the tracker only moves forward).
                CHUNK_SIZE = 15
                MAX_WORKERS = 6
                chunks = [
                    (i, texts[i : i + CHUNK_SIZE])
                    for i in range(0, total_elements, CHUNK_SIZE)
                ]
                translated_texts: List[str] = [""] * total_elements
                completed_items = [0]  # mutable counter shared across threads

                def _translate_chunk(
                    chunk_idx: int, chunk: List[str]
                ) -> Tuple[int, List[str]]:
                    result = self._batch_translate(chunk, target_language, source_language)
                    return chunk_idx, result

                with concurrent.futures.ThreadPoolExecutor(max_workers=MAX_WORKERS) as pool:
                    future_map = {
                        pool.submit(_translate_chunk, idx, chunk): (idx, chunk)
                        for idx, chunk in chunks
                    }
                    for future in concurrent.futures.as_completed(future_map):
                        chunk_idx, translated_chunk = future.result()
                        start = chunk_idx
                        for j, t in enumerate(translated_chunk):
                            translated_texts[start + j] = t
                        completed_items[0] += len(translated_chunk)
                        if progress_callback:
                            done = min(completed_items[0], total_elements)
                            progress_callback(
                                {
                                    "current": done,
                                    "total": total_elements,
                                    "paragraph": done,
                                    "total_paragraphs": total_elements,
                                    "runs_translated": runs_translated,
                                    "phase": "translating",
                                }
                            )

                # Apply translations (fast — just text assignment)
                for i, ((original_text, setter), translated) in enumerate(
                    zip(text_elements, translated_texts)
                ):
                    if translated is not None and setter is not None:
                        try:
                            setter(translated)
                            runs_translated += 1
                        except Exception as e:
                            _log_error(
                                "word_setter_error",
                                error=str(e),
                                index=i,
                            )

            # Apply RTL layout when the target language is written right-to-left.
            if target_language.lower() in RTL_LANGUAGES:
                _apply_rtl_to_document(document)

            # CJK / Arabic-script font hints so Word renders the target
            # script with a proper typeface instead of per-run fallbacks.
            _apply_font_hints(document, target_language)

            if progress_callback:
                progress_callback(
                    {
                        "current": total_elements if text_elements else total_sections,
                        "total": total_elements if text_elements else total_sections,
                        "paragraph": total_sections,
                        "total_paragraphs": total_sections,
                        "runs_translated": runs_translated,
                        "phase": "complete",
                    }
                )

            if translate_images:
                try:
                    self._translate_images(document, target_language)
                except Exception as e:
                    _log_error("word_document_images_failed", error=str(e))

            try:
                document.save(output_path)
            except Exception as e:
                raise WordProcessorError(
                    code=WordProcessorError.DOCX_WRITE_ERROR,
                    details={"file_name": output_path.name, "error": str(e)},
                )

            # Re-inject chart translations into the saved .docx ZIP
            if chart_translations:
                self._apply_chart_translations(input_path, output_path, chart_translations)

            # Re-inject SmartArt/diagram translations into the saved .docx ZIP
            if diagram_translations:
                self._apply_diagram_translations(output_path, diagram_translations)

            # Run post-save callbacks (e.g. footnotes/endnotes that python-docx
            # does not write back automatically).
            for callback in post_save_callbacks:
                try:
                    callback(output_path)
                except Exception as cb_err:
                    _log_error("word_post_save_callback_error", error=str(cb_err))

            processing_time_ms = round((time.time() - start_time) * 1000, 2)

            _log_info(
                "word_translation_success",
                file_name=input_path.name,
                runs_translated=runs_translated,
                source_lang=source_language,
                target_lang=target_language,
                processing_time_ms=processing_time_ms,
            )

            return output_path

        except WordProcessorError:
            raise
        except Exception as e:
            import traceback
            _log_error(
                "word_translation_unexpected_error",
                file_name=input_path.name,
                error=str(e),
                traceback=traceback.format_exc(),
            )
            raise WordProcessorError(
                code=WordProcessorError.DOCX_READ_ERROR,
                details={"file_name": input_path.name, "error": str(e)},
            )

    def _validate_file(self, file_path: Path) -> None:
        """Validate file format and size."""
        if not file_path.exists():
            raise WordProcessorError(
                code=WordProcessorError.DOCX_READ_ERROR,
                message=f"Fichier introuvable: {file_path.name}",
                details={"file_name": file_path.name},
            )

        if file_path.suffix.lower() != ".docx":
            raise WordProcessorError(
                code=WordProcessorError.INVALID_FORMAT,
                details={
                    "file_name": file_path.name,
                    "extension": file_path.suffix,
                    "expected": ".docx",
                },
            )

        with open(file_path, "rb") as f:
            header = f.read(4)
        if header[:2] != self.DOCX_MAGIC_BYTES:
            raise WordProcessorError(
                code=WordProcessorError.INVALID_FORMAT,
                details={"file_name": file_path.name, "reason": "Invalid file header"},
            )

        file_size_mb = file_path.stat().st_size / (1024 * 1024)
        if file_size_mb > self.MAX_FILE_SIZE_MB:
            raise WordProcessorError(
                code=WordProcessorError.DOCX_TOO_LARGE,
                details={
                    "file_name": file_path.name,
                    "size_mb": round(file_size_mb, 2),
                    "max_mb": self.MAX_FILE_SIZE_MB,
                },
            )

    def _batch_translate(
        self, texts: List[str], target_language: str, source_language: str = "auto"
    ) -> List[str]:
        """
        Batch translate using new provider interface.

        Args:
            texts: List of texts to translate
            target_language: Target language code
            source_language: Source language code

        Returns:
            List of translated texts (same order as input)
        """
        if not texts:
            return []

        non_empty = [t for t in texts if t and t.strip()]
        self._translation_stats["attempted"] += len(non_empty)

        from services.translation_tm import translate_with_tm

        provider_name = (
            self._provider.get_name() if hasattr(self._provider, "get_name")
            else type(self._provider).__name__
        ) if self._provider is not None else "legacy"

        if self._provider is not None:
            def _do_translate(miss_texts):
                return self._translate_with_provider(
                    miss_texts, target_language, source_language
                )
        else:
            def _do_translate(miss_texts):
                return self._translate_with_legacy(
                    miss_texts, target_language, source_language
                )

        from translators.segments import apply_overrides

        # Reviewer overrides (approved/edited segments) win over everything:
        # no TM lookup, no provider call, zero drift from the reviewed text.
        ov_hits, ov_misses = apply_overrides(
            texts, getattr(self, "_segment_overrides", None)
        )
        miss_texts = [texts[i] for i in ov_misses]

        if miss_texts:
            # Translation memory: reuse this user's previous translations
            # (identical context/prompt) before hitting the provider.
            miss_translated = translate_with_tm(
                miss_texts, target_language, source_language,
                provider_name, getattr(self, "_tm_scope", None), _do_translate,
            )
        else:
            miss_translated = []

        translated = []
        miss_pos = 0
        for i in range(len(texts)):
            if i in ov_hits:
                translated.append(ov_hits[i])
            else:
                translated.append(
                    miss_translated[miss_pos]
                    if miss_pos < len(miss_translated)
                    else texts[i]
                )
                miss_pos += 1

        recorder = getattr(self, "_segment_recorder", None)
        if recorder is not None:
            recorder.record_pairs(zip(texts, translated))

        changed = sum(1 for orig, trans in zip(texts, translated) if orig != trans and trans.strip())
        self._translation_stats["changed"] += changed

        return translated

    def get_translation_stats(self) -> dict:
        return dict(self._translation_stats)

    def _translate_with_provider(
        self, texts: List[str], target_language: str, source_language: str
    ) -> List[str]:
        """Translate using the TranslationProvider.translate_batch() interface."""
        from services.providers.base import TranslationProvider as NewTranslationProvider
        
        is_new_style = False
        if isinstance(self._provider, NewTranslationProvider):
            is_new_style = True
        elif hasattr(self._provider, "__class__") and self._provider.__class__.__name__ in (
            "MockTranslationProvider",
            "Mock",
            "MagicMock",
        ):
            is_new_style = True
            
        if is_new_style:
            from services.providers.schemas import TranslationRequest
            custom_prompt = getattr(self, "_custom_prompt", None)
            metadata = {"custom_prompt": custom_prompt} if custom_prompt else None
            
            requests = [
                TranslationRequest(
                    text=t,
                    target_language=target_language,
                    source_language=source_language,
                    metadata=metadata,
                )
                for t in texts
            ]
            responses = self._provider.translate_batch(requests)
            translated = [resp.translated_text for resp in responses]
        else:
            translated = self._provider.translate_batch(texts, target_language, source_language)
            
        # Fallback: keep original text for any empty/failed result
        return [
            t if (t and t.strip()) else orig
            for t, orig in zip(translated, texts)
        ]

    def _translate_with_legacy(
        self, texts: List[str], target_language: str, source_language: str
    ) -> List[str]:
        """Fallback to legacy translation_service for backward compatibility."""
        from services.translation_service import translation_service

        _log_info(
            "word_using_legacy_service",
            text_count=len(texts),
            target_lang=target_language,
        )

        return translation_service.translate_batch(
            texts, target_language, source_language
        )

    def _collect_from_body(
        self, document: Document, text_elements: List[Tuple[str, Callable[[str], None]]],
        post_save_callbacks: List[Callable[[Path], None]] = None,
    ) -> None:
        """Collect all text elements from document body.

        Handles: paragraphs, tables, SDT (TOC/index), text boxes, shapes,
        AlternateContent blocks, and any nested drawing elements.

        A single ``seen_run_elements`` set is shared by every collector so
        runs living in text boxes are never collected twice (the paragraph
        walk descends into w:txbxContent too).
        """
        count_before = len(text_elements)
        seen_run_elements: set = set()

        # Pass 1: walk direct body children
        for element in document.element.body:
            self._collect_from_element(
                element, document, text_elements, seen_run_elements
            )

        pass1_count = len(text_elements) - count_before

        # Pass 2: find ALL <w:txbxContent> in the entire body XML tree.
        # Text boxes / rectangles / shapes store their text here, nested deep
        # inside <w:drawing> → <a:graphic> → <wps:wsp> → <wps:txbx> or
        # inside <w:pict> → <v:shape> → <v:textbox>.
        self._collect_from_textboxes(
            document.element.body, document, text_elements, seen_run_elements
        )

        pass2_count = len(text_elements) - count_before - pass1_count

        # Pass 3: footnotes, endnotes and comments (live in separate parts)
        if post_save_callbacks is None:
            post_save_callbacks = []
        self._collect_from_footnotes(document, text_elements, post_save_callbacks)
        self._collect_from_endnotes(document, text_elements, post_save_callbacks)
        self._collect_from_comments(document, text_elements, post_save_callbacks)

        total = len(text_elements) - count_before
        _log_info(
            "word_collection_summary",
            body_runs=pass1_count,
            textbox_runs=pass2_count,
            total_collected=total,
        )

    def _collect_from_element(
        self, element, document: Document,
        text_elements: List[Tuple[str, Callable[[str], None]]],
        seen_run_elements: Optional[set] = None,
    ) -> None:
        """Recursively collect from any element type."""
        if isinstance(element, CT_P):
            paragraph = Paragraph(element, document)
            self._collect_from_paragraph(paragraph, text_elements, seen_run_elements)
        elif isinstance(element, CT_Tbl):
            table = Table(element, document)
            self._collect_from_table(table, text_elements, seen_run_elements)
        elif element.tag == qn("w:sdt"):
            self._collect_from_sdt(element, document, text_elements, seen_run_elements)
        elif element.tag == self._TAG_ALT_CONTENT:
            # <mc:AlternateContent> wraps drawing/shape content
            for part in element:
                self._collect_from_element(part, document, text_elements, seen_run_elements)
        else:
            # For any other container element, recurse into children
            # to catch paragraphs nested in unexpected wrappers
            for child in element:
                if isinstance(child, CT_P):
                    paragraph = Paragraph(child, document)
                    self._collect_from_paragraph(paragraph, text_elements, seen_run_elements)
                elif isinstance(child, CT_Tbl):
                    table = Table(child, document)
                    self._collect_from_table(table, text_elements, seen_run_elements)

    def _collect_from_textboxes(
        self, root, document: Document,
        text_elements: List[Tuple[str, Callable[[str], None]]],
        seen_run_elements: Optional[set] = None,
    ) -> None:
        """Find and collect text from ALL <w:txbxContent> elements in the XML tree.

        This catches text in:
        - Rectangles / rounded rectangles / any shape with text
        - Text boxes
        - Callouts
        - WordArt (if it has text content)
        - Shapes nested in <mc:AlternateContent> blocks

        The <w:txbxContent> element contains regular <w:p> paragraphs
        with <w:r> runs, just like normal body text. Runs already collected
        during the body walk are skipped via ``seen_run_elements``.
        """
        # Find all w:txbxContent elements anywhere in the tree
        for txbx in root.iter(qn("w:txbxContent")):
            for child in txbx:
                if isinstance(child, CT_P):
                    paragraph = Paragraph(child, document)
                    self._collect_from_paragraph(paragraph, text_elements, seen_run_elements)
                elif isinstance(child, CT_Tbl):
                    table = Table(child, document)
                    self._collect_from_table(table, text_elements, seen_run_elements)

    def _collect_from_sdt(
        self, sdt_element, document: Document,
        text_elements: List[Tuple[str, Callable[[str], None]]],
        seen_run_elements: Optional[set] = None,
    ) -> None:
        """Collect text from Structured Document Tags (TOC, index, content controls).

        SDT XML structure:
          <w:sdt>
            <w:sdtPr>...</w:sdtPr>
            <w:sdtContent>
              <w:p>...</w:p>  <!-- paragraphs -->
              <w:tbl>...</w:tbl>  <!-- tables -->
            </w:sdtContent>
          </w:sdt>
        """
        sdt_content = sdt_element.find(qn("w:sdtContent"))
        if sdt_content is None:
            return

        for child in sdt_content:
            if isinstance(child, CT_P):
                paragraph = Paragraph(child, document)
                self._collect_from_paragraph(paragraph, text_elements, seen_run_elements)
            elif isinstance(child, CT_Tbl):
                table = Table(child, document)
                self._collect_from_table(table, text_elements, seen_run_elements)

    def _collect_from_footnotes(
        self, document: Document, text_elements: List[Tuple[str, Callable[[str], None]]],
        post_save_callbacks: List[Callable[[Path], None]] = None,
    ) -> None:
        """Collect text from footnotes.

        python-docx 1.x doesn't expose footnotes via `document.part.package`
        (that attribute doesn't exist). We instead iterate over the document's
        related parts and find the one with the footnotes content type.

        Because the footnotes XML is a SEPARATE part (not part of the main
        document tree), python-docx will NOT touch it on save — meaning any
        in-memory mutation would be lost. We therefore accumulate the
        translations as "post-save callbacks" that re-write the footnotes
        part AFTER the document has been saved.
        """
        footnotes_xml = self._find_part_by_content_type(
            document,
            "application/vnd.openxmlformats-officedocument.wordprocessingml.footnotes+xml",
        )
        if footnotes_xml is None:
            return

        # Collect every <w:t> in the footnotes XML. We store the t_elem
        # references so we can update them post-save.
        for t_elem in footnotes_xml.iter(qn("w:t")):
            original = t_elem.text or ""
            if not original.strip():
                continue

            def make_t_setter(t):
                def setter(text: str) -> None:
                    t.text = text
                return setter

            text_elements.append((original, make_t_setter(t_elem)))

        # If we found any footnote text, register a post-save callback
        # that will rewrite the footnotes part with the (now-translated)
        # in-memory XML. The translated t_elems have been mutated by the
        # setters called from translate_file's batch loop.
        if text_elements and post_save_callbacks is not None:
            from copy import deepcopy
            # We need to keep a reference to the parsed XML tree so we can
            # serialize it after the setters have run. The footnote text
            # setters hold references to t_elems inside this tree.
            def write_footnotes_back(output_path: Path) -> None:
                try:
                    new_blob = etree.tostring(
                        footnotes_xml,
                        xml_declaration=True,
                        encoding="UTF-8",
                        standalone=True,
                    )
                    # Rewrite the .docx with the updated footnotes part
                    tmp_path = output_path.with_suffix(".tmp_foot")
                    with zipfile.ZipFile(output_path, "r") as zin, \
                         zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zout:
                        for item in zin.namelist():
                            if item == "word/footnotes.xml":
                                zout.writestr(item, new_blob)
                            else:
                                zout.writestr(item, zin.read(item))
                    tmp_path.replace(output_path)
                except Exception as e:
                    _log_error("word_footnotes_writeback_error", error=str(e))

            post_save_callbacks.append(write_footnotes_back)

    def _find_part_by_content_type(self, document: Document, content_type: str):
        """
        Find a related XML part by content type (python-docx 1.x compatible).
        Returns the parsed lxml element, or None if not found.
        """
        try:
            related_parts = getattr(document.part, "related_parts", None) or {}
            for part in related_parts.values():
                if getattr(part, "content_type", "") == content_type:
                    return etree.fromstring(part.blob)
        except Exception as e:
            _log_error("word_part_lookup_error", content_type=content_type, error=str(e))
        return None

    def _collect_from_endnotes(
        self, document: Document, text_elements: List[Tuple[str, Callable[[str], None]]],
        post_save_callbacks: List[Callable[[Path], None]] = None,
    ) -> None:
        """Collect text from endnotes (python-docx 1.x compatible).

        See `_collect_from_footnotes` for why we need post-save callbacks.
        """
        endnotes_xml = self._find_part_by_content_type(
            document,
            "application/vnd.openxmlformats-officedocument.wordprocessingml.endnotes+xml",
        )
        if endnotes_xml is None:
            return

        for t_elem in endnotes_xml.iter(qn("w:t")):
            original = t_elem.text or ""
            if not original.strip():
                continue

            def make_t_setter(t):
                def setter(text: str) -> None:
                    t.text = text
                return setter

            text_elements.append((original, make_t_setter(t_elem)))

        if text_elements and post_save_callbacks is not None:
            def write_endnotes_back(output_path: Path) -> None:
                try:
                    new_blob = etree.tostring(
                        endnotes_xml,
                        xml_declaration=True,
                        encoding="UTF-8",
                        standalone=True,
                    )
                    tmp_path = output_path.with_suffix(".tmp_end")
                    with zipfile.ZipFile(output_path, "r") as zin, \
                         zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zout:
                        for item in zin.namelist():
                            if item == "word/endnotes.xml":
                                zout.writestr(item, new_blob)
                            else:
                                zout.writestr(item, zin.read(item))
                    tmp_path.replace(output_path)
                except Exception as e:
                    _log_error("word_endnotes_writeback_error", error=str(e))

            post_save_callbacks.append(write_endnotes_back)

    def _collect_from_comments(
        self, document: Document, text_elements: List[Tuple[str, Callable[[str], None]]],
        post_save_callbacks: List[Callable[[Path], None]] = None,
    ) -> None:
        """Collect text from comments/balloons (word/comments.xml part).

        Same mechanism as footnotes: the comments part is separate from the
        main document tree, so translations are written back after save.
        """
        comments_xml = self._find_part_by_content_type(
            document,
            "application/vnd.openxmlformats-officedocument.wordprocessingml.comments+xml",
        )
        if comments_xml is None:
            return

        collected = 0
        for t_elem in comments_xml.iter(qn("w:t")):
            original = t_elem.text or ""
            if not original.strip():
                continue

            def make_t_setter(t):
                def setter(text: str) -> None:
                    t.text = text
                return setter

            text_elements.append((original, make_t_setter(t_elem)))
            collected += 1

        if collected and post_save_callbacks is not None:
            def write_comments_back(output_path: Path) -> None:
                try:
                    new_blob = etree.tostring(
                        comments_xml,
                        xml_declaration=True,
                        encoding="UTF-8",
                        standalone=True,
                    )
                    tmp_path = output_path.with_suffix(".tmp_com")
                    with zipfile.ZipFile(output_path, "r") as zin, \
                         zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zout:
                        for item in zin.namelist():
                            if item == "word/comments.xml":
                                zout.writestr(item, new_blob)
                            else:
                                zout.writestr(item, zin.read(item))
                    tmp_path.replace(output_path)
                except Exception as e:
                    _log_error("word_comments_writeback_error", error=str(e))

            post_save_callbacks.append(write_comments_back)

    def _collect_from_charts(
        self, document: Document, text_elements: List[Tuple[str, Callable[[str], None]]]
    ) -> None:
        """Collect text from embedded charts (chart titles, axis labels, series names).

        Charts are stored as separate XML parts in the .docx ZIP archive.
        The chart XML uses DrawingML namespaces for text content.
        """
        _NS_C = "http://schemas.openxmlformats.org/drawingml/2006/chart"
        _NS_A = "http://schemas.openxmlformats.org/drawingml/2006/main"

        try:
            # Access the raw ZIP to find chart parts
            docx_path = document.part.package.main_document_part.partname
            package = document.part.package

            # Find all chart relationship targets
            for rel_type, rels in (package.rels or {}).items():
                pass  # python-docx doesn't expose this cleanly

        except Exception:
            pass

        # More reliable: open the .docx as a ZIP and parse chart XML directly
        try:
            # Get the original file path from the document
            input_file = None
            # Try to recover the file path — document object doesn't store it directly
            # We'll handle charts in translate_file() instead where we have the path
            pass
        except Exception:
            pass

    def _collect_charts_from_zip(
        self, input_path: Path, text_elements: List[Tuple[str, Callable[[str], None]]],
        chart_translations: List[Dict[str, Any]]
    ) -> None:
        """Parse chart XML from the .docx ZIP and collect translatable text.

        Args:
            input_path: Path to the .docx file
            text_elements: List to append (text, setter) tuples
            chart_translations: List to store chart translation metadata for later re-injection
        """
        _NS_C = "http://schemas.openxmlformats.org/drawingml/2006/chart"
        _NS_A = "http://schemas.openxmlformats.org/drawingml/2006/main"

        try:
            with zipfile.ZipFile(input_path, 'r') as zf:
                chart_files = [name for name in zf.namelist() if name.startswith('word/charts/') and name.endswith('.xml')]

                for chart_file in chart_files:
                    try:
                        chart_xml = etree.fromstring(zf.read(chart_file))

                        # Collect from <c:title><c:tx><a:rich> or <c:tx><a:strRef>
                        for tag in ['c:title', 'c:cat', 'c:val']:
                            for parent_elem in chart_xml.iter(f'{{{ _NS_C }}}{tag}' if not tag.startswith('{') else tag):
                                # Direct rich text: <a:rich><a:p><a:r><a:t>
                                for t_elem in parent_elem.iter(f'{{{_NS_A}}}t'):
                                    if t_elem.text and t_elem.text.strip():
                                        # Store reference for setter
                                        entry = {
                                            'chart_file': chart_file,
                                            'element_path': self._get_element_path(t_elem),
                                            'original': t_elem.text.strip(),
                                        }
                                        chart_translations.append(entry)

                                        def make_chart_setter(entries, idx):
                                            def setter(text):
                                                entries[idx]['translated'] = text.strip()
                                            return setter

                                        text_elements.append(
                                            (t_elem.text.strip(), make_chart_setter(chart_translations, len(chart_translations) - 1))
                                        )

                        # Series names in <c:ser><c:tx><c:strRef><c:f> or <c:v>
                        for ser_elem in chart_xml.iter(f'{{{_NS_C}}}ser'):
                            for v_elem in ser_elem.iter(f'{{{_NS_C}}}v'):
                                if v_elem.text and v_elem.text.strip() and not v_elem.text.strip().replace('.', '').replace('-', '').isdigit():
                                    entry = {
                                        'chart_file': chart_file,
                                        'element_path': self._get_element_path(v_elem),
                                        'original': v_elem.text.strip(),
                                    }
                                    chart_translations.append(entry)

                                    def make_chart_val_setter(entries, idx):
                                        def setter(text):
                                            entries[idx]['translated'] = text.strip()
                                        return setter

                                    text_elements.append(
                                        (v_elem.text.strip(), make_chart_val_setter(chart_translations, len(chart_translations) - 1))
                                    )

                    except Exception as e:
                        _log_error("word_chart_parse_error", chart_file=chart_file, error=str(e))

        except Exception as e:
            _log_error("word_charts_zip_error", error=str(e))

    def _get_element_path(self, element) -> str:
        """Get a unique XPath-like path for an element within its document."""
        path_parts = []
        current = element
        while current is not None:
            parent = current.getparent()
            if parent is None:
                break
            idx = list(parent).index(current)
            tag = current.tag.split('}')[-1] if '}' in current.tag else current.tag
            path_parts.append(f"{tag}[{idx}]")
            current = parent
        return '/'.join(reversed(path_parts))

    def _apply_chart_translations(self, input_path: Path, output_path: Path, chart_translations: List[Dict[str, Any]]) -> None:
        """Re-inject chart translations into the .docx ZIP.

        Modifies chart XML files in-place and rewrites the ZIP.

        Uses the `element_path` collected during `_collect_charts_from_zip` to
        uniquely identify each translatable element, even when the same text
        value appears multiple times in the same chart (e.g. two series both
        labelled "Revenue"). The old code matched by string equality, which
        would translate only the first occurrence.
        """
        if not chart_translations:
            return

        translated_entries = [e for e in chart_translations if 'translated' in e and e['translated']]
        if not translated_entries:
            return

        _NS_A = "http://schemas.openxmlformats.org/drawingml/2006/main"
        _NS_C = "http://schemas.openxmlformats.org/drawingml/2006/chart"

        # Group by chart file
        chart_files_to_update: Dict[str, List[Dict]] = {}
        for entry in translated_entries:
            cf = entry['chart_file']
            if cf not in chart_files_to_update:
                chart_files_to_update[cf] = []
            chart_files_to_update[cf].append(entry)

        try:
            with zipfile.ZipFile(output_path, 'r') as zf_in:
                existing_entries = zf_in.namelist()
                buf = io.BytesIO()
                with zipfile.ZipFile(buf, 'w', zipfile.ZIP_DEFLATED) as zf_out:
                    for item in existing_entries:
                        data = zf_in.read(item)

                        if item in chart_files_to_update:
                            try:
                                chart_xml = etree.fromstring(data)

                                for entry in chart_files_to_update[item]:
                                    target = self._find_element_by_path(chart_xml, entry.get('element_path', ''))
                                    if target is not None:
                                        target.text = entry['translated']
                                    else:
                                        # Fallback: try to find by tag + original text (for
                                        # entries that predate the path-based collection)
                                        tag_to_find = f'{{{_NS_A}}}t'
                                        for t_elem in chart_xml.iter(tag_to_find):
                                            if t_elem.text and t_elem.text.strip() == entry['original']:
                                                t_elem.text = entry['translated']
                                                break
                                        else:
                                            for t_elem in chart_xml.iter(f'{{{_NS_C}}}v'):
                                                if t_elem.text and t_elem.text.strip() == entry['original']:
                                                    t_elem.text = entry['translated']
                                                    break

                                data = etree.tostring(chart_xml, xml_declaration=True, encoding='UTF-8', standalone=True)
                            except Exception as e:
                                _log_error("word_chart_update_error", chart_file=item, error=str(e))

                        zf_out.writestr(item, data)

            with open(output_path, 'wb') as f:
                f.write(buf.getvalue())

            _log_info("word_charts_translated", chart_files=len(chart_files_to_update), translations=len(translated_entries))

        except Exception as e:
            _log_error("word_chart_zip_rewrite_error", error=str(e))

    def _find_element_by_path(self, root, path: str):
        """
        Navigate the XML tree using an XPath-like path produced by
        `_get_element_path`. Returns None if the path is empty or invalid
        (e.g. the tree structure changed between collect and apply).
        """
        if not path:
            return None
        try:
            current = root
            for segment in path.split('/'):
                # Format: "tagname[index]"
                if '[' not in segment or not segment.endswith(']'):
                    return None
                tag_name, idx_str = segment[:-1].split('[', 1)
                try:
                    idx = int(idx_str)
                except ValueError:
                    return None
                children = list(current)
                # The path used `list(parent).index(current)` which counts ALL
                # children, so we use a simple position lookup.
                if idx < 0 or idx >= len(children):
                    return None
                candidate = children[idx]
                # Verify tag name (with or without namespace) to avoid silent
                # mis-navigation if the tree changed.
                candidate_local_tag = candidate.tag.split('}')[-1] if '}' in candidate.tag else candidate.tag
                if candidate_local_tag != tag_name:
                    return None
                current = candidate
            return current
        except Exception:
            return None

    # ------------------------------------------------------------------
    # SmartArt / Diagram support
    # ------------------------------------------------------------------
    _NS_DGM = "http://schemas.openxmlformats.org/drawingml/2006/diagram"
    _NS_A = "http://schemas.openxmlformats.org/drawingml/2006/main"

    def _collect_diagrams_from_zip(
        self,
        input_path: Path,
        text_elements: List[Tuple[str, Callable[[str], None]]],
        diagram_translations: List[Dict[str, Any]],
    ) -> None:
        """Parse SmartArt diagram XML from the .docx ZIP and collect translatable text.

        SmartArt text lives in ``word/diagrams/data*.xml`` inside the ZIP.
        Each diagram data file contains ``<dgm:pt>`` elements with ``<a:t>``
        text nodes.
        """
        _TAG_A_T = f"{{{self._NS_A}}}t"

        try:
            with zipfile.ZipFile(input_path, 'r') as zf:
                diag_files = [
                    n for n in zf.namelist()
                    if n.startswith('word/diagrams/data') and n.endswith('.xml')
                ]

                for diag_file in diag_files:
                    try:
                        diag_xml = etree.fromstring(zf.read(diag_file))

                        for t_elem in diag_xml.iter(_TAG_A_T):
                            if t_elem.text and t_elem.text.strip():
                                original = t_elem.text.strip()

                                # Skip numeric-only or very short tokens
                                if original.replace('.', '').replace('-', '').replace(',', '').isdigit():
                                    continue
                                if len(original) <= 1:
                                    continue

                                entry: Dict[str, Any] = {
                                    'diag_file': diag_file,
                                    'element_path': self._get_element_path(t_elem),
                                    'original': original,
                                }
                                diagram_translations.append(entry)

                                def _make_diag_setter(
                                    entries: List[Dict[str, Any]], idx: int
                                ):
                                    def setter(text: str) -> None:
                                        entries[idx]['translated'] = text.strip()
                                    return setter

                                text_elements.append(
                                    (original, _make_diag_setter(diagram_translations, len(diagram_translations) - 1))
                                )

                    except Exception as e:
                        _log_error("word_diagram_parse_error", diag_file=diag_file, error=str(e))

            if diagram_translations:
                _log_info(
                    "word_diagram_collection",
                    diagram_files=len(diag_files),
                    text_count=len(diagram_translations),
                )

        except Exception as e:
            _log_error("word_diagrams_zip_error", error=str(e))

    def _apply_diagram_translations(
        self,
        output_path: Path,
        diagram_translations: List[Dict[str, Any]],
    ) -> None:
        """Re-inject SmartArt/diagram translations into the .docx ZIP.

        Modifies diagram data XML files in-place and rewrites the ZIP.
        """
        if not diagram_translations:
            return

        translated_entries = [e for e in diagram_translations if 'translated' in e and e['translated']]
        if not translated_entries:
            return

        _TAG_A_T = f"{{{self._NS_A}}}t"

        # Group by diagram file
        diag_files_to_update: Dict[str, List[Dict]] = {}
        for entry in translated_entries:
            df = entry['diag_file']
            if df not in diag_files_to_update:
                diag_files_to_update[df] = []
            diag_files_to_update[df].append(entry)

        try:
            with zipfile.ZipFile(output_path, 'r') as zf_in:
                existing_entries = zf_in.namelist()

                buf = io.BytesIO()
                with zipfile.ZipFile(buf, 'w', zipfile.ZIP_DEFLATED) as zf_out:
                    for item in existing_entries:
                        data = zf_in.read(item)

                        if item in diag_files_to_update:
                            try:
                                diag_xml = etree.fromstring(data)

                                for entry in diag_files_to_update[item]:
                                    for t_elem in diag_xml.iter(_TAG_A_T):
                                        if t_elem.text and t_elem.text.strip() == entry['original']:
                                            t_elem.text = entry['translated']
                                            break

                                data = etree.tostring(diag_xml, xml_declaration=True, encoding='UTF-8', standalone=True)
                            except Exception as e:
                                _log_error("word_diagram_update_error", diag_file=item, error=str(e))

                        zf_out.writestr(item, data)

            with open(output_path, 'wb') as f:
                f.write(buf.getvalue())

            _log_info(
                "word_diagrams_translated",
                diagram_files=len(diag_files_to_update),
                translations=len(translated_entries),
            )

        except Exception as e:
            _log_error("word_diagram_zip_rewrite_error", error=str(e))

    @staticmethod
    def _rpr_signature(run_element) -> str:
        """Formatting signature of a run: serialized rPr XML (or "")."""
        rpr = run_element.find(qn("w:rPr"))
        if rpr is None:
            return ""
        import lxml.etree as _et

        return _et.tostring(rpr, encoding="unicode")

    def _collect_from_paragraph(
        self,
        paragraph: Paragraph,
        text_elements: List[Tuple[str, Callable[[str], None]]],
        seen_run_elements: Optional[set] = None,
    ) -> None:
        """Collect text from paragraph runs, preserving inter-run whitespace.

        Adjacent runs sharing the SAME parent element and the SAME run
        formatting (rPr) are merged into ONE translation unit: the sentence
        is translated whole — not fragment by fragment — and the result is
        written into the first run while the sibling runs are blanked.
        This is what keeps mid-sentence bold spans ("This is *very*
        important") coherent in the target language, like DeepL's inline
        tag handling.

        Note: python-docx's `paragraph.runs` only returns DIRECT child <w:r>
        elements, not those inside <w:hyperlink> (used for TOC entries,
        cross-references, bookmark links). We therefore iterate the full
        XML tree to find every <w:r> and deduplicate by element identity —
        `seen_run_elements` is shared across paragraphs so runs living in
        text boxes (also collected by _collect_from_textboxes) are not
        translated twice.
        """
        # Check full paragraph text including nested content (hyperlinks, etc.)
        full_text = ''.join(
            t.text or '' for t in paragraph._p.iter(qn('w:t'))
        ).strip()
        if not full_text:
            return

        if seen_run_elements is None:
            seen_run_elements = set()

        # Every <w:r> in the paragraph tree, in document order, deduplicated
        # by element identity (paragraph.runs and the manual iter overlap).
        ordered_runs = []
        for r_elem in paragraph._p.iter(qn('w:r')):
            if id(r_elem) in seen_run_elements:
                continue
            seen_run_elements.add(id(r_elem))
            ordered_runs.append(r_elem)

        # Merge adjacent runs: same parent + same formatting signature.
        # Merging never crosses a parent boundary, so runs belonging to
        # different hyperlinks stay separate units.
        group: list = []  # list of r_elems
        group_signature: Optional[str] = None

        def _flush_group():
            combined = "".join(
                (t.text or "")
                for r in group
                for t in r.findall(qn("w:t"))
            )
            if not combined.strip():
                return
            non_empty = [r for r in group if r.findall(qn("w:t"))]
            if len(non_empty) == 1:
                run = Run(non_empty[0], paragraph)
                self._append_run_translation(run, text_elements)
                return
            leading = combined[: len(combined) - len(combined.lstrip())]
            trailing = combined[len(combined.rstrip()):]
            stripped = combined.strip()
            if not stripped:
                return

            first = non_empty[0]

            def make_group_setter(first_r, siblings, lead: str, trail: str):
                def setter(text: str) -> None:
                    from docx.text.run import Run as _Run

                    run = _Run(first_r, paragraph)
                    # Reapply the group's boundary whitespace so words are
                    # never concatenated with the next differently-formatted
                    # run ("This is quite" + "very" → "quite very").
                    run.text = lead + text.strip() + trail
                    # Blank the merged siblings: the whole sentence now
                    # lives in the first run (formatting is identical).
                    for sib in siblings:
                        for t_elem in sib.findall(qn("w:t")):
                            t_elem.text = ""

                return setter

            siblings = non_empty[1:]
            text_elements.append(
                (stripped, make_group_setter(first, siblings, leading, trailing))
            )

        for r_elem in ordered_runs:
            # Whitespace-only runs join the group: dropping them would
            # concatenate words ("Hello" + " " + "World" → "HelloWorld").
            # They carry no w:t text, so a group of only whitespace runs is
            # skipped at flush time by the strip() check.
            signature = self._rpr_signature(r_elem)
            same_parent = (
                group and group[-1].getparent() is r_elem.getparent()
            )
            if group and same_parent and signature == group_signature:
                group.append(r_elem)
            else:
                _flush_group()
                group = [r_elem]
                group_signature = signature
        _flush_group()

    def _append_run_translation(
        self,
        run,
        text_elements: List[Tuple[str, Callable[[str], None]]],
    ) -> None:
        """Extract translatable text from a Run and append a (text, setter) tuple."""
        original = run.text
        # Capture leading/trailing whitespace that must survive translation.
        leading = original[: len(original) - len(original.lstrip())]
        trailing = original[len(original.rstrip()) :]
        stripped = original.strip()

        def make_setter(r, lead: str, trail: str):
            def setter(text: str) -> None:
                # Strip any whitespace the translator may have added/removed
                # and reapply the original boundary whitespace.
                r.text = lead + text.strip() + trail

            return setter

        text_elements.append((stripped, make_setter(run, leading, trailing)))

    def _collect_from_table(
        self, table: Table, text_elements: List[Tuple[str, Callable[[str], None]]],
        seen_run_elements: Optional[set] = None,
    ) -> None:
        """Collect text from table cells."""
        for row in table.rows:
            for cell in row.cells:
                for paragraph in cell.paragraphs:
                    self._collect_from_paragraph(paragraph, text_elements, seen_run_elements)
                for nested_table in cell.tables:
                    self._collect_from_table(nested_table, text_elements, seen_run_elements)

    def _collect_from_section(
        self, section: Section, text_elements: List[Tuple[str, Callable[[str], None]]]
    ) -> None:
        """Collect text from headers and footers."""
        headers_footers = [
            section.header,
            section.footer,
            section.first_page_header,
            section.first_page_footer,
            section.even_page_header,
            section.even_page_footer,
        ]

        for hf in headers_footers:
            if hf:
                for paragraph in hf.paragraphs:
                    self._collect_from_paragraph(paragraph, text_elements)
                for table in hf.tables:
                    self._collect_from_table(table, text_elements)

    def _translate_images(self, document: Document, target_language: str) -> None:
        """Extract and translate text from images in Word document.
        Inserts the translated text as a caption paragraph under each image."""
        try:
            inline_shapes = getattr(document, "inline_shapes", [])
            _log_info("word_image_translation_start", count=len(inline_shapes))
            
            for idx, shape in enumerate(inline_shapes):
                # Type 3 is picture, type 12 is linked picture
                if not (hasattr(shape, "type") and shape.type in (3, 12)):
                    continue
                
                try:
                    image = getattr(shape, "image", None)
                    if not image:
                        continue
                    
                    image_data = image.blob
                    ext = getattr(image, "ext", "png") or "png"
                    
                    import tempfile
                    import os
                    with tempfile.NamedTemporaryFile(suffix=f".{ext}", delete=False) as tmp:
                        tmp.write(image_data)
                        tmp_path = tmp.name
                        
                    translated_text = self._translate_image_text(tmp_path, target_language)
                    try:
                        os.unlink(tmp_path)
                    except:
                        pass
                        
                    if translated_text and translated_text.strip():
                        parent = shape._inline.getparent()
                        while parent is not None and parent.tag != qn("w:p"):
                            parent = parent.getparent()
                        
                        if parent is not None:
                            p_elem = parent
                            new_p_elem = OxmlElement("w:p")
                            p_elem.addnext(new_p_elem)
                            
                            from docx.text.paragraph import Paragraph
                            new_p = Paragraph(new_p_elem, document)
                            
                            from docx.shared import Pt, RGBColor
                            run = new_p.add_run(f" [Image translation: {translated_text.strip()}] ")
                            run.font.italic = True
                            run.font.size = Pt(9)
                            run.font.color.rgb = RGBColor(128, 128, 128)
                            
                            _log_info("word_image_translation_added", index=idx)
                except Exception as shape_err:
                    _log_error("word_image_shape_translation_error", index=idx, error=str(shape_err))
        except Exception as e:
            _log_error("word_image_processing_error", error=str(e))

    def _translate_image_text(
        self, image_path: str, target_language: str
    ) -> str:
        """Translate image using active provider or legacy service."""
        if self._provider and hasattr(self._provider, "translate_image"):
            try:
                return self._provider.translate_image(image_path, target_language)
            except Exception as e:
                _log_error("word_image_translation_provider_error", error=str(e))

        from services.translation_service import translation_service
        # Temporarily enable translate_images flag on translation_service to bypass the hardcoded check
        old_val = getattr(translation_service, "translate_images", False)
        try:
            translation_service.translate_images = True
            if hasattr(translation_service, "translate_image"):
                return translation_service.translate_image(image_path, target_language)
        except Exception as e:
            _log_error("word_image_translation_legacy_error", error=str(e))
        finally:
            translation_service.translate_images = old_val
        return ""


word_translator = WordTranslator()