"""doc / wps → docx 转换。"""

from __future__ import annotations

import shutil
import subprocess
from pathlib import Path

from fastapi_modules.fastapi_leaudit.govdoc_engine.config import get_settings


class UnsupportedFormat(Exception):
    pass


class ConversionError(Exception):
    pass


_SUPPORTED_DIRECT = {".docx"}
_SUPPORTED_CONVERT = {".doc", ".wps"}
_SOFFICE_FALLBACK_PATHS = (
    "/opt/homebrew/bin/soffice",
    "/usr/local/bin/soffice",
    "/Applications/LibreOffice.app/Contents/MacOS/soffice",
    "/usr/bin/soffice",
)


def load_to_docx(src: Path) -> Path:
    """统一返回 .docx 路径。.doc/.wps 调 soffice 转换。"""
    ext = src.suffix.lower()
    if ext in _SUPPORTED_DIRECT:
        return src
    if ext in _SUPPORTED_CONVERT:
        return _convert_via_soffice(src)
    raise UnsupportedFormat(f"unsupported file type: {ext}")


def _convert_via_soffice(src: Path) -> Path:
    soffice = _resolve_soffice_path(get_settings().soffice_path)

    out_dir = src.parent
    cmd = [
        soffice, "--headless", "--convert-to", "docx",
        "--outdir", str(out_dir), str(src),
    ]
    try:
        result = subprocess.run(
            cmd, capture_output=True, timeout=60,
        )
    except subprocess.TimeoutExpired as e:
        raise ConversionError("soffice timeout") from e

    if result.returncode != 0:
        raise ConversionError(
            f"soffice exit {result.returncode}: {result.stderr.decode(errors='ignore')}"
        )

    out = out_dir / (src.stem + ".docx")
    if not out.exists():
        raise ConversionError(f"expected output not found: {out}")
    return out


def _resolve_soffice_path(configured: str) -> str:
    candidates = [configured, *_SOFFICE_FALLBACK_PATHS]
    checked: list[str] = []
    for candidate in candidates:
        if candidate in checked:
            continue
        checked.append(candidate)

        resolved = shutil.which(candidate)
        if resolved:
            return resolved
        if Path(candidate).exists():
            return candidate

    raise ConversionError(
        f"soffice not found; checked: {', '.join(checked)}. "
        "Install LibreOffice or set SOFFICE_PATH."
    )