"""旧版 Word (.doc) 解析器

优先级：
1. Windows + pywin32 → 通过 Word COM 接口转换
2. LibreOffice → 跨平台 fallback
"""

import os
import subprocess
import sys
import tempfile
from typing import List

from exceptions import ParseError
from parsers.base import BaseParser
from parsers.doc_parser import DocParser


class LegacyDocParser(BaseParser):
    """旧版 .doc 文件解析器，自动选择最佳转换方式"""

    def __init__(self):
        self._docx_parser = DocParser()

    def supported_extensions(self) -> List[str]:
        return [".doc"]

    def parse(self, file_path: str) -> str:
        file_name = os.path.basename(file_path)

        # Windows 优先尝试 Word COM 接口
        if sys.platform == "win32":
            try:
                return self._parse_via_com(file_path, file_name)
            except ParseError:
                raise
            except Exception:
                # COM 失败（Word 未安装等），fallback 到 LibreOffice
                pass

        return self._parse_via_libreoffice(file_path, file_name)

    def _parse_via_com(self, file_path: str, file_name: str) -> str:
        """通过 pywin32 COM 接口调用 Microsoft Word 转换 .doc → .docx"""
        try:
            import win32com.client
            import pythoncom
        except ImportError:
            raise RuntimeError("pywin32 未安装")

        abs_path = os.path.abspath(file_path)

        with tempfile.TemporaryDirectory() as tmp_dir:
            docx_path = os.path.join(tmp_dir, os.path.splitext(file_name)[0] + ".docx")

            pythoncom.CoInitialize()
            word = None
            doc = None
            try:
                word = win32com.client.Dispatch("Word.Application")
                word.Visible = False
                word.DisplayAlerts = False
                doc = word.Documents.Open(abs_path, ReadOnly=True)
                # SaveAs2 格式 16 = wdFormatDocumentDefault (.docx)
                doc.SaveAs2(os.path.abspath(docx_path), FileFormat=16)
                doc.Close(False)
                doc = None
            except Exception as e:
                raise ParseError(file_name, f"Word COM 转换失败: {e}")
            finally:
                if doc:
                    try:
                        doc.Close(False)
                    except Exception:
                        pass
                if word:
                    try:
                        word.Quit()
                    except Exception:
                        pass
                pythoncom.CoUninitialize()

            if not os.path.exists(docx_path):
                raise ParseError(file_name, "Word COM 转换后未找到 .docx 文件")

            return self._docx_parser.parse(docx_path)

    def _parse_via_libreoffice(self, file_path: str, file_name: str) -> str:
        """通过 LibreOffice 转换 .doc → .docx（跨平台 fallback）"""
        with tempfile.TemporaryDirectory() as tmp_dir:
            try:
                subprocess.run(
                    [
                        "libreoffice", "--headless", "--convert-to", "docx",
                        "--outdir", tmp_dir, os.path.abspath(file_path),
                    ],
                    capture_output=True,
                    timeout=120,
                    check=True,
                )
            except FileNotFoundError:
                raise ParseError(
                    file_name,
                    "无法处理 .doc 文件。Windows 需要安装 Microsoft Word，"
                    "其他系统需要安装 LibreOffice: https://www.libreoffice.org/download/",
                )
            except subprocess.TimeoutExpired:
                raise ParseError(file_name, "LibreOffice 转换超时（120秒）")
            except subprocess.CalledProcessError as e:
                stderr = e.stderr.decode("utf-8", errors="replace") if e.stderr else "未知错误"
                raise ParseError(file_name, f"LibreOffice 转换失败: {stderr}")

            base_name = os.path.splitext(file_name)[0] + ".docx"
            converted_path = os.path.join(tmp_dir, base_name)

            if not os.path.exists(converted_path):
                raise ParseError(file_name, "LibreOffice 转换后未找到 .docx 文件")

            return self._docx_parser.parse(converted_path)