#!/usr/bin/env python3
"""整合的 DOCX 解析器，按优先级尝试多种解析方法：
1. MarkItDown (微软官方库)
2. python-docx (成熟的 Python 库)
3. XML 原生解析 (备选方案)

代码风格要求：
- Python 3.6+ 兼容
- 遵循 PEP 8 规范
- 所有公共 API 函数添加类型提示
- 字符串优先内联使用，不提取为常量，除非被使用超过3次
- 其他被多次使用的对象根据具体情况可考虑被提取为常量（如正则表达式）
- 模块级和公共 API 函数保留文档字符串
- 内部辅助函数不添加文档字符串（函数名足够描述）
- 变量命名清晰，避免单字母变量名
"""

import argparse
import os
import re
import sys
import zipfile
import xml.etree.ElementTree as ET
from typing import List, Optional, Tuple

IMAGE_PATTERN = re.compile(r"!\[[^\]]*\]\([^)]+\)")


def normalize_markdown_whitespace(content: str) -> str:
    lines = content.split("\n")
    result = []
    empty_count = 0

    for line in lines:
        stripped = line.strip()
        if not stripped:
            empty_count += 1
            if empty_count == 1:
                result.append(line)
        else:
            empty_count = 0
            result.append(line)

    return "\n".join(result)


def is_valid_docx(file_path: str) -> bool:
    try:
        with zipfile.ZipFile(file_path, "r") as zip_file:
            required_files = ["[Content_Types].xml", "_rels/.rels", "word/document.xml"]
            for required in required_files:
                if required not in zip_file.namelist():
                    return False
        return True
    except (zipfile.BadZipFile, zipfile.LargeZipFile):
        return False


def remove_markdown_images(markdown_text: str) -> str:
    return IMAGE_PATTERN.sub("", markdown_text)


def extract_titles(markdown_text: str) -> List[str]:
    """提取 markdown 文本中的所有标题行（1-6级）"""
    title_lines = []
    for line in markdown_text.split("\n"):
        stripped = line.lstrip()
        if stripped.startswith("#"):
            level = 0
            for char in stripped:
                if char == "#":
                    level += 1
                else:
                    break
            if 1 <= level <= 6:
                title_lines.append(stripped)
    return title_lines


def get_heading_level(line: str) -> int:
    stripped = line.lstrip()
    if not stripped.startswith("#"):
        return 0
    level = 0
    for char in stripped:
        if char == "#":
            level += 1
        else:
            break
    return level if 1 <= level <= 6 else 0


def extract_title_content(markdown_text: str, title_name: str) -> Optional[str]:
    """提取所有指定标题及其下级内容（每个包含上级标题）"""
    lines = markdown_text.split("\n")
    match_indices = []

    for i, line in enumerate(lines):
        level = get_heading_level(line)
        if level > 0:
            stripped = line.lstrip()
            title_text = stripped[level:].strip()
            if title_text == title_name:
                match_indices.append(i)

    if not match_indices:
        return None

    result_lines = []
    for idx in match_indices:
        target_level = get_heading_level(lines[idx])

        parent_titles = []
        current_level = target_level
        for i in range(idx - 1, -1, -1):
            line_level = get_heading_level(lines[i])
            if line_level > 0 and line_level < current_level:
                parent_titles.append(lines[i])
                current_level = line_level
                if current_level == 1:
                    break

        parent_titles.reverse()
        result_lines.extend(parent_titles)

        result_lines.append(lines[idx])
        for i in range(idx + 1, len(lines)):
            line = lines[i]
            line_level = get_heading_level(line)
            if line_level == 0 or line_level > target_level:
                result_lines.append(line)
            else:
                break

    return "\n".join(result_lines)


def search_markdown(
    content: str, pattern: str, context_lines: int = 0
) -> Optional[str]:
    """使用正则表达式搜索 markdown 文档，返回匹配结果及其上下文"""
    try:
        regex = re.compile(pattern)
    except re.error:
        return None

    lines = content.split("\n")

    non_empty_indices = []
    non_empty_to_original = {}
    for i, line in enumerate(lines):
        if line.strip():
            non_empty_indices.append(i)
            non_empty_to_original[i] = len(non_empty_indices) - 1

    matched_non_empty_indices = []
    for orig_idx in non_empty_indices:
        if regex.search(lines[orig_idx]):
            matched_non_empty_indices.append(non_empty_to_original[orig_idx])

    if not matched_non_empty_indices:
        return None

    merged_ranges = []
    current_start = matched_non_empty_indices[0]
    current_end = matched_non_empty_indices[0]

    for idx in matched_non_empty_indices[1:]:
        if idx - current_end <= context_lines * 2:
            current_end = idx
        else:
            merged_ranges.append((current_start, current_end))
            current_start = idx
            current_end = idx
    merged_ranges.append((current_start, current_end))

    results = []
    for start, end in merged_ranges:
        actual_start = max(0, start - context_lines)
        actual_end = min(len(non_empty_indices) - 1, end + context_lines)

        start_line_idx = non_empty_indices[actual_start]
        end_line_idx = non_empty_indices[actual_end]

        selected_indices = set(non_empty_indices[actual_start : actual_end + 1])
        result_lines = [
            line
            for i, line in enumerate(lines)
            if start_line_idx <= i <= end_line_idx
            and (line.strip() or i in selected_indices)
        ]
        results.append("\n".join(result_lines))

    return "\n---\n".join(results)


def parse_with_markitdown(file_path: str) -> Optional[Tuple[str, None]]:
    try:
        from markitdown import MarkItDown

        md = MarkItDown()
        result = md.convert(file_path)
        if not result.text_content.strip():
            return None, "文档为空"
        return result.text_content, None
    except ImportError:
        return None, "MarkItDown 库未安装"
    except Exception as e:
        return None, f"MarkItDown 解析失败: {str(e)}"


def parse_with_python_docx(file_path: str) -> Optional[Tuple[str, None]]:
    try:
        from docx import Document
    except ImportError:
        return None, "python-docx 库未安装"

    try:
        doc = Document(file_path)

        def get_heading_level(para) -> int:
            if para.style and para.style.name:
                style_name = para.style.name
                if "Heading 1" in style_name or "Title" in style_name:
                    return 1
                elif "Heading 2" in style_name:
                    return 2
                elif "Heading 3" in style_name:
                    return 3
                elif "Heading 4" in style_name:
                    return 4
                elif "Heading 5" in style_name:
                    return 5
                elif "Heading 6" in style_name:
                    return 6
            return 0

        def get_list_style(para) -> Optional[str]:
            if not para.style or not para.style.name:
                return None
            style_name = para.style.name
            if "List Bullet" in style_name or "Bullet" in style_name:
                return "bullet"
            elif "List Number" in style_name or "Number" in style_name:
                return "number"
            return None

        def convert_runs_to_markdown(runs) -> str:
            result = []
            for run in runs:
                text = run.text
                if not text:
                    continue
                if run.bold:
                    text = f"**{text}**"
                if run.italic:
                    text = f"*{text}*"
                if run.underline:
                    text = f"<u>{text}</u>"
                result.append(text)
            return "".join(result)

        def convert_table_to_markdown(table) -> str:
            md_lines = []
            for i, row in enumerate(table.rows):
                cells = []
                for cell in row.cells:
                    cell_text = cell.text.strip().replace("\n", " ")
                    cells.append(cell_text)
                if cells:
                    md_line = "| " + " | ".join(cells) + " |"
                    md_lines.append(md_line)
                    if i == 0:
                        sep_line = "| " + " | ".join(["---"] * len(cells)) + " |"
                        md_lines.append(sep_line)
            return "\n".join(md_lines)

        markdown_lines = []

        for para in doc.paragraphs:
            text = convert_runs_to_markdown(para.runs)
            if not text.strip():
                continue
            heading_level = get_heading_level(para)
            if heading_level > 0:
                markdown_lines.append(f"{'#' * heading_level} {text}")
            else:
                list_style = get_list_style(para)
                if list_style == "bullet":
                    markdown_lines.append(f"- {text}")
                elif list_style == "number":
                    markdown_lines.append(f"1. {text}")
                else:
                    markdown_lines.append(text)
            markdown_lines.append("")

        for table in doc.tables:
            table_md = convert_table_to_markdown(table)
            markdown_lines.append(table_md)
            markdown_lines.append("")

        content = "\n".join(markdown_lines)
        if not content.strip():
            return None, "文档为空"
        return content, None
    except Exception as e:
        return None, f"python-docx 解析失败: {str(e)}"


def parse_with_xml(file_path: str) -> Optional[Tuple[str, None]]:
    word_namespace = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
    namespaces = {"w": word_namespace}

    def safe_open_zip(zip_file: zipfile.ZipFile, name: str):
        if name.startswith("..") or "/" not in name:
            return None
        return zip_file.open(name)

    def get_heading_level(style_id: Optional[str], style_to_level: dict) -> int:
        return style_to_level.get(style_id, 0)

    def get_list_style(style_id: Optional[str], style_to_list: dict) -> Optional[str]:
        return style_to_list.get(style_id, None)

    def extract_text_with_formatting(para, namespaces: dict) -> str:
        texts = []
        for run in para.findall(".//w:r", namespaces=namespaces):
            text_elem = run.find(".//w:t", namespaces=namespaces)
            if text_elem is not None and text_elem.text:
                text = text_elem.text
                bold = run.find(".//w:b", namespaces=namespaces) is not None
                italic = run.find(".//w:i", namespaces=namespaces) is not None
                if bold:
                    text = f"**{text}**"
                if italic:
                    text = f"*{text}*"
                texts.append(text)
        return "".join(texts).strip()

    def convert_table_to_markdown(table_elem, namespaces: dict) -> str:
        rows = table_elem.findall(".//w:tr", namespaces=namespaces)
        if not rows:
            return ""
        md_lines = []
        for i, row in enumerate(rows):
            cells = row.findall(".//w:tc", namespaces=namespaces)
            cell_texts = []
            for cell in cells:
                cell_text = extract_text_with_formatting(cell, namespaces)
                cell_text = cell_text.replace("\n", " ").strip()
                cell_texts.append(cell_text if cell_text else "")
            if cell_texts:
                md_line = "| " + " | ".join(cell_texts) + " |"
                md_lines.append(md_line)
                if i == 0:
                    sep_line = "| " + " | ".join(["---"] * len(cell_texts)) + " |"
                    md_lines.append(sep_line)
        return "\n".join(md_lines)

    try:
        style_to_level = {}
        style_to_list = {}
        markdown_lines = []

        with zipfile.ZipFile(file_path) as zip_file:
            try:
                styles_file = safe_open_zip(zip_file, "word/styles.xml")
                if styles_file:
                    styles_root = ET.parse(styles_file)
                    for style in styles_root.findall(
                        ".//w:style", namespaces=namespaces
                    ):
                        style_id = style.get(f"{{{word_namespace}}}styleId")
                        style_name_elem = style.find("w:name", namespaces=namespaces)
                        if style_id and style_name_elem is not None:
                            style_name = style_name_elem.get(f"{{{word_namespace}}}val")
                            if style_name:
                                if style_name == "Title":
                                    style_to_level[style_id] = 1
                                elif style_name == "heading 1":
                                    style_to_level[style_id] = 1
                                elif style_name == "heading 2":
                                    style_to_level[style_id] = 2
                                elif style_name == "heading 3":
                                    style_to_level[style_id] = 3
                                elif style_name == "heading 4":
                                    style_to_level[style_id] = 4
                                elif style_name == "heading 5":
                                    style_to_level[style_id] = 5
                                elif style_name == "heading 6":
                                    style_to_level[style_id] = 6
                                elif (
                                    "List Bullet" in style_name
                                    or "Bullet" in style_name
                                ):
                                    style_to_list[style_id] = "bullet"
                                elif (
                                    "List Number" in style_name
                                    or "Number" in style_name
                                ):
                                    style_to_list[style_id] = "number"
            except Exception:
                pass

            document_file = safe_open_zip(zip_file, "word/document.xml")
            if not document_file:
                return None, "document.xml 不存在或无法访问"

            root = ET.parse(document_file)
            body = root.find(".//w:body", namespaces=namespaces)
            if body is None:
                return None, "document.xml 中未找到 w:body 元素"

            for child in body.findall("./*", namespaces=namespaces):
                if child.tag.endswith("}p"):
                    style_elem = child.find(".//w:pStyle", namespaces=namespaces)
                    style_id = (
                        style_elem.get(f"{{{word_namespace}}}val")
                        if style_elem is not None
                        else None
                    )

                    heading_level = get_heading_level(style_id, style_to_level)
                    list_style = get_list_style(style_id, style_to_list)
                    para_text = extract_text_with_formatting(child, namespaces)

                    if para_text:
                        if heading_level > 0:
                            markdown_lines.append(f"{'#' * heading_level} {para_text}")
                        elif list_style == "bullet":
                            markdown_lines.append(f"- {para_text}")
                        elif list_style == "number":
                            markdown_lines.append(f"1. {para_text}")
                        else:
                            markdown_lines.append(para_text)
                        markdown_lines.append("")

                elif child.tag.endswith("}tbl"):
                    table_md = convert_table_to_markdown(child, namespaces)
                    if table_md:
                        markdown_lines.append(table_md)
                        markdown_lines.append("")

        content = "\n".join(markdown_lines)
        if not content.strip():
            return None, "文档为空"
        return content, None
    except Exception as e:
        return None, f"XML 解析失败: {str(e)}"


def main() -> None:
    parser = argparse.ArgumentParser(description="将 DOCX 文件解析为 Markdown")

    parser.add_argument("file_path", help="DOCX 文件的绝对路径")

    parser.add_argument(
        "-n",
        "--context",
        type=int,
        default=2,
        help="与 -s 配合使用，指定每个检索结果包含的前后行数（不包含空行）",
    )

    group = parser.add_mutually_exclusive_group()
    group.add_argument(
        "-c", "--count", action="store_true", help="返回解析后的 markdown 文档的总字数"
    )
    group.add_argument(
        "-l", "--lines", action="store_true", help="返回解析后的 markdown 文档的总行数"
    )
    group.add_argument(
        "-t",
        "--titles",
        action="store_true",
        help="返回解析后的 markdown 文档的标题行（1-6级）",
    )
    group.add_argument(
        "-tc",
        "--title-content",
        help="指定标题名称，输出该标题及其下级内容（不包含#号）",
    )
    group.add_argument(
        "-s",
        "--search",
        help="使用正则表达式搜索文档，返回所有匹配结果（用---分隔）",
    )

    args = parser.parse_args()

    if not os.path.exists(args.file_path):
        print(f"错误: 文件不存在: {args.file_path}")
        sys.exit(1)

    if not args.file_path.lower().endswith(".docx"):
        print(f"警告: 文件扩展名不是 .docx: {args.file_path}")

    if not is_valid_docx(args.file_path):
        print(f"错误: 文件不是有效的 DOCX 格式或已损坏: {args.file_path}")
        sys.exit(1)

    parsers = [
        ("MarkItDown", parse_with_markitdown),
        ("python-docx", parse_with_python_docx),
        ("XML 原生解析", parse_with_xml),
    ]

    failures = []
    content = None

    for parser_name, parser_func in parsers:
        content, error = parser_func(args.file_path)
        if content is not None:
            content = remove_markdown_images(content)
            content = normalize_markdown_whitespace(content)
            break
        else:
            failures.append(f"- {parser_name}: {error}")

    if content is None:
        print("所有解析方法均失败:")
        for failure in failures:
            print(failure)
        sys.exit(1)

    if args.count:
        print(len(content.replace("\n", "")))
    elif args.lines:
        print(len(content.split("\n")))
    elif args.titles:
        titles = extract_titles(content)
        for title in titles:
            print(title)
    elif args.title_content:
        title_content = extract_title_content(content, args.title_content)
        if title_content is None:
            print(f"错误: 未找到标题 '{args.title_content}'")
            sys.exit(1)
        print(title_content, end="")
    elif args.search:
        search_result = search_markdown(content, args.search, args.context)
        if search_result is None:
            print(f"错误: 正则表达式无效或未找到匹配: '{args.search}'")
            sys.exit(1)
        print(search_result, end="")
    else:
        print(content, end="")


if __name__ == "__main__":
    main()