lyxy-document/readers/pptx/native_xml.py

"""使用 XML 原生解析 PPTX 文件"""

import re
import xml.etree.ElementTree as ET
import zipfile
from typing import Any, List, Optional, Tuple

from core import build_markdown_table, flush_list_stack


def parse(file_path: str) -> Tuple[Optional[str], Optional[str]]:
    """使用 XML 原生解析 PPTX 文件"""
    pptx_namespace = {
        "a": "http://schemas.openxmlformats.org/drawingml/2006/main",
        "p": "http://schemas.openxmlformats.org/presentationml/2006/main",
        "r": "http://schemas.openxmlformats.org/officeDocument/2006/relationships",
    }

    def extract_text_with_formatting(text_elem: Any, namespaces: dict) -> str:
        result = []
        runs = text_elem.findall(".//a:r", namespaces=namespaces)
        for run in runs:
            t_elem = run.find(".//a:t", namespaces=namespaces)
            if t_elem is None or not t_elem.text:
                continue

            text = t_elem.text

            rPr = run.find(".//a:rPr", namespaces=namespaces)
            is_bold = False
            is_italic = False

            if rPr is not None:
                is_bold = rPr.find(".//a:b", namespaces=namespaces) is not None
                is_italic = rPr.find(".//a:i", namespaces=namespaces) is not None

            if is_bold and is_italic:
                text = f"***{text}***"
            elif is_bold:
                text = f"**{text}**"
            elif is_italic:
                text = f"*{text}*"

            result.append(text)

        return "".join(result).strip() if result else ""

    def convert_table_to_md(table_elem: Any, namespaces: dict) -> str:
        rows = table_elem.findall(".//a:tr", namespaces=namespaces)
        if not rows:
            return ""

        rows_data = []
        for row in rows:
            cells = row.findall(".//a:tc", namespaces=namespaces)
            row_data = []
            for cell in cells:
                cell_text = extract_text_with_formatting(cell, namespaces)
                if cell_text:
                    cell_text = cell_text.replace("\n", " ").replace("\r", "")
                row_data.append(cell_text if cell_text else "")
            rows_data.append(row_data)
        return build_markdown_table(rows_data)

    def is_list_item(p_elem: Any, namespaces: dict) -> Tuple[bool, bool]:
        if p_elem is None:
            return False, False

        pPr = p_elem.find(".//a:pPr", namespaces=namespaces)
        if pPr is None:
            return False, False

        buChar = pPr.find(".//a:buChar", namespaces=namespaces)
        if buChar is not None:
            return True, False

        buAutoNum = pPr.find(".//a:buAutoNum", namespaces=namespaces)
        if buAutoNum is not None:
            return True, True

        return False, False

    def get_indent_level(p_elem: Any, namespaces: dict) -> int:
        if p_elem is None:
            return 0

        pPr = p_elem.find(".//a:pPr", namespaces=namespaces)
        if pPr is None:
            return 0

        lvl = pPr.get("lvl")
        return int(lvl) if lvl else 0

    try:
        md_content = []

        with zipfile.ZipFile(file_path) as zip_file:
            slide_files = [
                f
                for f in zip_file.namelist()
                if re.match(r"ppt/slides/slide\d+\.xml$", f)
            ]
            slide_files.sort(
                key=lambda f: int(re.search(r"slide(\d+)\.xml$", f).group(1))
            )

            for slide_idx, slide_file in enumerate(slide_files, 1):
                md_content.append("\n## Slide {}\n".format(slide_idx))

                with zip_file.open(slide_file) as slide_xml:
                    slide_root = ET.parse(slide_xml).getroot()

                    tx_bodies = slide_root.findall(
                        ".//p:sp/p:txBody", namespaces=pptx_namespace
                    )

                    tables = slide_root.findall(".//a:tbl", namespaces=pptx_namespace)
                    for table in tables:
                        table_md = convert_table_to_md(table, pptx_namespace)
                        if table_md:
                            md_content.append(table_md)

                    for tx_body in tx_bodies:
                        paragraphs = tx_body.findall(
                            ".//a:p", namespaces=pptx_namespace
                        )
                        list_stack = []

                        for para in paragraphs:
                            is_list, is_ordered = is_list_item(para, pptx_namespace)

                            if is_list:
                                level = get_indent_level(para, pptx_namespace)

                                while len(list_stack) <= level:
                                    list_stack.append("")

                                text = extract_text_with_formatting(
                                    para, pptx_namespace
                                )
                                if text:
                                    marker = "1. " if is_ordered else "- "
                                    indent = "  " * level
                                    list_stack[level] = f"{indent}{marker}{text}"

                                    for i in range(len(list_stack)):
                                        if list_stack[i]:
                                            md_content.append(list_stack[i] + "\n")
                                            list_stack[i] = ""
                            else:
                                if list_stack:
                                    flush_list_stack(list_stack, md_content)

                                text = extract_text_with_formatting(
                                    para, pptx_namespace
                                )
                                if text:
                                    md_content.append(f"{text}\n")

                        if list_stack:
                            flush_list_stack(list_stack, md_content)

                    md_content.append("---\n")

        content = "\n".join(md_content)
        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)}"