feat(export): 新增 PDF/DOCX 导出与 StaticRenderer 内部契约

- 新增 PdfExporter（reportlab）与 DocxExporter（python-docx），实现与 HtmlExporter 一致的同步 render + 异步 export，v1 文本优先（标题/段落/ 行内强调与链接/列表/引用/表格/代码块/数学文本），function_plot 与 mermaid 保留源码占位并记 warning。 - service 层加 _EXPORTERS 注册表按格式分发，删除 format!=html 硬限制，扩展名/MIME/产物清理泛化到 html/pdf/docx 三种格式。 - 新增 app/plot/renderer.py：StaticRenderRequest + StaticRenderer Protocol + FunctionPlotStaticRenderer + MermaidStaticRenderer；HtmlExporter 改经 FunctionPlotStaticRenderer 消费，去除对 render_svg 的直接依赖。 - 补齐 PDF/DOCX 魔法字节、CJK 字体、占位 warning 与 StaticRenderer 契约测试。 - 更新 Export开发说明.md。 Co-Authored-By: Claude Code <noreply@anthropic.com>
2026-09-06 17:04:58 +08:00
parent 966a94cad8
commit 406dd42571
11 changed files with 1334 additions and 51 deletions
@@ -0,0 +1,330 @@
+"""DocxExporter：Document AST → DOCX（python-docx）。
+
+v1 为文本优先：标题/段落/行内强调与链接/列表/引用/表格/代码块/数学文本均可导出；
+function_plot 与 mermaid 保留源码占位并记 warning。中文字体通过 Normal 样式挂载
+w:eastAsia=宋体，保证 Word 打开时中文正常显示；bold/italic 由 Word 原生渲染。
+"""
+
+from __future__ import annotations
+
+from io import BytesIO
+
+from docx import Document as DocxDocument
+from docx.enum.text import WD_ALIGN_PARAGRAPH
+from docx.opc.constants import RELATIONSHIP_TYPE
+from docx.oxml import OxmlElement
+from docx.oxml.ns import qn
+from docx.shared import Inches, Mm, Pt, RGBColor
+
+from app.contracts import ExportOptions
+from app.export.document import Document, DocumentNode, ExportResult
+from app.export.exporters._common import (
+    MERMAID_WARNING,
+    PLOT_PLACEHOLDER_WARNING,
+    RAW_HTML_WARNING,
+    format_meta_value,
+    safe_url,
+)
+
+_MIME = "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+
+_HEADING_SIZES = {1: 20, 2: 16, 3: 14, 4: 12, 5: 11, 6: 10.5}
+
+
+def _plain_text(children: list[DocumentNode]) -> str:
+    """递归拼接行内节点的纯文本，供标题/链接文字等需要纯文本处使用。"""
+    parts: list[str] = []
+    for child in children:
+        if child.type == "text":
+            parts.append(child.text)
+        elif child.children:
+            parts.append(_plain_text(child.children))
+        elif child.text:
+            parts.append(child.text)
+    return "".join(parts)
+
+
+class DocxExporter:
+    """实现 DocumentExporter：递归渲染 Document AST 为 DOCX 字节流。"""
+
+    def render(self, document: Document, options: ExportOptions) -> ExportResult:
+        """同步渲染；CPU 密集，调用方应放入线程执行，避免阻塞事件循环。"""
+        self._doc = DocxDocument()
+        self._configure_normal_style()
+        self._configure_page(options)
+        warnings: list[str] = []
+
+        self._render_header(document, options, warnings)
+        self._render_children(document.children, warnings)
+
+        buf = BytesIO()
+        self._doc.save(buf)
+        return ExportResult(content=buf.getvalue(), mime_type=_MIME, warnings=warnings)
+
+    async def export(self, document: Document, options: ExportOptions) -> ExportResult:
+        """契约要求的 async 接口；渲染本身同步，直接转发到 render。"""
+        return self.render(document, options)
+
+    def _configure_normal_style(self) -> None:
+        """Normal 样式挂载 CJK 字体；拉丁用 Calibri，中文用宋体。"""
+        style = self._doc.styles["Normal"]
+        style.font.name = "Calibri"
+        style.font.size = Pt(11)
+        rfonts = style.element.get_or_add_rPr().get_or_add_rFonts()
+        rfonts.set(qn("w:eastAsia"), "宋体")
+
+    def _configure_page(self, options: ExportOptions) -> None:
+        section = self._doc.sections[0]
+        size = (options.page_size or "A4").lower()
+        if size == "a4":
+            section.page_width = Mm(210)
+            section.page_height = Mm(297)
+        elif size == "letter":
+            section.page_width = Inches(8.5)
+            section.page_height = Inches(11)
+
+    # --- 文档头部 ---
+    def _render_header(self, document: Document, options: ExportOptions, warnings: list[str]) -> None:
+        title = str(document.attributes.get("title") or "")
+        if options.include_title and title:
+            p = self._doc.add_paragraph()
+            run = p.add_run(title)
+            run.bold = True
+            run.font.size = Pt(22)
+            p.paragraph_format.space_after = Pt(12)
+        if options.include_metadata:
+            metadata = document.attributes.get("metadata")
+            if metadata:
+                for key, value in metadata.items():
+                    p = self._doc.add_paragraph()
+                    run = p.add_run(f"{key}: {format_meta_value(value)}")
+                    run.font.size = Pt(9)
+                    run.font.color.rgb = RGBColor(0x57, 0x60, 0x6A)
+
+    # --- 块级 ---
+    def _render_children(self, children: list[DocumentNode], warnings: list[str]) -> None:
+        for child in children:
+            self._render_block(child, warnings)
+
+    def _render_block(self, node: DocumentNode, warnings: list[str]) -> None:
+        handler = getattr(self, f"_block_{node.type}", None)
+        if handler is not None:
+            handler(node, warnings)
+        else:
+            warnings.append(f"无法表示的节点类型已跳过：{node.type}")
+
+    def _block_heading(self, node: DocumentNode, warnings: list[str]) -> None:
+        level = max(1, min(6, int(node.attributes.get("level", 1))))
+        p = self._doc.add_paragraph()
+        run = p.add_run(_plain_text(node.children))
+        run.bold = True
+        run.font.size = Pt(_HEADING_SIZES[level])
+        p.paragraph_format.space_before = Pt(14 if level <= 2 else 10)
+        p.paragraph_format.space_after = Pt(6)
+
+    def _block_paragraph(self, node: DocumentNode, warnings: list[str]) -> None:
+        p = self._doc.add_paragraph()
+        self._render_inline(p, node.children, warnings)
+
+    def _block_blockquote(self, node: DocumentNode, warnings: list[str]) -> None:
+        p = self._doc.add_paragraph()
+        self._render_inline(p, node.children, warnings)
+        p.paragraph_format.left_indent = Pt(16)
+        for run in p.runs:
+            run.font.color.rgb = RGBColor(0x57, 0x60, 0x6A)
+
+    def _block_list(self, node: DocumentNode, warnings: list[str], level: int = 0) -> None:
+        ordered = bool(node.attributes.get("ordered"))
+        for index, item in enumerate(node.children, start=1):
+            self._block_list_item(item, warnings, ordered, index, level)
+
+    def _block_list_item(
+        self,
+        item: DocumentNode,
+        warnings: list[str],
+        ordered: bool,
+        index: int,
+        level: int,
+    ) -> None:
+        if item.attributes.get("task"):
+            marker = "☑ " if item.attributes.get("checked") else "☐ "
+        else:
+            marker = f"{index}. " if ordered else "• "
+        indent = Pt(18 + 18 * level)
+        first = True
+        for child in item.children:
+            if child.type == "list":
+                self._block_list(child, warnings, level + 1)
+                continue
+            if child.type == "paragraph":
+                p = self._doc.add_paragraph()
+                p.paragraph_format.left_indent = indent
+                if first:
+                    self._add_run(p, marker)
+                    first = False
+                self._render_inline(p, child.children, warnings)
+            elif child.children:
+                # 直接行内子节点：拼进一个段落
+                p = self._doc.add_paragraph()
+                p.paragraph_format.left_indent = indent
+                if first:
+                    self._add_run(p, marker)
+                    first = False
+                self._render_inline(p, child.children, warnings)
+            else:
+                self._render_block(child, warnings)
+                first = False
+
+    def _block_table(self, node: DocumentNode, warnings: list[str]) -> None:
+        rows = node.children
+        ncols = max((len(r.children) for r in rows), default=0)
+        if not rows or ncols == 0:
+            return
+        table = self._doc.add_table(rows=len(rows), cols=ncols)
+        table.style = "Table Grid"
+        for ri, row in enumerate(rows):
+            head = bool(row.attributes.get("head"))
+            for ci in range(ncols):
+                cell = table.cell(ri, ci)
+                p = cell.paragraphs[0]
+                if ci < len(row.children):
+                    self._render_inline(p, row.children[ci].children, warnings, bold=head)
+
+    def _block_code_block(self, node: DocumentNode, warnings: list[str]) -> None:
+        lines = node.text.split("\n")
+        p = self._doc.add_paragraph()
+        self._shade_paragraph(p)
+        p.paragraph_format.left_indent = Pt(8)
+        p.paragraph_format.right_indent = Pt(8)
+        p.paragraph_format.space_before = Pt(6)
+        p.paragraph_format.space_after = Pt(8)
+        for i, line in enumerate(lines):
+            run = p.add_run(line)
+            run.font.name = "Consolas"
+            run.font.size = Pt(10)
+            if i < len(lines) - 1:
+                run.add_break()
+
+    def _block_thematic_break(self, node: DocumentNode, warnings: list[str]) -> None:
+        p = self._doc.add_paragraph()
+        pPr = p._p.get_or_add_pPr()
+        pBdr = OxmlElement("w:pBdr")
+        bottom = OxmlElement("w:bottom")
+        bottom.set(qn("w:val"), "single")
+        bottom.set(qn("w:sz"), "6")
+        bottom.set(qn("w:space"), "1")
+        bottom.set(qn("w:color"), "D0D7DE")
+        pBdr.append(bottom)
+        pPr.append(pBdr)
+
+    def _block_mermaid(self, node: DocumentNode, warnings: list[str]) -> None:
+        warnings.append(MERMAID_WARNING)
+        self._block_code_block(node, warnings)
+
+    def _block_function_plot(self, node: DocumentNode, warnings: list[str]) -> None:
+        warnings.append(PLOT_PLACEHOLDER_WARNING)
+        self._block_code_block(node, warnings)
+
+    def _block_math_block(self, node: DocumentNode, warnings: list[str]) -> None:
+        p = self._doc.add_paragraph()
+        p.alignment = WD_ALIGN_PARAGRAPH.CENTER
+        p.add_run(f"$${node.text}$$")
+
+    def _block_html_block(self, node: DocumentNode, warnings: list[str]) -> None:
+        # 原始 HTML 不可信，按纯文本保留正文
+        warnings.append(RAW_HTML_WARNING)
+        self._doc.add_paragraph(node.text)
+
+    # --- 行内（写入 run） ---
+    def _render_inline(
+        self,
+        paragraph,
+        children: list[DocumentNode],
+        warnings: list[str],
+        bold: bool = False,
+        italic: bool = False,
+    ) -> None:
+        for child in children:
+            self._render_inline_node(paragraph, child, warnings, bold, italic)
+
+    def _render_inline_node(
+        self, paragraph, node: DocumentNode, warnings: list[str], bold: bool, italic: bool
+    ) -> None:
+        t = node.type
+        if t == "text":
+            self._add_run(paragraph, node.text, bold=bold, italic=italic)
+        elif t == "strong":
+            self._render_inline(paragraph, node.children, warnings, bold=True, italic=italic)
+        elif t == "emphasis":
+            self._render_inline(paragraph, node.children, warnings, bold=bold, italic=True)
+        elif t == "codespan":
+            self._add_run(paragraph, node.text, code=True)
+        elif t == "link":
+            inner = _plain_text(node.children)
+            href = str(node.attributes.get("href") or "")
+            safe_href = safe_url(href)
+            if safe_href is None:
+                warnings.append(f"链接协议不安全，已降级为纯文本：{href!r}")
+                self._render_inline(paragraph, node.children, warnings, bold, italic)
+            else:
+                self._add_hyperlink(paragraph, safe_href, inner)
+        elif t == "image":
+            src = str(node.attributes.get("src") or "")
+            alt = str(node.attributes.get("alt") or "")
+            if safe_url(src) is None:
+                warnings.append(f"图片地址不安全，已跳过：{src!r}")
+            else:
+                warnings.append("图片未内嵌到 DOCX，已用替代文本表示")
+            if alt:
+                self._add_run(paragraph, alt)
+        elif t == "math_inline":
+            self._add_run(paragraph, f"\\({node.text}\\)")
+        elif t == "linebreak":
+            self._add_run(paragraph, "").add_break()
+        else:
+            warnings.append(f"无法表示的行内节点已跳过：{t}")
+
+    def _add_run(self, paragraph, text: str, bold: bool = False, italic: bool = False, code: bool = False):
+        run = paragraph.add_run(text)
+        run.bold = bold
+        run.italic = italic
+        if code:
+            run.font.name = "Consolas"
+            run.font.size = Pt(10)
+        return run
+
+    def _add_hyperlink(self, paragraph, url: str, text: str) -> None:
+        """写入可点击的超链接 run（python-docx 无公开 API，需手写 w:hyperlink）。"""
+        part = paragraph.part
+        r_id = part.relate_to(url, RELATIONSHIP_TYPE.HYPERLINK, is_external=True)
+        hyperlink = OxmlElement("w:hyperlink")
+        hyperlink.set(qn("r:id"), r_id)
+        run = OxmlElement("w:r")
+        rPr = OxmlElement("w:rPr")
+        rFonts = OxmlElement("w:rFonts")
+        rFonts.set(qn("w:ascii"), "Calibri")
+        rFonts.set(qn("w:hAnsi"), "Calibri")
+        rFonts.set(qn("w:eastAsia"), "宋体")
+        rPr.append(rFonts)
+        color = OxmlElement("w:color")
+        color.set(qn("w:val"), "0969DA")
+        rPr.append(color)
+        u = OxmlElement("w:u")
+        u.set(qn("w:val"), "single")
+        rPr.append(u)
+        run.append(rPr)
+        t = OxmlElement("w:t")
+        t.text = text
+        t.set(qn("xml:space"), "preserve")
+        run.append(t)
+        hyperlink.append(run)
+        paragraph._p.append(hyperlink)
+
+    def _shade_paragraph(self, paragraph, fill: str = "F2F2F2") -> None:
+        """给段落加浅灰底纹，用于代码块占位。"""
+        pPr = paragraph._p.get_or_add_pPr()
+        shd = OxmlElement("w:shd")
+        shd.set(qn("w:val"), "clear")
+        shd.set(qn("w:color"), "auto")
+        shd.set(qn("w:fill"), fill)
+        pPr.append(shd)