"""HtmlExporter：Document AST → 完整 HTML5 文档（内嵌基础 CSS）。对无法静态表达的节点（mermaid / function_plot）渲染为占位代码块并记 warning，不静默丢失；严重内容缺失由 service 层以 EXPORT_UNSUPPORTED_CONTENT 判定，本层只负责逐节点渲染。 """ from __future__ import annotations import html from datetime import datetime from app.contracts import ExportOptions from app.export.document import Document, DocumentNode, ExportResult _MERMAID_WARNING = "mermaid 需前端渲染，已保留为占位代码块" _FUNCTION_PLOT_WARNING = "函数图像渲染将在后续版本提供，已保留为占位代码块" _BASE_CSS = """ body { margin: 0; background: #f6f7f9; color: #1f2328; font: 15px/1.7 -apple-system, 'Segoe UI', 'Microsoft YaHei', sans-serif; } article { max-width: 860px; margin: 0 auto; padding: 40px 48px; background: #fff; } article.theme-dark { background: #0d1117; color: #c9d1d9; } h1, h2, h3, h4, h5, h6 { line-height: 1.3; margin: 1.4em 0 0.6em; } h1.title { margin-top: 0; } p { margin: 0.6em 0; } a { color: #0969da; } code { font-family: 'JetBrains Mono', Consolas, monospace; font-size: 0.9em; background: #f0f1f3; padding: 0.15em 0.35em; border-radius: 3px; } pre { background: #f6f8fa; padding: 14px 16px; border-radius: 6px; overflow-x: auto; } pre.code-theme-github-dark { background: #0d1117; color: #c9d1d9; } pre code { background: none; padding: 0; } pre.mermaid, pre.function-plot { border: 1px dashed #d0d7de; } blockquote { margin: 0.8em 0; padding: 0.2em 1em; border-left: 4px solid #d0d7de; color: #57606a; } img { max-width: 100%; } table { border-collapse: collapse; margin: 0.8em 0; } th, td { border: 1px solid #d0d7de; padding: 6px 12px; } th { background: #f6f8fa; } dl.metadata { font-size: 0.85em; color: #57606a; border-top: 1px solid #eaeef2; border-bottom: 1px solid #eaeef2; padding: 0.6em 0; } dl.metadata dt { display: inline; font-weight: 600; margin-right: 0.4em; } dl.metadata dd { display: inline; margin: 0 1.2em 0 0; } .math, .math-block { overflow-x: auto; padding: 0.4em 0; } .task-list-item { list-style: none; } .task-list-item input { margin-right: 0.4em; } hr { border: none; border-top: 1px solid #d0d7de; margin: 1.4em 0; } """.strip() class HtmlExporter: """实现 DocumentExporter：递归渲染 Document AST 为完整 HTML5 文档。""" async def export(self, document: Document, options: ExportOptions) -> ExportResult: self._options = options warnings: list[str] = [] body = self._render_children(document.children, warnings) content = self._assemble(document, options, body, warnings) return ExportResult( content=content.encode("utf-8"), mime_type="text/html", warnings=warnings ) def _assemble( self, document: Document, options: ExportOptions, body: str, warnings: list[str] ) -> str: title = str(document.attributes.get("title") or "") parts = [ "", '', "", '', '', ] if title: parts.append(f"{html.escape(title)}") parts.append(f"") parts.append("") parts.append("") parts.append(f'

') if options.include_title and title: parts.append(f'

{html.escape(title)}

') if options.include_metadata: metadata = document.attributes.get("metadata") if metadata: parts.append(self._render_metadata(metadata)) parts.append(body) parts.append("

") parts.append("") parts.append("") return "\n".join(parts) + "\n" def _render_metadata(self, metadata: dict) -> str: entries = ["'] for key, value in metadata.items(): entries.append(f"

{html.escape(str(key))}

") entries.append(f"

{html.escape(self._fmt_meta_value(value))}

") entries.append("") return "".join(entries) @staticmethod def _fmt_meta_value(value: object) -> str: if isinstance(value, datetime): return value.isoformat() if isinstance(value, list): return ", ".join(str(item) for item in value) return str(value) def _render_children(self, children: list[DocumentNode], warnings: list[str]) -> str: return "".join(self._render_node(child, warnings) for child in children) def _render_node(self, node: DocumentNode, warnings: list[str]) -> str: handler = getattr(self, f"_render_{node.type}", None) if handler is not None: return handler(node, warnings) warnings.append(f"无法表示的节点类型已跳过：{node.type}") return "" # --- 块级 --- def _render_heading(self, node: DocumentNode, warnings: list[str]) -> str: level = max(1, min(6, int(node.attributes.get("level", 1)))) return f"{self._render_children(node.children, warnings)}" def _render_paragraph(self, node: DocumentNode, warnings: list[str]) -> str: return f"

{self._render_children(node.children, warnings)}

" def _render_blockquote(self, node: DocumentNode, warnings: list[str]) -> str: return f"

{self._render_children(node.children, warnings)}

" def _render_list(self, node: DocumentNode, warnings: list[str]) -> str: tag = "ol" if node.attributes.get("ordered") else "ul" return f"<{tag}>{self._render_children(node.children, warnings)}" def _render_list_item(self, node: DocumentNode, warnings: list[str]) -> str: inner = self._render_children(node.children, warnings) if node.attributes.get("task"): checked = " checked" if node.attributes.get("checked") else "" return ( '

' f'{inner}

' ) return f"

{inner}

" def _render_table(self, node: DocumentNode, warnings: list[str]) -> str: rows = node.children head_rows = [r for r in rows if r.attributes.get("head")] body_rows = [r for r in rows if not r.attributes.get("head")] parts = [""] if head_rows: parts.append("") parts.extend(self._render_node(r, warnings) for r in head_rows) parts.append("") if body_rows: parts.append("") parts.extend(self._render_node(r, warnings) for r in body_rows) parts.append("") parts.append("

") return "".join(parts) def _render_table_row(self, node: DocumentNode, warnings: list[str]) -> str: return f"{self._render_children(node.children, warnings)}" def _render_table_cell(self, node: DocumentNode, warnings: list[str]) -> str: tag = "th" if node.attributes.get("head") else "td" return f"<{tag}>{self._render_children(node.children, warnings)}" def _render_code_block(self, node: DocumentNode, warnings: list[str]) -> str: lang = str(node.attributes.get("language") or "") code = html.escape(node.text) lang_cls = f' class="language-{html.escape(lang)}"' if lang else "" theme = html.escape(self._options.code_theme) return f'

{code}

' def _render_thematic_break(self, node: DocumentNode, warnings: list[str]) -> str: return "

" def _render_mermaid(self, node: DocumentNode, warnings: list[str]) -> str: warnings.append(_MERMAID_WARNING) return f'

{html.escape(node.text)}

' def _render_function_plot(self, node: DocumentNode, warnings: list[str]) -> str: warnings.append(_FUNCTION_PLOT_WARNING) return f'

{html.escape(node.text)}

' def _render_math_block(self, node: DocumentNode, warnings: list[str]) -> str: return f'

$${html.escape(node.text)}$$

' # --- 行内 --- def _render_text(self, node: DocumentNode, warnings: list[str]) -> str: return html.escape(node.text) def _render_emphasis(self, node: DocumentNode, warnings: list[str]) -> str: return f"{self._render_children(node.children, warnings)}" def _render_strong(self, node: DocumentNode, warnings: list[str]) -> str: return f"{self._render_children(node.children, warnings)}" def _render_link(self, node: DocumentNode, warnings: list[str]) -> str: href = html.escape(str(node.attributes.get("href") or "")) title = str(node.attributes.get("title") or "") attrs = [f'href="{href}"'] if title: attrs.append(f'title="{html.escape(title)}"') return f"{self._render_children(node.children, warnings)}" def _render_codespan(self, node: DocumentNode, warnings: list[str]) -> str: return f"{html.escape(node.text)}" def _render_image(self, node: DocumentNode, warnings: list[str]) -> str: src = html.escape(str(node.attributes.get("src") or "")) alt = html.escape(str(node.attributes.get("alt") or "")) title = str(node.attributes.get("title") or "") attrs = [f'src="{src}"', f'alt="{alt}"'] if title: attrs.append(f'title="{html.escape(title)}"') return f"" def _render_math_inline(self, node: DocumentNode, warnings: list[str]) -> str: return f"\\({html.escape(node.text)}\\)" def _render_linebreak(self, node: DocumentNode, warnings: list[str]) -> str: return "
"