refactor: share markdown renderer via baoyu-md

packages/baoyu-md/src/content.ts

@@ -0,0 +1,105 @@
+import { Lexer } from "marked";
+
+export type FrontmatterFields = Record<string, string>;
+
+export function parseFrontmatter(content: string): {
+  frontmatter: FrontmatterFields;
+  body: string;
+} {
+  const match = content.match(/^\s*---\r?\n([\s\S]*?)\r?\n---\r?\n?([\s\S]*)$/);
+  if (!match) {
+    return { frontmatter: {}, body: content };
+  }
+
+  const frontmatter: FrontmatterFields = {};
+  const lines = match[1]!.split("\n");
+  for (const line of lines) {
+    const colonIdx = line.indexOf(":");
+    if (colonIdx <= 0) continue;
+
+    const key = line.slice(0, colonIdx).trim();
+    const value = line.slice(colonIdx + 1).trim();
+    frontmatter[key] = stripWrappingQuotes(value);
+  }
+
+  return { frontmatter, body: match[2]! };
+}
+
+export function serializeFrontmatter(frontmatter: FrontmatterFields): string {
+  const entries = Object.entries(frontmatter);
+  if (entries.length === 0) return "";
+  return `---\n${entries.map(([key, value]) => `${key}: ${value}`).join("\n")}\n---\n`;
+}
+
+export function stripWrappingQuotes(value: string): string {
+  if (!value) return value;
+
+  const doubleQuoted = value.startsWith('"') && value.endsWith('"');
+  const singleQuoted = value.startsWith("'") && value.endsWith("'");
+  const cjkDoubleQuoted = value.startsWith("\u201c") && value.endsWith("\u201d");
+  const cjkSingleQuoted = value.startsWith("\u2018") && value.endsWith("\u2019");
+
+  if (doubleQuoted || singleQuoted || cjkDoubleQuoted || cjkSingleQuoted) {
+    return value.slice(1, -1).trim();
+  }
+
+  return value.trim();
+}
+
+export function toFrontmatterString(value: unknown): string | undefined {
+  if (typeof value === "string") {
+    return stripWrappingQuotes(value);
+  }
+  if (typeof value === "number" || typeof value === "boolean") {
+    return String(value);
+  }
+  return undefined;
+}
+
+export function pickFirstString(
+  frontmatter: Record<string, unknown>,
+  keys: string[],
+): string | undefined {
+  for (const key of keys) {
+    const value = toFrontmatterString(frontmatter[key]);
+    if (value) return value;
+  }
+  return undefined;
+}
+
+export function extractTitleFromMarkdown(markdown: string): string {
+  const tokens = Lexer.lex(markdown, { gfm: true, breaks: true });
+  for (const token of tokens) {
+    if (token.type !== "heading" || (token.depth !== 1 && token.depth !== 2)) continue;
+    return stripWrappingQuotes(token.text);
+  }
+  return "";
+}
+
+export function extractSummaryFromBody(body: string, maxLen: number): string {
+  const lines = body.split("\n");
+
+  for (const line of lines) {
+    const trimmed = line.trim();
+    if (!trimmed) continue;
+    if (trimmed.startsWith("#")) continue;
+    if (trimmed.startsWith("![")) continue;
+    if (trimmed.startsWith(">")) continue;
+    if (trimmed.startsWith("-") || trimmed.startsWith("*")) continue;
+    if (/^\d+\./.test(trimmed)) continue;
+    if (trimmed.startsWith("```")) continue;
+
+    const cleanText = trimmed
+      .replace(/\*\*(.+?)\*\*/g, "$1")
+      .replace(/\*(.+?)\*/g, "$1")
+      .replace(/\[([^\]]+)\]\([^)]+\)/g, "$1")
+      .replace(/`([^`]+)`/g, "$1");
+
+    if (cleanText.length > 20) {
+      if (cleanText.length <= maxLen) return cleanText;
+      return `${cleanText.slice(0, maxLen - 3)}...`;
+    }
+  }
+
+  return "";
+}