1import fs from "node:fs";
2import os from "node:os";
3import path from "node:path";
4import process from "node:process";
5 
6import {
7  cleanSummaryText,
8  extractSummaryFromBody,
9  extractTitleFromMarkdown,
10  parseFrontmatter,
11  preprocessMermaidInMarkdown,
12  renderMarkdownDocument,
13  replaceMarkdownImagesWithPlaceholders,
14  resolveColorToken,
15  resolveContentImages,
16  serializeFrontmatter,
17  stripWrappingQuotes,
18} from "baoyu-md";
19import { closeRenderer, renderMermaidToPng } from "baoyu-chrome-cdp/mermaid";
20 
21interface ImageInfo {
22  placeholder: string;
23  localPath: string;
24  originalPath: string;
25  alt?: string;
26}
27 
28interface ParsedResult {
29  title: string;
30  author: string;
31  summary: string;
32  htmlPath: string;
33  contentImages: ImageInfo[];
34}
35 
36export async function convertMarkdown(
37  markdownPath: string,
38  options?: { title?: string; theme?: string; color?: string; citeStatus?: boolean },
39): Promise<ParsedResult> {
40  const baseDir = path.dirname(markdownPath);
41  const content = fs.readFileSync(markdownPath, "utf-8");
42  const citeStatus = options?.citeStatus ?? true;
43 
44  const { frontmatter, body } = parseFrontmatter(content);
45 
46  let title = stripWrappingQuotes(options?.title ?? "")
47    || stripWrappingQuotes(frontmatter.title ?? "")
48    || extractTitleFromMarkdown(body);
49  if (!title) {
50    title = path.basename(markdownPath, path.extname(markdownPath));
51  }
52 
53  const author = stripWrappingQuotes(frontmatter.author ?? "");
54  const frontmatterSummary = stripWrappingQuotes(frontmatter.description ?? "")
55    || stripWrappingQuotes(frontmatter.summary ?? "");
56  let summary = cleanSummaryText(frontmatterSummary);
57  if (!summary) {
58    summary = extractSummaryFromBody(body, 120);
59  }
60 
61  const { markdown: mermaidProcessedBody, images: mermaidImages } =
62    await preprocessMermaidInMarkdown(body, {
63      baseDir,
64      renderFn: renderMermaidToPng,
65      onError: (error, block) => {
66        const message = error instanceof Error ? error.message : String(error);
67        console.error(
68          `[md-to-wechat] mermaid render failed (${block.code.slice(0, 40).replace(/\s+/g, " ")}…): ${message}`,
69        );
70      },
71    });
72 
73  if (mermaidImages.length > 0) {
74    const fresh = mermaidImages.filter((image) => !image.cached).length;
75    console.error(
76      `[md-to-wechat] mermaid: ${mermaidImages.length} block(s), ${fresh} rendered, ${mermaidImages.length - fresh} cached`,
77    );
78  }
79 
80  const { images, markdown: rewrittenBody } = replaceMarkdownImagesWithPlaceholders(
81    mermaidProcessedBody,
82    "WECHATIMGPH_",
83  );
84  const rewrittenMarkdown = `${serializeFrontmatter(frontmatter)}${rewrittenBody}`;
85 
86  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "wechat-article-images-"));
87  const htmlPath = path.join(tempDir, "temp-article.html");
88 
89  console.error(
90    `[md-to-wechat] Rendering markdown with theme: ${options?.theme ?? "default"}${options?.color ? `, color: ${options.color}` : ""}, citeStatus: ${citeStatus}`,
91  );
92 
93  const { html } = await renderMarkdownDocument(rewrittenMarkdown, {
94    citeStatus,
95    defaultTitle: title,
96    keepTitle: false,
97    primaryColor: resolveColorToken(options?.color),
98    theme: options?.theme,
99  });
100  fs.writeFileSync(htmlPath, html, "utf-8");
101 
102  const contentImages = await resolveContentImages(images, baseDir, tempDir, "md-to-wechat");
103 
104  return {
105    title,
106    author,
107    summary,
108    htmlPath,
109    contentImages,
110  };
111}
112 
113function printUsage(): never {
114  console.log(`Convert Markdown to WeChat-ready HTML with image placeholders
115 
116Usage:
117  npx -y bun md-to-wechat.ts <markdown_file> [options]
118 
119Options:
120  --title <title>     Override title
121  --theme <name>      Theme name (default, grace, simple, modern)
122  --color <name|hex>  Primary color (blue, green, vermilion, etc. or hex)
123  --no-cite           Disable bottom citations for ordinary external links
124  --help              Show this help
125 
126Output JSON format:
127{
128  "title": "Article Title",
129  "htmlPath": "/tmp/wechat-article-images/temp-article.html",
130  "contentImages": [
131    {
132      "placeholder": "WECHATIMGPH_1",
133      "localPath": "/tmp/wechat-image/img.png",
134      "originalPath": "imgs/image.png"
135    }
136  ]
137}
138 
139Example:
140  npx -y bun md-to-wechat.ts article.md
141  npx -y bun md-to-wechat.ts article.md --theme grace
142  npx -y bun md-to-wechat.ts article.md --theme modern --color blue
143  npx -y bun md-to-wechat.ts article.md --no-cite
144`);
145  process.exit(0);
146}
147 
148async function main(): Promise<void> {
149  const args = process.argv.slice(2);
150  if (args.length === 0 || args.includes("--help") || args.includes("-h")) {
151    printUsage();
152  }
153 
154  let markdownPath: string | undefined;
155  let title: string | undefined;
156  let theme: string | undefined;
157  let color: string | undefined;
158  let citeStatus = true;
159 
160  for (let i = 0; i < args.length; i++) {
161    const arg = args[i]!;
162    if (arg === "--title" && args[i + 1]) {
163      title = args[++i];
164    } else if (arg === "--theme" && args[i + 1]) {
165      theme = args[++i];
166    } else if (arg === "--color" && args[i + 1]) {
167      color = args[++i];
168    } else if (arg === "--cite") {
169      citeStatus = true;
170    } else if (arg === "--no-cite") {
171      citeStatus = false;
172    } else if (!arg.startsWith("-")) {
173      markdownPath = arg;
174    }
175  }
176 
177  if (!markdownPath) {
178    console.error("Error: Markdown file path is required");
179    process.exit(1);
180  }
181 
182  if (!fs.existsSync(markdownPath)) {
183    console.error(`Error: File not found: ${markdownPath}`);
184    process.exit(1);
185  }
186 
187  const result = await convertMarkdown(markdownPath, { title, theme, color, citeStatus });
188  console.log(JSON.stringify(result, null, 2));
189}
190 
191try {
192  await main();
193} catch (error) {
194  console.error(`Error: ${error instanceof Error ? error.message : String(error)}`);
195  process.exitCode = 1;
196} finally {
197  await closeRenderer();
198}
199