concurrently and frontmatter

server.js

@@ -1,6 +1,8 @@
 // @ts-check
 import { WebSocketServer } from 'ws';
 import { readFileSync, mkdirSync, writeFileSync } from "fs";
+import { join as joinPath } from 'path'
+import matter from 'gray-matter';
 
 const PORT = 8080
 
@@ -12,10 +14,11 @@ wss.on('connection', (ws) => {
   console.log('New client connected');
 
   let filename = ''
+  const ROOT_DIR = 'docs';
 
   ws.on('message', (message, isBinary) => {
     if (message instanceof Buffer && isBinary) {
-      writeFileSync(filename, message);
+      writeFileSync(joinPath(ROOT_DIR, filename), message);
 
       return;
     }
@@ -24,37 +27,54 @@ wss.on('connection', (ws) => {
 
     switch (name) {
       case 'download_q': {
-        const { q } = payload;
+        const { q, duration } = payload;
         console.log(`Start ${q}`)
 
+        const q_stem = q.replace(/\.[a-z0-9]+$/, "");
+
         try {
-          mkdirSync(`docs/${q}`);
+          mkdirSync(joinPath(ROOT_DIR, q_stem));
         } catch (e) {}
 
         let outMd = "";
+        let isChanged = false;
 
         const re = /^(?<min>\d{1,2}):(?<sec>\d{2})\s*$/;
         const ts = [];
 
-        for (const line of readFileSync(`docs/${q}.md`, "utf-8").trimEnd().split("\n")) {
+        const { data, content } = matter(readFileSync(joinPath(ROOT_DIR, `${q_stem}.md`), 'utf-8'));
+        data.video = '/' + q;
+
+        for (const line of content.split("\n")) {
           const m = re.exec(line);
           if (m?.groups) {
             const { min, sec } = m.groups;
             const t = `${min}_${sec}`;
             ts.push(t);
             outMd += `\n![${line}](./${q}/${t}.png)\n\n`;
+            isChanged = true;
           } else {
             outMd += `${line}\n`;
           }
         }
 
-        writeFileSync(`docs/${q}.md`, outMd);
+        const interval = data.interval;
+        if (typeof interval === 'number') {
+          for (let t = 0; t < duration; t += interval) {
+            ts.push(t);
+            isChanged = true;
+          }
+        }
 
-        ws.send(JSON.stringify({ name: "seek_q_ts", q, ts }));
+        if (isChanged){
+          writeFileSync(joinPath(ROOT_DIR, `${q_stem}.md`), matter.stringify(outMd, data));
+          ws.send(JSON.stringify({ name: "seek_q_ts", q, ts }));
+        }
       } break;
       case 'timed_q' : {
         const { q, t } = payload;
-        filename = t ? `docs/${q}/${t}.png` : '';
+        const q_stem = q.replace(/\.[a-z0-9]+$/, "");
+        filename = t ? joinPath(q_stem, `${t}.png`) : '';
       } break;
       case 'done' : {
         const { q } = payload