chore: import upstream snapshot with attribution

scripts/plan-canvas.js

@@ -0,0 +1,339 @@
+#!/usr/bin/env node
+'use strict';
+
+/**
+ * Plan Canvas CLI — open plan artifacts in a browser review canvas and block
+ * on human feedback.
+ *
+ *   node scripts/plan-canvas.js open .claude/plans/feature.plan.md
+ *   node scripts/plan-canvas.js await .claude/plans/feature.plan.md
+ *   node scripts/plan-canvas.js await <file> --reply "Updated section 3."
+ *   node scripts/plan-canvas.js end <file>
+ *   node scripts/plan-canvas.js stop
+ *
+ * Agents: `open` returns immediately (the server is a detached process);
+ * `await` long-polls until the human sends feedback, a verdict, or ends the
+ * session, then prints a JSON payload to stdout. Progress notes go to stderr
+ * so stdout stays parseable.
+ */
+
+const fs = require('fs');
+const http = require('http');
+const path = require('path');
+const { spawn } = require('child_process');
+
+const {
+  canonicalizeArtifactPath,
+  createSessionStore,
+  resolveStateDir,
+  sessionKeyFor
+} = require('./lib/plan-canvas/sessions');
+const {
+  DEFAULT_HOST,
+  createPlanCanvasServer,
+  resolveIdleTimeoutMs,
+  resolvePort
+} = require('./lib/plan-canvas/server');
+
+const VERSION = require('../package.json').version;
+
+function usage() {
+  return [
+    'Plan Canvas - review plans and HTML artifacts in the browser',
+    '',
+    'Usage:',
+    '  node scripts/plan-canvas.js                      Show server status and sessions',
+    '  node scripts/plan-canvas.js open <file>          Open (or resume) a review session',
+    '  node scripts/plan-canvas.js await <file>         Block until the human sends feedback',
+    '  node scripts/plan-canvas.js end <file>           End a session as the agent',
+    '  node scripts/plan-canvas.js stop                 Shut down the canvas server',
+    '  node scripts/plan-canvas.js server               Run the server in the foreground',
+    '',
+    'Options:',
+    '  open:  --no-open      Do not launch a browser window',
+    '         --reopen       Reopen a session the user ended from the browser',
+    '  await: --reply <msg>  Show an agent reply in the canvas chat before waiting',
+    '         --timeout-ms <n>  Return {status:"waiting"} after n ms (tests/debug only)',
+    '  server: --port <n> --host <h>',
+    '',
+    'Environment: ECC_PLAN_CANVAS_PORT, ECC_PLAN_CANVAS_STATE_DIR, ECC_PLAN_CANVAS_IDLE_MS'
+  ].join('\n');
+}
+
+function valueAfter(args, name) {
+  const index = args.indexOf(name);
+  return index >= 0 && index + 1 < args.length ? args[index + 1] : null;
+}
+
+function serverInfoPath(stateDir) {
+  return path.join(stateDir, 'server.json');
+}
+
+function readServerInfo(stateDir) {
+  try {
+    return JSON.parse(fs.readFileSync(serverInfoPath(stateDir), 'utf8'));
+  } catch {
+    return null;
+  }
+}
+
+function request(port, method, requestPath, body = null) {
+  return new Promise((resolve, reject) => {
+    const payload = body === null ? null : JSON.stringify(body);
+    const req = http.request(
+      {
+        host: DEFAULT_HOST,
+        port,
+        method,
+        path: requestPath,
+        headers: payload
+          ? { 'content-type': 'application/json', 'content-length': Buffer.byteLength(payload) }
+          : {}
+      },
+      res => {
+        let data = '';
+        res.on('data', chunk => {
+          data += chunk;
+        });
+        res.on('end', () => {
+          try {
+            resolve({ statusCode: res.statusCode, body: JSON.parse(data.trim() || '{}') });
+          } catch {
+            resolve({ statusCode: res.statusCode, body: {} });
+          }
+        });
+      }
+    );
+    req.on('error', reject);
+    if (payload) req.write(payload);
+    req.end();
+  });
+}
+
+async function healthCheck(port) {
+  try {
+    const res = await request(port, 'GET', '/health');
+    return res.body && res.body.app === 'ecc-plan-canvas' ? res.body : null;
+  } catch {
+    return null;
+  }
+}
+
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+// Start (or reuse) the detached canvas server and return its port. A version
+// mismatch after an ECC update restarts the server so browser and CLI never
+// disagree about the protocol.
+async function ensureServer({ stateDir, port }) {
+  const health = await healthCheck(port);
+  if (health && health.version === VERSION) return port;
+  if (health) {
+    await request(port, 'POST', '/shutdown').catch(() => {});
+    for (let i = 0; i < 20 && (await healthCheck(port)); i++) await sleep(100);
+  }
+  fs.mkdirSync(stateDir, { recursive: true });
+  const logFd = fs.openSync(path.join(stateDir, 'server.log'), 'a');
+  const child = spawn(process.execPath, [__filename, 'server', '--port', String(port)], {
+    detached: true,
+    stdio: ['ignore', logFd, logFd],
+    env: { ...process.env, ECC_PLAN_CANVAS_STATE_DIR: stateDir }
+  });
+  child.unref();
+  fs.closeSync(logFd);
+  for (let i = 0; i < 50; i++) {
+    await sleep(100);
+    if (await healthCheck(port)) return port;
+  }
+  throw new Error(`plan-canvas server did not become healthy on port ${port}; check ${path.join(stateDir, 'server.log')}`);
+}
+
+function openBrowser(url) {
+  const platform = process.platform;
+  const [cmd, args] =
+    platform === 'darwin' ? ['open', [url]]
+      : platform === 'win32' ? ['cmd', ['/c', 'start', '', url]]
+        : ['xdg-open', [url]];
+  try {
+    spawn(cmd, args, { detached: true, stdio: 'ignore' }).unref();
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function output(payload) {
+  process.stdout.write(`${JSON.stringify(payload, null, 2)}\n`);
+}
+
+async function cmdStatus({ stateDir, port }) {
+  const health = await healthCheck(port);
+  if (!health) {
+    return { server: 'not running', hint: 'open an artifact to start one', stateDir };
+  }
+  const sessions = await request(port, 'GET', '/api/sessions');
+  return { server: `http://${DEFAULT_HOST}:${port}`, version: health.version, sessions: sessions.body.sessions };
+}
+
+async function cmdOpen(file, args, { stateDir, port }) {
+  if (!file) throw new Error('open requires a file path');
+  if (!fs.existsSync(path.resolve(file))) throw new Error(`artifact not found: ${file}`);
+  await ensureServer({ stateDir, port });
+  const res = await request(port, 'POST', '/api/sessions', {
+    file: path.resolve(file),
+    reopen: args.includes('--reopen')
+  });
+  if (res.statusCode === 409) return res.body;
+  if (res.statusCode !== 200) throw new Error(res.body.error || `open failed (HTTP ${res.statusCode})`);
+  const url = `http://${DEFAULT_HOST}:${port}${res.body.url}`;
+  const launched = args.includes('--no-open') ? false : openBrowser(url);
+  return {
+    status: 'open',
+    url,
+    browser: launched ? 'opened' : 'not opened',
+    next_step:
+      'Run `ecc-plan-canvas await <file>` and leave it running; it returns when the human sends feedback, a verdict, or ends the session.'
+  };
+}
+
+function awaitRequest(port, file, timeoutMs) {
+  const params = new URLSearchParams({ file });
+  if (timeoutMs !== null) params.set('timeoutMs', String(timeoutMs));
+  return new Promise((resolve, reject) => {
+    const req = http.request(
+      { host: DEFAULT_HOST, port, method: 'GET', path: `/api/await?${params}` },
+      res => {
+        let data = '';
+        res.on('data', chunk => {
+          data += chunk;
+        });
+        res.on('end', () => {
+          try {
+            resolve(JSON.parse(data.trim()));
+          } catch {
+            reject(new Error('await response was not JSON (server restarted?) - re-run await; feedback is never lost'));
+          }
+        });
+      }
+    );
+    req.setTimeout(0);
+    req.on('error', reject);
+    req.end();
+  });
+}
+
+async function cmdAwait(file, args, { stateDir, port }) {
+  if (!file) throw new Error('await requires a file path');
+  if (!(await healthCheck(port))) {
+    return { status: 'no-server', hint: 'no canvas server is running; use `open` first', stateDir };
+  }
+  const reply = valueAfter(args, '--reply');
+  if (reply) {
+    const key = sessionKeyFor(canonicalizeArtifactPath(file));
+    await request(port, 'POST', `/api/session/${key}/reply`, { text: reply });
+  }
+  const timeoutRaw = valueAfter(args, '--timeout-ms');
+  const timeoutMs = timeoutRaw === null ? null : Number.parseInt(timeoutRaw, 10) || 0;
+  process.stderr.write('[plan-canvas] waiting for human feedback... leave this running (re-run if interrupted; queued feedback is never lost)\n');
+  const result = await awaitRequest(port, path.resolve(file), timeoutMs);
+  if (result.status === 'feedback') {
+    result.next_step = result.sessionEnded
+      ? 'The user sent this feedback and ended the session. Address it and report in chat; do not reopen the canvas uninvited.'
+      : 'Address the feedback, then run `ecc-plan-canvas await <file> --reply "<what you changed>"` to answer in the canvas and keep listening.';
+  } else if (result.status === 'ended') {
+    result.next_step =
+      result.endedBy === 'user'
+        ? 'The user ended this review. Stop polling and deliver any remaining updates in chat; do not reopen uninvited.'
+        : 'Session ended. Stop polling.';
+  }
+  return result;
+}
+
+async function cmdEnd(file, { port }) {
+  if (!file) throw new Error('end requires a file path');
+  if (!(await healthCheck(port))) return { status: 'no-server' };
+  const res = await request(port, 'POST', '/api/end', { file: path.resolve(file) });
+  return res.body;
+}
+
+async function cmdStop({ stateDir, port }) {
+  if (!(await healthCheck(port))) return { status: 'not running' };
+  await request(port, 'POST', '/shutdown').catch(() => {});
+  fs.rmSync(serverInfoPath(stateDir), { force: true });
+  return { status: 'stopping' };
+}
+
+async function cmdServer(args, { stateDir, port }) {
+  const portArg = valueAfter(args, '--port');
+  const hostArg = valueAfter(args, '--host');
+  const listenPort = portArg !== null ? Number.parseInt(portArg, 10) : port;
+  const store = createSessionStore({ stateDir });
+  let shuttingDown = false;
+  const shutdown = async code => {
+    if (shuttingDown) return;
+    shuttingDown = true;
+    fs.rmSync(serverInfoPath(stateDir), { force: true });
+    await canvas.close().catch(() => {});
+    process.exit(code);
+  };
+  const canvas = createPlanCanvasServer({
+    store,
+    host: hostArg || DEFAULT_HOST,
+    version: VERSION,
+    idleTimeoutMs: resolveIdleTimeoutMs(),
+    onIdleShutdown: () => shutdown(0),
+    log: line => process.stderr.write(`${line}\n`)
+  });
+  const bound = await canvas.listen(listenPort);
+  fs.mkdirSync(stateDir, { recursive: true });
+  fs.writeFileSync(
+    serverInfoPath(stateDir),
+    JSON.stringify({ pid: process.pid, port: bound.port, version: VERSION, startedAt: new Date().toISOString() }, null, 2)
+  );
+  // Sessions restored from disk resume their file watchers.
+  for (const session of store.list()) {
+    if (session.status !== 'ended') canvas.watchSession(store.get(session.key));
+  }
+  process.on('SIGINT', () => shutdown(0));
+  process.on('SIGTERM', () => shutdown(0));
+  process.stderr.write(`[plan-canvas] serving on http://${bound.host}:${bound.port}\n`);
+  return new Promise(() => {}); // run until a signal or idle shutdown
+}
+
+async function main(argv = process.argv.slice(2)) {
+  const args = argv.slice();
+  if (args.includes('--help') || args.includes('-h')) {
+    process.stdout.write(`${usage()}\n`);
+    return 0;
+  }
+  const command = args[0] && !args[0].startsWith('--') ? args.shift() : null;
+  const stateDir = resolveStateDir();
+  // A running server may sit on a non-default port; trust its recorded info.
+  const recorded = readServerInfo(stateDir);
+  const context = { stateDir, port: (recorded && recorded.port) || resolvePort() };
+  try {
+    if (command === null) output(await cmdStatus(context));
+    else if (command === 'open') output(await cmdOpen(args[0], args, context));
+    else if (command === 'await') output(await cmdAwait(args[0], args, context));
+    else if (command === 'end') output(await cmdEnd(args[0], context));
+    else if (command === 'stop') output(await cmdStop(context));
+    else if (command === 'server') await cmdServer(args, context);
+    else {
+      process.stderr.write(`Unknown command: ${command}\n\n${usage()}\n`);
+      return 1;
+    }
+    return 0;
+  } catch (error) {
+    output({ error: error.message });
+    return 1;
+  }
+}
+
+if (require.main === module) {
+  main().then(code => {
+    process.exitCode = code;
+  });
+}
+
+module.exports = { main, ensureServer, healthCheck };