打印任务状态回调：怎么知道纸真的出来了

queued -> dispatched -> printing -> completed
                                 \
                                  -> failed

async function waitForJob(jobId, { timeoutMs = 60_000, intervalMs = 2000 } = {}) {
  const deadline = Date.now() + timeoutMs;

  while (Date.now() < deadline) {
    const res = await fetch(`https://api.printbase.cloud/v1/print-jobs/${jobId}`, {
      headers: { Authorization: `Bearer ${process.env.PRINTBASE_API_KEY}` },
    });
    const job = await res.json();

    if (job.status === 'completed' || job.status === 'failed') return job;
    await new Promise((r) => setTimeout(r, intervalMs));
  }
  throw new Error(`任务 ${jobId} 在超时前没有出结果`);
}

curl https://api.printbase.cloud/v1/webhooks \
  -H "Authorization: Bearer $PRINTBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "发货服务",
    "url": "https://example.com/hooks/printbase",
    "events": ["print_job.completed", "print_job.failed"]
  }'

X-PrintBase-Event:     print_job.failed
X-PrintBase-Event-Id:  evt_abc
X-PrintBase-Signature: t=1755852761,v1=9f2c...

{
  "id": "evt_abc",
  "type": "print_job.failed",
  "created_at": "2026-08-22T09:12:41Z",
  "organization_id": "org_abc",
  "data": {
    "job_id": "job_abc",
    "printer_id": "printer_123",
    "printer_name": "仓库斑马机",
    "computer_id": "cmp_456",
    "computer_name": "wh-pc-02",
    "status": "failed",
    "reason_code": "PRINTER_OFFLINE",
    "message": "printer is offline"
  }
}

import express from 'express';
import crypto from 'node:crypto';

const app = express();

function verify(rawBody, header, secret) {
  const { t, v1 } = Object.fromEntries(
    (header ?? '').split(',').map((kv) => kv.split('=').map((s) => s.trim()))
  );
  if (!t || !v1) return false;
  // 拒绝重放很久以前那条合法签名
  if (Math.abs(Date.now() / 1000 - Number(t)) > 300) return false;

  const expected = crypto
    .createHmac('sha256', secret)
    .update(`${t}.${rawBody}`)
    .digest('hex');

  const a = Buffer.from(expected, 'hex');
  const b = Buffer.from(v1, 'hex');
  return a.length === b.length && crypto.timingSafeEqual(a, b);
}

app.post('/hooks/printbase', express.raw({ type: 'application/json' }), async (req, res) => {
  const raw = req.body.toString('utf8');
  if (!verify(raw, req.get('X-PrintBase-Signature'), process.env.PRINTBASE_WEBHOOK_SECRET)) {
    return res.sendStatus(400);
  }

  res.sendStatus(200);            // 先在超时内应答……
  queue.push(JSON.parse(raw));    // ……再把耗时的活挪出请求
});

async function handleEvent(event) {
  const fresh = await db.markEventSeen(event.id); // 事件 id 上建唯一索引
  if (!fresh) return;                             // 处理过了，丢弃
  ...
}

const RETRYABLE = new Set(['PRINT_ERROR', 'DOWNLOAD_FAILED']);

if (event.type === 'print_job.failed') {
  const { job_id, reason_code, printer_name, computer_name } = event.data;
  if (RETRYABLE.has(reason_code)) {
    await scheduleReprint(job_id, { attempt: 1 });
  } else {
    await alertOps(`${printer_name}（${computer_name}）：${reason_code}`);
  }
}

// 每 10 分钟一次
const stale = await db.jobsAwaitingResult({ olderThanMin: 10 });

for (const { jobId } of stale) {
  const res = await fetch(`https://api.printbase.cloud/v1/print-jobs/${jobId}`, {
    headers: { Authorization: `Bearer ${process.env.PRINTBASE_API_KEY}` },
  });
  const job = await res.json();
  if (job.status === 'completed' || job.status === 'failed') {
    await handleEvent({ id: `sweep_${jobId}`, type: `print_job.${job.status}`, data: job });
  }
}

curl -X POST https://api.printbase.cloud/v1/webhooks/wh_abc/test \
  -H "Authorization: Bearer $PRINTBASE_API_KEY"