Generate videos in bulk

import { writeFile } from "node:fs/promises";

// Each entry becomes a separate video.
const CUSTOMERS = [
  { name: "Acme Corp", product: "Analytics Dashboard", cta: "Start your free trial" },
  { name: "Globex Inc", product: "Workflow Automation", cta: "Book a demo today" },
  { name: "Initech", product: "Team Collaboration", cta: "See it in action" },
];


// One prompt per row, built from a fixed template.
function buildPrompt(customer) {
  return [
    "Create a 30-second product demo video.",
    "Open with the text '" + customer.name + "' as a title card.",
    "Show the product name '" + customer.product + "' with a sleek animation.",
    "End with a call-to-action: '" + customer.cta + "'.",
    "Use professional background music.",
  ].join(" ");
}


// Start one agent run. Returns before any editing happens.
async function startJob(customer) {
  const response = await fetch(`${API}/agent`, {
    method: "POST",
    headers,
    body: JSON.stringify({ prompt: buildPrompt(customer) }),
  });

  if (!response.ok) {
    throw new Error("Could not start a job: " + response.status);
  }

  const body = await response.json();
  const data = body.data;

  return { ...customer, job_id: data.job_id, project_id: data.project_id };
}


// Render one finished project and save the MP4 beside this script.
async function exportAndDownload(name, job) {
  const response = await fetch(`${API}/export`, {
    method: "POST",
    headers,
    body: JSON.stringify({ project_id: job.project_id }),
  });

  const body = await response.json();

  let exportJob;
  try {
    exportJob = await waitForJob(body.data.job_id);
  } catch (error) {
    console.log("  Export failed for " + name + ": " + error.message);
    return;
  }

  // The finished job carries a signed URL. Download it before it expires.
  const file = await fetch(exportJob.output.url);

  if (!file.ok) {
    console.log("  Download failed for " + name + ": " + file.status);
    return;
  }

  const filename = name.toLowerCase().replace(/ /g, "-") + ".mp4";
  const bytes = Buffer.from(await file.arrayBuffer());

  await writeFile(filename, bytes);
  console.log("  Saved " + filename);
}


// 1. Fan out: start all jobs at once.
console.log("Starting " + CUSTOMERS.length + " jobs...");
const jobs = await Promise.all(CUSTOMERS.map(startJob));

// 2. Poll in parallel, so the batch takes about as long as its slowest row.
// allSettled, not all: waitForAgentJob throws on a failed edit, and one bad
// prompt should not take the whole batch down with it.
console.log("Waiting for edits to finish...");
const results = await Promise.allSettled(
  jobs.map((row) => waitForAgentJob(row.job_id)),
);

// 3. Export and download each video.
console.log("Exporting videos...");

for (const [i, result] of results.entries()) {
  const name = jobs[i].name;

  if (result.status === "rejected") {
    console.log("  Skipping " + name + ": " + result.reason.message);
    continue;
  }

  await exportAndDownload(name, result.value);
}

console.log("Done!");