// AccesPub API quickstart (Node.js 18+, no dependencies).
//
// One EPUB from start to finish: create a batch, upload, wait for the analysis,
// list what needs human review, finalise and download the outputs.
//
//   export ACCESPUB_KEY=ap_test_...     # use a test key first: it uses no credits
//   node quickstart.mjs my-book.epub
//
// Docs: https://api.accespub.app/docs
import { readFile, writeFile } from "node:fs/promises";
import { basename } from "node:path";
import { randomUUID } from "node:crypto";

const API = (process.env.ACCESPUB_API || "https://api.accespub.app/v1").replace(/\/$/, "");
const KEY = process.env.ACCESPUB_KEY;
const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

async function call(method, path, { body, idempotent = false, raw = false } = {}) {
  const headers = { Authorization: `Bearer ${KEY}` };
  if (idempotent) headers["Idempotency-Key"] = randomUUID(); // safe to retry
  if (body && !(body instanceof FormData)) {
    headers["Content-Type"] = "application/json";
    body = JSON.stringify(body);
  }
  let res = await fetch(API + path, { method, headers, body });
  if (res.status === 429) {
    await sleep(1000 * Number(res.headers.get("Retry-After") || 5));
    res = await fetch(API + path, { method, headers, body });
  }
  if (!res.ok) {
    // Errors are RFC 9457 problem documents: {type, title, status, detail}
    const p = await res.json().catch(() => ({}));
    throw new Error(`${method} ${path} → ${res.status} ${p.title || ""}: ${p.detail || ""}`);
  }
  return raw ? res : res.json();
}

async function main() {
  const file = process.argv[2];
  if (!KEY || !file) {
    console.error("Usage: ACCESPUB_KEY=ap_test_... node quickstart.mjs my-book.epub");
    process.exit(1);
  }
  const org = await call("GET", "/organization");
  console.log(`${org.name} · mode ${org.mode} · credits available ${org.credits.available}`);

  const batch = await call("POST", "/batches", { idempotent: true, body: { name: "Quickstart (Node)" } });
  const form = new FormData();
  form.append("file", new Blob([await readFile(file)], { type: "application/epub+zip" }), basename(file));
  let job = await call("POST", `/batches/${batch.id}/jobs`, { idempotent: true, body: form });
  console.log(`Uploaded ${job.filename} → job ${job.id}`);

  while (["queued", "processing"].includes(job.status)) {
    await sleep(10000);
    job = await call("GET", `/jobs/${job.id}`);
    console.log(`   status: ${job.status}`);
  }
  if (job.status === "failed") throw new Error(`Processing failed: ${JSON.stringify(job.error)}`);

  const b = job.billing;
  console.log(`${b.images} images → ${b.credits_required} credit(s) on finalisation`);
  let cursor = "";
  do { // lists are paginated: up to 100 items per page, follow next_cursor
    const page = await call("GET", `/jobs/${job.id}/review-items?status=pending&limit=100${cursor ? `&cursor=${cursor}` : ""}`);
    for (const it of page.data) console.log(`   pending ${it.kind} ${it.id} (${it.document})`);
    cursor = page.next_cursor || "";
  } while (cursor);
  // Here your own front end would show each item to a reviewer and send
  // POST /jobs/{id}/decisions — see section 4 of the integration guide.

  const allowPending = job.review.pending > 0; // without review: no conformance declared
  await call("POST", `/jobs/${job.id}/finalize`, { idempotent: true, body: { allow_pending: allowPending } });
  while (job.status !== "completed") {
    await sleep(5000);
    job = await call("GET", `/jobs/${job.id}`);
    if (job.error && job.status !== "finalizing") throw new Error(`Finalisation failed: ${JSON.stringify(job.error)}`);
  }
  console.log(`Completed · conformance: ${job.conformance}`);

  const stem = basename(file).replace(/\.epub$/i, "");
  for (const [kind, name] of [["epub", `${stem}-accessible.epub`], ["report_html", `${stem}-report.html`],
                              ["onix_a11y", `${stem}-onix.xml`]]) {
    const res = await call("GET", `/jobs/${job.id}/files/${kind}`, { raw: true });
    await writeFile(name, Buffer.from(await res.arrayBuffer()));
    console.log(`   saved ${name}`);
  }
}

main().catch((e) => { console.error(e.message); process.exit(1); });