// Printables importer. Printables exposes a public GraphQL API at
// api.printables.com/graphql — the file list and per-file download links are
// available anonymously for free models. A bearer token (optional) is sent when
// configured, for anything that needs an account.

const ENDPOINT = 'https://api.printables.com/graphql/';

async function gql(query, variables, token) {
  const headers = { 'Content-Type': 'application/json', Origin: 'https://www.printables.com' };
  if (token) headers.Authorization = `Bearer ${token}`;
  const res = await fetch(ENDPOINT, { method: 'POST', headers, body: JSON.stringify({ query, variables }) });
  if (!res.ok) throw new Error(`Printables GraphQL HTTP ${res.status}`);
  const json = await res.json();
  if (json.errors) throw new Error('Printables GraphQL: ' + json.errors.map((e) => e.message).join('; '));
  return json.data;
}

const PRINT_QUERY = `query($id: ID!) {
  print(id: $id) {
    id name
    license { name abbreviation content }
    stls { id name fileSize }
    slas { id name fileSize }
    otherFiles { id name fileSize }
  }
}`;

// Returns { name, license, licenseContent, files: [{ id, name, fileType }] }.
// (Commercial use is decided by the caller from licenseContent — the on-page
// excludeCommercialUsage flag is unreliable, e.g. false for the strictly
// non-commercial "Standard Digital File License".)
async function fetchModel(printId, token) {
  const data = await gql(PRINT_QUERY, { id: String(printId) }, token);
  const p = data.print;
  if (!p) throw new Error('Print not found');
  const files = [];
  (p.stls || []).forEach((f) => files.push({ id: f.id, name: f.name, fileType: 'stl' }));
  (p.slas || []).forEach((f) => files.push({ id: f.id, name: f.name, fileType: 'sla' }));
  (p.otherFiles || []).forEach((f) => files.push({ id: f.id, name: f.name, fileType: 'other' }));
  return {
    name: p.name,
    license: p.license ? p.license.name : null,
    licenseContent: p.license ? p.license.content : null,
    files,
  };
}

const DOWNLOAD_MUTATION = `mutation($printId: ID!, $files: [DownloadFileInput], $src: DownloadSourceEnum!) {
  getDownloadLink(printId: $printId, files: $files, source: $src) {
    ok
    output { link }
  }
}`;

// Resolve one file to a direct CDN download URL.
async function getDownloadLink(printId, fileType, fileId, token) {
  const data = await gql(
    DOWNLOAD_MUTATION,
    { printId: String(printId), files: [{ fileType, ids: [String(fileId)] }], src: 'model_detail' },
    token
  );
  const r = data.getDownloadLink;
  if (!r || !r.ok || !r.output || !r.output.link) throw new Error('No download link returned');
  return r.output.link;
}

module.exports = { fetchModel, getDownloadLink };