// Builds every brand image of the two frontends from the two source SVGs in
// the repo root (see docs/BRANDING.md):
//   logo.svg     black mark on transparent — pages, favicons, PWA icons
//   logo_bk.svg  the same mark on a white rounded card — dark backdrops
//
//   node scripts/generate-brand-icons.cjs
//
// sharp is resolved from apps/api, which already depends on it.
const { createRequire } = require('node:module');
const { readFileSync, writeFileSync } = require('node:fs');
const { join } = require('node:path');

const root = join(__dirname, '..');
const sharp = createRequire(join(root, 'apps/api/package.json'))('sharp');

const userApp = join(root, 'apps/user-app-v2');
const admin = join(root, 'apps/admin-panel');

// Illustrator's "<title>Asset 1</title>" is noise in an <img>.
const clean = (file) => readFileSync(join(root, file), 'utf8').replace(/\s*<title>[^<]*<\/title>/, '');
const logo = clean('logo.svg');
const card = clean('logo_bk.svg');

/** The mark rendered `width` px wide, transparent. */
const mark = (width) => sharp(Buffer.from(logo), { density: 600 }).resize({ width }).png().toBuffer();

/**
 * Square icon: the mark centred on white. `fill` is the mark's width as a
 * share of the side; `radius` rounds the white square (0 = full bleed, as the
 * OS masks PWA icons itself).
 */
async function icon(size, { fill, radius }) {
  const r = Math.round(size * radius);
  const plate = Buffer.from(
    `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}">` +
      `<rect width="${size}" height="${size}" rx="${r}" ry="${r}" fill="#fff"/></svg>`,
  );
  return sharp(plate)
    .composite([{ input: await mark(Math.round(size * fill)), gravity: 'center' }])
    .png()
    .toBuffer();
}

/** .ico holding PNG entries (supported by every current browser). */
function ico(pngs) {
  const header = Buffer.alloc(6);
  header.writeUInt16LE(1, 2);
  header.writeUInt16LE(pngs.length, 4);
  const entries = [];
  let offset = 6 + 16 * pngs.length;
  for (const { size, data } of pngs) {
    const e = Buffer.alloc(16);
    e.writeUInt8(size >= 256 ? 0 : size, 0);
    e.writeUInt8(size >= 256 ? 0 : size, 1);
    e.writeUInt16LE(1, 4);
    e.writeUInt16LE(32, 6);
    e.writeUInt32LE(data.length, 8);
    e.writeUInt32LE(offset, 12);
    offset += data.length;
    entries.push(e);
  }
  return Buffer.concat([header, ...entries, ...pngs.map((p) => p.data)]);
}

function write(path, data) {
  writeFileSync(path, data);
  console.log('wrote', path.slice(root.length + 1));
}

(async () => {
  write(join(userApp, 'public/img/brand-logo.svg'), logo);
  write(join(userApp, 'public/img/brand-logo-card.svg'), card);
  write(join(userApp, 'src/assets/img/brand-logo.svg'), logo);
  write(join(admin, 'src/assets/images/logo/brand-logo.svg'), logo);

  // Raster copies at the old public URLs, for anything linking them directly.
  const big = await mark(1024);
  write(join(userApp, 'public/img/brand-logo.png'), big);
  write(join(userApp, 'public/img/brand-logo.webp'), await sharp(big).webp({ quality: 90 }).toBuffer());

  // PWA: one file serves "any" and "maskable", so the mark stays inside the
  // maskable safe circle (80% of the side): a 1.45:1 mark at 64% width does.
  write(join(userApp, 'public/icon-192.png'), await icon(192, { fill: 0.64, radius: 0 }));
  write(join(userApp, 'public/icon-512.png'), await icon(512, { fill: 0.64, radius: 0 }));

  // Tab icons: white rounded chip, so the black mark shows on dark tab strips too.
  const chip = { fill: 0.86, radius: 0.2 };
  const favicon = ico(await Promise.all([16, 32, 48, 64].map(async (size) => ({ size, data: await icon(size, chip) }))));
  write(join(userApp, 'public/favicon.ico'), favicon);
  write(join(admin, 'public/favicon.ico'), favicon);
  write(join(admin, 'public/favicon.png'), await icon(192, chip));
})().catch((e) => {
  console.error(e);
  process.exit(1);
});