/**
 * Erzeugt Favicon/PWA-Icons aus dem Craftvia-Signet (src/components/brand/craftvia-logo.tsx,
 * Geometrie `SIGNET`). Keine Netzwerkzugriffe; PNGs via `sharp` (liegt über Next.js bei).
 *
 * Lauf: npx tsx scripts/generate-brand-icons.ts
 * Ausgabe: public/favicon/*.svg|png, public/favicon.ico (PNG-in-ICO, 32×32)
 */
import { mkdirSync, writeFileSync } from "node:fs";
import { join } from "node:path";
import sharp from "sharp";
import { BRAND_COLORS } from "../src/lib/brand";
import { SIGNET } from "../src/components/brand/craftvia-logo";

const OUT = join(process.cwd(), "public", "favicon");
mkdirSync(OUT, { recursive: true });

function signetSvg(opts: { tile: boolean; padding?: number; radius?: number }): string {
  const arc = opts.tile ? BRAND_COLORS.white : BRAND_COLORS.lotsenblau;
  const check = BRAND_COLORS.signalorange;
  const pad = opts.padding ?? 9.6;
  const scale = (64 - 2 * pad) / 64;
  const bg = opts.tile
    ? `<rect x="0" y="0" width="64" height="64" rx="${opts.radius ?? 14}" fill="${BRAND_COLORS.lotsenblau}"/>`
    : "";
  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64" width="64" height="64">
  <defs>
    <mask id="cut" maskUnits="userSpaceOnUse" x="0" y="0" width="64" height="64">
      <rect x="0" y="0" width="64" height="64" fill="#fff"/>
      <path d="${SIGNET.check}" fill="none" stroke="#000" stroke-width="${SIGNET.checkWidth + 6}" stroke-linejoin="miter"/>
    </mask>
  </defs>
  ${bg}
  <g transform="translate(${pad} ${pad}) scale(${scale})">
    <path d="${SIGNET.arc}" fill="none" stroke="${arc}" stroke-width="${SIGNET.arcWidth}" stroke-linecap="butt" mask="url(#cut)"/>
    <path d="${SIGNET.check}" fill="none" stroke="${check}" stroke-width="${SIGNET.checkWidth}" stroke-linejoin="miter"/>
    <path d="${SIGNET.arrow}" fill="${check}"/>
  </g>
</svg>
`;
}

async function png(svg: string, size: number, file: string) {
  await sharp(Buffer.from(svg), { density: 72 * (size / 64) * 2 })
    .resize(size, size)
    .png()
    .toFile(join(OUT, file));
}

/** Minimaler ICO-Container mit einem eingebetteten PNG (von allen Browsern unterstützt). */
function icoFromPng(pngBuf: Buffer, size: number): Buffer {
  const header = Buffer.alloc(6);
  header.writeUInt16LE(0, 0);
  header.writeUInt16LE(1, 2);
  header.writeUInt16LE(1, 4);
  const entry = Buffer.alloc(16);
  entry.writeUInt8(size >= 256 ? 0 : size, 0);
  entry.writeUInt8(size >= 256 ? 0 : size, 1);
  entry.writeUInt8(0, 2);
  entry.writeUInt8(0, 3);
  entry.writeUInt16LE(1, 4);
  entry.writeUInt16LE(32, 6);
  entry.writeUInt32LE(pngBuf.length, 8);
  entry.writeUInt32LE(6 + 16, 12);
  return Buffer.concat([header, entry, pngBuf]);
}

async function main() {
  // Favicon: freistehendes Signet (transparent) als SVG — skaliert verlustfrei.
  const plain = signetSvg({ tile: false, padding: 2 });
  writeFileSync(join(OUT, "craftvia-signet.svg"), plain);
  // App-Icon-Kachel (Lotsenblau) für PWA/Apple/OG.
  const tile = signetSvg({ tile: true });
  writeFileSync(join(OUT, "craftvia-app-icon.svg"), tile);
  // Maskable: volle Fläche ohne Rundung, Signet in der Safe-Zone (80 %).
  const maskable = signetSvg({ tile: true, padding: 14, radius: 0 });

  await png(plain, 16, "icon-16.png");
  await png(plain, 32, "icon-32.png");
  await png(plain, 48, "icon-48.png");
  await png(tile, 180, "apple-touch-icon-180.png");
  await png(tile, 192, "pwa-192.png");
  await png(tile, 512, "pwa-512.png");
  await png(maskable, 512, "maskable-512.png");

  const ico32 = await sharp(Buffer.from(plain), { density: 144 }).resize(32, 32).png().toBuffer();
  writeFileSync(join(process.cwd(), "public", "favicon.ico"), icoFromPng(ico32, 32));
  console.log("✓ Craftvia-Icons erzeugt in public/favicon (+ public/favicon.ico)");
}

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