import { readFile } from 'node:fs/promises';
import path from 'node:path';

/**
 * The 1-bit wordmark, inlined as a data URI.
 *
 * It is read from the committed `public/brand/logo-eink.png` and embedded in
 * the SVG rather than linked: the renderer must not depend on the network, and
 * an image the rasteriser silently failed to fetch would leave a hole in the
 * shop window. Regenerate the file with `npm run brand`.
 */

/** Matches the committed asset; see scripts/brand.ts. */
export const LOGO_WIDTH = 260;
export const LOGO_HEIGHT = 36;

let cached: string | null | undefined;

export async function loadLogoDataUri(): Promise<string | null> {
  if (cached !== undefined) {
    return cached;
  }
  try {
    const file = path.join(process.cwd(), 'public', 'brand', 'logo-eink.png');
    cached = `data:image/png;base64,${(await readFile(file)).toString('base64')}`;
  } catch {
    // Not fatal: the header falls back to the shop name set in the settings,
    // which is worse-looking but still a working screen.
    cached = null;
  }
  return cached;
}