import {readFileSync} from 'node:fs';
import path from 'node:path';
import {describe, expect, it} from 'vitest';

const root = path.resolve(import.meta.dirname, '..');
const read = (file) => readFileSync(path.join(root, file));
const manifest = JSON.parse(read('public/manifest.webmanifest'));

// Width and height sit at bytes 16-23 of every PNG.
const pngSize = (file) => {
    const png = read(path.join('public', file));
    return `${png.readUInt32BE(16)}x${png.readUInt32BE(20)}`;
};

describe('PWA manifest', () => {
    it('links every icon to a PNG of the size it claims', () => {
        for (const icon of manifest.icons) {
            expect(pngSize(icon.src)).toBe(icon.sizes);
        }
    });

    it('has the icons Chrome needs to offer the install', () => {
        const sizes = manifest.icons.filter((icon) => icon.purpose === 'any').map((icon) => icon.sizes);
        expect(sizes).toEqual(expect.arrayContaining(['192x192', '512x512']));
        expect(manifest.display).toBe('standalone');
        expect(manifest.icons.some((icon) => icon.purpose === 'maskable')).toBe(true);
    });

    it('is linked from index.html together with the iOS icon', () => {
        const html = read('index.html').toString();
        expect(html).toContain('<link rel="manifest" href="/manifest.webmanifest" />');
        expect(html).toContain('<link rel="apple-touch-icon" href="/apple-touch-icon.png" />');
        expect(pngSize('apple-touch-icon.png')).toBe('180x180');
    });
});