import { existsSync, readFileSync } from 'node:fs'
import { fileURLToPath } from 'node:url'
import { describe, expect, it } from 'vitest'

// Every showcase visit 404'd on both /favicon.ico and /favicon.svg (stage sweep,
// 2026-10-11) because the template shipped no favicon at all. `app/favicon.ico` is
// Next's own file convention for /favicon.ico; `public/favicon.svg` is a plain static
// file for /favicon.svg, which Next's convention does not cover (it only serves
// `icon.svg` at /icon.svg). The root layout's `metadata.icons` must name both, so the
// rendered <link> tags match what is actually shipped.
describe('favicon', () => {
  it('ships a valid favicon.ico for Next’s /favicon.ico convention', () => {
    const path = fileURLToPath(new URL('../app/favicon.ico', import.meta.url))
    expect(existsSync(path)).toBe(true)
    const bytes = readFileSync(path)
    // ICO header: reserved=0, type=1 (icon), at least one image.
    expect(bytes.readUInt16LE(0)).toBe(0)
    expect(bytes.readUInt16LE(2)).toBe(1)
    expect(bytes.readUInt16LE(4)).toBeGreaterThan(0)
  })

  it('ships public/favicon.svg, served verbatim at /favicon.svg', () => {
    const path = fileURLToPath(new URL('../public/favicon.svg', import.meta.url))
    expect(existsSync(path)).toBe(true)
    expect(readFileSync(path, 'utf8')).toContain('<svg')
  })

  it('names both favicons in the root layout’s metadata', () => {
    const layout = readFileSync(
      new URL('../src/app/layouts/root.tsx', import.meta.url),
      'utf8',
    )
    expect(layout).toMatch(/\/favicon\.svg/)
    expect(layout).toMatch(/\/favicon\.ico/)
  })
})