import { assertVideoPreviewImageIsSafeToDecode } from './image-processor'

function createPngFile(name: string, width: number, height: number) {
  const bytes = new Uint8Array(24)
  bytes.set([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])
  const view = new DataView(bytes.buffer)
  view.setUint32(16, width)
  view.setUint32(20, height)
  return new File([bytes], name, { type: 'image/png' })
}

describe('video preview image decode guard', () => {
  test('允许常规预览图', async () => {
    await expect(assertVideoPreviewImageIsSafeToDecode(
      createPngFile('cover.png', 3840, 2160),
    )).resolves.toBeUndefined()
  })

  test('在浏览器解码前拒绝超大像素图片', async () => {
    await expect(assertVideoPreviewImageIsSafeToDecode(
      createPngFile('huge.png', 10_000, 7_000),
    )).rejects.toThrow('像素总量超过 60,000,000')
  })

  test('无法读取尺寸时给出可恢复的格式提示', async () => {
    await expect(assertVideoPreviewImageIsSafeToDecode(
      new File(['not-an-image'], 'broken.jpg', { type: 'image/jpeg' }),
    )).rejects.toThrow('请改用 JPG、PNG 或 WebP 图片')
  })
})