import { afterEach, describe, expect, it, vi } from 'vitest'

import { installRendererAnimationPauseState, RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE } from './renderer-loop-pause'

describe('installRendererAnimationPauseState', () => {
  afterEach(() => {
    document.documentElement.removeAttribute(RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE)
    vi.restoreAllMocks()
  })

  it('pauses on blur, resumes on focus, and cleans up its root state', () => {
    let focused = true
    vi.spyOn(document, 'hasFocus').mockImplementation(() => focused)

    const dispose = installRendererAnimationPauseState()
    expect(document.documentElement.hasAttribute(RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE)).toBe(false)

    focused = false
    window.dispatchEvent(new Event('blur'))
    expect(document.documentElement.hasAttribute(RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE)).toBe(true)

    focused = true
    window.dispatchEvent(new Event('focus'))
    expect(document.documentElement.hasAttribute(RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE)).toBe(false)

    focused = false
    window.dispatchEvent(new Event('blur'))
    dispose()
    expect(document.documentElement.hasAttribute(RENDERER_ANIMATIONS_PAUSED_ATTRIBUTE)).toBe(false)
  })
})