import { afterEach, describe, expect, it, vi } from 'vitest'
import {
  CAPTURE_MAX_EDGE,
  CameraEye,
  classifyFailure,
  isSupported,
  toBase64,
} from './camera'

afterEach(() => {
  vi.unstubAllGlobals()
})

/** getUserMedia whose resolution we control, with track-stop spies. */
function stubCamera() {
  const stopped: string[] = []
  const tracks = [{ stop: () => stopped.push('video') }]
  let release: (() => void) | null = null
  const pending = new Promise<MediaStream>((resolve) => {
    release = () => resolve({ getTracks: () => tracks } as unknown as MediaStream)
  })
  vi.stubGlobal('navigator', { mediaDevices: { getUserMedia: () => pending } })
  return { stopped, release: () => release!() }
}

function fakeVideo(w = 1920, h = 1080) {
  return {
    videoWidth: w,
    videoHeight: h,
    srcObject: null as unknown,
    muted: false,
    playsInline: false,
    play: () => Promise.resolve(),
  } as unknown as HTMLVideoElement
}

describe('classifyFailure', () => {
  it('distinguishes a real refusal from every other cause', () => {
    vi.stubGlobal('navigator', { mediaDevices: { getUserMedia: () => undefined } })
    expect(classifyFailure(new DOMException('x', 'NotAllowedError'))).toBe('denied')
    expect(classifyFailure(new DOMException('x', 'SecurityError'))).toBe('insecure')
    expect(classifyFailure(new DOMException('x', 'NotFoundError'))).toBe('absent')
    expect(classifyFailure(new DOMException('x', 'NotReadableError'))).toBe('busy')
    // An unrecognised error must not be reported as a refusal the seeker made.
    expect(classifyFailure(new Error('who knows'))).toBe('unknown')
  })

  it('reports an unsupported context as insecure rather than denied', () => {
    vi.stubGlobal('navigator', {})
    expect(isSupported()).toBe(false)
    expect(classifyFailure(new DOMException('x', 'NotAllowedError'))).toBe('insecure')
  })
})

describe('toBase64', () => {
  it('strips the data-URL prefix Ollama does not want', () => {
    expect(toBase64('data:image/jpeg;base64,AAAA')).toBe('AAAA')
  })

  it('passes through a string that is already bare base64', () => {
    expect(toBase64('AAAA')).toBe('AAAA')
  })
})

describe('CameraEye lifecycle', () => {
  it('releases the camera when closed while the permission prompt is open', async () => {
    // The hazard: the stream is only assigned after the await, so a close()
    // during the prompt would otherwise release nothing and the camera would
    // go live *after* teardown, leaving the recording light on.
    const { stopped, release } = stubCamera()
    const eye = new CameraEye()
    const video = fakeVideo()

    const opening = eye.open(video)
    eye.close() // seeker switches mode mid-prompt
    release()
    await opening

    expect(stopped).toEqual(['video'])
    expect(eye.isOpen).toBe(false)
  })

  it('opens normally when nobody interrupts', async () => {
    const { stopped, release } = stubCamera()
    const eye = new CameraEye()
    const video = fakeVideo()

    const opening = eye.open(video)
    release()
    await opening

    expect(eye.isOpen).toBe(true)
    expect(stopped).toEqual([])
    // iOS Safari refuses to start a stream without both of these.
    expect(video.muted).toBe(true)
    expect(video.playsInline).toBe(true)

    eye.close()
    expect(stopped).toEqual(['video'])
    expect(eye.isOpen).toBe(false)
  })

  it('captures nothing when the lens is closed', () => {
    const eye = new CameraEye()
    expect(eye.capture(fakeVideo())).toBeNull()
  })

  it('captures nothing before video metadata arrives', async () => {
    const { release } = stubCamera()
    const eye = new CameraEye()
    const video = fakeVideo(0, 0) // dimensions not known yet
    const opening = eye.open(video)
    release()
    await opening
    expect(eye.capture(video)).toBeNull()
  })

  it('downscales a large frame so the payload stays small', async () => {
    const { release } = stubCamera()
    const eye = new CameraEye()
    const video = fakeVideo(1920, 1080)

    // Record what the canvas was sized to.
    const sizes: Array<{ w: number; h: number }> = []
    const canvas = {
      width: 0,
      height: 0,
      getContext: () => ({ drawImage: () => undefined }),
      toDataURL: () => {
        sizes.push({ w: canvas.width, h: canvas.height })
        return 'data:image/jpeg;base64,ZZZZ'
      },
    }
    vi.stubGlobal('document', { createElement: () => canvas })

    const opening = eye.open(video)
    release()
    await opening

    expect(eye.capture(video)).toBe('data:image/jpeg;base64,ZZZZ')
    expect(sizes).toHaveLength(1)
    // Longest edge clamped, aspect ratio preserved.
    expect(sizes[0].w).toBe(CAPTURE_MAX_EDGE)
    expect(sizes[0].h).toBe(Math.round((1080 / 1920) * CAPTURE_MAX_EDGE))
  })

  it('never upscales a frame smaller than the cap', async () => {
    const { release } = stubCamera()
    const eye = new CameraEye()
    const video = fakeVideo(320, 240)
    const canvas = {
      width: 0,
      height: 0,
      getContext: () => ({ drawImage: () => undefined }),
      toDataURL: () => 'data:image/jpeg;base64,S',
    }
    vi.stubGlobal('document', { createElement: () => canvas })

    const opening = eye.open(video)
    release()
    await opening
    eye.capture(video)

    expect(canvas.width).toBe(320)
    expect(canvas.height).toBe(240)
  })
})