import { describe, it, expect, vi, beforeEach } from 'vitest'
import { render, screen, waitFor, act } from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import { PlayerProvider, usePlayer, playerReducer, type PlayerState } from '../src/player/PlayerContext.js'
import type { Track } from '../src/types.js'

vi.mock('../src/api.js', async (importOriginal) => {
  const actual = await importOriginal<typeof import('../src/api.js')>()
  return { ...actual, api: { ...actual.api, getAlbumTracks: vi.fn(), markPlayed: vi.fn() } }
})

import { api } from '../src/api.js'

beforeEach(() => {
  vi.spyOn(HTMLMediaElement.prototype, 'play').mockResolvedValue()
  vi.spyOn(HTMLMediaElement.prototype, 'pause').mockReturnValue(undefined)
})

const tracks: Track[] = [
  { id: 's1', title: 'Overture', duration: 200, track: 1 },
  { id: 's2', title: 'Theme de Yoyo', duration: 300, track: 2 },
]

function Probe() {
  const { state, load, toggle, next, prev, close } = usePlayer()
  return (
    <div>
      <div>phase:{state.album ? (state.playing ? 'playing' : 'paused') : 'empty'}</div>
      <div>track:{state.tracks[state.index]?.title ?? 'none'}</div>
      <button type="button" onClick={() => load({ id: 'a1', title: 'Motion', artist: 'TCO' })}>load</button>
      <button type="button" onClick={() => toggle()}>toggle</button>
      <button type="button" onClick={() => next()}>next</button>
      <button type="button" onClick={() => prev()}>prev</button>
      <button type="button" onClick={() => close()}>close</button>
    </div>
  )
}

function renderPlayer() {
  return render(
    <PlayerProvider>
      <Probe />
    </PlayerProvider>
  )
}

describe('PlayerProvider', () => {
  it('loads a queue, stamps played, starts at track 1', async () => {
    vi.mocked(api.getAlbumTracks).mockResolvedValue({ id: 'a1', title: 'Motion', artist: 'TCO', tracks } as never)
    vi.mocked(api.markPlayed).mockResolvedValue({ ok: true } as never)
    renderPlayer()
    await userEvent.click(screen.getByRole('button', { name: 'load' }))
    await waitFor(() => expect(screen.getByText('phase:playing')).toBeTruthy())
    expect(screen.getByText('track:Overture')).toBeTruthy()
    expect(api.getAlbumTracks).toHaveBeenCalledWith('a1')
    expect(api.markPlayed).toHaveBeenCalledWith('a1')
  })

  it('toggle pauses and resumes', async () => {
    vi.mocked(api.getAlbumTracks).mockResolvedValue({ id: 'a1', title: 'Motion', artist: 'TCO', tracks } as never)
    vi.mocked(api.markPlayed).mockResolvedValue({ ok: true } as never)
    renderPlayer()
    await userEvent.click(screen.getByRole('button', { name: 'load' }))
    await waitFor(() => expect(screen.getByText('phase:playing')).toBeTruthy())
    await userEvent.click(screen.getByRole('button', { name: 'toggle' }))
    expect(screen.getByText('phase:paused')).toBeTruthy()
    await userEvent.click(screen.getByRole('button', { name: 'toggle' }))
    expect(screen.getByText('phase:playing')).toBeTruthy()
  })

  it('next/prev move through the queue and stop at the edges', async () => {
    vi.mocked(api.getAlbumTracks).mockResolvedValue({ id: 'a1', title: 'Motion', artist: 'TCO', tracks } as never)
    vi.mocked(api.markPlayed).mockResolvedValue({ ok: true } as never)
    renderPlayer()
    await userEvent.click(screen.getByRole('button', { name: 'load' }))
    await waitFor(() => expect(screen.getByText('track:Overture')).toBeTruthy())
    await userEvent.click(screen.getByRole('button', { name: 'next' }))
    expect(screen.getByText('track:Theme de Yoyo')).toBeTruthy()
    await userEvent.click(screen.getByRole('button', { name: 'next' }))
    expect(screen.getByText('track:Theme de Yoyo')).toBeTruthy() // last track: no advance
    await userEvent.click(screen.getByRole('button', { name: 'prev' }))
    expect(screen.getByText('track:Overture')).toBeTruthy()
    await userEvent.click(screen.getByRole('button', { name: 'prev' }))
    expect(screen.getByText('track:Overture')).toBeTruthy() // first track: no rewind
  })

  it('close empties the player', async () => {
    vi.mocked(api.getAlbumTracks).mockResolvedValue({ id: 'a1', title: 'Motion', artist: 'TCO', tracks } as never)
    vi.mocked(api.markPlayed).mockResolvedValue({ ok: true } as never)
    renderPlayer()
    await userEvent.click(screen.getByRole('button', { name: 'load' }))
    await waitFor(() => expect(screen.getByText('phase:playing')).toBeTruthy())
    await userEvent.click(screen.getByRole('button', { name: 'close' }))
    expect(screen.getByText('phase:empty')).toBeTruthy()
  })

  it('audio error marks the track failed and skips to the next', async () => {
    vi.mocked(api.getAlbumTracks).mockResolvedValue({ id: 'a1', title: 'Motion', artist: 'TCO', tracks } as never)
    vi.mocked(api.markPlayed).mockResolvedValue({ ok: true } as never)
    renderPlayer()
    await userEvent.click(screen.getByRole('button', { name: 'load' }))
    await waitFor(() => expect(screen.getByText('track:Overture')).toBeTruthy())
    act(() => {
      document.querySelector('audio')!.dispatchEvent(new Event('error'))
    })
    await waitFor(() => expect(screen.getByText('track:Theme de Yoyo')).toBeTruthy())
  })
})

const twoTracks: Track[] = [
  { id: 's1', title: 'Overture', duration: 200, track: 1 },
  { id: 's2', title: 'Theme de Yoyo', duration: 300, track: 2 },
]

describe('playerReducer edges', () => {
  const loaded: PlayerState = playerReducer(
    { album: null, tracks: [], index: 0, playing: false, failed: [] },
    { type: 'LOAD', album: { id: 'a1', title: 'Motion', artist: 'TCO' }, tracks: twoTracks }
  )

  it('LOAD with empty tracks does not play', () => {
    const s = playerReducer(loaded, { type: 'LOAD', album: loaded.album!, tracks: [] })
    expect(s.playing).toBe(false)
  })

  it('TRACK_ERROR at last track pauses without advancing, records failure once', () => {
    const atLast = playerReducer(loaded, { type: 'NEXT' })
    const err = playerReducer(atLast, { type: 'TRACK_ERROR' })
    expect(err.index).toBe(1)
    expect(err.playing).toBe(false)
    expect(err.failed).toEqual([1])
    const again = playerReducer(err, { type: 'TRACK_ERROR' })
    expect(again.failed).toEqual([1])
  })
})