// The replay viewer (replay.html) on every track, judged against the pure model. The recording is
// fixtures/replay-sample.json, which the pages fetch and the oracle reads from disk.
import { test, expect, TRACKS } from '../lib/app.mjs'
import { FRAME } from '../lib/clock.mjs'
import { recording, REPLAY_MS } from '../lib/oracle.mjs'

const LAST = recording.actions.length
const lastScene = (shapes) => shapes.slice(Math.max(0, shapes.findLastIndex((s) => s.tag === 'Rect' && s.x === 0 && s.y === 0 && s.w === 400)))
const stepOf = (shapes) => {
  const t = lastScene(shapes).find((s) => s.tag === 'Text' && s.text.startsWith('step '))
  return Number(/^step (\d+) \//.exec(t.text)[1])
}
const textsOf = (shapes) => lastScene(shapes).filter((s) => s.tag === 'Text').map((s) => s.text)
// Multiples of `ms` in (a, b]: how many beats of a `ms` interval fall between two frames at times a and b.
const beats = (ms, a, b) => Math.floor(b / ms) - Math.floor(a / ms)
// Time of the last animation frame so far, in the page's own clock (ms since its first frame).
const lastFrameTime = (a) => Math.floor(a.clock.now / FRAME) * FRAME - a.clock.t0

for (const track of TRACKS) {
  test.describe(`${track}: replay`, () => {
    test('Right, Left, Home and End show the model\'s frames', async ({ app }) => {
      const a = await (await app(track, 'replay')).start()
      expect(stepOf(await a.expectInSync())).toBe(0)
      const seen = []
      for (const key of ['ArrowRight', 'ArrowRight', 'ArrowRight', 'ArrowLeft', 'End', 'ArrowRight', 'ArrowLeft', 'Home', 'ArrowLeft']) {
        await a.press(key)
        seen.push(stepOf(await a.expectInSync(`after ${key}`)))
        await a.advance(50)
      }
      await a.expectInSync()
      expect(seen).toEqual([1, 2, 3, 2, LAST, LAST, LAST - 1, 0, 0])
      expect(textsOf(a.lastPageFrame)).toContain(`step 0 / ${LAST}`)
    })

    test('autoplay advances one frame per 100 ms of fake time and stops on the last frame', async ({ app }) => {
      const a = await (await app(track, 'replay')).start()
      await a.advance(130)
      await a.press(' ')
      const pressedAt = lastFrameTime(a)
      expect(textsOf(await a.expectInSync('play'))).toContain('Space: pause')
      // For a while, check every 100 ms: the step shown is the number of 100 ms beats since the key.
      for (let i = 0; i < 12; i++) {
        await a.advance(REPLAY_MS)
        expect(stepOf(await a.expectInSync(`playing, ${i}`))).toBe(beats(REPLAY_MS, pressedAt, lastFrameTime(a)))
      }
      // Then run to the end and beyond, a second at a time; it stops on the last frame.
      while (a.state.playing) {
        await a.advance(1000)
        await a.expectInSync('playing on')
      }
      await a.advance(1000)
      const end = await a.expectInSync('stopped')
      expect(stepOf(end)).toBe(LAST)
      expect(textsOf(end)).toContain('Left/Right: step   Home/End: jump   Space: play')
      expect(beats(REPLAY_MS, pressedAt, lastFrameTime(a))).toBeGreaterThan(LAST)
    })
  })
}