const assert = require('node:assert/strict')
const { writeFileSync } = require('node:fs')
const { nativeImage, BrowserWindow } = require('electron')

module.exports = async function previewsSmoke({ control, output, evaluate, inspect, state, command, poll, targetDisplay }) {
  const miniature = (index) => `[data-testid="screen-plan"] [data-step-index="${index}"] .step-preview`
  const metrics = (root, videoSelector) => `(() => {
    const root = document.querySelector(${JSON.stringify(root)});
    if (!root) return null;
    const bounds = root.getBoundingClientRect();
    return ['.background', '.cover', '.message', '.intro-waveform', '.timer h1', '.timer strong', '.results', '.results h1', '.results .empty', '.results table', ${JSON.stringify(videoSelector)}].flatMap(selector => {
      const e = root.querySelector(selector); if (!e) return [];
      const r = e.getBoundingClientRect(); const s = getComputedStyle(e); if (s.display === 'none') return [];
      return [{ selector: selector.includes('video') ? 'video' : selector, text: e.textContent.trim(), x: (r.x-bounds.x)/bounds.width, y: (r.y-bounds.y)/bounds.height, width: r.width/bounds.width, height: r.height/bounds.height, font: s.fontSize, fit: s.objectFit, filter: s.filter }];
    });
  })()`
  const compare = async (index) => {
    const actual = await inspect(metrics('.output', 'video'))
    const thumbnail = await evaluate(metrics(miniature(index), 'video'))
    // Hidden main video remains mounted in the output to preserve playback state.
    const expected = actual.filter(item => item.selector !== 'video' || index === 3)
    assert.equal(thumbnail.length, expected.length, `step ${index + 1}: ${JSON.stringify({ expected, thumbnail })}`)
    for (let i = 0; i < expected.length; i++) {
      const a = expected[i], b = thumbnail[i]
      for (const key of ['selector', 'text', 'font', 'fit', 'filter']) {
        if (a.selector === 'video' && key === 'font') continue
        assert.equal(b[key], a[key], `step ${index + 1}: ${key}`)
      }
      for (const key of ['x', 'y', 'width', 'height'])
        assert.ok(Math.abs(a[key] - b[key]) < 0.002, `step ${index + 1}: ${key}: ${a[key]} / ${b[key]}`)
    }
  }
  for (const [width, height] of [[1280, 720], [1024, 768]]) {
    targetDisplay.size = { width, height }
    output.webContents.enableDeviceEmulation({ screenPosition: 'desktop', screenSize: { width, height }, viewSize: { width, height }, deviceScaleFactor: 1, scale: 1 })
    await poll(() => inspect(`innerWidth === ${width} && innerHeight === ${height}`), 'output viewport')
    await poll(() => evaluate(`(() => { const r = document.querySelector('${miniature(0)}').getBoundingClientRect(); return Math.abs(r.width/r.height - ${width/height}) < 0.001 && document.querySelector('${miniature(0)} .preview-viewport').style.width === '${width}px' })()`), 'thumbnail viewport follows display')
    for (let index = 0; index < 8; index++) {
      await command({ action: 'step', index })
      await poll(async () => {
        const s = await state()
        if (s.scene.status === 'error') throw new Error(s.scene.error)
        return s.scene.stepIndex === index && s.scene.status === 'ready'
      }, `scene ${index + 1}`)
      await poll(() => evaluate(`Array.from(document.querySelectorAll('${miniature(index)} img')).every(i => i.complete && i.naturalWidth > 0)`), 'thumbnail images loaded')
      if (index === 3) {
        await poll(() => evaluate(`document.querySelector('${miniature(index)} video').readyState >= 2`), 'video thumbnail first frame')
        assert.ok(await evaluate(`(() => { const v = document.querySelector('${miniature(index)} video'); return v.paused && v.muted && v.currentTime === 0 })()`))
      }
      await compare(index)
      assert.ok(await evaluate('Array.from(document.querySelectorAll(".step-preview video")).every(v => v.paused && v.muted)'))
      assert.equal((await state()).channels.main.desired, 'stopped')
      const staticScroll = await evaluate(`document.querySelector('${miniature(5)} .results-scroll')?.scrollTop ?? 0`)
      assert.equal(staticScroll, 0)
    }
    await command({ action: 'step', index: 6 })
    await evaluate(`document.querySelector('${miniature(6)}').scrollIntoView({ block: 'center' })`)
    writeFileSync(`/tmp/screen-previews-${width}.png`, (await control.webContents.capturePage()).toPNG())
    writeFileSync(`/tmp/screen-output-${width}.png`, (await output.webContents.capturePage()).toPNG())
  }
  await evaluate('window.screenBridge.closeOutput()')
  await poll(async () => !(await state()).outputOpen, 'output closed')
  assert.equal(await evaluate('document.querySelectorAll(".step-preview").length'), 8)
  assert.ok(await evaluate('Array.from(document.querySelectorAll(".step-preview video")).every(v => v.paused && v.muted)'))
  await evaluate(`window.screenBridge.show(${targetDisplay.id})`)
  output = await poll(() => BrowserWindow.getAllWindows().find(w => w.webContents.getURL() === 'screen-app://app/index.html?output=1'), 'reopen after static preview')
  output.webContents.enableDeviceEmulation({ screenPosition: 'desktop', screenSize: { width: 1024, height: 768 }, viewSize: { width: 1024, height: 768 }, deviceScaleFactor: 1, scale: 1 })
  await poll(async () => (await state()).scene.status === 'ready', 'reopened scene')
  // Exercise missing media, long text, portrait cover and different result snapshots.
  const original = await state()
  let revision = original.revision + 1000
  const portrait = nativeImage.createFromBitmap(Buffer.alloc(80 * 160 * 4, 180), { width: 80, height: 160 }).toDataURL()
  const cases = [
    { index: 0, catalog: { ...original.catalog, cover: portrait } },
    { index: 7, catalog: { ...original.catalog, steps: original.catalog.steps.map((step, i) => i === 7 ? { ...step, text: 'Длинный многострочный текст\n' + 'Расследование продолжается. '.repeat(12) } : step) } },
    { index: 1, catalog: { ...original.catalog, media: [] } },
    { index: 3, catalog: { ...original.catalog, media: [] } },
    { index: 0, catalog: { ...original.catalog, cover: null } },
    { index: 5, results: { packageKey: original.catalog.key, capturedAt: new Date().toISOString(), questions: [], teams: [] } },
    { index: 5, results: { packageKey: original.catalog.key, capturedAt: new Date().toISOString(), questions: [{ code: 'A', text: 'Вопрос' }], teams: [{ id: 'one', name: 'Детективы', place: 1, totalScore: 5, actionsCount: 1, answers: [{ questionCode: 'A', score: 5 }] }] } },
  ]
  for (const item of cases) {
    const catalog = item.catalog ?? original.catalog
    const step = catalog.steps[item.index]
    const snapshot = { ...original, revision: ++revision, catalog, results: item.results ?? original.results,
      scene: { ...original.scene, revision, mode: step.mode, text: step.text, stepIndex: item.index },
      channels: { ...original.channels, main: { ...original.channels.main, source: catalog.media.find(m => m.kind === (step.mode === 2 ? 'audio' : 'video')) ?? null } } }
    control.webContents.send('state', snapshot)
    output.webContents.send('state', snapshot)
    await poll(() => inspect(`document.querySelector('.output').dataset.mode === '${step.mode}'`), 'fixture output')
    await poll(() => evaluate(`document.querySelector('${miniature(item.index)} .scene-view').dataset.mode === '${step.mode}'`), 'fixture thumbnail')
    await new Promise(resolve => setTimeout(resolve, 50))
    await compare(item.index)
  }
  console.log('SCREEN_PREVIEWS_PASS')
}