/**
 * 票 26 诊断探针：主场景静置期间的画面抽搐来源定位（不联网后端，走 dev server 真数据源）。
 *
 * 反馈回路（先建再判，不猜）：
 *   ① 页内 rAF 帧间隔连续记录 + PerformanceObserver 长任务；
 *   ② 每 250ms 采一次 `__cockpitMap` 的相机 hpr、雾状态、交接状态、区域状态、引擎态；
 *   ③ 对帧间隔按 5s 分桶出 p50/p95/max，对相机 hpr 做振荡检测（相邻差分变号频率 + 振幅）；
 *   ④ 抽搐若与某状态机翻转同频 → 锁定来源；帧间隔有周期尖峰 → 渲染/加载抖动。
 *
 * 运行（dev server 需已在 :8000）：
 *   node .scratch/cockpit-real-data-wayfinding/verify/artifacts/t26/probe-jitter.mjs
 */
import { cdpLaunch } from '../../../../cockpit-shell-panel-layout/verify/cdp-driver.mjs'

const CHROME = process.env.CHROME_PATH || 'C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe'
const TARGET_URL = process.env.T26_URL || 'http://127.0.0.1:8000/#/cockpit'
const WAIT_MS = Number(process.env.T26_WAIT_MS || 75000)
const POLL_MS = 250

const sleep = (ms) => new Promise((r) => setTimeout(r, ms))

function stats(values) {
    if (!values.length) return null
    const sorted = [...values].sort((a, b) => a - b)
    const at = (q) => sorted[Math.min(sorted.length - 1, Math.floor(q * sorted.length))]
    const mean = sorted.reduce((s, v) => s + v, 0) / sorted.length
    return { n: sorted.length, p50: at(0.5), p95: at(0.95), max: sorted[sorted.length - 1], mean: Number(mean.toFixed(3)) }
}

/** 振荡检测：差分序列里符号翻转的比例 + 逐次摆幅。静止时翻转≈0，抽搐时显著>0。 */
function oscillation(values) {
    if (values.length < 4) return null
    const deltas = []
    for (let i = 1; i < values.length; i += 1) deltas.push(values[i] - values[i - 1])
    const signs = deltas.map((d) => (d > 1e-9 ? 1 : d < -1e-9 ? -1 : 0)).filter((s) => s !== 0)
    if (signs.length < 3) return { flips: 0, ratio: 0, amplitude: 0, samples: values.length }
    let flips = 0
    for (let i = 1; i < signs.length; i += 1) if (signs[i] !== signs[i - 1]) flips += 1
    const amplitude = Math.max(...values) - Math.min(...values)
    return { flips, ratio: Number((flips / (signs.length - 1)).toFixed(3)), amplitude, samples: values.length }
}

const browser = await cdpLaunch({ executablePath: CHROME, width: 1280, height: 800 })
console.log(`Chrome: ${await browser.version()}`)
const page = await browser.newPage()
const pageErrors = []
page.on('pageerror', (e) => pageErrors.push(String(e && e.message ? e.message : e)))

await page.goto(TARGET_URL, { timeout: 60000 })
await page.waitForSelector('.cockpit-shell', { timeout: 20000 })

// 装采样器（帧间隔 + 长任务 + WS 入站帧 + REST 请求完成时刻）。
await page.evaluate(() => {
    window.__t26 = { frames: [], longTasks: [], wsFrames: [], requests: [] }
    let last = performance.now()
    const tick = (now) => {
        window.__t26.frames.push({ t: now, dt: now - last })
        last = now
        requestAnimationFrame(tick)
    }
    requestAnimationFrame(tick)
    try {
        new PerformanceObserver((list) => {
            for (const entry of list.getEntries()) window.__t26.longTasks.push({ start: entry.startTime, dur: entry.duration })
        }).observe({ entryTypes: ['longtask'] })
    } catch { /* 无 longtask 支持则跳过 */ }

    // WS 入站帧时刻（外壳的 runtimeSocket 用 addEventListener('message') 收帧）。
    const NativeWS = window.WebSocket
    window.WebSocket = class extends NativeWS {
        addEventListener(type, listener, ...rest) {
            if (type === 'message') {
                const wrapped = (event) => {
                    try {
                        const data = typeof event.data === 'string' ? event.data.slice(0, 100) : ''
                        window.__t26.wsFrames.push({ t: performance.now(), head: data })
                    } catch { /* 记录失败不影响收帧 */ }
                    return listener.apply(this, arguments)
                }
                return super.addEventListener(type, wrapped, ...rest)
            }
            return super.addEventListener(type, listener, ...rest)
        }
    }

    // REST 完成时刻（axios 浏览器适配器走 XHR，另兜 fetch）。
    const nativeFetch = window.fetch.bind(window)
    window.fetch = async (...args) => {
        const url = String((args[0] && args[0].url) || args[0])
        try {
            const resp = await nativeFetch(...args)
            window.__t26.requests.push({ t: performance.now(), url: url.split('?')[0].slice(-70) })
            return resp
        } catch (error) {
            window.__t26.requests.push({ t: performance.now(), url: `ERR ${url.slice(-50)}` })
            throw error
        }
    }
    const XHR = XMLHttpRequest.prototype
    const nativeOpen = XHR.open
    XHR.open = function (method, url, ...rest) {
        this.__t26url = String(url).split('?')[0].slice(-70)
        return nativeOpen.call(this, method, url, ...rest)
    }
    const nativeSend = XHR.send
    XHR.send = function (...args) {
        const el = this
        const url = el.__t26url || ''
        el.addEventListener('loadend', () => window.__t26.requests.push({ t: performance.now(), url }))
        return nativeSend.apply(el, args)
    }
})

// 真实用户路径：点「点击进入系统」。
if (await page.$('[data-cockpit-intro]')) {
    await page.click('[data-cockpit-intro]')
    await page.waitForSelector('[data-cockpit-intro]', { hidden: true, timeout: 10000 }).catch(() => {})
}
await page.waitForFunction(
    () => ['ready', 'failed', 'disabled'].includes(document.querySelector('.cockpit-shell__map .map-canvas')?.dataset.mapEngine),
    { timeout: 40000 },
).catch(() => {})
await sleep(3000)

// 静置轮询采样（不做任何交互——票面现象是「等待一段时间后」自发出现）。
const series = []
const poll = async () => {
    const snap = await page.evaluate(() => {
        const dev = window.__cockpitMap
        if (!dev) return null
        const cam = dev.getCameraState ? dev.getCameraState() : null
        const fog = dev.getFogState ? dev.getFogState() : null
        const hand = dev.getHandoverState ? dev.getHandoverState() : null
        const area = dev.getAreaState ? dev.getAreaState() : null
        const host = document.querySelector('.cockpit-shell__map .map-canvas')
        return {
            t: performance.now(),
            engine: (host && host.dataset.mapEngine) || '',
            cam: cam && cam.hpr ? { h: cam.hpr.heading, p: cam.hpr.pitch, r: cam.hpr.range } : null,
            fog: fog ? { state: fog.state, strength: fog.strength, supported: fog.supported, degraded: fog.degradedReason || '' } : null,
            hand: hand ? { phase: hand.phase, alpha: hand.alpha, blocked: hand.blockedBy || '' } : null,
            area: area || null,
        }
    })
    if (snap) series.push(snap)
}
console.log(`静置采样 ${(WAIT_MS / 1000).toFixed(0)}s（每 ${POLL_MS}ms 一拍，无任何交互）…`)
const deadline = Date.now() + WAIT_MS
while (Date.now() < deadline) {
    await poll()
    await sleep(POLL_MS)
}

// ── 判定 ──
const report = { waitedMs: WAIT_MS, samples: series.length, pageErrors: pageErrors.slice(0, 5) }
const perWindow = await page.evaluate(() => {
    const frames = window.__t26.frames
    const start = frames.length ? frames[0].t : 0
    const out = []
    let bucket = []
    let bucketStart = start
    for (const frame of frames) {
        if (frame.t - bucketStart >= 5000) {
            out.push({ from: bucketStart - start, dts: bucket.map((f) => f.dt) })
            bucket = []
            bucketStart = frame.t
        }
        bucket.push(frame)
    }
    if (bucket.length) out.push({ from: bucketStart - start, dts: bucket.map((f) => f.dt) })
    return {
        windows: out.map((w) => ({ from: w.from, stats: null, _dts: w.dts })),
        longTasks: window.__t26.longTasks,
        wsFrames: window.__t26.wsFrames,
        requests: window.__t26.requests,
    }
})
report.fpsWindows = perWindow.windows.map((w) => ({ from: w.from, ...stats(w._dts) }))
// 票 33：验收判据要逐条复算——补导出**全量**长任务与原始帧分桶（票 26 原探针只存 Top8 与统计）。
report.frameBuckets = perWindow.windows.map((w) => ({ from: w.from, dts: w._dts }))
report.longTasksAll = perWindow.longTasks
report.longTaskCount = perWindow.longTasks.length
report.longTasksTop = perWindow.longTasks.sort((a, b) => b.dur - a.dur).slice(0, 8)
report.wsFrameCount = perWindow.wsFrames.length
report.wsFrameHeads = perWindow.wsFrames.slice(0, 30)
report.requestCount = perWindow.requests.length
report.requests = perWindow.requests

/** 相关：每个长任务（≥100ms）前后 400ms 内有没有 WS 帧 / REST 完成 / 状态机翻转。 */
const t0 = series.length ? series[0].t : 0
const near = (t, list, windowMs) => list.filter((item) => Math.abs(item.t - t) <= windowMs)
report.longTaskCorrelation = perWindow.longTasks
    .filter((task) => task.dur >= 100)
    .map((task) => ({
        start: Number(task.start.toFixed(0)),
        dur: task.dur,
        ws: near(task.start, perWindow.wsFrames, 400).length,
        rest: near(task.start, perWindow.requests, 400).map((r) => r.url),
    }))
    .slice(0, 40)

for (const key of ['h', 'p', 'r']) {
    const values = series.map((s) => (s.cam ? s.cam[key] : null)).filter((v) => v !== null)
    report[`cam_${key}`] = { ...oscillation(values), first: values[0], last: values[values.length - 1] }
}

const track = (pick, label) => {
    const seen = []
    for (const s of series) {
        const v = pick(s)
        const text = JSON.stringify(v)
        if (!seen.length || seen[seen.length - 1].text !== text) seen.push({ at: s.t, text })
    }
    report[label] = { transitions: seen.length - 1, timeline: seen.slice(0, 20) }
}
track((s) => s.fog && { state: s.fog.state, strength: s.fog.strength }, 'fogTrack')
track((s) => s.hand && { phase: s.hand.phase, alpha: s.hand.alpha }, 'handoverTrack')
track((s) => s.area, 'areaTrack')

const outPath = new URL('./jitter-report.json', import.meta.url).pathname.replace(/^\//, '')
const { writeFileSync } = await import('node:fs')
writeFileSync(outPath.startsWith('/E') ? `E:${outPath.slice(2)}` : outPath, JSON.stringify(report, null, 2))
console.log(`report -> ${outPath}`)
console.log(JSON.stringify({
    samples: report.samples,
    fps: report.fpsWindows.map((w) => `${w.from / 1000}s p50=${w.p50} p95=${w.p95} max=${w.max}`),
    cam_r: report.cam_r,
    fogTransitions: report.fogTrack.transitions,
    handoverTransitions: report.handoverTrack.transitions,
    areaTransitions: report.areaTrack.transitions,
    longTasks: report.longTaskCount,
    wsFrames: report.wsFrameCount,
    requests: report.requestCount,
    longTaskCorrelation: report.longTaskCorrelation,
}, null, 2))

await browser.close()