import test from 'node:test'
import assert from 'node:assert/strict'
import { createVideoLiveSession } from '../../src/modules/cockpit/services/videoLiveSession.js'

const media = (code) => ({ native: true, url: `https://media.invalid/${code}.mp4` })
const data = (code) => ({ deviceCode: code, sessionId: `session-${code}`, mode: 'LIVE', status: 'ACTIVE', media: media(code) })
const prepared = (code) => ({ deviceCode: code, sessionId: `session-${code}`, sessionToken: `owner-${code}`, mode: 'LIVE', status: 'PREPARED' })
const stopped = (session) => ({ sessionId: session.sessionId, status: 'STOPPED' })

class Clock {
    now = 0; next = 1; jobs = new Map()
    setTimeout(fn, delay) { const id = this.next++; this.jobs.set(id, { fn, at: this.now + delay }); return id }
    clearTimeout(id) { this.jobs.delete(id) }
    setInterval(fn, delay) { const id = this.setTimeout(fn, delay); this.jobs.get(id).interval = delay; return id }
    clearInterval(id) { this.clearTimeout(id) }
    async advance(duration) {
        const end = this.now + duration
        while (true) {
            const due = Array.from(this.jobs).filter(([, job]) => job.at <= end).sort((a, b) => a[1].at - b[1].at)[0]
            if (!due) break
            const [id, job] = due; this.now = job.at
            if (job.interval) job.at += job.interval; else this.jobs.delete(id)
            job.fn(); await new Promise(setImmediate)
        }
        this.now = end; await new Promise(setImmediate)
    }
}

/** Builds a session whose live start always fails, and records every attempt. */
function failingLive(clock, options = {}) {
    const attempts = [], updates = []
    let visible = {}
    const live = createVideoLiveSession({
        prepare: async (code) => prepared(code),
        start: async (session) => {
            attempts.push({ at: clock.now, code: session.deviceCode })
            if (options.fail) throw options.fail(attempts.length)
            throw new Error('暂时无法连接视频')
        },
        status: async () => ({ sessionId: 'session-A', status: 'FAILED' }),
        stop: async (session) => stopped(session),
        heartbeat: async () => {},
    }, (patch) => { updates.push(patch); visible = { ...visible, ...patch } }, clock)
    return { live, attempts, updates, visible: () => visible }
}

test('live reconnects at most five times and never for the first normal play', async () => {
    const clock = new Clock(), h = failingLive(clock)
    try {
        const opening = h.live.start('A')
        await new Promise(setImmediate)
        await clock.advance(200000)
        await opening
        assert.equal(h.attempts.length, 6, 'one initial attempt plus five bounded retries')
        assert.equal(h.visible().phase, 'failed')
    } finally { await h.live.dispose() }
})

test('retries wait 2/4/8/16/30 seconds serially without stacking sessions', async () => {
    const clock = new Clock(), h = failingLive(clock)
    try {
        const opening = h.live.start('A')
        await new Promise(setImmediate)
        await clock.advance(200000)
        await opening
        const gaps = h.attempts.slice(1).map((attempt, index) => attempt.at - h.attempts[index].at)
        assert.deepEqual(gaps, [2000, 4000, 8000, 16000, 30000])
        const retrying = h.updates.filter((patch) => patch.phase === 'retrying').map((patch) => patch.retryAttempt)
        assert.deepEqual(retrying, [1, 2, 3, 4, 5], 'each waiting attempt is observable')
    } finally { await h.live.dispose() }
})

test('only thirty seconds of real playback restores the retry budget', async () => {
    // Control: playback shorter than the stable window keeps the already-spent budget,
    // so the following disconnect can only fan out from the remaining allowance.
    const short = await fixtureWithPlayback(29000)
    try {
        await short.drain()
        assert.equal(short.attempts.length, 6, 'a short window keeps the already-spent budget')
    } finally { await short.live.dispose() }
    // Full 30 seconds of playback replenishes the budget, so the next disconnect gets five fresh tries.
    const full = await fixtureWithPlayback(30000)
    try {
        await full.drain()
        assert.equal(full.attempts.length, 7, 'a full stable window restores the budget')
    } finally { await full.live.dispose() }
})

/** Plays successfully, stays up for `stableMs`, then drops and reports how many starts happened. */
async function fixtureWithPlayback(stableMs) {
    const clock = new Clock(), attempts = []
    let healthy = false
    const live = createVideoLiveSession({
        prepare: async (code) => prepared(code),
        start: async () => { attempts.push(clock.now); if (healthy) return data('A'); throw new Error('暂时无法连接视频') },
        stop: async (session) => stopped(session), heartbeat: async () => {},
    }, () => {}, clock)
    const opening = live.start('A')
    await new Promise(setImmediate)
    healthy = true
    await clock.advance(2000)
    await opening
    live.ready()
    await clock.advance(stableMs)
    healthy = false
    live.fail('断流')
    await clock.advance(4000)
    return { live, attempts, drain: () => clock.advance(200000) }
}

test('unrecoverable outcomes never retry automatically', async () => {
    // VideoRequestError uses `category`; these are the real terminal categories from videoApi.
    for (const category of ['DEVICE_NOT_FOUND', 'VIDEO_UNAVAILABLE', 'SESSION_FORBIDDEN', 'INVALID_RESPONSE']) {
        const clock = new Clock(), h = failingLive(clock, { fail: () => { throw Object.assign(new Error(category), { category }) } })
        try {
            const opening = h.live.start('A')
            await new Promise(setImmediate)
            await clock.advance(120000)
            await opening
            assert.equal(h.attempts.length, 1, `${category} must not be retried`)
            assert.equal(h.visible().phase, 'failed')
        } finally { await h.live.dispose() }
    }
    // A temporary 503-style failure is retried.
    const clock = new Clock(), retryable = failingLive(clock, { fail: () => { throw Object.assign(new Error('暂时不可用'), { category: 'VIDEO_START_FAILED' }) } })
    try {
        const opening = retryable.live.start('A')
        await new Promise(setImmediate)
        await clock.advance(120000)
        await opening
        assert.equal(retryable.attempts.length, 6, 'a temporary failure spends the whole budget')
    } finally { await retryable.live.dispose() }
})

test('closing cancels pending retries and releases the prepared identity', async () => {
    const clock = new Clock(), h = failingLive(clock)
    try {
        const opening = h.live.start('A')
        await new Promise(setImmediate)
        await h.live.stop()
        await clock.advance(200000)
        await opening
        assert.equal(h.attempts.length, 1, 'no retry may run after close')
        assert.equal(h.visible().media, null)
    } finally { await h.live.dispose() }
})