/**
 * 覆盖网络 **直连（打洞）** 单测（序㊵ · P2 · S5）。
 *
 * ⚠️ **刻意不进 `npm test`** —— 那是**硬编码文件列表**，加进去会改测试总数（既有口径：
 * `test/overlay-join.test.mjs` 同样"刻意不进"）。本文件单独跑：
 * ```bash
 * node --test test/overlay-direct.test.mjs
 * ```
 *
 * | 用例 | 判据 | 断言的东西 |
 * |---|---|---|
 * | T1 | D3 ｜开关解析 | 缺省=开；关集/开集；**非法值 ⇒ `null`（⛔ 不静默取缺省）**；本机配置次之 |
 * | T2 | D2 ｜关闭生效 | 关闭 ⇒ **零 UDP socket** ＋ **零候选**（⛔ 不是"少发几条"） |
 * | T3 | D1 ｜候选准入矩阵 | 同网＋白名单内接受；跨网 / 替第三人申报 / 白名单外 / 本机不在白名单 / 坏形状 / 夹带凭据 / 坏地址 / 超限 / 过期 **各自具名拒绝**；`silentRejections = 0` |
 * | T4 | D1 ｜**准入策略与 server.ts 等价** | 读 `server.ts` 源码核对两处闸门与 `isAllowedDialer` **同策略**（⛔ 防"两处写分叉"） |
 * | T5 | D5 ｜打洞成功路径 | NAT 模拟器 ＋ 真 `dgram` ⇒ 双向成立（`punchOk ≥ 1`） |
 * | T6 | D5 ｜**单向不算直连** | 一个方向成立 ⇒ 判死 `one-way`（⛔ 不许把单向当成功） |
 * | T7 | D6 ｜失败判死有界 | 对端不响应 ⇒ 窗内判死，且耗时**有界**（⛔ 不无限重试） |
 * | T8 | D6 ｜冷却 | 判死后二次尝试被挡（**且不开 socket**）；`ms = 0` ⇒ **构造即抛** |
 * | T9 | D3/D4 ｜join 回读 ＋ 提示 | 本机配置读回 `direct = true`；`--direct 0` 被尊重 |
 * | T10 | D4 ｜提示可行动 | 三段齐（谁可能连 / 怎么关 / 关掉影响什么），且**含开关键与关值** |
 */

import assert from 'node:assert/strict'
import { existsSync, mkdirSync, mkdtempSync, readFileSync, renameSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { fileURLToPath } from 'node:url'
import { randomBytes } from 'node:crypto'
import { test } from 'node:test'
import { createSocket } from 'node:dgram'

import { signPayloadWith } from '../lib/net/relay/identity.js'
import {
  CandidateLedger,
  DEFAULT_DIRECT_COOLDOWN_MS,
  DEFAULT_DIRECT_ENABLED,
  DIRECT_CAND_MAX_ADDRS,
  DIRECT_ENV_KEY,
  DIRECT_OFF_VALUES,
  DirectCooldown,
  DirectPath,
  NODES_REGISTRY_VERSION,
  PUNCH_PORT_BASE,
  PUNCH_PORT_SPAN,
  directFromNodeConfig,
  directHintLines,
  directHintText,
  encodeDirectMessage,
  generateAuthorityKey,
  generateNodeKey,
  isAllowedDialer,
  isValidAddress,
  networkInvitePayload,
  newInviteNonce,
  nodeJoinIo,
  normalizeDialers,
  publicKeyOfPrivate,
  readNodeConfig,
  resolveDirectSwitch,
  runJoin,
  runPunchAttempt,
  runPunchPair,
  writeNodeConfigDirect,
} from '../lib/net/relay/index.js'

const sleep = (ms) => new Promise((r) => setTimeout(r, ms))
const root = fileURLToPath(new URL('..', import.meta.url))
const ssPath = join(root, 'src', 'net', 'relay', 'network.ts')
const serverPath = join(root, 'src', 'net', 'relay', 'server.ts')

/** 真·白名单（**走既有归一化实现** ⇒ 量的是"同一份策略"的行为）。 */
const dialers = () =>
  normalizeDialers(
    new Map([
      ['ops', new Set(['manager', 'w-2'])],
      ['u:5', new Set(['w-2'])],
    ]),
  )

/** 找一个没人监听的本地 UDP 端口（用于产出 `deadline` 负腿）。 */
async function deadPort() {
  const s = createSocket('udp4')
  await new Promise((r) => s.bind({ port: 0, address: '127.0.0.1' }, r))
  const p = s.address().port
  await new Promise((r) => s.close(r))
  return p
}

const candidate = (over = {}) =>
  encodeDirectMessage({
    hostId: 'w-2',
    network: 'ops',
    addrs: [{ host: '10.0.0.9', port: PUNCH_PORT_BASE + 1 }],
    ts: Date.now(),
    ...over,
  })

// ── T1 · 开关解析 ────────────────────────────────────────────────────────────────
test('T1 开关：缺省=开｜开集/关集｜非法值 ⇒ null（⛔ 不静默取缺省）｜本机配置次之', () => {
  const d = resolveDirectSwitch({})
  assert.equal(d.enabled, true, '缺省必须 = 开（用户口径②）')
  assert.equal(d.source, 'default')
  assert.equal(DEFAULT_DIRECT_ENABLED, true)

  for (const v of ['1', 'true', 'ON', 'Yes']) {
    const s = resolveDirectSwitch({ [DIRECT_ENV_KEY]: v })
    assert.equal(s.enabled, true, `${v} 应判开`)
    assert.equal(s.source, 'env')
  }
  for (const v of DIRECT_OFF_VALUES) {
    const s = resolveDirectSwitch({ [DIRECT_ENV_KEY]: v.toUpperCase() })
    assert.equal(s.enabled, false, `${v} 应判关`)
  }
  // 🔴 非法值：**既不许当开也不许当关**
  const bad = resolveDirectSwitch({ [DIRECT_ENV_KEY]: 'maybe' })
  assert.equal(bad.enabled, null)
  assert.match(bad.invalid, /不静默取缺省/)
  // 本机配置（用户设置）在 env 缺省时生效；env 显式设了就压过它
  assert.equal(resolveDirectSwitch({}, { localDirect: false }).enabled, false)
  assert.equal(resolveDirectSwitch({}, { localDirect: false }).source, 'node-config')
  assert.equal(resolveDirectSwitch({ [DIRECT_ENV_KEY]: '1' }, { localDirect: false }).enabled, true)
  // 空串 = 未设（⛔ 不算非法值）
  assert.equal(resolveDirectSwitch({ [DIRECT_ENV_KEY]: '   ' }).enabled, true)
})

// ── T2 · 关闭 ⇒ 零 socket / 零候选 ──────────────────────────────────────────────
test('T2 关闭 ⇒ 零 UDP socket ＋ 零候选；开启才真的开', async () => {
  const ctxOf = { dialers: dialers(), from: { network: 'ops', hostId: 'w-2' }, selfHostId: 'manager' }
  const off = new DirectPath({ switchState: resolveDirectSwitch({ [DIRECT_ENV_KEY]: 'false' }), deadlineMs: 300 })
  const v = off.offerCandidate(candidate(), ctxOf)
  assert.equal(v.ok, false)
  assert.equal(v.reason, 'disabled')
  const a = await off.attempt('ops/void', [{ host: '127.0.0.1', port: await deadPort() }], { sleep })
  assert.equal(a.reason, 'disabled')
  const st = off.status()
  assert.equal(st.counters.udpSocketsOpened, 0, '关闭 ⇒ ⛔ 一个 UDP socket 都不许开')
  assert.equal(st.counters.candidatesEmitted, 0, '关闭 ⇒ ⛔ 一条候选都不许发')

  // 非法开关值同样**两种动作都不做**（避免"取值写错 ⇒ 静默当成开"）
  const bad = new DirectPath({ switchState: resolveDirectSwitch({ [DIRECT_ENV_KEY]: 'maybe' }), deadlineMs: 300 })
  assert.equal(bad.offerCandidate(candidate(), ctxOf).reason, 'invalid-switch')
  assert.equal((await bad.attempt('ops/void', [{ host: '127.0.0.1', port: await deadPort() }], { sleep })).reason, 'invalid-switch')
  assert.equal(bad.status().counters.udpSocketsOpened, 0)

  const on = new DirectPath({ switchState: resolveDirectSwitch({ [DIRECT_ENV_KEY]: 'true' }), deadlineMs: 300 })
  assert.equal(on.offerCandidate(candidate(), ctxOf).ok, true)
  await on.attempt('ops/void', [{ host: '127.0.0.1', port: await deadPort() }], { sleep })
  assert.equal(on.status().counters.udpSocketsOpened, 1, '开启 ⇒ 真的绑了 1 个 UDP socket')
  assert.equal(on.status().counters.candidatesEmitted, 1)
})

// ── T3 · 候选准入矩阵 ───────────────────────────────────────────────────────────
test('T3 候选准入：同网＋白名单内接受；其余**逐类具名**拒绝；静默拒绝 = 0', () => {
  const led = new CandidateLedger()
  const inOps = { dialers: dialers(), from: { network: 'ops', hostId: 'w-2' }, selfHostId: 'manager' }
  const expectOk = (raw, ctx = inOps) => {
    const v = led.judge(raw, ctx)
    assert.equal(v.ok, true, `应接受：${v.ok ? '' : v.reason} ${v.ok ? '' : v.detail}`)
  }
  const expectReject = (raw, reason, ctx = inOps) => {
    const v = led.judge(raw, ctx)
    assert.equal(v.ok, false)
    assert.equal(v.reason, reason)
    assert.ok(typeof v.detail === 'string' && v.detail !== '', '拒绝必须带人读原因（⛔ 不许只回 false）')
  }

  expectOk(candidate())
  expectOk(candidate({ addrs: [{ host: '10.0.0.9', port: PUNCH_PORT_BASE + 1 }, { host: '2001:db8::1', port: PUNCH_PORT_BASE + 2 }] }))
  // 同名跨网**互不可见**：同一 hostId 在另一张网里是合法身份
  expectOk(candidate({ network: 'u:5' }), { dialers: dialers(), from: { network: 'u:5', hostId: 'w-2' }, selfHostId: 'w-2' })

  expectReject(candidate({ network: 'u:5' }), 'cross-network')
  expectReject(candidate({ hostId: 'w-999' }), 'not-self-candidate')
  expectReject(candidate(), 'not-a-dialer', { ...inOps, dialers: normalizeDialers(new Map([['ops', new Set(['manager'])]])) })
  expectReject(candidate(), 'self-not-a-dialer', { ...inOps, selfHostId: 'w-nobody' })
  expectReject('{"kind":"DIRECT_CANDIDATE"}', 'bad-shape')
  expectReject('not json at all', 'bad-shape')
  expectReject(
    JSON.stringify({ kind: 'DIRECT_CANDIDATE', hostId: 'w-2', network: 'ops', addrs: [{ host: '10.0.0.9', port: PUNCH_PORT_BASE + 1 }], nodeKey: 'deadbeef' }),
    'secret-field',
  )
  expectReject(candidate({ addrs: [{ host: 'example.com', port: 80 }] }), 'bad-address')
  expectReject(candidate({ addrs: [{ host: '10.0.0.9', port: 0 }] }), 'bad-address')
  expectReject(
    candidate({ addrs: Array.from({ length: DIRECT_CAND_MAX_ADDRS + 1 }, (_, i) => ({ host: '10.0.0.9', port: PUNCH_PORT_BASE + i })) }),
    'too-many-addrs',
  )
  expectReject(candidate({ ts: Date.now() - 10 * 60_000 }), 'stale')

  const snap = led.snapshot()
  assert.equal(snap.accepted, 3)
  assert.equal(snap.rejected.length, 11, '负腿 11 条：跨网/替第三人/白名单外/本机不在白名单/坏形状×2/凭据字段/坏地址×2/超限/过期')
  assert.equal(snap.silentRejections, 0, '静默拒绝必须为 0（本线老病根的不变量守卫）')
  assert.equal(snap.received, 14)
  // 每一条拒绝**都有具名原因**
  for (const r of snap.rejected) assert.ok(typeof r.reason === 'string' && r.reason !== '')
  // 白名单是**按网络分桶**的：拿 ops 的桶查 u:5 的同名 hostId 必须为假
  assert.equal(isAllowedDialer(dialers(), 'ops', 'w-2'), true)
  assert.equal(isAllowedDialer(dialers(), 'u:5', 'w-2'), true)
  assert.equal(isAllowedDialer(dialers(), 'u:7', 'w-2'), false)
  assert.equal(isAllowedDialer(dialers(), 'ops', 'w-999'), false)
  // 地址形状：IPv4/IPv6 收，主机名不收
  assert.equal(isValidAddress({ host: '10.0.0.9', port: 21100 }), true)
  assert.equal(isValidAddress({ host: '1.2.3', port: 21100 }), false)
  assert.equal(isValidAddress({ host: '256.1.1.1', port: 21100 }), false)
  assert.equal(isValidAddress({ host: 'a.b.c', port: 21100 }), false)
})

// ── T4 · 准入策略与 server.ts 的等价性（机器守卫） ──────────────────────────────
test('T4 准入策略**复用** server.ts 的那一条（⛔ 防两处写分叉）', () => {
  const netSrc = readFileSync(ssPath, 'utf8')
  const srvSrc = readFileSync(serverPath, 'utf8')

  // ① 唯一出口确实在 network.ts 里，且语义就是"该网桶里有没有这个 hostId"
  assert.match(netSrc, /export function isAllowedDialer\(/)
  assert.match(netSrc, /return map\.get\(network\)\?\.has\(hostId\) === true/)

  // ② server.ts 的两处闸门与它**同策略**（同 map 、同 `=== true` 默认拒绝）
  const registerGate = srvSrc.includes('const wantDialer = this.dialers.get(network)?.has(hostId) === true')
  const dialGate = srvSrc.includes('if (this.dialers.get(session.network)?.has(session.hostId) !== true) {')
  assert.ok(registerGate, '注册闸门（server.ts）应仍是 dialers.get(network)?.has(hostId) === true（⛔ 本棒不许改它的语义）')
  assert.ok(dialGate, 'DIAL 闸门（server.ts）应仍是 dialers.get(session.network)?.has(session.hostId) !== true')

  // ③ 直连模块**不许**自己再判一遍（⛔ 防"同一事实两处写"）
  for (const f of ['direct/candidate.ts', 'direct/index.ts', 'direct/punch.ts']) {
    const src = readFileSync(join(root, 'src', 'net', 'relay', f), 'utf8')
    assert.ok(!/dialers\.get\(/.test(src), `${f} 里出现了 dialers.get( ⇒ 疑似把白名单判定抄了一份`)
    assert.ok(!/\.has\(hostId\)/.test(src), `${f} 里出现了 .has(hostId) ⇒ 疑似把白名单判定抄了一份`)
  }

  // ④ 等价性：默认拒绝（空桶 / 未列网络 / 名字错）—— 与 server.ts 同为"默认拒绝"
  assert.equal(isAllowedDialer(new Map(), 'ops', 'manager'), false)
  assert.equal(isAllowedDialer(dialers(), 'ops', 'MANAGER'), false, 'hostId 大小写敏感（与 HOST_RE 口径一致）')
})

// ── T5 · 打洞成功路径（真 dgram ＋ NAT 模拟） ────────────────────────────────────
test('T5 打洞成功路径：双向都成立才算直连（punchOk ≥ 1）', async () => {
  const r = await runPunchPair({ aPeer: 'ops/w-1', bPeer: 'ops/w-2', deadlineMs: 2500 }, { sleep })
  assert.equal(r.a.bidirectional, true, `A 侧应双向成立：${r.a.detail}`)
  assert.equal(r.b.bidirectional, true, `B 侧应双向成立：${r.b.detail}`)
  assert.equal(r.a.reason, 'ok')
  assert.equal(r.b.reason, 'ok')
  assert.equal(r.bidirectional, true)
  assert.ok(r.a.recvLocal > 0 && r.b.recvLocal > 0, '两侧都必须真的收到包')
  assert.equal(r.nat.a.forwardedIn > 0, true, 'NAT 侧记录：真的放行了入向包')
})

// ── T6 · 单向不算直连 ───────────────────────────────────────────────────────────
test('T6 单向 ⇒ 判死 one-way（⛔ 不许把单向当成功）', async () => {
  const r = await runPunchPair({ aPeer: 'ops/w-1', bPeer: 'ops/w-2', deadlineMs: 1200, oneWay: 'a' }, { sleep })
  assert.equal(r.bidirectional, false)
  assert.equal(r.a.reason, 'one-way', `A 侧（只能出不能进）应判 one-way：${r.a.detail}`)
  assert.equal(r.a.bidirectional, false)
  assert.equal(r.b.reason, 'one-way', `B 侧（收到包但对端没收到）应判 one-way：${r.b.detail}`)
  assert.equal(r.b.recvLocal > 0, true, 'B 的确收到了包 ⇒ 不能因为"有收包"就判成功')
  assert.equal(r.b.peerSeen, false)
})

// ── T7 · 失败判死有界 ───────────────────────────────────────────────────────────
test('T7 对端不响应 ⇒ 窗内判死，且耗时**有界**（⛔ 不无限重试）', async () => {
  const cd = new DirectCooldown(DEFAULT_DIRECT_COOLDOWN_MS)
  const deadlineMs = 600
  const r = await runPunchAttempt(
    {
      peer: 'ops/void',
      selfPort: 0,
      targets: [{ host: '127.0.0.1', port: await deadPort() }],
      deadlineMs,
      cooldown: cd,
      bindHost: '127.0.0.1',
    },
    { sleep },
  )
  assert.equal(r.reason, 'deadline')
  assert.equal(r.ok, false)
  assert.equal(r.recvLocal, 0)
  assert.ok(r.sent > 1, '窗内应重发（单发一次赶不上对端同时发包）')
  assert.ok(r.elapsedMs <= deadlineMs + 3 * 150, `耗时必须有界：${r.elapsedMs} ms`)
  assert.equal(cd.snapshot().cooling.includes('ops/void'), true, '判死 ⇒ 该候选进冷却')
  // 没有候选 ⇒ **不是**打洞失败 ⇒ ⛔ 不进冷却
  const cd2 = new DirectCooldown(DEFAULT_DIRECT_COOLDOWN_MS)
  const r2 = await runPunchAttempt({ peer: 'ops/none', selfPort: 0, targets: [], cooldown: cd2 }, { sleep })
  assert.equal(r2.reason, 'no-address')
  assert.equal(cd2.snapshot().cooling.length, 0)
})

// ── T8 · 冷却 ──────────────────────────────────────────────────────────────────
test('T8 冷却：判死后二次被挡且**不开 socket**；`ms = 0` 构造即抛', async () => {
  const cd = new DirectCooldown(5_000)
  let opened = 0
  const port = await deadPort()
  const mk = (targets) =>
    runPunchAttempt(
      {
        peer: 'ops/void',
        selfPort: 0,
        targets,
        deadlineMs: 300,
        cooldown: cd,
        bindHost: '127.0.0.1',
        onSocketOpen: () => {
          opened += 1
        },
      },
      { sleep },
    )
  const first = await mk([{ host: '127.0.0.1', port }])
  assert.equal(first.reason, 'deadline')
  assert.equal(opened, 1)
  const second = await mk([{ host: '127.0.0.1', port }])
  assert.equal(second.reason, 'cooldown')
  assert.equal(opened, 1, '冷却命中的路径**一个 socket 都不许开**')
  assert.ok(cd.snapshot().blocked >= 1)
  // 🔴 0 = 重试风暴 ⇒ 构造期就炸（本线硬禁令）
  assert.throws(() => new DirectCooldown(0), /必须 > 0/)
  assert.throws(() => new DirectCooldown(-1), /必须 > 0/)
  assert.throws(() => new DirectCooldown(Number.NaN), /必须 > 0/)
})

// ── T9/T10 · join 回读 ＋ 提示 ─────────────────────────────────────────────────
test('T9 join 本机配置读回 direct = true，且 --direct 0 被尊重', async () => {
  const tmp = mkdtempSync(join(tmpdir(), 'dshs-direct-t9-'))
  const signer = generateAuthorityKey()
  const issue = () => {
    const doc = {
      version: NODES_REGISTRY_VERSION,
      network: 't9-net',
      nonce: newInviteNonce(randomBytes),
      issuedAt: new Date().toISOString(),
      expiresAt: new Date(Date.now() + 60_000).toISOString(),
    }
    return { doc, sig: signPayloadWith(signer.privateKeyPem, networkInvitePayload(doc)) }
  }
  const io = nodeJoinIo({
    fss: { existsSync, readFileSync, writeFileSync, mkdirSync },
    crypto: { generateNodeKey: () => generateNodeKey(), publicKeyOfPrivate: (pem) => publicKeyOfPrivate(pem) },
    os: { hostname: () => 't9-host' },
    fetchImpl: async () => ({ status: 599, body: 'n/a' }),
  })
  const run = (name, extra) =>
    runJoin(
      {
        network: 't9-net',
        hostId: name,
        invite: issue(),
        trustedSigners: [signer.publicKey],
        nodeKeyFile: join(tmp, `${name}.key`),
        localConfigFile: join(tmp, `${name}.json`),
        outFile: join(tmp, `${name}-app.json`),
        ...extra,
      },
      io,
    )
  const a = await run('node-a', {})
  assert.equal(a.ok, true)
  const cfgA = JSON.parse(readFileSync(join(tmp, 'node-a.json'), 'utf8'))
  assert.equal(cfgA.direct, true, '缺省必须写进本机配置 = 开（用户口径②）')
  assert.equal(directFromNodeConfig(cfgA), true)
  assert.match(a.steps.find((s) => s.step === 'local-config').detail, /直连\(打洞\)=开/)

  const b = await run('node-b', { direct: false })
  assert.equal(b.ok, true)
  assert.equal(directFromNodeConfig(JSON.parse(readFileSync(join(tmp, 'node-b.json'), 'utf8'))), false)

  // 管理面写回：**只改 direct 一个字段**，其余原样；缺失文件 ⇒ 具名失败（⛔ 不凭空创建）
  const file = join(tmp, 'node-a.json')
  const before = JSON.parse(readFileSync(file, 'utf8'))
  const writer = {
    exists: existsSync,
    read: (p) => readFileSync(p, 'utf8'),
    write: (p, t, mode) => writeFileSync(p, t, { mode }),
    rename: renameSync,
  }
  const w = writeNodeConfigDirect(file, false, writer)
  assert.equal(w.ok, true)
  const after = JSON.parse(readFileSync(file, 'utf8'))
  assert.equal(after.direct, false)
  assert.deepEqual({ ...after, direct: true }, before, '⛔ 除 direct 外任何字段都不许被动到')
  const miss = writeNodeConfigDirect(join(tmp, 'nope.json'), true, writer)
  assert.equal(miss.ok, false)
  assert.equal(miss.reason, 'node-config-missing')
  // 形状坏 ⇒ 具名
  writeFileSync(join(tmp, 'bad.json'), '[1,2,3]')
  assert.throws(() => readNodeConfig(join(tmp, 'bad.json'), { exists: () => true, read: (p) => readFileSync(p, 'utf8') }), /不是 JSON 对象/)
})

test('T10 提示文案必须**可行动**：三段齐 ＋ 含开关键与关值', () => {
  const lines = directHintLines()
  assert.equal(lines.length, 3)
  const text = directHintText()
  assert.ok(text.includes('同一张覆盖网') && text.includes('白名单'), '①段要写清"谁可能连进来"')
  assert.ok(text.includes(DIRECT_ENV_KEY), '②段要写清"怎么关"（含开关键名）')
  assert.ok(DIRECT_OFF_VALUES.some((v) => text.includes(v)), '②段要给出具体的关闭取值')
  assert.ok(text.includes('不影响'), '③段要写清"关掉不影响什么"')
  assert.ok(text.includes('中继'), '③段要写清回落路径')
  // ⛔ 禁止只写"已启用直连"
  assert.ok(!/^已启用直连$/.test(text.trim()))
  // 编码侧的结构性防线：**只吃白名单字段** ⇒ 多给的任何字段（含凭据）都进不了载荷
  const encoded = JSON.parse(encodeDirectMessage({ hostId: 'w-2', network: 'ops', addrs: [{ host: '10.0.0.9', port: 1 }], secret: 'x' }))
  assert.deepEqual(Object.keys(encoded).sort(), ['addrs', 'hostId', 'kind', 'network', 'ts'])
  assert.equal(encoded.secret, undefined, '⛔ 载荷里不可能夹带凭据字段（构造侧结构性排除）')
})