/**
 * hunt-room.js — 《围猎》(web/hunt) 房间管理器 + 服务端权威战斗模拟（零依赖，CommonJS）。
 *
 * 设计契约：docs/design/23-hunt.md §3/§5/§6/§7（协议字段以 §6 为唯一契约）。
 * 职责（§6.4-§6.6、§7 的权威实现）：
 * - 房间：快速匹配 / 显式 4 位房码、lobby ≤12s（act start / 满 4 人立即开局）、
 *   开局 bot 补位至 max(3, 人类数)、断线 30s 宽限 resume 回槽、超时转 bot
 *   （剩余人类 ≥3 改为槽位移除）、房灭回收、终局保留 30s 后 close 1000。
 * - 战斗：波次表（§3.4）刷怪剧本（§3.5 seed 复现）、100ms tick 推进 eta、突入扣耐久
 *   （狼 -1 / 熊 -2）、出击弧 ±45° + eta≤4 近战窗、冷却 2.5s / 旋风斩 8s / 呼喊节流 5s、
 *   评级结算（§3.6，ev end.grade 服务端直发）。教学房（§5）：强制单人、教学波 3 狼
 *   零惩罚（突入不扣耐久）、教学段 bot AI 挂起（呼喊必答）、教学波完接续第 1 波。
 * - bot（§7）：与真人同一套裁决管线；500ms AI tick：P(d)=Σ(1/eta) 方向压力 +
 *   主防区 ×1.5 偏置 + 反应带（eta ≤ 2.2+rng×1.2，rng 走房间 seed）；旋风斩
 *   （全场 eta≤3 ≥3）；压力呼救（主防区 eta≤6 ≥3，20s 节流）；补位（§7.3）与
 *   喊话调度（§7.4：全局 10s 窗氛围 ≤2 条，callout/help_ack 优先不丢）。
 *
 * 时钟模型：房间一切时间逻辑由 tick(dtMs) 推进——生产环境 server.js 以 100ms
 * setInterval 驱动；测试直接快进 tick 复现（test/hunt-sim.test.mjs）。
 * 消息 ts = 房间单调时钟 ms（开局为 0，§6.3）；内部一律用 now（建房起单调 ms）。
 *
 * 连接契约（与 ws.js 的 WsConn 对齐，测试用 FakeConn 替身）：
 *   conn: EventEmitter，'message'(jsonString) / 'close'()；方法 send(str, {droppable}) 、
 *   close(code)；管理器在 attach 时挂上 joinedRoom/slotId/限流状态。
 */
'use strict';

const crypto = require('node:crypto');

// ---------------- 常量（§3 数值的权威实现） ----------------

const DIRS = ['N', 'NE', 'E', 'SE', 'S', 'SW', 'W', 'NW'];
const DIR_IDX = Object.fromEntries(DIRS.map((d, i) => [d, i]));
const CHARS = ['yan', 'zheng', 'zhou', null]; // 座位角色（§3.3；座 3 恒 null，呼喊用哨音）
const CHAR_NAMES = { yan: '阿岩', zheng: '小筝', zhou: '老周' };
// §3.3 防区表（center 供客户端取呼喊/喊话 pan 方位）
const LAYOUTS = {
  3: [
    { sector: ['N', 'NE', 'E'], center: 'NE' },
    { sector: ['SE', 'S', 'SW'], center: 'S' },
    { sector: ['W', 'NW'], center: 'WNW' },
  ],
  4: [
    { sector: ['N', 'NE'], center: 'NNE' },
    { sector: ['E', 'SE'], center: 'ESE' },
    { sector: ['S', 'SW'], center: 'SSW' },
    { sector: ['W', 'NW'], center: 'WNW' },
  ],
};
// §3.4 波次表
const WAVE_TABLE = [
  null,
  { wolf: 4, bear: 0, wolfEta: 10.0, bearEta: 0, gap: 3.0 },
  { wolf: 6, bear: 0, wolfEta: 9.5, bearEta: 0, gap: 2.5 },
  { wolf: 7, bear: 1, wolfEta: 9.0, bearEta: 12.0, gap: 2.2 },
  { wolf: 8, bear: 1, wolfEta: 8.5, bearEta: 11.5, gap: 1.8 },
  { wolf: 10, bear: 2, wolfEta: 8.0, bearEta: 11.0, gap: 1.5 },
];
const LAST_WAVE = 5;
const DUR_MAX = 10;
const MELEE_ETA = 4.0; // 内圈近战窗（§3.1）
const ATTACK_CD_MS = 2500;
const SKILL_CD_MS = 8000;
const CALLOUT_THROTTLE_MS = 5000;
const LOBBY_MS = 12000;
const GRACE_MS = 30000;
const END_KEEP_MS = 30000;
const REST_MS = 8000; // 波间休整
const WAVE1_DELAY_MS = 2000; // 开局到 ev wave 1 的间隔（room_start 播报留白）
const TICK_MS = 100;
const BOT_TICK_MS = 500;
const SNAP_MS = 500; // 2Hz
const ROOM_CODE_CHARS = '23456789ABCDEFGHJKMNPQRSTUVWXYZ'; // §6.2 无歧义字符集
const BOTLINE_WINDOW_MS = 10000; // §7.4 全局节流窗口
const BOTLINE_BUDGET = 3; // 窗口内氛围句上限（v2 S5① 真人座位角色接线后 2→3；help_* 恒优先）
const GREET_FIRST_MS = 1000;
const GREET_GAP_MS = 1600; // ≥1.5s（§7.4 greet 间隔）
const COVER_MS = 10000; // §7.3 补位偏置持续 10s
const RATE_PER_SEC = 20; // §6.1 应用消息速率帽
const RATE_STRIKE_MS = 10000; // 再犯判定窗
const SECTOR_YIELD_MS = 2000; // v2 S7③：bot 对人类防区怪的让位窗
const CALLOUT_ACK_DELAY_MS = 2500; // v2 S5②：无 bot 应答时邻座角色代答延迟

// §7.2 bot 难度校准（§15 裁决 10 调参；初版 2.2+1.2r 无犹豫实测零泄漏过强）：
// 反应带更迟、出手决策带空转概率（500ms tick 内愣神）、旋风斩节制。
// 目标口径见 §3.4：挂机局失守/C、3 bot 水准局 A/B。默认值经
// test/hunt-balance-scan.mjs 多种子扫描选定；改动只涉及服务端 AI 参数，不动协议字段。
const BOT_TUNING_DEFAULT = {
  reactBase: 2.0,   // 反应带：eta ≤ reactBase + rng×reactSpan 才出手
  reactSpan: 1.0,
  hesitateP: 0.8,   // 决策空转概率（500ms tick 内 80% 愣神——bot 有效出手周期 ~4.5s）
  skillEta: 2.5,    // 旋风斩触发：全场 eta≤skillEta 的怪 ≥skillMin 且 60% 想起
  skillMin: 3,
  skillP: 0.6,
};

// ---------------- 确定性随机（§3.5/§7.2） ----------------

function mulberry32(a) {
  return function () {
    a |= 0; a = (a + 0x6D2B79F5) | 0;
    let t = Math.imul(a ^ (a >>> 15), 1 | a);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

/** §3.5：rng(wave) = mulberry32((seed ^ (wave * 0x9E3779B9)) >>> 0) */
function waveRng(seed, wave) {
  return mulberry32((seed ^ (wave * 0x9E3779B9)) >>> 0);
}

/**
 * §3.5 刷怪剧本：同 seed → 同剧本（可复现断言）。
 * 怪物按座位数轮转发牌到各座位防区内的随机方位；熊确定性洗牌混入。
 * 返回 [{ at, mkind, dir, seat, eta }]（at = 波开始后的 ms；首只 = 1×gap）。
 */
function buildWaveScript(seed, wave, seatCount) {
  const spec = WAVE_TABLE[wave];
  const counts = waveCounts(spec, seatCount);
  const rng = waveRng(seed, wave);
  const layout = LAYOUTS[seatCount];
  const mkinds = [];
  for (let i = 0; i < counts.wolf; i++) mkinds.push('wolf');
  for (let i = 0; i < counts.bear; i++) mkinds.push('bear');
  for (let i = mkinds.length - 1; i > 0; i--) { // Fisher-Yates，走波次 rng
    const j = Math.floor(rng() * (i + 1));
    [mkinds[i], mkinds[j]] = [mkinds[j], mkinds[i]];
  }
  return mkinds.map((mkind, i) => {
    const seat = i % seatCount;
    const sector = layout[seat].sector;
    const dir = sector[Math.floor(rng() * sector.length)];
    return {
      at: (i + 1) * spec.gap * 1000,
      mkind,
      dir,
      seat,
      eta: mkind === 'bear' ? spec.bearEta : spec.wolfEta,
    };
  });
}

/**
 * 波次量按座位缩放（v2 修复 S7①：3 人房维持原值；4 人房 ×4/3——
 * 6 局真人快速局全部零损耗满血 S 的根因之一是吞吐冗余，见 research/hunt-sim/analysis/01）。
 */
function waveCounts(spec, seatCount) {
  const f = seatCount / 3;
  return {
    wolf: Math.round(spec.wolf * f),
    bear: spec.bear ? Math.max(1, Math.round(spec.bear * f)) : 0,
  };
}

/**
 * 齐压拍（v2 修复 S7②）：第 3-5 波把既有剧本里 1-2 组「不同座位」的怪
 * 重定时到同一毫秒进内圈（数量不变、种子确定性）。单人 2.5s 出击冷却在
 * 齐压拍数学上必漏 → 呼喊/分工/旋风斩分配第一次成为唯一解。
 * 纯函数：不动 buildWaveScript（A2 单测口径）。
 */
function alignPincers(script, seed, wave) {
  if (wave < 3) return script;
  const rng = waveRng((seed ^ 0x91CE) >>> 0, wave);
  const groups = wave === 3 ? 1 : 2;
  const used = new Set();
  for (let g = 0; g < groups; g++) {
    const avail = script.map((e, i) => ({ e, i }))
      .filter(({ e, i }) => !used.has(i));
    // 找一对不同座位、同种类的条目（齐压必须跨防区才有强制分工意义；
    // 同种类保证 eta 原值不动——狼仍是狼速，只是同秒抵达）
    let pair = null;
    for (let a = 0; a < avail.length && !pair; a++) {
      for (let b = avail.length - 1; b > a && !pair; b--) {
        if (avail[a].e.seat !== avail[b].e.seat && avail[a].e.mkind === avail[b].e.mkind) {
          pair = [avail[a], avail[b]];
        }
      }
    }
    if (!pair) break;
    // 对齐到较晚时刻（同秒进内圈），加 ≤300ms 微差防叠声
    const late = Math.max(pair[0].e.at, pair[1].e.at);
    pair[0].e.at = late;
    pair[1].e.at = late + Math.floor(rng() * 300);
    used.add(pair[0].i);
    used.add(pair[1].i);
  }
  return script.sort((a, b) => a.at - b.at);
}

/**
 * 评级（v2 修复 S7④ 双轴）：S = 耐久≥9 且 至少两名猎人均有 ≥6 个人击杀
 * （零损耗 + 打了配合的房间才是 S；「1 高手带飞局」上限 A）。
 * gradeFor 保留原单轴口径供兼容引用。
 */
function gradeForEx(dur, killsBySlot) {
  if (dur >= 9) {
    const contributors = Object.values(killsBySlot || {}).filter((k) => k >= 6).length;
    if (contributors >= 2) return 'S';
    return 'A';
  }
  return gradeFor(dur);
}

/** §3.6 评级（服务端直发，客户端不算分） */
function gradeFor(dur) {
  if (dur >= 9) return 'S';
  if (dur >= 7) return 'A';
  if (dur >= 4) return 'B';
  if (dur >= 1) return 'C';
  return null;
}

function round2(x) {
  return Math.round(x * 100) / 100;
}

function arcOf(dir) { // 出击弧 = dir±45°（3 个罗盘向，§3.2）
  const c = DIR_IDX[dir];
  return [(c + 7) % 8, c, (c + 1) % 8];
}

// ---------------- 房间 ----------------

class Room {
  constructor(manager, { code, teach = false, seed } = {}) {
    this.manager = manager;
    this.code = code;
    this.teach = !!teach;
    this.seed = (seed === undefined ? crypto.randomInt(0, 2 ** 32) : seed) >>> 0;
    this.phase = 'lobby'; // lobby / teach / wave / end
    this.now = 0; // 建房起单调 ms（tick 推进）
    this.startedAt = null; // 开局时刻（now 基准）；ts = now - startedAt
    this.slots = [null, null, null, null];
    this.seatCount = 0; // 开局定（3 或 4，§3.3）
    this.mobs = new Map(); // id -> { id, mkind, dir, eta, breached? }
    this.nextMobId = 1;
    this.wave = 0;
    this.dur = DUR_MAX;
    this.killsBySlot = {}; // 结算个人击杀账（含已离场槽位）
    this.script = null; // 当前波剧本（atTs 绝对 ts）
    this.scriptIdx = 0;
    this.pendingWave = null; // { wave, atTs } 波间休整/开局延迟
    this.teachState = null;
    this.botRng = mulberry32((this.seed ^ 0xB07A17) >>> 0); // bot 反应带流（§7.2 复现用）
    this.botTuning = manager.botTuning; // §15 裁决 10 调参（默认 BOT_TUNING_DEFAULT）
    this.lineLog = []; // 喊话/callout 发出时刻（§7.4 全局节流）
    this.pendingLines = []; // [{ at, slot, line }]（greet 间隔调度，at 为 ts）
    this.waveLineIdx = 0;
    this.lastBotAt = -Infinity;
    this.lastSnapAt = -Infinity;
    this.endAt = null;
    this.destroyed = false;
  }

  ts() { return this.startedAt === null ? 0 : this.now - this.startedAt; }
  occupiedSlots() { return this.slots.filter(Boolean); }
  humanCount() { return this.slots.filter((s) => s && !s.bot).length; }
  botSlots() { return this.slots.filter((s) => s && s.bot); }

  // ---------------- 槽位 ----------------

  _newSlot(slotId, { bot, conn, name }) {
    const provisional = slotId <= 2 ? LAYOUTS[3][slotId] : LAYOUTS[4][3];
    return {
      slot: slotId,
      name,
      bot,
      char: CHARS[slotId],
      sector: provisional.sector.slice(), // 开局时按最终布局重排（roster ev 下发）
      center: provisional.center,
      conn: conn || null,
      alive: true, // bot 恒 true；人类=连接存活
      resume: bot ? null : crypto.randomBytes(8).toString('hex'), // 16 hex，槽位存活期不变
      cdUntil: 0,
      skillCdUntil: 0,
      calloutUntil: 0,
      lastSeq: -1,
      graceUntil: 0,
      kills: 0,
      // bot 状态（§7）
      lastActAt: -Infinity,
      lastCalloutAt: -Infinity,
      lastKillLineAt: -Infinity,
      lastBreachLineAt: -Infinity,
      recentKills: [],
      cover: null, // { callerSlot, callerSector, until, killDone, settled }
    };
  }

  addHuman(slotId, conn, name) {
    const slot = this._newSlot(slotId, { bot: false, conn, name });
    this.slots[slotId] = slot;
    return slot;
  }

  addBot(slotId) {
    const char = CHARS[slotId];
    const slot = this._newSlot(slotId, { bot: true, name: CHAR_NAMES[char] || '老猎手' });
    this.slots[slotId] = slot;
    return slot;
  }

  removeSlot(slot) {
    this.slots[slot.slot] = null;
    if (slot.resume) this.manager.resumeIndex.delete(slot.resume);
    this.broadcastRoster();
  }

  /** §6.6 宽限超时/主动 leave 的槽位转 bot（不可逆）；char 沿用座角色，播 cover。 */
  convertToBot(slot) {
    if (slot.resume) this.manager.resumeIndex.delete(slot.resume);
    slot.resume = null;
    slot.bot = true;
    slot.conn = null;
    slot.alive = true;
    slot.name = CHAR_NAMES[slot.char] || '老猎手';
    slot.lastActAt = -Infinity;
    slot.lastCalloutAt = -Infinity;
    slot.cover = null;
    // 冷却不清零：真人用过的冷却延续到 bot（§7.3 公平口径）
    this.broadcastRoster();
    this.tryBotline(slot, 'cover'); // 转 bot 接管（§7.4 cover 触发源）
  }

  // ---------------- 消息发送 ----------------

  roster() {
    return this.occupiedSlots()
      .sort((a, b) => a.slot - b.slot)
      .map((s) => ({
        slot: s.slot, name: s.name, bot: s.bot, char: s.char, sector: s.sector, alive: s.alive,
      }));
  }

  /** 房间内广播（序列化一次）；bots/断线槽无 conn 自动跳过。 */
  broadcast(obj, opts) {
    const str = JSON.stringify(obj);
    for (const s of this.occupiedSlots()) {
      if (s.conn) s.conn.send(str, opts);
    }
  }

  /** ev 事件流（§6.3；即时下发，不丢） */
  broadcastEv(fields) {
    this.broadcast({ t: 'ev', ts: this.ts(), ...fields });
  }

  broadcastRoster() {
    this.broadcastEv({ kind: 'roster', roster: this.roster() });
  }

  sendJoined(slot) {
    this.manager.sendMsg(slot.conn, {
      t: 'joined',
      room: this.code,
      slot: slot.slot,
      resume: slot.resume,
      char: slot.char,
      sector: slot.sector,
      seed: this.seed,
      state: { phase: this.phase, wave: this.wave, dur: this.dur },
      roster: this.roster(),
    });
  }

  buildSnap() {
    return {
      t: 'snap',
      ts: this.ts(),
      phase: this.phase,
      wave: this.wave,
      dur: this.dur,
      mobs: [...this.mobs.values()].map((m) => ({
        id: m.id, mkind: m.mkind, dir: m.dir, eta: round2(m.eta),
      })),
      slots: this.occupiedSlots().sort((a, b) => a.slot - b.slot).map((s) => ({
        slot: s.slot,
        alive: s.alive,
        bot: s.bot,
        cd: round2(Math.max(0, s.cdUntil - this.now) / 1000),
        skillCd: round2(Math.max(0, s.skillCdUntil - this.now) / 1000),
      })),
    };
  }

  /** snap 可丢（新顶旧，§6.1 背压纪律） */
  broadcastSnap() {
    this.broadcast(this.buildSnap(), { droppable: true });
  }

  sendErrTo(slot, code, msg) {
    if (slot.conn) this.manager.sendErr(slot.conn, code, msg);
  }

  // ---------------- 开局 / 波次 ----------------

  /** 开局：bot 补位至 max(3, 人类数)；防区按在座顺序分配；教学房进 TEACH。 */
  startGame() {
    if (this.phase !== 'lobby') return;
    const humans = this.humanCount();
    const target = Math.max(3, humans);
    for (let i = 0; i < target; i++) {
      if (!this.slots[i]) this.addBot(i);
    }
    const occupied = this.occupiedSlots().sort((a, b) => a.slot - b.slot);
    this.seatCount = occupied.length; // 3 或 4（槽 3 有人类占用时按 4 猎人布局）
    const layout = LAYOUTS[this.seatCount];
    occupied.forEach((s, i) => {
      s.sector = layout[i].sector.slice();
      s.center = layout[i].center;
    });
    this.startedAt = this.now;
    this.phase = this.teach ? 'teach' : 'wave';
    this.broadcastRoster(); // 补位完成花名册
    this.occupiedSlots().sort((a, b) => a.slot - b.slot).forEach((s, i) => { // v2 S5①：真人座位角色也打招呼（§7.4 间隔）
      if (s.char) this.pendingLines.push({ at: GREET_FIRST_MS + i * GREET_GAP_MS, slot: s.slot, line: 'greet' });
    });
    if (this.teach) {
      // §5 教学波：3 狼、逼近 12s、突入零惩罚。狼 1 至多补放 2 次（做错重教 ≤2 次）。
      this.teachState = { stage: 1, attempts: 0, currentMob: null, nextAt: 6000, spawn23: null, done: false };
    } else {
      this.pendingWave = { wave: 1, atTs: WAVE1_DELAY_MS };
    }
  }

  startWave(n) {
    this.phase = 'wave';
    this.wave = n;
    this.broadcastEv({ kind: 'wave', wave: n });
    const base = this.ts();
    this.script = alignPincers(
      buildWaveScript(this.seed, n, this.seatCount).map((e) => ({ ...e, atTs: base + e.at })),
      this.seed, n,
    );
    this.scriptIdx = 0;
    if (n >= 2) { // §7.4 wave 喊话：第 2 波起轮转一只 bot
      const bots = this.botSlots().sort((a, b) => a.slot - b.slot);
      if (bots.length) this.tryBotline(bots[this.waveLineIdx++ % bots.length], 'wave');
    }
  }

  /**
   * 刷怪（§3.5 防叠声：同方位同刻最多 2 只在场，必要时同防区内换向）。
   * 独立成方法供剧本与测试钩子共用。
   */
  spawnMob({ mkind, dir, eta, seat }) {
    let d = dir;
    const countAt = (dd) => [...this.mobs.values()].filter((m) => m.dir === dd).length;
    if (countAt(d) >= 2) {
      const sector = seat !== undefined && this.seatCount ? LAYOUTS[this.seatCount][seat].sector : DIRS;
      const alt = sector.find((dd) => countAt(dd) < 2);
      if (alt) d = alt;
    }
    const id = this.nextMobId++;
    const mob = { id, mkind, dir: d, eta, seat, innerAt: null }; // seat/innerAt：bot 让位判定（S7③）
    this.mobs.set(id, mob);
    this.broadcastEv({ kind: 'spawn', id, mkind, dir: d, eta });
    return mob;
  }

  /**
   * bot 让位窗（v2 修复 S7③，bot 单侧礼貌版）：怪进内圈头 2 秒，bot 不与
   * 该防区的人类座位抢——弱者的保底出手窗。只约束 bot（对真人不可见、
   * 不拦截真人出手，避免「挥空真话说谎」的暗墙）。
   */
  mobYielded(mob) {
    if (mob.innerAt === null || mob.seat === undefined) return false;
    if (this.now - mob.innerAt >= SECTOR_YIELD_MS) return false;
    const owner = this.slots[mob.seat];
    return !!(owner && !owner.bot && owner.alive);
  }

  breachMob(mob) {
    this.mobs.delete(mob.id);
    mob.breached = true;
    if (this.phase !== 'teach') { // §5 教学波突入零惩罚（不扣耐久）
      this.dur = Math.max(0, this.dur - (mob.mkind === 'bear' ? 2 : 1));
    }
    this.broadcastEv({ kind: 'breach', id: mob.id, mkind: mob.mkind, dir: mob.dir, dur: this.dur });
    // §7.4 breach 喊话：本防区漏怪（20s/只节流，氛围预算）
    const guard = this.botSlots()
      .filter((b) => b.char && b.sector.includes(mob.dir) && this.now - b.lastBreachLineAt >= 20000)
      .sort((a, b) => a.slot - b.slot)[0];
    if (guard) {
      guard.lastBreachLineAt = this.now;
      this.tryBotline(guard, 'breach');
    }
    if (this.dur <= 0 && this.phase !== 'teach') this.endGame(false); // 失守：立即终局
  }

  // ---------------- 裁决（§3.2 服务端权威） ----------------

  adjudicateAttack(slot, dir) {
    if (this.now < slot.cdUntil) {
      return this.sendErrTo(slot, 'cooldown', '出击冷却中（2.5 秒）');
    }
    slot.cdUntil = this.now + ATTACK_CD_MS; // 挥空也进冷却（与客户端本地预扣一致）
    slot.lastActAt = this.now;
    const arc = arcOf(dir);
    let best = null;
    for (const mob of this.mobs.values()) {
      if (!arc.includes(DIR_IDX[mob.dir]) || mob.eta > MELEE_ETA) continue;
      if (!best || mob.eta < best.eta) best = mob;
    }
    if (!best) {
      this.broadcastEv({ kind: 'miss', slot: slot.slot, dir });
      return;
    }
    this.mobs.delete(best.id);
    this.broadcastEv({ kind: 'kill', id: best.id, slot: slot.slot, dir: best.dir, mkind: best.mkind });
    this.creditKill(slot, best);
  }

  adjudicateSkill(slot) {
    if (this.now < slot.skillCdUntil) {
      return this.sendErrTo(slot, 'skill_cd', '旋风斩冷却中（8 秒）');
    }
    slot.skillCdUntil = this.now + SKILL_CD_MS;
    slot.lastActAt = this.now;
    const clearedMobs = [...this.mobs.values()]
      .filter((m) => m.eta <= MELEE_ETA && !(slot.bot && this.mobYielded(m))); // bot 旋风斩也让位（S7③）
    for (const mob of clearedMobs) this.mobs.delete(mob.id);
    this.broadcastEv({ kind: 'skill', slot: slot.slot, cleared: clearedMobs.map((m) => m.id) });
    for (const mob of clearedMobs) this.creditKill(slot, mob);
    if (slot.char && clearedMobs.length >= 3) this.tryBotline(slot, 'skill'); // v2 S5①：真人大清场也报
  }

  adjudicateCallout(slot) {
    if (this.now < slot.calloutUntil) {
      return this.sendErrTo(slot, 'cooldown', '呼喊太频繁（5 秒节流）');
    }
    slot.calloutUntil = this.now + CALLOUT_THROTTLE_MS;
    slot.lastActAt = this.now;
    this._logLine(); // callout 计入喊话窗（氛围句须让路，§7.4）
    this.broadcastEv({ kind: 'callout', slot: slot.slot });
    // §7.3 补位：空闲 bot（500ms 未出手、座位号小者优先）必答 help_ack + 10s 偏置
    const responder = this.botSlots()
      .filter((b) => b.slot !== slot.slot && this.now - b.lastActAt >= BOT_TICK_MS)
      .sort((a, b) => a.slot - b.slot)[0];
    if (responder) {
      this.emitBotline(responder, 'help_ack', { priority: true }); // 呼救语义不可被顶掉
      responder.cover = {
        callerSlot: slot.slot,
        callerSector: slot.sector.slice(),
        until: this.now + COVER_MS,
        killDone: false,
        settled: false,
      };
    } else {
      // v2 S5②：满编真人房无 bot 可应——2.5s 后由邻座真人「扮演的角色」代答
      // help_ack（呼喊-应答听觉闭环在真人房成立的兜底；v3 若加真人应答手势则替换）
      const neighbor = this.occupiedSlots()
        .filter((s) => s.slot !== slot.slot && s.char && s.alive)
        .sort((a, b) => a.slot - b.slot)[0];
      if (neighbor) {
        this.pendingLines.push({
          at: this.ts() + CALLOUT_ACK_DELAY_MS, slot: neighbor.slot, line: 'help_ack', priority: true,
        });
      }
    }
  }

  creditKill(slot, mob) {
    slot.kills += 1;
    this.killsBySlot[String(slot.slot)] = slot.kills;
    if (slot.cover && !slot.cover.settled && slot.cover.callerSector.includes(mob.dir)) {
      slot.cover.killDone = true;
    }
    if (slot.char) { // v2 S5①：真人也「扮演座位角色」——杀熊/三连杀照播角色 kill 句（§3.3 声音身份接线）
      slot.recentKills.push(this.now);
      slot.recentKills = slot.recentKills.filter((t) => this.now - t <= 6000);
      const triple = slot.recentKills.length >= 3;
      if ((mob.mkind === 'bear' || triple) && this.now - slot.lastKillLineAt >= 15000) {
        slot.lastKillLineAt = this.now;
        this.tryBotline(slot, 'kill');
      }
    }
  }

  // ---------------- bot 喊话调度（§7.4 + §8 R2 服务端纪律） ----------------

  _logLine() {
    this.lineLog.push(this.now);
  }

  /**
   * 全局节流：10s 窗氛围 ≤2 条，超出丢弃；priority（callout/help_ack）永远投递——
   * 呼救语义不可被氛围句顶掉（其速率已由 5s/座源头节流约束）。
   */
  emitBotline(slot, line, { priority = false } = {}) {
    if (!slot.char) return; // 座 3 无角色声（§15 裁决 6，客户端用哨音；无 bot 在座 3）
    const cutoff = this.now - BOTLINE_WINDOW_MS;
    this.lineLog = this.lineLog.filter((t) => t > cutoff);
    if (!priority && this.lineLog.length >= BOTLINE_BUDGET) return; // 丢弃氛围句
    this._logLine();
    this.broadcastEv({ kind: 'botline', slot: slot.slot, line });
  }

  tryBotline(slot, line) {
    this.emitBotline(slot, line, { priority: false });
  }

  // ---------------- bot AI（§7.2，500ms tick，确定性） ----------------

  /** 方向压力 P(d)=Σ(1/eta)（仅计 eta≤4 且未被让位的怪）；主防区 ×1.5；补位期呼喊者防区 ×2.0（覆盖主防区偏置）。 */
  botPickDir(bot) {
    const cov = bot.cover && this.now < bot.cover.until ? bot.cover : null;
    let bestDir = null;
    let bestP = 0;
    for (let d = 0; d < 8; d++) {
      let p = 0;
      for (const m of this.mobs.values()) {
        if (DIR_IDX[m.dir] === d && m.eta <= MELEE_ETA && !this.mobYielded(m)) p += 1 / Math.max(m.eta, 0.1);
      }
      if (p <= 0) continue;
      if (cov ? cov.callerSector.includes(DIRS[d]) : bot.sector.includes(DIRS[d])) {
        p *= cov ? 2.0 : 1.5;
      }
      if (p > bestP) { bestP = p; bestDir = DIRS[d]; }
    }
    return bestDir;
  }

  /** §7.2 单 slot 的 500ms 决策（bot 由 botTick 驱动；平衡仿真脚本可对真人槽复用同一口径）。 */
  botDecide(bot) {
    const tune = this.botTuning;
    // 旋风斩：全场 eta≤skillEta ≥skillMin 只 + 技能就绪 + skillP 想起（裁决 10 节制）
    if (this.now >= bot.skillCdUntil) {
      const close = [...this.mobs.values()].filter((m) => m.eta <= tune.skillEta).length;
      if (close >= tune.skillMin && this.botRng() < tune.skillP) this.adjudicateSkill(bot);
    }
    // 出击：冷却就绪 + max P 方向 + 反应带 + 犹豫空转（裁决 10）；让位怪不抢（S7③）
    if (this.now >= bot.cdUntil) {
      const dir = this.botPickDir(bot);
      if (dir) {
        const arc = arcOf(dir);
        let best = null;
        for (const m of this.mobs.values()) {
          if (!arc.includes(DIR_IDX[m.dir]) || m.eta > MELEE_ETA || this.mobYielded(m)) continue;
          if (!best || m.eta < best.eta) best = m;
        }
        if (best
          && best.eta <= tune.reactBase + this.botRng() * tune.reactSpan
          && this.botRng() >= tune.hesitateP) {
          this.adjudicateAttack(bot, dir);
        }
      }
    }
    // 呼救：主防区压力 ≥3（eta≤6）且 20s 节流
    if (this.now - bot.lastCalloutAt >= 20000) {
      const pressure = [...this.mobs.values()]
        .filter((m) => bot.sector.includes(m.dir) && m.eta <= 6).length;
      if (pressure >= 3) {
        bot.lastCalloutAt = this.now;
        this.adjudicateCallout(bot);
      }
    }
    // §7.3 补位落定：首次在新防区击杀后再无怪 → cover（每次指派 1 次）
    const cov = bot.cover;
    if (cov && !cov.settled && cov.killDone
      && ![...this.mobs.values()].some((m) => cov.callerSector.includes(m.dir))) {
      cov.settled = true;
      this.tryBotline(bot, 'cover');
    }
  }

  botTick() {
    if (this.phase !== 'wave') return; // §5 教学段 bot AI 挂起（呼喊必答走 callout 路径）
    for (const bot of this.botSlots().sort((a, b) => a.slot - b.slot)) this.botDecide(bot);
  }

  // ---------------- 教学波（§5） ----------------

  tickTeach() {
    const st = this.teachState;
    if (!st || st.done) return;
    const ts = this.ts();
    if (st.stage === 1) {
      if (!st.currentMob && ts >= st.nextAt && st.attempts < 3) {
        st.currentMob = this.spawnMob({ mkind: 'wolf', dir: 'N', eta: 12 }); // T1 教学狼，方位 N
        st.attempts += 1;
      }
      if (st.currentMob && !this.mobs.has(st.currentMob.id)) {
        if (st.currentMob.breached && st.attempts < 3) { // 突入零惩罚，补放重教
          st.currentMob = null;
          st.nextAt = ts + 2000;
        } else { // 杀掉（或最后一次放过）→ T3 双狼
          st.currentMob = null;
          st.stage = 2;
          st.nextAt = ts + 4000;
        }
      }
    } else if (st.stage === 2) {
      if (!st.spawn23 && ts >= st.nextAt) {
        const a = this.spawnMob({ mkind: 'wolf', dir: 'N', eta: 5 }); // T3 教学狼 2、3，贴近
        const b = this.spawnMob({ mkind: 'wolf', dir: 'NE', eta: 5 });
        st.spawn23 = [a.id, b.id];
      }
      if (st.spawn23 && st.spawn23.every((id) => !this.mobs.has(id))) {
        st.done = true;
        this.pendingWave = { wave: 1, atTs: ts + REST_MS }; // 教学完同场接续第 1 波
      }
    }
  }

  // ---------------- 终局 ----------------

  endGame(win) {
    this.phase = 'end';
    this.mobs.clear();
    this.script = null;
    this.pendingWave = null;
    const kills = {};
    for (const [k, v] of Object.entries(this.killsBySlot)) kills[k] = v;
    for (const s of this.occupiedSlots()) kills[String(s.slot)] = s.kills;
    const grade = win ? gradeForEx(this.dur, kills) : null; // v2 S7④ 双轴评级（失守无评级，§3.6/§15 裁决 9）
    this.broadcastEv({ kind: 'end', win, dur: this.dur, grade, kills });
    this.endAt = this.now;
  }

  /** 房灭回收：断全部连接（end 后 close 1000）、清 resume 索引、出管理器。 */
  destroy(code = 1000) {
    if (this.destroyed) return;
    this.destroyed = true;
    for (const s of this.occupiedSlots()) {
      const c = s.conn;
      s.conn = null;
      if (s.resume) this.manager.resumeIndex.delete(s.resume);
      if (c) {
        c.joinedRoom = null;
        c.slotId = null;
        try { c.close(code); } catch (_) { /* 忽略 */ }
      }
    }
    this.manager.rooms.delete(this.code);
  }

  // ---------------- 断线宽限（§6.6） ----------------

  graceTimeout(slot) {
    const remaining = this.humanCount() - 1; // 除本槽外剩余人类
    if (remaining <= 0) { // 最后一个人类宽限耗尽 → 房灭（bot 不续命）
      this.destroy();
      return;
    }
    if (this.phase === 'lobby' || this.phase === 'end' || remaining >= 3) {
      this.removeSlot(slot); // 剩余人类 ≥3 → 槽位移除
    } else {
      this.convertToBot(slot); // 否则槽位转 bot（不可逆）
    }
  }

  // ---------------- 主循环 ----------------

  tick(dt) {
    if (this.destroyed) return;
    this.now += dt;

    // 断线宽限到期处理
    for (const s of this.occupiedSlots()) {
      if (!s.bot && !s.alive && !s.conn && s.graceUntil && this.now >= s.graceUntil) {
        this.graceTimeout(s);
        if (this.destroyed) return;
      }
    }

    if (this.phase === 'lobby') {
      if (this.now >= LOBBY_MS) this.startGame(); // LOBBY 上限 12s
      return;
    }
    if (this.phase === 'end') {
      if (this.endAt !== null && this.now >= this.endAt + END_KEEP_MS) this.destroy(1000);
      return;
    }

    const ts = this.ts();
    // 波次启动（开局延迟 / 波间休整 / 教学接续）
    if (this.pendingWave && ts >= this.pendingWave.atTs) {
      const w = this.pendingWave.wave;
      this.pendingWave = null;
      this.startWave(w);
    }
    // 剧本刷怪
    if (this.script) {
      while (this.scriptIdx < this.script.length && this.script[this.scriptIdx].atTs <= ts) {
        this.spawnMob(this.script[this.scriptIdx++]);
      }
    }
    // 教学波推进
    if (this.phase === 'teach') this.tickTeach();
    // 怪物推进 + 突入结算（进内圈打让位时间戳，S7③）
    for (const mob of [...this.mobs.values()]) {
      mob.eta -= dt / 1000;
      if (mob.innerAt === null && mob.eta <= MELEE_ETA) mob.innerAt = this.now;
      if (mob.eta <= 0) {
        this.breachMob(mob);
        if (this.phase === 'end' || this.destroyed) return;
      }
    }
    // 波出清 → 休整 → 下一波 / 终局
    if (this.phase === 'wave' && !this.pendingWave && this.script
      && this.scriptIdx >= this.script.length && this.mobs.size === 0 && this.wave >= 1) {
      if (this.wave >= LAST_WAVE) {
        this.endGame(true);
        return;
      }
      this.broadcastEv({ kind: 'waveclear', wave: this.wave });
      this.pendingWave = { wave: this.wave + 1, atTs: ts + REST_MS };
    }
    // bot AI（500ms）
    if (this.now - this.lastBotAt >= BOT_TICK_MS) {
      this.lastBotAt = this.now;
      this.botTick();
    }
    // 喊话调度（greet 等；v2 S5② 真人代答 help_ack 也走此队列）
    while (this.pendingLines.length && this.pendingLines[0].at <= ts) {
      const l = this.pendingLines.shift();
      const s = this.slots[l.slot];
      if (s && s.char && s.alive !== false) {
        this.emitBotline(s, l.line, { priority: !!l.priority });
      }
    }
    // 快照兜底（2Hz）
    if (this.now - this.lastSnapAt >= SNAP_MS) {
      this.lastSnapAt = this.now;
      this.broadcastSnap();
    }
  }
}

// ---------------- 房间管理器（§6.4 匹配 + 消息路由） ----------------

class HuntManager {
  constructor(opts = {}) {
    this.rooms = new Map(); // code -> Room
    this.resumeIndex = new Map(); // resume token -> { room, slotId }
    this.joinTimeoutMs = opts.joinTimeoutMs || 5000; // §6.2 连接后 5s 内须发 join
    // 速率帽（§6.1）按真实墙钟计；仿真测试以快进 tick 驱动、瞬间大量消息，可传 Infinity 关闭
    this.rateLimit = opts.rateLimit === undefined ? RATE_PER_SEC : opts.rateLimit;
    // bot 难度参数（§15 裁决 10）：生产用默认值；平衡扫描/测试可覆盖
    this.botTuning = { ...BOT_TUNING_DEFAULT, ...(opts.botTuning || {}) };
  }

  createRoom(opts = {}) {
    let code = opts.code;
    if (!code) {
      do {
        code = Array.from({ length: 4 }, () => ROOM_CODE_CHARS[crypto.randomInt(ROOM_CODE_CHARS.length)]).join('');
      } while (this.rooms.has(code));
    }
    const room = new Room(this, { ...opts, code });
    this.rooms.set(code, room);
    return room;
  }

  /** 生产驱动（server.js setInterval）与测试快进共用入口。 */
  tick(dtMs) {
    for (const room of [...this.rooms.values()]) room.tick(dtMs);
  }

  attach(conn) {
    conn.joinedRoom = null;
    conn.slotId = null;
    conn.rlWindowStart = 0;
    conn.rlCount = 0;
    conn.rlStrikeAt = 0;
    conn.joinTimer = setTimeout(() => {
      if (!conn.joinedRoom) conn.close(1008, 'join timeout'); // 5s 未 join
    }, this.joinTimeoutMs);
    if (conn.joinTimer.unref) conn.joinTimer.unref();
    conn.on('message', (str) => {
      try {
        this.handleMessage(conn, str);
      } catch (e) {
        console.error('[hunt] 消息处理异常:', e);
      }
    });
    conn.on('close', () => this.handleClose(conn));
  }

  sendMsg(conn, obj) {
    if (conn) conn.send(JSON.stringify(obj));
  }

  sendErr(conn, code, msg) {
    this.sendMsg(conn, { t: 'err', code, msg });
  }

  handleMessage(conn, str) {
    // §6.1 速率帽：20 条/s，超限 err rate，10s 内再犯 close
    const now = Date.now();
    if (now - conn.rlWindowStart > 1000) {
      conn.rlWindowStart = now;
      conn.rlCount = 0;
    }
    conn.rlCount += 1;
    if (conn.rlCount > this.rateLimit) {
      if (conn.rlStrikeAt && now - conn.rlStrikeAt < RATE_STRIKE_MS) {
        conn.close(1008, 'rate limit');
        return;
      }
      conn.rlStrikeAt = now;
      return this.sendErr(conn, 'rate', '消息太快，慢一点。');
    }

    let msg;
    try {
      msg = JSON.parse(str);
    } catch (_) {
      return this.sendErr(conn, 'bad_msg', '不是合法 JSON');
    }
    if (!msg || typeof msg !== 'object' || Array.isArray(msg)) {
      return this.sendErr(conn, 'bad_msg', '消息需为 JSON 对象');
    }

    if (!conn.joinedRoom) {
      if (msg.t !== 'join') return this.sendErr(conn, 'bad_msg', '首条消息必须是 join');
      return this.handleJoin(conn, msg);
    }
    if (msg.t === 'act') return this.handleAct(conn, msg);
    if (msg.t === 'leave') return this.handleLeave(conn);
    return this.sendErr(conn, 'bad_msg', '未知消息类型');
  }

  handleClose(conn) {
    if (conn.joinTimer) {
      clearTimeout(conn.joinTimer);
      conn.joinTimer = null;
    }
    const room = conn.joinedRoom;
    if (!room) return;
    conn.joinedRoom = null;
    const slotId = conn.slotId;
    conn.slotId = null;
    if (room.destroyed) return;
    const slot = room.slots[slotId];
    if (!slot || slot.conn !== conn || slot.bot) return;
    // §6.6：断线 → 标记 + roster 广播 + 30s 宽限（lobby/end 同走宽限，到期按规则处理）
    slot.conn = null;
    slot.alive = false;
    slot.graceUntil = room.now + GRACE_MS;
    room.broadcastRoster();
  }

  handleJoin(conn, msg) {
    if (msg.ver !== 1) return this.sendErr(conn, 'bad_msg', '协议版本不符（ver 恒 1）');
    if (msg.resume !== undefined && msg.resume !== null) return this.handleResume(conn, msg);

    const roomName = msg.room;
    const isCode = typeof roomName === 'string' && /^[23456789ABCDEFGHJKMNPQRSTUVWXYZ]{4}$/.test(roomName);
    if (roomName !== 'quick' && !isCode) {
      return this.sendErr(conn, 'bad_msg', 'room 需为 "quick" 或 4 位房码');
    }
    let name = String(msg.name === undefined || msg.name === null ? '猎人' : msg.name).trim().slice(0, 24);
    if (!name) name = '猎人';

    let room;
    if (msg.teach === true) {
      room = this.createRoom({ teach: true }); // §5/§6.4 教学房强制单人
    } else if (roomName === 'quick') {
      room = [...this.rooms.values()].find(
        (r) => !r.destroyed && r.phase === 'lobby' && !r.teach && r.occupiedSlots().length < 4,
      );
      if (!room) room = this.createRoom({});
    } else {
      room = this.rooms.get(roomName);
      if (room && (room.destroyed || room.phase !== 'lobby' || room.teach)) {
        return this.sendErr(conn, 'room_full', '房间已开局或不可用'); // §6.4 对局中 join → room_full
      }
      if (!room) room = this.createRoom({ code: roomName });
    }

    const slotId = room.slots.findIndex((s) => s === null);
    if (slotId === -1) return this.sendErr(conn, 'room_full', '房间已满（4 人）');

    const slot = room.addHuman(slotId, conn, name);
    conn.joinedRoom = room;
    conn.slotId = slotId;
    if (conn.joinTimer) {
      clearTimeout(conn.joinTimer);
      conn.joinTimer = null;
    }
    this.resumeIndex.set(slot.resume, { room, slotId });

    if (room.teach && room.phase === 'lobby') room.startGame(); // 教学房直入 TEACH（无 lobby 等待）
    room.sendJoined(slot);
    room.broadcastRoster();
    if (!room.teach && room.humanCount() === 4) room.startGame(); // 满 4 人立即开局
  }

  /** §6.6 宽限内 resume 回槽：重发 joined（同 slot/seed/char）+ 紧随 snap 全量。 */
  handleResume(conn, msg) {
    const token = String(msg.resume);
    const rec = this.resumeIndex.get(token);
    if (!rec || rec.room.destroyed) {
      return this.sendErr(conn, 'room_gone', '那场围猎已经结束了'); // 房灭后迟到 resume
    }
    const { room, slotId } = rec;
    const slot = room.slots[slotId];
    if (!slot || slot.bot || slot.resume !== token) {
      return this.sendErr(conn, 'room_gone', '座位已经没了（已转 bot）');
    }
    if (slot.conn && slot.conn !== conn) { // 顶号：旧连接让位
      const old = slot.conn;
      old.joinedRoom = null;
      old.slotId = null;
      try { old.close(1008, 'replaced'); } catch (_) { /* 忽略 */ }
    }
    slot.conn = conn;
    slot.alive = true;
    slot.graceUntil = 0;
    conn.joinedRoom = room;
    conn.slotId = slotId;
    if (conn.joinTimer) {
      clearTimeout(conn.joinTimer);
      conn.joinTimer = null;
    }
    room.sendJoined(slot);
    this.sendMsg(conn, room.buildSnap()); // 紧随 snap 全量
    room.broadcastRoster();
  }

  handleAct(conn, msg) {
    const room = conn.joinedRoom;
    const slot = room.slots[conn.slotId];
    if (!slot || slot.bot) return this.sendErr(conn, 'bad_msg', '座位状态异常');
    const kind = msg.kind;
    if (!['attack', 'callout', 'skill', 'start'].includes(kind)) {
      return this.sendErr(conn, 'bad_msg', '未知 act.kind');
    }
    if (typeof msg.seq === 'number') { // 乱序/重复不拒，仅日志（§6.2）
      if (msg.seq <= slot.lastSeq) {
        console.log(`[hunt] act 乱序/重复: room=${room.code} slot=${slot.slot} seq=${msg.seq} last=${slot.lastSeq}`);
      }
      slot.lastSeq = Math.max(slot.lastSeq, msg.seq);
    }
    if (kind === 'start') {
      if (room.phase !== 'lobby') return this.sendErr(conn, 'not_ingame', '已经开局了');
      room.startGame();
      return;
    }
    if (room.phase !== 'wave' && room.phase !== 'teach') {
      return this.sendErr(conn, 'not_ingame', '不在对局中');
    }
    if (kind === 'attack') {
      if (typeof msg.dir !== 'string' || !(msg.dir in DIR_IDX)) {
        return this.sendErr(conn, 'bad_dir', '方位需为 8 罗盘向之一');
      }
      room.adjudicateAttack(slot, msg.dir);
    } else if (kind === 'skill') {
      room.adjudicateSkill(slot);
    } else {
      room.adjudicateCallout(slot);
    }
  }

  /** leave：主动退出，槽位立即按 §6.6 处理（无 30s 宽限）。 */
  handleLeave(conn) {
    const room = conn.joinedRoom;
    if (!room) {
      conn.close(1000);
      return;
    }
    conn.joinedRoom = null;
    const slotId = conn.slotId;
    conn.slotId = null;
    const slot = room.slots[slotId];
    if (!room.destroyed && slot && !slot.bot) {
      slot.conn = null;
      if (slot.resume) this.resumeIndex.delete(slot.resume);
      slot.resume = null;
      if (room.phase === 'lobby' || room.phase === 'end') {
        room.slots[slotId] = null;
        room.broadcastRoster();
        if (room.humanCount() === 0) room.destroy();
      } else {
        const remaining = room.humanCount() - 1;
        if (remaining <= 0) room.destroy(); // 无人类即灭
        else if (remaining >= 3) room.removeSlot(slot);
        else room.convertToBot(slot);
      }
    }
    conn.close(1000);
  }
}

function createManager(opts) {
  return new HuntManager(opts);
}

module.exports = {
  createManager,
  Room,
  buildWaveScript,
  waveCounts,
  alignPincers,
  gradeFor,
  gradeForEx,
  mulberry32,
  DIRS,
  LAYOUTS,
  WAVE_TABLE,
  LAST_WAVE,
  DUR_MAX,
  MELEE_ETA,
  TICK_MS,
  ATTACK_CD_MS,
  SKILL_CD_MS,
  CALLOUT_THROTTLE_MS,
  LOBBY_MS,
  GRACE_MS,
  END_KEEP_MS,
  REST_MS,
  ROOM_CODE_CHARS,
  BOT_TUNING_DEFAULT,
  SECTOR_YIELD_MS,
};