Poker/server/hand.js

'use strict';

const config = require('./config');
const { newDeck, bestHand, compareScore } = require('./cards');

// 1ハンド分の進行（配札・ベッティング・ショーダウン・ポット分配）
// seats は Table.seats への参照で、スタックはここで直接増減する。
// 参加者の席はハンド終了まで空席にならない（退席者は Table 側で予約したまま）。
class Hand {
  constructor({ number, seats, order, button, sb, bb, now }) {
    this.number = number;
    this.seats = seats;
    this.order = order; // 参加者の席番号。ボタンの次から時計回り
    this.button = button;
    this.sb = sb;
    this.bb = bb;

    this.deck = newDeck();
    this.board = [];
    this.street = 'PREFLOP';
    this.pot = 0; // 前のストリートまでに集めた額
    this.currentBet = 0;
    this.minRaise = bb;
    this.toAct = null;
    this.deadline = null;
    this.runoutAt = null;
    this.revealed = false; // オールインで以降のアクションが無いとき、ショーダウン時に公開
    this.finished = false;
    this.showdown = false;
    this.results = null;

    this.players = new Map();
    for (const i of order) {
      this.players.set(i, {
        seat: i,
        token: seats[i].token,
        cards: [],
        bet: 0, // このストリートで出した額
        committed: 0, // このハンドで出した合計
        folded: false,
        allIn: false,
        acted: false,
        last: null, // 直前のアクション（表示用）
        won: 0,
        best: null,
      });
    }
    for (let r = 0; r < 2; r++) for (const i of order) this.players.get(i).cards.push(this.deck.pop());

    // ヘッズアップはボタンが SB
    const headsUp = order.length === 2;
    this.sbSeat = headsUp ? button : order[0];
    this.bbSeat = headsUp ? order[0] : order[1];
    this.post(this.sbSeat, sb);
    this.post(this.bbSeat, bb);
    this.currentBet = bb; // BB がショートでもコール額は BB
    this.setNextActor(this.bbSeat, now);
  }

  get list() {
    return this.order.map((i) => this.players.get(i));
  }

  live() {
    return this.list.filter((p) => !p.folded);
  }

  put(p, amount) {
    const s = this.seats[p.seat];
    s.stack -= amount;
    p.bet += amount;
    p.committed += amount;
    if (s.stack === 0) p.allIn = true;
  }

  post(seat, amount) {
    const p = this.players.get(seat);
    this.put(p, Math.min(amount, this.seats[seat].stack));
  }

  needsToAct(p) {
    return !p.folded && !p.allIn && (!p.acted || p.bet < this.currentBet);
  }

  bettingClosed() {
    const live = this.live();
    if (live.length <= 1) return true;
    const actors = live.filter((p) => !p.allIn);
    if (actors.length === 0) return true;
    // 動ける人が1人だけで、誰かのベットに応じる必要もない
    const maxBet = Math.max(...live.map((p) => p.bet));
    if (actors.length === 1 && actors[0].bet >= maxBet) return true;
    return actors.every((p) => !this.needsToAct(p));
  }

  setNextActor(fromSeat, now) {
    this.toAct = null;
    this.deadline = null;
    if (this.bettingClosed()) return this.endStreet(now);
    const n = this.order.length;
    const start = this.order.indexOf(fromSeat);
    for (let k = 1; k <= n; k++) {
      const p = this.players.get(this.order[(start + k) % n]);
      if (!this.needsToAct(p)) continue;
      this.toAct = p.seat;
      this.deadline = now + config.ACTION_TIME_MS;
      // 離席中・退席済みの人は自動でチェック/フォールド
      const s = this.seats[p.seat];
      if (s.sittingOut || s.left) this.autoAct(now);
      return;
    }
    this.endStreet(now);
  }

  // 手番の人の選択肢（手番でなければ null）
  options(seat) {
    if (this.finished || this.toAct !== seat) return null;
    const p = this.players.get(seat);
    const stack = this.seats[seat].stack;
    const toCall = Math.min(this.currentBet - p.bet, stack);
    const maxTo = p.bet + stack;
    // 他の全員がオールインならレイズしても意味がない
    const opponentCanAct = this.live().some((q) => q !== p && !q.allIn);
    return {
      toCall,
      canCheck: p.bet >= this.currentBet,
      canRaise: !p.acted && stack > toCall && opponentCanAct,
      minRaiseTo: Math.min(this.currentBet + this.minRaise, maxTo),
      maxRaiseTo: maxTo,
      isBet: this.currentBet === 0,
    };
  }

  // type: fold / check / call / raise（amount = このストリートでの合計額 "raise to"）
  act(seat, type, amount, now) {
    const o = this.options(seat);
    if (!o) return 'あなたの番ではありません';
    const p = this.players.get(seat);

    if (type === 'fold') {
      p.folded = true;
      p.last = { type: 'FOLD' };
    } else if (type === 'check') {
      if (!o.canCheck) return 'チェックできません';
      p.last = { type: 'CHECK' };
    } else if (type === 'call') {
      if (o.canCheck || o.toCall <= 0) return 'コールする額がありません';
      this.put(p, o.toCall);
      p.last = { type: 'CALL', amount: p.bet };
    } else if (type === 'raise') {
      if (!o.canRaise) return 'レイズできません';
      if (!Number.isInteger(amount) || amount < o.minRaiseTo || amount > o.maxRaiseTo) {
        return `${o.minRaiseTo}〜${o.maxRaiseTo} の額を指定してください`;
      }
      const raiseSize = amount - this.currentBet;
      this.put(p, amount - p.bet);
      p.last = { type: o.isBet ? 'BET' : 'RAISE', amount };
      if (raiseSize >= this.minRaise) {
        // 正規のレイズ: 他の人はもう一度アクションできる
        this.minRaise = raiseSize;
        for (const q of this.list) if (q !== p) q.acted = false;
      }
      // 足りないオールインのレイズはアクション済みの人に再レイズ権を与えない
      this.currentBet = amount;
    } else {
      return '不正なアクションです';
    }
    if (p.allIn) p.last = { type: 'ALLIN', amount: p.bet };
    p.acted = true;
    this.setNextActor(seat, now);
    return null;
  }

  autoAct(now) {
    const o = this.options(this.toAct);
    if (o) this.act(this.toAct, o.canCheck ? 'check' : 'fold', 0, now);
  }

  // 退席などで手番に関係なくフォールドさせる
  forceFold(seat, now) {
    const p = this.players.get(seat);
    if (!p || p.folded || this.finished) return;
    if (this.toAct === seat) return this.act(seat, 'fold', 0, now);
    p.folded = true;
    p.last = { type: 'FOLD' };
    if (this.live().length === 1) {
      this.runoutAt = null;
      this.endStreet(now);
    } else if (this.toAct != null && this.bettingClosed()) {
      this.endStreet(now);
    }
  }

  // 誰もコールしなかった分を返す
  returnUncalled() {
    const bets = this.list.map((p) => p.bet).sort((a, b) => b - a);
    const excess = bets[0] - (bets[1] || 0);
    if (excess <= 0) return;
    const p = this.list.find((q) => q.bet === bets[0]);
    if (p.folded) return; // 退席でフォールドした人のベットはそのままポットに残る
    p.bet -= excess;
    p.committed -= excess;
    this.seats[p.seat].stack += excess;
    p.allIn = this.seats[p.seat].stack === 0;
    if (!p.allIn && p.last && p.last.type === 'ALLIN') p.last = null;
  }

  endStreet(now) {
    this.toAct = null;
    this.deadline = null;
    this.returnUncalled();
    for (const p of this.list) {
      this.pot += p.bet;
      p.bet = 0;
      p.acted = false;
      if (p.last && p.last.type !== 'FOLD' && p.last.type !== 'ALLIN') p.last = null;
    }
    if (this.live().length === 1) return this.finish(false);
    if (this.street === 'RIVER') return this.finish(true);
    this.currentBet = 0;
    this.minRaise = this.bb;

    if (this.live().filter((p) => !p.allIn).length >= 2) {
      this.dealStreet();
      this.setNextActor(this.button, now);
    } else {
      // これ以上ベットが無いので手札を公開して残りのカードを順にめくる
      this.revealed = true;
      this.runoutAt = now + config.RUNOUT_STEP_MS;
    }
  }

  dealStreet() {
    this.deck.pop(); // バーン
    if (this.street === 'PREFLOP') {
      this.board.push(this.deck.pop(), this.deck.pop(), this.deck.pop());
      this.street = 'FLOP';
    } else if (this.street === 'TURN' || this.street === 'FLOP') {
      this.board.push(this.deck.pop());
      this.street = this.street === 'FLOP' ? 'TURN' : 'RIVER';
    }
  }

  runoutStep(now) {
    if (this.street === 'RIVER') {
      this.runoutAt = null;
      return this.finish(true);
    }
    this.dealStreet();
    this.runoutAt = now + config.RUNOUT_STEP_MS;
  }

  // 手番の時間切れ。true なら時間切れ処理をした
  timeout(now) {
    if (this.finished || this.toAct == null || now < this.deadline) return false;
    this.autoAct(now);
    return true;
  }

  // メインポット・サイドポット（同じ参加者のポットはまとめる）
  buildPots() {
    const all = this.list;
    const levels = [...new Set(all.map((p) => p.committed).filter((c) => c > 0))].sort((a, b) => a - b);
    const pots = [];
    let prev = 0;
    for (const level of levels) {
      let amount = 0;
      for (const p of all) amount += Math.max(0, Math.min(p.committed, level) - prev);
      prev = level;
      let eligible = all.filter((p) => !p.folded && p.committed >= level).map((p) => p.seat);
      const last = pots[pots.length - 1];
      if (eligible.length === 0) eligible = last ? last.eligible : this.live().map((p) => p.seat);
      if (last && last.eligible.join() === eligible.join()) last.amount += amount;
      else pots.push({ amount, eligible });
    }
    return pots;
  }

  finish(showdown) {
    this.finished = true;
    this.showdown = showdown;
    this.toAct = null;
    this.deadline = null;
    this.runoutAt = null;
    const results = [];

    if (!showdown) {
      const winner = this.live()[0];
      winner.won = this.pot;
      this.seats[winner.seat].stack += this.pot;
      results.push({ amount: this.pot, winners: [winner.seat], handName: null, bestCards: [] });
    } else {
      this.revealed = true;
      for (const p of this.live()) p.best = bestHand(p.cards.concat(this.board));
      for (const pot of this.buildPots()) {
        const contenders = pot.eligible.map((s) => this.players.get(s));
        let top = null;
        for (const c of contenders) if (!top || compareScore(c.best.score, top) > 0) top = c.best.score;
        const winners = contenders.filter((c) => compareScore(c.best.score, top) === 0);
        // 割り切れない端数はボタンの左から順に
        const share = Math.floor(pot.amount / winners.length);
        let rest = pot.amount - share * winners.length;
        for (const w of winners) {
          const amount = share + (rest > 0 ? 1 : 0);
          if (rest > 0) rest--;
          w.won += amount;
          this.seats[w.seat].stack += amount;
        }
        results.push({
          amount: pot.amount,
          winners: winners.map((w) => w.seat),
          handName: winners[0].best.name,
          bestCards: winners[0].best.cards,
        });
      }
    }
    this.pot = results.reduce((sum, r) => sum + r.amount, 0);
    this.results = results;
  }

  // 閲覧者 viewerSeat に見せてよい情報だけを返す（他人の手札は公開時のみ）
  view(viewerSeat, viewerToken) {
    const players = {};
    for (const p of this.list) {
      const mine = p.seat === viewerSeat && p.token === viewerToken;
      const shown = mine || (this.revealed && !p.folded);
      let handName = null;
      if (shown && !p.folded && this.board.length >= 3) {
        handName = (p.best || bestHand(p.cards.concat(this.board))).name;
      }
      players[p.seat] = {
        bet: p.bet,
        folded: p.folded,
        allIn: p.allIn,
        last: p.last,
        cards: shown ? p.cards : null,
        handName,
        won: p.won,
      };
    }
    return {
      number: this.number,
      street: this.street,
      board: this.board,
      pot: this.pot,
      potTotal: this.pot + this.list.reduce((sum, p) => sum + p.bet, 0),
      currentBet: this.currentBet,
      button: this.button,
      sbSeat: this.sbSeat,
      bbSeat: this.bbSeat,
      toAct: this.toAct,
      finished: this.finished,
      showdown: this.showdown,
      results: this.results,
      players,
    };
  }
}

module.exports = { Hand };