// AI 전투 밸런스 시뮬레이터 — 오프라인 몬테카를로.
// ⚠️ 전투 규칙은 tools/deck/gen-slaydeck.mjs 의 Lua(SlayDeckController)와 동기화 유지할 것.
//    (데이터는 data/*.json 공유, 규칙 로직은 JS로 중복 재현)
import { readFileSync } from 'node:fs';

export const PLAYER_HP = 80; // 데이터 미포함 placeholder (codeblock과 일치)
export const ENERGY = 3;
export const HAND_SIZE = 5;
export const MAX_TURNS = 100;

export function mulberry32(seed) {
  let a = seed >>> 0;
  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;
  };
}

export function shuffle(arr, rng) {
  const a = arr.slice();
  for (let i = a.length - 1; i > 0; i--) {
    const j = Math.floor(rng() * (i + 1));
    [a[i], a[j]] = [a[j], a[i]];
  }
  return a;
}

function prepareCombatDrawPile(deck, cards) {
  const rest = [];
  const innate = [];
  for (const id of deck) {
    if (cards[id]?.innate === true) innate.push(id);
    else rest.push(id);
  }
  return rest.concat(innate);
}

// 공격 피해 공식 — Lua CalcPlayerAttack(힘·약화) + DealDamageToTarget(취약)과 동기화.
// floor((base + str) * (weak>0 ? 0.75 : 1)) → floor(... * (vulnOnTarget>0 ? 1.5 : 1))
// 보상 카드 등급 추첨 (Lua OfferReward 미러) — roll ∈ 1..100, normal 70 / unique 25 / legend 5
export function rarityForRoll(roll) {
  if (roll > 95) return 'legend';
  if (roll > 70) return 'unique';
  return 'normal';
}

export function calcAttack(base, str, weak, vulnOnTarget) {
  let dmg = base + str;
  if (weak > 0) dmg = Math.floor(dmg * 0.75);
  if (vulnOnTarget > 0) dmg = Math.floor(dmg * 1.5);
  if (dmg < 0) dmg = 0;
  return dmg;
}

// 방어 우선 차감 후 hp 적용 → { hp, block }
export function applyDamage(hp, block, amount) {
  let dmg = amount;
  if (block > 0) {
    const absorbed = Math.min(block, dmg);
    block -= absorbed;
    dmg -= absorbed;
  }
  hp -= dmg;
  if (hp < 0) hp = 0;
  return { hp, block };
}

export function loadData() {
  const cardsData = JSON.parse(readFileSync('data/cards.json', 'utf8'));
  const enemiesData = JSON.parse(readFileSync('data/enemies.json', 'utf8'));
  const ids = enemiesData.simEncounter || [enemiesData.activeEnemy];
  const monsters = ids.map((id) => {
    const e = enemiesData.enemies[id];
    if (!e) throw new Error(`simEncounter 적 없음: ${id}`);
    return { name: e.name, maxHp: e.maxHp, intents: e.intents };
  });
  // 시뮬 기본 덱은 전사 시작 덱 (클래스별 시뮬은 starterDeck 직접 주입으로 가능)
  return { cards: cardsData.cards, starterDeck: cardsData.starterDecks.warrior, monsters };
}

function canPlayCardNow(card, ctx = {}) {
  if (!card) return false;
  if (card.playableWhenDrawPileEmpty === true && (ctx.drawPileCount || 0) > 0) return false;
  return true;
}

// 주의: 인게임은 플레이어가 카드를 직접 선택한다. 이 chooseAction은 밸런스 추정용 자동 플레이 휴리스틱일 뿐
// 이며, Lua에 대응 AI가 없다(동기화 대상은 데미지/방어/의도/승패 규칙이지 플레이어 선택이 아님).
// 손패에서 낼 카드 인덱스(-1=종료). 파워 우선(지속 가치) → 공격 → 스킬.
export function chooseAction(hand, cards, energy, ctx = {}) {
  const entries = hand.map((id, i) => ({ id, i })).filter((x) => {
    const card = cards[x.id];
    if (!card || card.unplayable || !canPlayCardNow(card, ctx)) return false;
    let effectiveCost = card.cost || 0;
    if (ctx.handCostZeroThisTurn === true) effectiveCost = 0;
    else if (card.useAllEnergy === true) effectiveCost = 1;
    else if (card.kind === 'Skill') {
      if (ctx.nextSkillCostZero === true) effectiveCost = 0;
      else effectiveCost = Math.max(0, effectiveCost - (ctx.skillCostReductionThisTurn || 0));
    }
    return card.useAllEnergy === true ? true : effectiveCost <= energy;
  });
  const powers = entries.filter((x) => cards[x.id].kind === 'Power');
  const attacks = entries.filter((x) => cards[x.id].kind === 'Attack');
  const skills = entries.filter((x) => cards[x.id].kind === 'Skill');
  const effectiveCost = (card) => {
    let cost = card.cost || 0;
    if (ctx.handCostZeroThisTurn === true) cost = 0;
    else if (card.useAllEnergy === true) cost = 1;
    else if (card.kind === 'Skill') {
      if (ctx.nextSkillCostZero === true) cost = 0;
      else cost = Math.max(0, cost - (ctx.skillCostReductionThisTurn || 0));
    }
    return cost;
  };
  const dmgEff = (x) => (cards[x.id].damage || 0) / Math.max(effectiveCost(cards[x.id]), 1);
  const blkEff = (x) => (cards[x.id].block || 0) / Math.max(effectiveCost(cards[x.id]), 1);
  const bestBy = (list, fn) => list.slice().sort((a, b) => fn(b) - fn(a))[0];
  if (powers.length) return powers[0].i;
  if (attacks.length) return bestBy(attacks, dmgEff).i;
  if (skills.length) return bestBy(skills, blkEff).i;
  return -1;
}

// 공격 타겟 선택: 이번 타격으로 처치 가능한 최소 유효체력, 없으면 유효체력 최소.
export function chooseTarget(aliveMonsters, plannedDamage) {
  const eff = (m) => m.hp + m.block;
  const killable = aliveMonsters.filter((m) => eff(m) <= plannedDamage);
  const pool = killable.length ? killable : aliveMonsters;
  return pool.slice().sort((a, b) => eff(a) - eff(b) || pool.indexOf(a) - pool.indexOf(b))[0];
}

function bump(s, cost, dmg, blk) {
  s = s || { plays: 0, energy: 0, damage: 0, block: 0 };
  s.plays++; s.energy += cost; s.damage += dmg; s.block += blk;
  return s;
}

// 단일 전투 시뮬. stats(선택): {cardId: {plays,energy,damage,block}} 누적.
// 반환: { win, turns, playerHpRemaining, draw? }
export function simulateCombat(data, rng, stats) {
  const { cards, starterDeck, monsters } = data;
  if (monsters.length === 0) return { win: true, turns: 0, playerHpRemaining: PLAYER_HP };
  let drawPile = prepareCombatDrawPile(shuffle(starterDeck, rng), cards);
  let discard = [];
  const exhaust = [];
  let hand = [];
  let pHp = PLAYER_HP, pBlock = 0;
  let pStr = 0, pDex = 0, pThorns = 0, pWeak = 0, pVuln = 0, pIntangible = 0;
  let blockGainMultiplier = 1;
  let handCostZeroThisTurn = false;
  let drawDisabledThisTurn = false;
  let nextSkillCostZero = false;
  let nextSkillRepeatCount = 0;
  let skillCostReductionThisTurn = 0;
  let nextTurnBlock = 0, nextTurnDraw = 0, nextTurnKeepBlock = false;
  let nextTurnAttackMultiplier = 1, turnAttackMultiplier = 1;
  let nextTurnAddCards = [];
  let turnAttackCardsPlayed = 0, turnDiscardedCards = 0;
  let shivFirstDamageBonusUsed = false;
  let drawDamageThisTurn = 0;
  let drawPoisonThisTurn = 0;
  let shivAoeThisCombat = false;
  let cardsDrawnThisCombat = 0;
  let bonusRewardScreens = 0;
  let activeKillReward = 0;
  let energy = 0;
  const powers = [];
  const mob = monsters.map((m) => ({
    name: m.name, hp: m.maxHp, maxHp: m.maxHp, block: 0, str: 0, weak: 0, vuln: 0, poison: 0,
    intents: m.intents, intentIdx: 0, alive: true,
  }));
  let turns = 0;

  function draw(n) {
    const drawn = [];
    if (drawDisabledThisTurn === true) return drawn;
    for (let k = 0; k < n; k++) {
      if (drawPile.length === 0) { drawPile = shuffle(discard, rng); discard = []; }
      if (drawPile.length === 0) break;
      const card = drawPile.pop();
      drawn.push(card);
      cardsDrawnThisCombat++;
      const drawDamage = powerFieldTotal('drawDamage') + drawDamageThisTurn;
      const drawPoison = powerFieldTotal('drawPoison') + drawPoisonThisTurn;
      if ((drawDamage > 0 || drawPoison > 0) && mob.some((m) => m.alive)) {
        for (const m of mob) {
          if (!m.alive) continue;
          let dmg = drawDamage;
          if (m.vuln > 0) dmg = Math.floor(dmg * 1.5);
          if (m.block > 0) {
            const absorbed = Math.min(m.block, dmg);
            m.block -= absorbed;
            dmg -= absorbed;
          }
          if (drawPoison > 0) m.poison += drawPoison;
          if (dmg > 0) m.hp -= dmg;
          if (m.hp <= 0) { m.hp = 0; m.alive = false; }
        }
      }
      // 손패 10장 상한 — 초과 드로는 자동 버림 (Lua DrawCards 동기화)
      if (hand.length >= 10) {
        discard.push(card);
        triggerSly(card);
      } else hand.push(card);
    }
    return drawn;
  }
  function addCardsToHand(id, n) {
    for (let k = 0; k < n; k++) {
      if (hand.length >= 10) discard.push(id);
      else hand.push(id);
    }
  }
  function addBlock(base) {
    let amount = base || 0;
    if (amount > 0) amount += pDex;
    if (blockGainMultiplier > 1) amount *= blockGainMultiplier;
    if (amount < 0) amount = 0;
    pBlock += amount;
    return amount;
  }
  function discardForTurnStart(n) {
    const cnt = Math.min(n, hand.length);
    for (let i = 0; i < cnt; i++) {
      const idx = hand
        .map((id, k) => ({ id, k, card: cards[id] }))
        .sort((a, b) => {
          const ac = a.card?.cost || 0;
          const bc = b.card?.cost || 0;
          if (ac !== bc) return ac - bc;
          const ad = a.card?.damage || 0;
          const bd = b.card?.damage || 0;
          if (ad !== bd) return ad - bd;
          return a.k - b.k;
        })[0]?.k;
      if (idx == null) break;
      discardHandCard(idx, true);
    }
  }
  function countOtherHandSkills(currentId) {
    let n = 0;
    let skippedSelf = false;
    for (const id of hand) {
      if (!skippedSelf && id === currentId) { skippedSelf = true; continue; }
      if (cards[id]?.kind === 'Skill') n++;
    }
    return n;
  }
  function attackBaseForCard(id, c) {
    let base = c.damage || 0;
    const otherHand = Math.max(0, hand.length - 1);
    if (c.damagePerOtherHandCard) base += otherHand * c.damagePerOtherHandCard;
    if (c.damagePerAttackPlayedThisTurn) base += turnAttackCardsPlayed * c.damagePerAttackPlayedThisTurn;
    if (c.damagePerDiscardedThisTurn) base += turnDiscardedCards * c.damagePerDiscardedThisTurn;
    if (c.damagePerSkillInHand) base += countOtherHandSkills(id) * c.damagePerSkillInHand;
    if (c.damagePerCardDrawnThisCombat) base += cardsDrawnThisCombat * c.damagePerCardDrawnThisCombat;
    if (c.class === 'shiv') {
      if (powerFieldTotal('shivDamageBonus') > 0) base += powerFieldTotal('shivDamageBonus');
      if (!shivFirstDamageBonusUsed && powerFieldTotal('firstShivDamageBonus') > 0) base += powerFieldTotal('firstShivDamageBonus');
    }
    if (base < 0) base = 0;
    return base;
  }
  function queueNextTurnAddCard(id, n) {
    if (!id || !n || n <= 0) return;
    const entry = nextTurnAddCards.find((x) => x.cardId === id);
    if (entry) entry.amount += n;
    else nextTurnAddCards.push({ cardId: id, amount: n });
  }
  function queueNextTurnEffects(c) {
    if (!c) return;
    if (c.nextTurnBlock) nextTurnBlock += c.nextTurnBlock;
    if (c.nextTurnDraw) nextTurnDraw += c.nextTurnDraw;
    if (c.nextTurnKeepBlock === true) nextTurnKeepBlock = true;
    if (c.nextTurnAttackMultiplier && c.nextTurnAttackMultiplier > 0) nextTurnAttackMultiplier *= c.nextTurnAttackMultiplier;
  }
  function queueSelectedReserve(c) {
    if (!c?.nextTurnSelectHandCard || !c.nextTurnCopies || hand.length === 0) return;
    const choice = hand
      .map((id, i) => ({ id, i, card: cards[id] }))
      .sort((a, b) => {
        const ak = a.card?.kind === 'Attack' ? 3 : a.card?.kind === 'Skill' ? 2 : 1;
        const bk = b.card?.kind === 'Attack' ? 3 : b.card?.kind === 'Skill' ? 2 : 1;
        if (bk !== ak) return bk - ak;
        const ad = a.card?.damage || 0;
        const bd = b.card?.damage || 0;
        if (bd !== ad) return bd - ad;
        return a.i - b.i;
      })[0];
    if (choice?.id) queueNextTurnAddCard(choice.id, c.nextTurnCopies);
  }
  const aliveList = () => mob.filter((m) => m.alive);
  function powerFieldTotal(field) {
    let total = 0;
    for (const pid of powers) {
      const pc = cards[pid];
      if (pc?.[field] != null) total += pc[field];
    }
    return total;
  }
  function resolveCardEffects(id, c, costSpent, recordStats = true) {
    const alive = aliveList();
    let dmg = 0;
    let blockGained = 0;
    if (c.blockGainMultiplier && c.blockGainMultiplier > 0) blockGainMultiplier *= c.blockGainMultiplier;
    if (c.nextSkillCostZero === true) nextSkillCostZero = true;
    if (c.nextSkillRepeatCount && c.nextSkillRepeatCount > 0) nextSkillRepeatCount += c.nextSkillRepeatCount;
    if (c.skillCostReductionThisTurn && c.skillCostReductionThisTurn > 0) skillCostReductionThisTurn += c.skillCostReductionThisTurn;
    if (c.handCostZeroThisTurn === true) handCostZeroThisTurn = true;
    if (c.drawDisabledThisTurn === true) drawDisabledThisTurn = true;
    if (c.drawDamage && c.kind !== 'Power') drawDamageThisTurn += c.drawDamage;
    if (c.drawPoison && c.kind !== 'Power') drawPoisonThisTurn += c.drawPoison;
    if (c.shivAoe === true && c.kind !== 'Power') shivAoeThisCombat = true;
    const xEnergy = costSpent || 0;
    if (c.kind === 'Attack') {
      if (alive.length && (c.damage || c.xDamagePerEnergy)) {
        const baseDamage = c.xDamagePerEnergy ? xEnergy * c.xDamagePerEnergy : attackBaseForCard(id, c);
        const bonusHits = (c.otherHandAtLeast && c.bonusHitsWhenOtherHandAtLeast && Math.max(0, hand.length - 1) >= c.otherHandAtLeast)
          ? c.bonusHitsWhenOtherHandAtLeast : 0;
        const hitN = (c.hits || 1) + bonusHits;
        const preview = calcAttack(baseDamage || 0, pStr, pWeak, 0) * turnAttackMultiplier;
        const target = chooseTarget(alive, preview);
        if (c.weak) target.weak += c.weak;
        if (c.vuln) target.vuln += c.vuln;
        let totalNv = 0;
        for (let h = 0; h < hitN; h++) totalNv += calcAttack(baseDamage || 0, pStr, pWeak, 0) * turnAttackMultiplier;
        dmg = totalNv;
        let useAoe = c.aoe === true;
        if (c.class === 'shiv' && shivAoeThisCombat === true) useAoe = true;
        if (useAoe === true) {
          for (const m2 of aliveList()) {
            let d2 = m2.vuln > 0 ? Math.floor(totalNv * 1.5) : totalNv;
            if (m2.weak > 0 && c.attackDamageVsWeakMultiplier && c.attackDamageVsWeakMultiplier > 1) {
              d2 = Math.floor(d2 * c.attackDamageVsWeakMultiplier);
            }
            const r2 = applyDamage(m2.hp, m2.block, d2);
            m2.hp = r2.hp; m2.block = r2.block;
            const attackPoison = powerFieldTotal('attackPoison');
            if (d2 > 0 && attackPoison > 0) m2.poison += attackPoison;
            if (m2.hp <= 0) {
              m2.alive = false;
              if (c.rewardOnKill) bonusRewardScreens += c.rewardOnKill;
            }
          }
        } else {
          dmg = target.vuln > 0 ? Math.floor(totalNv * 1.5) : totalNv;
          if (target.weak > 0 && c.attackDamageVsWeakMultiplier && c.attackDamageVsWeakMultiplier > 1) {
            dmg = Math.floor(dmg * c.attackDamageVsWeakMultiplier);
          }
          if (c.pierce === true) {
            target.hp -= dmg;
            if (target.hp < 0) target.hp = 0;
          } else {
            const r = applyDamage(target.hp, target.block, dmg);
            target.hp = r.hp; target.block = r.block;
          }
          const attackPoison = powerFieldTotal('attackPoison');
          if (dmg > 0 && attackPoison > 0) target.poison += attackPoison;
          if (target.hp <= 0) {
            target.alive = false;
            if (c.rewardOnKill) bonusRewardScreens += c.rewardOnKill;
          }
        }
      }
      if (c.block) blockGained = addBlock(c.block);
    } else if (c.kind === 'Power') {
      if (recordStats) powers.push(id);
    } else {
      if (c.block) blockGained = addBlock(c.block);
      const weakAmount = (c.weak || 0) + (c.xWeakPerEnergy || 0) * xEnergy;
      if ((weakAmount || c.vuln || c.poison) && alive.length) {
        const target = chooseTarget(alive, 0);
        if (weakAmount) target.weak += weakAmount;
        if (c.vuln) target.vuln += c.vuln;
        if (c.poison) {
          const poisonHits = c.poisonHits || 1;
          for (let i = 0; i < poisonHits; i++) {
            const target2 = c.poisonRandomTargets === true
              ? alive[Math.floor(rng() * alive.length)]
              : target;
            if (target2) target2.poison += c.poison;
          }
        }
        if (c.class === 'shiv' && !shivFirstDamageBonusUsed && powerFieldTotal('firstShivDamageBonus') > 0) {
          shivFirstDamageBonusUsed = true;
        }
      }
    }
    if (c.strength) pStr += c.strength;
    if (c.dex) pDex += c.dex;
    if (c.thorns) pThorns += c.thorns;
    if (c.selfVuln) pVuln += c.selfVuln;
    if (c.heal) pHp = Math.min(pHp + c.heal, PLAYER_HP);
    if (c.gainEnergy) energy += c.gainEnergy;
    activeKillReward = c.rewardOnKill || 0;
    if (c.intangible) pIntangible += c.intangible;
    queueNextTurnEffects(c);
    let drawnCards = [];
    if (c.draw) drawnCards = drawnCards.concat(draw(c.draw));
    if (c.drawUntilHandSize) {
      const need = c.drawUntilHandSize - Math.max(0, hand.length - 1);
      if (need > 0) drawnCards = drawnCards.concat(draw(need));
    }
    if (c.drawSkillBlock && c.drawSkillBlock > 0) {
      for (const drawnId of drawnCards) {
        if (cards[drawnId]?.kind === 'Skill') blockGained += addBlock(c.drawSkillBlock);
      }
    }
    if (c.addShiv && !c.discard && c.discardAll !== true) addCardsToHand('Shiv', c.addShiv);
    if (c.cardPlayedDamage && alive.length) {
      const target = chooseTarget(aliveList(), 0);
      if (target && target.alive) {
        target.hp -= c.cardPlayedDamage;
        dmg += c.cardPlayedDamage;
        if (target.hp <= 0) target.alive = false;
      }
    }
    if (c.cardPlayedRandomDamage && alive.length) {
      const pool = aliveList();
      if (pool.length) {
        const target = pool[Math.floor(rng() * pool.length)];
        if (target) {
          target.hp -= c.cardPlayedRandomDamage;
          dmg += c.cardPlayedRandomDamage;
          if (target.hp <= 0) target.alive = false;
        }
      }
    }
    if (recordStats && stats) stats[id] = bump(stats[id], costSpent, dmg, blockGained);
  }
  function triggerSly(id) {
    const c = cards[id];
    if (!c?.sly) return;
    resolveCardEffects(id, c, 0, false);
  }
  function discardHandCard(idx, trigger = true) {
    const [id] = hand.splice(idx, 1);
    if (!id) return;
    discard.push(id);
    turnDiscardedCards++;
    if (trigger) triggerSly(id);
  }
  function applyDiscardEffects(c) {
    let discarded = 0;
    if (c.discardAll) {
      while (hand.length) { discardHandCard(hand.length - 1, true); discarded++; }
    } else if (c.discard) {
      const n = Math.min(c.discard, hand.length);
      for (let i = 0; i < n; i++) { discardHandCard(hand.length - 1, true); discarded++; }
    }
    if (c.addShiv && (c.discard || c.discardAll === true)) addCardsToHand('Shiv', c.addShiv);
    if (c.addShivPerDiscard === true) addCardsToHand('Shiv', discarded);
    if (c.drawPerDiscarded) draw(discarded * c.drawPerDiscarded);
  }

  while (turns < MAX_TURNS) {
    turns++;
    turnAttackCardsPlayed = 0;
    turnDiscardedCards = 0;
    shivFirstDamageBonusUsed = false;
    drawDamageThisTurn = 0;
    drawPoisonThisTurn = 0;
    shivAoeThisCombat = false;
    blockGainMultiplier = 1;
    handCostZeroThisTurn = false;
    drawDisabledThisTurn = false;
    skillCostReductionThisTurn = 0;
    // 파워 발동 — Lua StartPlayerTurn 동기화 (블록 리셋 후 strength/energy/block 파워)
    if (nextTurnKeepBlock === true) nextTurnKeepBlock = false;
    else pBlock = 0;
    turnAttackMultiplier = nextTurnAttackMultiplier;
    nextTurnAttackMultiplier = 1;
    let energyBonus = 0;
    let powerTurnDraw = 0;
    let powerTurnDiscard = 0;
    for (const pid of powers) {
      const pc = cards[pid];
      if (!pc) continue;
      if (pc.powerEffect === 'strengthPerTurn') pStr += pc.value;
      else if (pc.powerEffect === 'energyPerTurn') energyBonus += pc.value;
      else if (pc.powerEffect === 'blockPerTurn') pBlock += pc.value;
      else if (pc.powerEffect === 'poisonPerTurn') {
        for (const m of mob) if (m.alive) m.poison += pc.value;
      } else if (pc.powerEffect === 'damagePerTurn') {
        for (const m of mob) {
          if (!m.alive) continue;
          const r = applyDamage(m.hp, m.block, pc.value || 0);
          m.hp = r.hp; m.block = r.block;
          if (m.hp <= 0) m.alive = false;
        }
      }
      if (pc.turnStartShiv) addCardsToHand('Shiv', pc.turnStartShiv);
      if (pc.turnStartDraw) powerTurnDraw += pc.turnStartDraw;
      if (pc.turnStartDiscard) powerTurnDiscard += pc.turnStartDiscard;
    }
    if (nextTurnBlock > 0) { addBlock(nextTurnBlock); nextTurnBlock = 0; }
    if (nextTurnAddCards.length) {
      for (const entry of nextTurnAddCards) addCardsToHand(entry.cardId, entry.amount);
      nextTurnAddCards = [];
    }
    energy = ENERGY + energyBonus;
    const drawBonus = nextTurnDraw + powerTurnDraw;
    nextTurnDraw = 0;
    draw(HAND_SIZE + drawBonus);
    if (powerTurnDiscard > 0) discardForTurnStart(powerTurnDiscard);
    while (true) {
      const alive = aliveList();
      if (alive.length === 0) break;
      const idx = chooseAction(hand, cards, energy, { drawPileCount: drawPile.length, nextSkillCostZero, skillCostReductionThisTurn, handCostZeroThisTurn });
      if (idx < 0) break;
      const id = hand[idx], c = cards[id];
      const skillFree = c.kind === 'Skill' && nextSkillCostZero === true;
      const skillRepeat = c.kind === 'Skill' ? nextSkillRepeatCount : 0;
      const baseCost = c.cost || 0;
      const cost = handCostZeroThisTurn === true ? 0 : (c.useAllEnergy === true ? energy : (skillFree ? 0 : (c.kind === 'Skill' ? Math.max(0, baseCost - skillCostReductionThisTurn) : baseCost)));
      energy -= cost;
      resolveCardEffects(id, c, cost);
      const playedBlock = powerFieldTotal('cardPlayedBlock');
      if (playedBlock > 0) addBlock(playedBlock);
      if (c.cardPlayedDamage && alive.length) {
        const target = chooseTarget(aliveList(), 0);
        if (target && target.alive) {
          target.hp -= c.cardPlayedDamage;
          dmg += c.cardPlayedDamage;
          if (target.hp <= 0) target.alive = false;
        }
      }
      if (c.cardPlayedRandomDamage && alive.length) {
        const pool = aliveList();
        if (pool.length) {
          const target = pool[Math.floor(rng() * pool.length)];
          if (target) {
            target.hp -= c.cardPlayedRandomDamage;
            dmg += c.cardPlayedRandomDamage;
            if (target.hp <= 0) target.alive = false;
          }
        }
      }
      if (skillRepeat > 0) {
        nextSkillRepeatCount = Math.max(0, nextSkillRepeatCount - skillRepeat);
        for (let r = 0; r < skillRepeat; r++) {
          resolveCardEffects(id, c, cost);
          if (playedBlock > 0) addBlock(playedBlock);
          if (c.cardPlayedDamage && alive.length) {
            const target = chooseTarget(aliveList(), 0);
            if (target && target.alive) {
              target.hp -= c.cardPlayedDamage;
              dmg += c.cardPlayedDamage;
              if (target.hp <= 0) target.alive = false;
            }
          }
          if (c.cardPlayedRandomDamage && alive.length) {
            const pool = aliveList();
            if (pool.length) {
              const target = pool[Math.floor(rng() * pool.length)];
              if (target) {
                target.hp -= c.cardPlayedRandomDamage;
                dmg += c.cardPlayedRandomDamage;
                if (target.hp <= 0) target.alive = false;
              }
            }
          }
        }
      }
      if (c.kind === 'Attack') turnAttackCardsPlayed++;
      if (skillFree === true && c.nextSkillCostZero !== true) nextSkillCostZero = false;
      hand.splice(idx, 1);
      queueSelectedReserve(c);
      if (c.exhaust === true || String(c.desc || '').includes('소멸.')) exhaust.push(id);
      else if (c.kind !== 'Power') discard.push(id);
      applyDiscardEffects(c);
      if (aliveList().length === 0) return { win: true, turns, playerHpRemaining: pHp, bonusRewardScreens };
    }
    // 화상(endTurnDamage) — 손패에 있으면 턴 종료 시 피해 (Lua EndPlayerTurn 동기화)
    let burn = 0;
    for (const hid of hand) { const hc = cards[hid]; if (hc && hc.endTurnDamage) burn += hc.endTurnDamage; }
    if (burn > 0) { pHp -= burn; if (pHp < 0) pHp = 0; }
    const kept = [];
    for (const hid of hand) {
      const hc = cards[hid];
      if (hc?.retain === true || (hc?.class === 'shiv' && powerFieldTotal('shivRetain') > 0)) kept.push(hid);
      else discard.push(hid);
    }
    hand = kept;
    for (const pid of powers) {
      const pc = cards[pid];
      if (pc?.endTurnDexLoss) {
        pDex -= pc.endTurnDexLoss;
        if (pDex < 0) pDex = 0;
      }
    }
    if (pIntangible > 0) pIntangible--;
    if (pHp <= 0) return { win: false, turns, playerHpRemaining: 0 };
    // 플레이어 디버프 감소 — Lua EndPlayerTurn 동기화 (적 행동 전)
    if (pWeak > 0) pWeak--;
    if (pVuln > 0) pVuln--;
    for (const m of mob) {
      if (!m.alive) continue;
      // 독 틱 — 행동 시작 시 (Lua EnemyActStep 동기화). 사망 시 행동 생략
      if (m.poison > 0) {
        m.hp -= m.poison;
        m.poison--;
        if (m.hp <= 0) { m.hp = 0; m.alive = false; continue; }
      }
      m.block = 0; // 매 턴 초기화 (이전 턴 블록 미이월)
      // 정의된 intent 중 랜덤 선택 (Lua EnemyActStep 동기화 — 순차→랜덤)
      const it = m.intents.length ? m.intents[Math.floor(rng() * m.intents.length)] : null;
      if (it) {
        if (it.kind === 'Attack') {
          const atk = calcAttack(it.value, m.str, m.weak, pVuln);
          const beforeHp = pHp;
          let incoming = atk;
          if (pIntangible > 0 && incoming > 1) incoming = 1;
          const r = applyDamage(pHp, pBlock, incoming); pHp = r.hp; pBlock = r.block;
          if (beforeHp > pHp && pThorns > 0) {
            m.hp -= pThorns;
            if (m.hp <= 0) m.alive = false;
          }
        } else if (it.kind === 'Defend') { m.block += it.value; }
        else if (it.kind === 'Debuff') {
          if (it.effect === 'weak') pWeak += it.value;
          else if (it.effect === 'vuln') pVuln += it.value;
        } else if (it.kind === 'AddCard') {
          // StS2식 덱 오염 — 저주 카드를 버린 더미에 추가 (Lua 동기화)
          const cnt = it.count || 1;
          for (let k = 0; k < cnt; k++) discard.push(it.card);
        }
      }
      // 적 디버프 감소 — Lua EnemyActStep 동기화 (자기 행동 후)
      if (m.weak > 0) m.weak--;
      if (m.vuln > 0) m.vuln--;
      if (pHp <= 0) return { win: false, turns, playerHpRemaining: 0 };
    }
    // 독 사망 등 적 페이즈 중 전멸 처리 (Lua FinishEnemyTurn→CheckCombatEnd 동기화)
    if (!mob.some((m) => m.alive)) return { win: true, turns, playerHpRemaining: pHp, bonusRewardScreens };
  }
  return { win: false, turns, playerHpRemaining: pHp, draw: true, bonusRewardScreens };
}

function mean(a) { return a.length ? a.reduce((s, x) => s + x, 0) / a.length : 0; }
function median(a) {
  if (!a.length) return 0;
  const s = a.slice().sort((x, y) => x - y), m = Math.floor(s.length / 2);
  return s.length % 2 ? s[m] : (s[m - 1] + s[m]) / 2;
}

export function runBatch(N, seed) {
  const data = loadData();
  const rng = mulberry32(seed);
  const cardStats = {};
  let wins = 0, draws = 0;
  const turnsArr = [], hpArr = [];
  for (let i = 0; i < N; i++) {
    const r = simulateCombat(data, rng, cardStats);
    if (r.draw) draws++;
    if (r.win) { wins++; hpArr.push(r.playerHpRemaining); }
    turnsArr.push(r.turns);
  }
  return {
    N, wins, draws, losses: N - wins - draws,
    winRate: wins / N,
    avgTurns: mean(turnsArr), medianTurns: median(turnsArr),
    avgHpOnWin: mean(hpArr),
    cardStats, cards: data.cards, monsters: data.monsters, seed,
  };
}

export function formatReport(r) {
  const L = [];
  L.push(`=== 밸런스 시뮬레이션 (인카운터: ${r.monsters.map((m) => `${m.name}(${m.maxHp})`).join(', ')}) ===`);
  L.push(`시뮬 ${r.N}회 (seed=${r.seed})`);
  L.push(`승률: ${(r.winRate * 100).toFixed(1)}%  (승 ${r.wins} / 패 ${r.losses}${r.draws ? ` / 무 ${r.draws}` : ''})`);
  L.push(`평균 턴: ${r.avgTurns.toFixed(2)}  중앙값 턴: ${r.medianTurns}`);
  L.push(`승리 시 평균 잔여 HP: ${r.avgHpOnWin.toFixed(1)} / ${PLAYER_HP}`);
  if (r.draws) L.push(`⚠️ 무승부 ${r.draws}건 (턴 상한 ${MAX_TURNS} 초과)`);
  L.push('');
  L.push('카드별:');
  const rows = Object.entries(r.cardStats).map(([id, s]) => {
    const kind = r.cards[id].kind;
    const eff = kind === 'Attack' ? s.damage / s.energy : s.block / s.energy;
    return { id, name: r.cards[id].name, kind, plays: s.plays, eff };
  });
  for (const kind of ['Attack', 'Skill', 'Power']) {
    const kr = rows.filter((x) => x.kind === kind);
    if (!kr.length) continue;
    const med = median(kr.map((x) => x.eff));
    const unit = kind === 'Attack' ? '뎀/E' : kind === 'Power' ? '(지속)' : '블록/E';
    for (const x of kr) {
      const op = med > 0 && x.eff >= med * 1.5 ? '  ⚠️ OP 의심' : '';
      L.push(`  ${x.name}(${x.id}): 사용 ${x.plays}, 효율 ${x.eff.toFixed(2)} ${unit}${op}`);
    }
  }
  const sorted = rows.slice().sort((a, b) => b.plays - a.plays);
  if (sorted.length) L.push(`최다 사용: ${sorted[0].name} / 최소 사용: ${sorted[sorted.length - 1].name}`);
  return L.join('\n');
}

function main() {
  const args = process.argv.slice(2);
  let N = 2000, seed = 1;
  for (let i = 0; i < args.length; i++) {
    if (args[i] === '--seed') seed = parseInt(args[++i], 10);
    else if (/^\d+$/.test(args[i])) N = parseInt(args[i], 10);
  }
  console.log(formatReport(runBatch(N, seed)));
}

if (process.argv[1] && process.argv[1].endsWith('sim-balance.mjs')) main();