// Simple Blackjack implementation
    const SUITS = ['♠','♥','♦','♣'];
    const RANKS = ['A','2','3','4','5','6','7','8','9','10','J','Q','K'];

    // DOM
    const dealerHandEl = document.getElementById('dealer-hand');
    const playerHandEl = document.getElementById('player-hand');
    const dealerValueEl = document.getElementById('dealer-value');
    const playerValueEl = document.getElementById('player-value');
    const balanceEl = document.getElementById('balance');
    const betInput = document.getElementById('bet-input');
    const betBtn = document.getElementById('bet-btn');
    const currentBetEl = document.getElementById('current-bet');
    const hitBtn = document.getElementById('hit');
    const standBtn = document.getElementById('stand');
    const doubleBtn = document.getElementById('double');
    const newRoundBtn = document.getElementById('new-round');
    const messageEl = document.getElementById('message');

    let deck = [];
    let dealer = [];
    let player = [];
    let dealerHidden = true;
    let balance = 1000;
    let currentBet = 0;
    let inRound = false;

    function makeDeck(){
      deck = [];
      for(const s of SUITS){
        for(const r of RANKS){
          deck.push({suit:s,rank:r});
        }
      }
    }

    function shuffle(){
      for(let i=deck.length-1;i>0;i--){
        const j = Math.floor(Math.random()*(i+1));
        [deck[i],deck[j]] = [deck[j],deck[i]];
      }
    }

    function cardValue(card){
      const r = card.rank;
      if(r==='A') return [1,11];
      if(['J','Q','K'].includes(r)) return [10];
      return [parseInt(r,10)];
    }

    function handValues(hand){
      // returns best value <=21 or smallest if bust
      let totals = [0];
      for(const c of hand){
        const vals = cardValue(c);
        const newTotals = [];
        for(const t of totals){
          for(const v of vals){ newTotals.push(t+v); }
        }
        totals = Array.from(new Set(newTotals));
      }
      // separate <=21 and >21
      const valid = totals.filter(t=>t<=21);
      if(valid.length) return Math.max(...valid);
      return Math.min(...totals);
    }

    function renderHand(el,hand,hideFirst=false){
      el.innerHTML='';
      hand.forEach((c,i)=>{
        const div = document.createElement('div');
        div.className='card'+(c.suit==='♥'||c.suit==='♦'?' red':'');
        if(hideFirst && i===0){ div.className='card back'; div.textContent='TERSEMBUNYI'; }
        else{
          const top = document.createElement('div'); top.textContent = c.rank + ' ' + c.suit; // top-left
          const bot = document.createElement('div'); bot.style.alignSelf='flex-end'; bot.textContent = c.rank + ' ' + c.suit; // bottom-right
          div.appendChild(top); div.appendChild(bot);
        }
        el.appendChild(div);
      });
    }

    function updateUI(){
      renderHand(dealerHandEl,dealer,dealerHidden);
      renderHand(playerHandEl,player,false);
      dealerValueEl.textContent = dealerHidden ? '??' : 'Nilai: '+handValues(dealer);
      playerValueEl.textContent = 'Nilai: '+handValues(player);
      balanceEl.textContent = balance;
      currentBetEl.textContent = currentBet;
    }

    function startRound(){
      if(inRound) return;
      const bet = Number(betInput.value) || 0;
      if(bet <=0 || bet > balance){ alert(' BANK TIDAK CUKUP! '); return; }
      currentBet = bet; balance -= bet; inRound=true; dealerHidden=true; messageEl.textContent='';

      makeDeck(); shuffle();
      dealer = [deck.pop(), deck.pop()];
      player = [deck.pop(), deck.pop()];

      // Check for natural blackjack
      updateUI();
      if(handValues(player)===21){
        dealerHidden=false; updateUI();
        const dealerVal = handValues(dealer);
        if(dealerVal===21){ // push
          balance += currentBet; messageEl.textContent = 'Tie (seri). Taruhan dikembalikan.';
        } else {
          // player blackjack 3:2
          const payout = Math.floor(currentBet * 2.5);
          balance += payout; messageEl.textContent = 'Blackjack! You Win.';
        }
        inRound=false; currentBet=0; updateUI();
      } else {
        updateUI();
      }
    }

    function playerHit(){
      if(!inRound) return; player.push(deck.pop()); updateUI();
      const val = handValues(player);
      if(val>21){ // bust
        dealerHidden=false; messageEl.textContent='Bust! Dealer Win!'; inRound=false; currentBet=0; updateUI();
      }
    }

    function playerStand(){
      if(!inRound) return; dealerHidden=false; // reveal dealer
      // dealer plays
      while(handValues(dealer)<17){ dealer.push(deck.pop()); }
      const pv = handValues(player); const dv = handValues(dealer);
      if(dv>21 || pv>dv){ // player wins
        const payout = currentBet*2; balance += payout; messageEl.textContent='You Win!';
      } else if(pv===dv){ // push
        balance += currentBet; messageEl.textContent='Tie (seri).';
      } else { messageEl.textContent='Dealer Win!'; }
      inRound=false; currentBet=0; updateUI();
    }

    function playerDouble(){
      if(!inRound) return;
      if(balance < currentBet){ alert('Bank tidak cukup untuk double.'); return; }
      // double: take exactly one card then stand
      balance -= currentBet; currentBet = currentBet*2; player.push(deck.pop()); updateUI();
      const val = handValues(player);
      if(val>21){ dealerHidden=false; messageEl.textContent='Bust setelah double. Dealer Win!'; inRound=false; currentBet=0; updateUI(); return; }
      playerStand();
    }

    // Events
    betBtn.addEventListener('click', startRound);
    hitBtn.addEventListener('click', playerHit);
    standBtn.addEventListener('click', playerStand);
    doubleBtn.addEventListener('click', playerDouble);
    newRoundBtn.addEventListener('click', ()=>{
      // reset everything
      if(inRound){ if(!confirm('Masih dalam ronde. Ingin reset?')) return; }
      balance = 1000; currentBet=0; inRound=false; dealer=[]; player=[]; deck=[]; dealerHidden=true; messageEl.textContent='Bank di-reset.'; updateUI();
    });

    // keyboard shortcuts
    window.addEventListener('keydown', e=>{
      if(e.key==='h') playerHit();
      if(e.key==='s') playerStand();
      if(e.key==='d') playerDouble();
      if(e.key==='Enter') startRound();
    });

    // initial UI
    updateUI();