const canvas = document.getElementById("board");
if (!canvas) alert("Canvas tidak ditemukan! ID harus 'board'");
const ctx = canvas.getContext("2d");

const CANVAS_W = canvas.width;
const CANVAS_H = canvas.height;

const size = 8;
const tileSize = CANVAS_W / size;

let board = [];
let currentTurn = 1;     // 1 = red, 2 = white
let selected = null;
let history = [];
let gameOver = false;

let aiEnabled = (typeof GAME_MODE !== "undefined" && GAME_MODE === "pvai");
let aiPlays = 2;
let aiThinkingDelay = 300;

let hintsEnabled = (typeof ENABLE_HINTS !== "undefined") ? !!ENABLE_HINTS : true;

// SOUND EFFECTS
const SFX = {
  move: new Audio("assets/sound/move.mp3"),
  capture: new Audio("assets/sound/capture.mp3")
};

let soundEnabled = true;
function playSound(name){
  if(!soundEnabled || !SFX[name]) return;
  SFX[name].currentTime = 0;
  SFX[name].play().catch(()=>{});
}

// TIMER PERMAINAN
let timerSeconds = 0;
let timerInterval = null;
let timerRunning = false;
function startTimer(){ if(timerRunning) return; timerRunning=true; timerInterval=setInterval(()=>{ timerSeconds++; const min=String(Math.floor(timerSeconds/60)).padStart(2,'0'); const sec=String(timerSeconds%60).padStart(2,'0'); const dom=document.getElementById('timer'); if(dom) dom.textContent = `${min}:${sec}`; },1000); }
function stopTimer(){ timerRunning=false; clearInterval(timerInterval); }
function resetTimer(){ stopTimer(); timerSeconds=0; const dom=document.getElementById('timer'); if(dom) dom.textContent='00:00'; }

// PEMBANTU FUNGSI
function opponentOf(p){ return p===1?2:1; }
function inside(r,c){ return Number.isInteger(r) && Number.isInteger(c) && r>=0 && r<size && c>=0 && c<size; }
function belongsTo(v, player){
  return (player===1 && (v===1||v===3)) || (player===2 && (v===2||v===4));
}

// RESET PAPAN
function resetBoard(){
  console.debug("resetBoard()");
  board = Array.from({length:size}, ()=>Array(size).fill(0));
  for(let r=0;r<3;r++) for(let c=0;c<size;c++) if((r+c)%2===1) board[r][c] = 2;
  for(let r=size-3;r<size;r++) for(let c=0;c<size;c++) if((r+c)%2===1) board[r][c] = 1;

  currentTurn = 1;
  selected = null;
  history = [];
  gameOver = false;

  const old = document.getElementById("endPopup");
  if(old) old.remove();

  resetTimer();
  startTimer();

  draw();
  // TRIGGER AI JIKA PERMAINAN DIMULAI OLEH AI
  if(aiEnabled && currentTurn === aiPlays){
    setTimeout(()=> triggerAI(), 120);
  }
}

// MENGGAMBAR PAPAN PADA CANVAS
function draw(){
  // MENGGAMBAR PAPAN
  ctx.clearRect(0,0,CANVAS_W,CANVAS_H);

  for(let r=0;r<size;r++){
    for(let c=0;c<size;c++){
      const x = c * tileSize;
      const y = r * tileSize;
      ctx.fillStyle = (r+c)%2===0? "#f3f4f6" : "#111827";
      ctx.fillRect(x,y,tileSize,tileSize);

      if(selected && selected.r===r && selected.c===c){
        ctx.fillStyle = "rgba(152, 253, 0, 0.58)";
        ctx.fillRect(x,y,tileSize,tileSize);
      }

      const v = board[r][c];
      if(v!==0) drawPiece(x+tileSize/2, y+tileSize/2, v);
    }
  }

  if(selected && hintsEnabled && !gameOver){
    const moves = generateMovesForPiece(selected.r, selected.c, currentTurn);
    drawMoveHints(moves);
  }
}

function drawPiece(cx,cy,v){
  ctx.beginPath();
  ctx.arc(cx,cy,tileSize*0.35,0,Math.PI*2);
  ctx.fillStyle = (v===1||v===3) ? "#ef4444" : "#ffffff";
  ctx.fill(); ctx.closePath();
  if(v===3||v===4){
    ctx.beginPath();
    ctx.arc(cx,cy,tileSize*0.15,0,Math.PI*2);
    ctx.fillStyle = "#fbbf24"; ctx.fill(); ctx.closePath();
  }
}

// MENGGAMBAR HINTS MOVE
function drawMoveHints(moves){
  if(!moves || moves.length===0) return;
  for(const m of moves){
    if(!inside(m.r2,m.c2)) continue;
    const x = m.c2*tileSize, y = m.r2*tileSize;
    ctx.fillStyle = m.capture ? "rgba(220,38,38,0.25)" : "rgba(34,197,94,0.25)";
    ctx.fillRect(x,y,tileSize,tileSize);
    ctx.beginPath();
    ctx.arc(x+tileSize/2, y+tileSize/2, tileSize*0.10, 0, Math.PI*2);
    ctx.fillStyle = m.capture ? "#dc2626" : "#22c55e";
    ctx.fill(); ctx.closePath();

    // GARIS HINT DARI MEMILIH PION KE TUJUAN
    const sx = selected.c*tileSize + tileSize/2;
    const sy = selected.r*tileSize + tileSize/2;
    const tx = x+tileSize/2, ty = y+tileSize/2;
    ctx.beginPath(); ctx.moveTo(sx,sy); ctx.lineWidth = 2; ctx.strokeStyle = "rgba(255,255,255,0.3)"; ctx.lineTo(tx,ty); ctx.stroke(); ctx.closePath();
  }
}

// LOGIKA UNTUK MOVE
function tryMove(r1,c1,r2,c2){
  console.debug("tryMove", {r1,c1,r2,c2, gameOver, currentTurn, aiEnabled});
  if(gameOver) { console.debug("move blocked: gameOver"); return false; }
  if(!inside(r1,c1) || !inside(r2,c2)) { console.debug("move blocked: outside"); return false; }
  const v = board[r1][c1];
  if(!v) { console.debug("move blocked: no piece at source"); return false; }
  if(!belongsTo(v, currentTurn)) { console.debug("move blocked: piece does not belong to currentTurn", currentTurn); return false; }
  if(board[r2][c2] !== 0) { console.debug("move blocked: dest occupied"); return false; }

  const dr = r2 - r1, dc = c2 - c1;
  const isKing = (v===3||v===4);
  const dir = (v===1||v===3) ? -1 : 1;

  // GERAKAN BIASA
  if(Math.abs(dr)===1 && Math.abs(dc)===1){
    if(isKing || dr === dir){
      saveHistory();
      board[r2][c2] = v;
      board[r1][c1] = 0;

      const before = v;
      crownIfNeeded(r2,c2);

      playSound("move");

      if((before === 1 && board[r2][c2] === 3) || (before === 2 && board[r2][c2] === 4)){
    playSound("king");
    }

    switchTurn();
    draw();
    if(!checkWinCondition()) triggerAI();
    return true;

    } else { console.debug("move blocked: wrong direction for non-king"); return false; }
  }

  // MEMAKAN PION
  if(Math.abs(dr)===2 && Math.abs(dc)===2){
    const mr = r1 + dr/2, mc = c1 + dc/2;
    if(!inside(mr,mc)) { console.debug("capture blocked: middle outside"); return false; }
    const mid = board[mr][mc];
    if(mid===0) { console.debug("capture blocked: no mid piece"); return false; }
    if(belongsTo(mid, currentTurn)) { console.debug("capture blocked: mid belongs to same player"); return false; }
    if(isKing || (dr/2) === dir){
      saveHistory();
    board[r2][c2] = v;
    board[r1][c1] = 0;
    board[mr][mc] = 0;

    const before = v;
    crownIfNeeded(r2,c2);
    playSound("capture");

    if((before === 1 && board[r2][c2] === 3) || (before === 2 && board[r2][c2] === 4)){
    playSound("king");
  }

    switchTurn();
    draw();
    if(!checkWinCondition()) triggerAI();
    return true;
    } else { console.debug("capture blocked: wrong direction for non-king"); return false; }
  }

  console.debug("move blocked: invalid delta");
  return false;
}

function crownIfNeeded(r,c){
  if(board[r][c] === 1 && r === 0) board[r][c] = 3;
  if(board[r][c] === 2 && r === size - 1) board[r][c] = 4;
}

function switchTurn(){ currentTurn = (currentTurn===1?2:1); }
function saveHistory(){ history.push(JSON.parse(JSON.stringify(board))); if(history.length>60) history.shift(); }

// MEMBUAT GERAKAN
function generateMovesForPiece(r,c,player){
  const v = board[r][c];
  if(v===0) return [];
  const isKing = (v===3||v===4);
  const dir = player===1? -1 : 1;
  const res = [];

  const dirs = isKing ? [[1,1],[1,-1],[-1,1],[-1,-1]] : [[dir,1],[dir,-1]];
  for(const [dr,dc] of dirs){
    const r2 = r+dr, c2 = c+dc;
    if(inside(r2,c2) && board[r2][c2]===0) res.push({r1:r,c1:c,r2:r2,c2:c2,capture:false});
  }

  const capDirs = [[1,1],[1,-1],[-1,1],[-1,-1]];
  for(const [dr,dc] of capDirs){
    const mr = r+dr, mc = c+dc;
    const r2 = r+dr*2, c2 = c+dc*2;
    if(!inside(mr,mc) || !inside(r2,c2)) continue;
    if(board[r2][c2] !== 0) continue;
    const mid = board[mr][mc];
    if(mid !== 0 && !belongsTo(mid, player)){
      if(isKing || dr === dir) res.push({r1:r,c1:c,r2:r2,c2:c2,capture:true, mr, mc});
    }
  }

  return res;
}

function getAllMovesFor(player){
  const all = [];
  for(let r=0;r<size;r++) for(let c=0;c<size;c++) if(belongsTo(board[r][c], player)) all.push(...generateMovesForPiece(r,c,player));
  return all;
}

// CEK KONDISI MENANG
function checkWinCondition(){
  if(gameOver) return true;
  let red=0, white=0;
  for(let r=0;r<size;r++) for(let c=0;c<size;c++){
    const v = board[r][c];
    if(v===1||v===3) red++;
    if(v===2||v===4) white++;
  }

  if(red===0){ showEnd("KALAH 😢","Semua pion merah hilang","loss"); return true; }
  if(white===0){ showEnd("MENANG 🎉","Semua pion putih hilang","win"); return true; }

  const redMoves = getAllMovesFor(1), whiteMoves = getAllMovesFor(2);
  if(currentTurn===1 && redMoves.length===0){ showEnd("KALAH 😢","Merah tidak dapat bergerak","loss"); return true; }
  if(currentTurn===2 && whiteMoves.length===0){ showEnd("MENANG 🎉","Putih tidak dapat bergerak","win"); return true; }

  return false;
}

// AI MOVE
function aiMakeMove(){
  if(!aiEnabled || currentTurn !== aiPlays || gameOver) { console.debug("aiMakeMove blocked", {aiEnabled, currentTurn, aiPlays, gameOver}); return; }
  const moves = getAllMovesFor(aiPlays);
  if(moves.length === 0) { checkWinCondition(); return; }

  let bestScore = -Infinity, bestMoves = [];
  for(const m of moves){
    let s = 0;
    if(m.capture) s += 100;
    if(aiPlays===2 && m.r2 === size-1) s += 50;
    s += (m.r2 || 0);
    if(s > bestScore){ bestScore = s; bestMoves = [m]; } else if(s === bestScore) bestMoves.push(m);
  }
  const chosen = bestMoves[Math.floor(Math.random()*bestMoves.length)];
  setTimeout(()=>{ tryMove(chosen.r1, chosen.c1, chosen.r2, chosen.c2); draw(); checkWinCondition(); }, aiThinkingDelay);
}

function triggerAI(){ setTimeout(()=>{ if(aiEnabled && currentTurn===aiPlays && !gameOver) aiMakeMove(); }, 120); }

// MENGKLIK PADA KANVAS
canvas.addEventListener("click", (e)=>{
  console.debug("canvas click", {gameOver, aiEnabled, currentTurn});
  if(gameOver) return;
  if(aiEnabled && currentTurn === aiPlays) { console.debug("click ignored: AI turn"); return; }

  const rect = canvas.getBoundingClientRect();
  const x = e.clientX - rect.left, y = e.clientY - rect.top;
  const c = Math.floor(x / tileSize), r = Math.floor(y / tileSize);

  console.debug("click coords", {x,y, r, c});

  if(!inside(r,c)) return;
  const v = board[r][c];

  if(selected){
    if(tryMove(selected.r, selected.c, r, c)){
      selected = null;
    } else if(v!==0 && belongsTo(v, currentTurn)){
      selected = {r,c};
    } else {
      selected = null;
    }
  } else {
    if(v!==0 && belongsTo(v, currentTurn)){
      selected = {r,c};
    }
  }
  draw();
});

// TOGGLE HINTS DENGAN 'H'
document.addEventListener("keydown", (e)=>{ if(e.key.toLowerCase()==='h'){ hintsEnabled = !hintsEnabled; draw(); } });

// BUTTONS
const newBtn = document.getElementById("newBtn");
if(newBtn) newBtn.onclick = ()=> resetBoard();

const undoBtn = document.getElementById("undoBtn");
if(undoBtn) undoBtn.onclick = ()=>{ if(history.length>0){ board = history.pop(); draw(); } };

// LEADERBOARD LOAD & SAVE
async function loadLeaderboard(){
  const box = document.getElementById("leaderboardList");
  if(!box) return;
  try{
    const res = await fetch("load_leaderboard.php");
    if(!res.ok) throw new Error("Network");
    const data = await res.json();
    box.innerHTML = "";
    if(!data || data.length===0){ box.innerHTML = "<p>Belum ada data</p>"; return; }
    data.forEach((row,i)=>{
      const div = document.createElement("div");
      div.className = "lb-row" + (typeof CURRENT_USERNAME!=='undefined' && row.username === CURRENT_USERNAME ? " me" : "");
      div.innerHTML = `<span>${i+1}. ${escapeHtml(row.username)}</span><span>${row.wins}W | ${row.losses}L</span>`;
      box.appendChild(div);
    });
  }catch(err){ console.error("loadLeaderboard error", err); }
}
function escapeHtml(s){ if(!s) return ''; return String(s).replace(/[&<>"']/g,m=>({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'})[m]); }
window.addEventListener("load", ()=>{ loadLeaderboard(); setInterval(loadLeaderboard,10000); });

async function saveResult(result){
  if(typeof CURRENT_USER_ID === 'undefined') return;
  try{
    const res = await fetch("save_result.php",{ method:'POST', headers: {'Content-Type':'application/json'}, body: JSON.stringify({result}) });
    if(res.ok) await loadLeaderboard();
  }catch(err){ console.error("saveResult error", err); }
}

// END GAME POPUP
function showEnd(title, msg, result){
  if(document.getElementById("endPopup")) return;
  gameOver = true;
  stopTimer();

  const div = document.createElement("div");
  div.id = "endPopup";
  div.style = `position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.75);display:flex;justify-content:center;align-items:center;z-index:999999999;pointer-events:auto;`;
  div.innerHTML = `<div style="background:#1e293b;padding:24px;border-radius:12px;width:310px;text-align:center;color:white;">
        <h2 style="margin:0 0 8px">${title}</h2>
        <p style="margin:0 0 16px">${msg}</p><div style="display:flex;gap:8px;justify-content:center;">
        <button id="popupNew" style="background:#0ea5a4;color:white;border:none;padding:10px 18px;border-radius:8px;">New Game</button>
        <button id="popupClose" style="background:#64748b;color:white;border:none;padding:10px 18px;border-radius:8px;">Close</button>
    </div>
  </div>`;
  document.body.appendChild(div);
  // save result async
  saveResult(result).catch(()=>{});
  document.getElementById("popupNew").onclick = ()=>{ div.remove(); resetBoard(); };
  document.getElementById("popupClose").onclick = ()=> div.remove();
}

// START GAME
resetBoard();