// ═══ main.js ═══
// ============================================================
//  MAIN.JS — Game loop, init, HUD updates
// ============================================================

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

// Fixed logical resolution — all gameplay runs at this size.
// The canvas is CSS-scaled to fill the viewport on resize.
const GAME_W = 1600;
const GAME_H = 900;
canvas.width  = GAME_W;
canvas.height = GAME_H;

function resize() {
  const vw = window.innerWidth;
  const vh = window.innerHeight;
  const scale = Math.min(vw / GAME_W, vh / GAME_H);
  const w = Math.floor(GAME_W * scale);
  const h = Math.floor(GAME_H * scale);
  canvas.style.width  = w + 'px';
  canvas.style.height = h + 'px';
  canvas.style.left   = Math.floor((vw - w) / 2) + 'px';
  canvas.style.top    = Math.floor((vh - h) / 2) + 'px';
}
window.addEventListener('resize', resize);
resize();

// ── HIGH SCORE ────────────────────────────────────────────────
let _best = (() => {
  try { return JSON.parse(localStorage.getItem('siegeprotocol_best')) || null; } catch(e) { return null; }
})();

const PERF_METRICS = {
  lastStamp: null,
  fps: 60,
  frameMs: 16.7,
  updateMs: 0,
  renderMs: 0,
  sampleMs: 0,
  sampleFrames: 0,
  uiTick: 0,
  uiEveryFrames: 6,
};

function perfNow() {
  return (typeof performance !== 'undefined' && performance.now) ? performance.now() : Date.now();
}

function setPaused(paused, showOverlay = true) {
  G.paused = paused;
  document.body.classList.toggle('paused',
    !!paused && showOverlay && !G.shopOpen &&
    !document.body.classList.contains('inventory-open') && !G.gameOver);
}

function togglePause() {
  setPaused(!document.body.classList.contains('paused'), true);
}

function updatePerfOverlay(frameStamp, updateMs, renderMs) {
  const overlay = document.getElementById('perf-overlay');
  if (!overlay) return;

  if (!DEV_MODE || !G._showPerfOverlay) {
    overlay.style.display = 'none';
    return;
  }
  overlay.style.display = 'block';

  const frameDelta = PERF_METRICS.lastStamp == null ? 16.7 : (frameStamp - PERF_METRICS.lastStamp);
  PERF_METRICS.lastStamp = frameStamp;

  PERF_METRICS.frameMs = PERF_METRICS.frameMs * 0.85 + frameDelta * 0.15;
  PERF_METRICS.updateMs = PERF_METRICS.updateMs * 0.8 + updateMs * 0.2;
  PERF_METRICS.renderMs = PERF_METRICS.renderMs * 0.8 + renderMs * 0.2;

  PERF_METRICS.sampleMs += frameDelta;
  PERF_METRICS.sampleFrames += 1;
  if (PERF_METRICS.sampleMs >= 250) {
    PERF_METRICS.fps = (PERF_METRICS.sampleFrames * 1000) / PERF_METRICS.sampleMs;
    PERF_METRICS.sampleMs = 0;
    PERF_METRICS.sampleFrames = 0;
  }

  PERF_METRICS.uiTick += 1;
  if (PERF_METRICS.uiTick < PERF_METRICS.uiEveryFrames) return;
  PERF_METRICS.uiTick = 0;

  let enemiesAlive = 0;
  for (const e of G.enemies) if (e.alive) enemiesAlive++;
  overlay.innerHTML = `
    <div class="perf-title">PERF</div>
    <div class="perf-row"><span>FPS</span><span>${PERF_METRICS.fps.toFixed(1)}</span></div>
    <div class="perf-row"><span>Frame</span><span>${PERF_METRICS.frameMs.toFixed(2)} ms</span></div>
    <div class="perf-row"><span>Logic</span><span>${PERF_METRICS.updateMs.toFixed(2)} ms</span></div>
    <div class="perf-row"><span>Render</span><span>${PERF_METRICS.renderMs.toFixed(2)} ms</span></div>
    <div class="perf-row"><span>Enemies</span><span>${enemiesAlive}</span></div>
    <div class="perf-row"><span>Projectiles</span><span>${G.projectiles.length}</span></div>
    <div class="perf-row"><span>Portals</span><span>${G.portals.length}</span></div>
  `;
}

// ── GAME LOOP ─────────────────────────────────────────────────
function gameLoop() {
  requestAnimationFrame(gameLoop);

  const frameStamp = perfNow();
  const updateStart = frameStamp;

  if (!G.paused && !G.gameOver) {
    const ticks = (DEV_MODE && G._speedMult && G._speedMult !== 1)
      ? Math.max(1, Math.round(G._speedMult))
      : 1;
    for (let t = 0; t < ticks; t++) {
      G.frame++;
      // Decay freshness every 5 seconds (300 frames)
      if (G.frame % 300 === 0) {
        for (const id in G.enemyFreshness) {
          if (G.enemyFreshness[id] > 0) G.enemyFreshness[id]--;
        }
      }
      updatePortals();
      updateEnemies();
      updateWeapons();
      updateShield();
      updateParticles();
      updateFloaters();
      if (G.paused || G.gameOver) break;
    }
  }

  checkBankruptcy();
  const updateEnd = perfNow();
  render();
  const renderEnd = perfNow();
  updatePerfOverlay(frameStamp, updateEnd - updateStart, renderEnd - updateEnd);
}

// ── RESERVE ───────────────────────────────────────────────────
function adjustReserve(delta) {
  const cheapest = cheapestEnemyCost();
  G.creditReserve = clamp(G.creditReserve + delta, cheapest, G.credits);
  updateHUD();
}

function spendableCredits() {
  return Math.max(0, G.credits - G.creditReserve);
}

// ── HUD ───────────────────────────────────────────────────────
function updateHUD() {
  // Clamp state — canvas renderer reads G.* directly each frame
  G.credits = Math.floor(Math.max(0, G.credits));
  const cheapest = cheapestEnemyCost();
  G.creditReserve = clamp(G.creditReserve, cheapest, G.credits);
  checkBankruptcy();
}

// ── COMBAT LOG ────────────────────────────────────────────────
function addLog(msg, type = '') {
  if (!G.logLines) G.logLines = [];
  G.logLines.unshift({ text: msg, type });
  if (G.logLines.length > 40) G.logLines.length = 40;
}

// ── BANKRUPTCY CHECK ──────────────────────────────────────────
function checkBankruptcy() {
  if (G.gameOver) return;

  // Bankrupt = 0 credits AND no enemies alive (no pending rewards coming in)
  // AND can't afford even the cheapest enemy
  const cheapest = cheapestEnemyCost();
  const activeEnemies = countAliveEnemies();
  const pendingPortals = G.portals.length;
  const now = typeof performance !== 'undefined' ? performance.now() : Date.now();

  if (G.credits < cheapest && activeEnemies === 0 && pendingPortals === 0) {
    // Give a brief grace window — maybe enemies just died and reward came in.
    if (!G._bankruptAt) G._bankruptAt = now;
    if (now - G._bankruptAt > 3000) {
      endBankrupt();
    }
  } else {
    G._bankruptAt = null;
  }
}

// ── GAME OVER ─────────────────────────────────────────────────
function endGame() {
  if (G.shopOpen) closeShop();
  setPaused(false);
  G.gameOver = true;
  G.isBankrupt = false;
  G._isNewBest = !_best || G.score > _best.score;
  if (G._isNewBest) {
    _best = { score: G.score, kills: G.totalKills };
    try { localStorage.setItem('siegeprotocol_best', JSON.stringify(_best)); } catch(e) {}
  }
}

function endBankrupt() {
  if (G.shopOpen) closeShop();
  setPaused(false);
  G.gameOver = true;
  G.isBankrupt = true;
  G._isNewBest = !_best || G.score > _best.score;
  if (G._isNewBest) {
    _best = { score: G.score, kills: G.totalKills };
    try { localStorage.setItem('siegeprotocol_best', JSON.stringify(_best)); } catch(e) {}
  }
  addLog('BANKRUPT. No credits, no enemies. Game over.', 'lose');
}

function restartGame() {
  G = makeGameState();
  setPaused(false);
  _sidePanelScrollY = 0;
  _logScrollY = 0;
  updateHUD();
  addLog('System online. Deploy enemies to earn credits.', 'info');
  addLog('[1–0] deploy  [scroll] qty  [Space] shop  [Esc/P] pause  [I] inventory', 'info');
}

// ── INIT ──────────────────────────────────────────────────────
function init() {
  resize(); // set canvas size after full page load — guaranteed correct dimensions
  updateHUD();
  initInput();
  addLog('SIEGE PROTOCOL initialized.', 'info');
  addLog('[1–0] deploy  [scroll] qty  [Space] shop  [Esc/P] pause  [I] inventory', 'info');
  gameLoop();
}

window.addEventListener('load', init);