/**
 * minigames/snake.js
 * 🐍 Snake — Steuere die Schlange, friss 10 Äpfel ohne gegen die Wand zu fahren
 */
window.MG_snake = (function() {

  const ID       = 'snake';
  const EMOJI    = '🐍';
  const NAME     = 'Snake';
  const DESC     = '3 Leben, 15 Äpfel sammeln. Pfeiltasten oder WASD.';
  const CONTROLS = 'Pfeiltasten / WASD';
  const MULTI    = 1;

  function run(wrap, W, H, cfg, onDone) {
    const { canvas, ctx } = MGAPI.makeCanvas(wrap, W, H);
    const SZ        = 20;
    const COLS      = Math.floor(W / SZ);
    const ROWS      = Math.floor(H / SZ);
    const WIN_SCORE = cfg.winScore || 15;
    const MAX_LIVES = cfg.lives    || 3;
    const theme     = cfg.theme || { primary: '#10b981', glow: 'rgba(16,185,129,0.4)' };

    // Startgeschwindigkeit 160ms, pro Apfel -12ms, Minimum 55ms
    const BASE_INTERVAL = 160;
    const SPEED_INC     = 12;
    const MIN_INTERVAL  = 55;

    function interval(sc) {
      return Math.max(MIN_INTERVAL, BASE_INTERVAL - sc * SPEED_INC);
    }

    function rndFood(snk) {
      let f;
      do { f = { x: Math.floor(Math.random() * COLS), y: Math.floor(Math.random() * ROWS) }; }
      while (snk.some(s => s.x === f.x && s.y === f.y));
      return f;
    }

    function startSnake() {
      return [{ x: 5, y: 5 }, { x: 4, y: 5 }, { x: 3, y: 5 }];
    }

    let snake   = startSnake();
    let dir     = { x: 1, y: 0 };
    let nextDir = { x: 1, y: 0 };
    let food    = rndFood(snake);
    let score   = 0;
    let lives   = MAX_LIVES;
    let dead    = false;
    let dying   = false;
    let stopped = false;
    let raf, endTimer, respawnTimer, last = 0;

    function onKey(e) {
      const map = {
        ArrowUp:    { x: 0,  y: -1 }, w: { x: 0,  y: -1 },
        ArrowDown:  { x: 0,  y:  1 }, s: { x: 0,  y:  1 },
        ArrowLeft:  { x: -1, y:  0 }, a: { x: -1, y:  0 },
        ArrowRight: { x: 1,  y:  0 }, d: { x: 1,  y:  0 },
      };
      const d = map[e.key];
      if (d && (d.x !== -dir.x || d.y !== -dir.y)) {
        e.preventDefault();
        nextDir = d;
      }
    }
    document.addEventListener('keydown', onKey);

    let touchStart = null;
    canvas.addEventListener('touchstart', e => {
      touchStart = { x: e.touches[0].clientX, y: e.touches[0].clientY };
    }, { passive: true });
    canvas.addEventListener('touchend', e => {
      if (!touchStart) return;
      const dx = e.changedTouches[0].clientX - touchStart.x;
      const dy = e.changedTouches[0].clientY - touchStart.y;
      if (Math.abs(dx) > Math.abs(dy))
        nextDir = dx > 0 ? { x: 1, y: 0 } : { x: -1, y: 0 };
      else
        nextDir = dy > 0 ? { x: 0, y: 1 } : { x: 0, y: -1 };
    }, { passive: true });

    function die() {
      if (dying) return;
      dying = true;
      dead  = true;
      lives--;
      if (lives <= 0) {
        if (!endTimer) endTimer = setTimeout(() => onDone(false), 1300);
      } else {
        respawnTimer = setTimeout(() => {
          snake   = startSnake();
          dir     = { x: 1, y: 0 };
          nextDir = { x: 1, y: 0 };
          food    = rndFood(snake);
          dead    = false;
          dying   = false;
          last    = 0;
        }, 1000);
      }
    }

    function drawGrid() {
      ctx.strokeStyle = 'rgba(255,255,255,0.04)';
      ctx.lineWidth   = 0.5;
      for (let x = 0; x < COLS; x++)
        for (let y = 0; y < ROWS; y++)
          ctx.strokeRect(x * SZ, y * SZ, SZ, SZ);
    }

    function loop(ts) {
      if (stopped) return;
      raf = requestAnimationFrame(loop);

      // Zeichnen immer, Spiellogik nur im Takt
      const tick = ts - last >= interval(score);

      if (tick && !dead) {
        last = ts;
        dir  = nextDir;
        const head = { x: snake[0].x + dir.x, y: snake[0].y + dir.y };
        if (
          head.x < 0 || head.x >= COLS ||
          head.y < 0 || head.y >= ROWS ||
          snake.some(s => s.x === head.x && s.y === head.y)
        ) {
          die();
        } else {
          snake.unshift(head);
          if (head.x === food.x && head.y === food.y) {
            score++;
            food = rndFood(snake);
            if (score >= WIN_SCORE && !endTimer)
              endTimer = setTimeout(() => onDone(true), 800);
            // Schlange wächst automatisch (kein pop)
          } else {
            snake.pop();
          }
        }
      }

      // --- Zeichnen ---
      ctx.fillStyle = '#050508';
      ctx.fillRect(0, 0, W, H);
      drawGrid();

      // Futter
      ctx.shadowColor = theme.primary;
      ctx.shadowBlur  = 12;
      ctx.font        = `${SZ - 2}px serif`;
      ctx.textAlign   = 'center';
      ctx.fillText('🍎', food.x * SZ + SZ / 2, food.y * SZ + SZ / 1.2);
      ctx.shadowBlur  = 0;

      // Schlange
      snake.forEach((s, i) => {
        const alpha = i === 0 ? 'ff' : Math.max(0x44, 0x88 - i * 2).toString(16).padStart(2, '0');
        ctx.fillStyle = i === 0 ? theme.primary : `${theme.primary}${alpha}`;
        if (i === 0) { ctx.shadowColor = theme.primary; ctx.shadowBlur = 8; }
        MGAPI.roundRect(ctx, s.x * SZ + 2, s.y * SZ + 2, SZ - 4, SZ - 4, 4, ctx.fillStyle, null);
        ctx.shadowBlur = 0;
      });

      // HUD
      MGAPI.text(ctx, `🍎 ${score} / ${WIN_SCORE}`, 8, 14,
        { align: 'left', size: 13, color: theme.primary });
      const hearts = '❤️'.repeat(lives) + '🖤'.repeat(Math.max(0, MAX_LIVES - lives));
      MGAPI.text(ctx, hearts, W / 2, 14, { align: 'center', size: 12 });
      // Geschwindigkeitsanzeige
      const spd = Math.round((BASE_INTERVAL / Math.max(MIN_INTERVAL, interval(score))) * 10) / 10;
      MGAPI.text(ctx, `⚡ ${spd.toFixed(1)}x`, W - 8, 14,
        { align: 'right', size: 11, color: 'rgba(255,255,255,0.4)' });

      if (dead && lives <= 0) {
        MGAPI.resultScreen(ctx, W, H, false,
          `Nur ${score} Äpfel — nächstes Mal!`);
      } else if (dead && dying) {
        MGAPI.text(ctx, `${lives} ${lives === 1 ? 'Leben' : 'Leben'} übrig`, W / 2, H / 2,
          { size: 16, color: '#ef4444' });
      }

      if (score >= WIN_SCORE && !dead)
        MGAPI.resultScreen(ctx, W, H, true, `${score} Äpfel gefressen — geschafft!`);
    }

    raf = requestAnimationFrame(loop);

    return {
      stop() {
        stopped = true;
        cancelAnimationFrame(raf);
        clearTimeout(endTimer);
        clearTimeout(respawnTimer);
        document.removeEventListener('keydown', onKey);
      },
    };
  }

  function launch(wrap, W, H, cfg)  { return run(wrap, W, H, cfg, won => MGAPI.onResult(won)); }
  function preview(wrap, W, H, cfg) { return run(wrap, W, H, { ...cfg, winScore: 15, lives: 3 }, won => MGAPI.onResult(won)); }

  return { id: ID, emoji: EMOJI, name: NAME, desc: DESC, controls: CONTROLS, multi: MULTI, launch, preview };

})();