/* ISLE SLINGERS — main.js
 * Glue: fixed-timestep loop, mouse+touch input, screens, HUD, progress.
 * Expects globals from core.js / levels.js / renderer.js / audio.js.
 */
(function () {
  'use strict';

  var CORE = window.ISLE_CORE;
  var LEVELS = window.ISLE_LEVELS.LEVELS;
  var SAVE_KEY = 'isleSlingers.progress.v1';

  var canvas = document.getElementById('game');
  var renderer = new window.ISLE_RENDERER.Renderer(canvas, { onEvent: function (e) { audio.play(e); } });
  var audio = new window.ISLE_AUDIO.AudioEngine();

  var state = null;          // core game state
  var levelIndex = 0;
  var drag = null;           // current pointer drag {x,y}
  var aiming = false;
  var paused = false;
  var screen = 'start';      // start | play | levelselect | win | lose | pause
  var fixedDt = 1 / 120;
  var acc = 0;
  var lastT = null;
  var winShownAt = 0;
  var loseShownAt = 0;

  // ------------------------------------------------------------- progress

  function loadProgress() {
    try {
      var raw = localStorage.getItem(SAVE_KEY);
      if (raw) {
        var p = JSON.parse(raw);
        if (p && p.stars) return p;
      }
    } catch (e) { /* ignore */ }
    return { stars: {}, unlocked: 1 };
  }
  var progress = loadProgress();

  function saveProgress() {
    try { localStorage.setItem(SAVE_KEY, JSON.stringify(progress)); } catch (e) { /* ignore */ }
  }

  // --------------------------------------------------------------- DOM

  var el = {
    start: document.getElementById('screen-start'),
    select: document.getElementById('screen-select'),
    win: document.getElementById('screen-win'),
    lose: document.getElementById('screen-lose'),
    pause: document.getElementById('screen-pause'),
    hud: document.getElementById('hud'),
    score: document.getElementById('hud-score'),
    levelName: document.getElementById('hud-level'),
    birdsLeft: document.getElementById('hud-birds'),
    starsWin: document.getElementById('win-stars'),
    scoreWin: document.getElementById('win-score'),
    nextBtn: document.getElementById('btn-next'),
    grid: document.getElementById('level-grid'),
    muteBtn: document.getElementById('btn-mute'),
    pauseBtn: document.getElementById('btn-pause')
  };

  function show(name) {
    screen = name;
    el.start.style.display = name === 'start' ? 'flex' : 'none';
    el.select.style.display = name === 'select' ? 'flex' : 'none';
    el.win.style.display = name === 'win' ? 'flex' : 'none';
    el.lose.style.display = name === 'lose' ? 'flex' : 'none';
    el.pause.style.display = name === 'pause' ? 'flex' : 'none';
    el.hud.style.display = (name === 'play' || name === 'pause') ? 'flex' : 'none';
  }

  function renderSelect() {
    el.grid.innerHTML = '';
    for (var i = 0; i < LEVELS.length; i++) {
      (function (i) {
        var lv = LEVELS[i];
        var locked = i + 1 > progress.unlocked;
        var tile = document.createElement('button');
        tile.className = 'level-tile' + (locked ? ' locked' : '');
        tile.disabled = locked;
        tile.innerHTML =
          '<div class="lt-num">' + lv.id + '</div>' +
          '<div class="lt-name">' + lv.name + '</div>' +
          '<div class="lt-stars">' + starRow(progress.stars[lv.id] || 0) + '</div>';
        if (!locked) tile.addEventListener('click', function () {
          audio.init(); audio.play({ type: 'ui' });
          startLevel(i);
        });
        el.grid.appendChild(tile);
      })(i);
    }
  }

  function starRow(n) {
    var s = '';
    for (var i = 0; i < 3; i++) s += '<span class="star' + (i < n ? ' on' : '') + '">★</span>';
    return s;
  }

  // ------------------------------------------------------------- levels

  function startLevel(i) {
    levelIndex = i;
    state = CORE.createGame(LEVELS[i]);
    drag = null;
    aiming = false;
    paused = false;
    acc = 0;
    lastT = null;
    winShownAt = 0;
    loseShownAt = 0;
    renderer.ring = null;
    renderer.particles.length = 0;
    updateHud();
    show('play');
  }

  function restartLevel() {
    audio.play({ type: 'ui' });
    startLevel(levelIndex);
  }

  function updateHud() {
    if (!state) return;
    el.score.textContent = String(state.score);
    el.levelName.textContent = 'Level ' + state.level.id + ' · ' + state.level.name;
    var left = CORE.birdsRemaining(state);
    var flying = false;
    for (var i = 0; i < state.birds.length; i++) if (state.birds[i].state === 'flying') flying = true;
    var s = '';
    for (var k = 0; k < left + (flying ? 1 : 0); k++) s += '<span class="hud-bird"></span>';
    el.birdsLeft.innerHTML = s;
  }

  function onWon() {
    var stars = CORE.starsFor(state);
    if (stars > (progress.stars[state.level.id] || 0)) progress.stars[state.level.id] = stars;
    if (state.level.id >= progress.unlocked && state.level.id < LEVELS.length) {
      progress.unlocked = state.level.id + 1;
    }
    saveProgress();
    el.starsWin.innerHTML = starRow(stars);
    el.scoreWin.textContent = state.score.toLocaleString();
    el.nextBtn.style.display = state.level.id < LEVELS.length ? 'inline-block' : 'none';
    audio.play({ type: 'level_won' });
    state.events.push({ type: 'confetti_burst', x: 640, y: 300 });
    setTimeout(function () { if (screen === 'play') show('win'); }, 900);
  }

  function onLost() {
    audio.play({ type: 'level_lost' });
    setTimeout(function () { if (screen === 'play') show('lose'); }, 1100);
  }

  // ------------------------------------------------------------- input

  function toWorld(ev) {
    var r = canvas.getBoundingClientRect();
    var VW = window.ISLE_RENDERER.VIEW_W, VH = window.ISLE_RENDERER.VIEW_H;
    var sx = (ev.clientX - r.left) / r.width * VW;
    var sy = (ev.clientY - r.top) / r.height * VH;
    var cam = state.camera;
    // inverse of the renderer's world transform: screen offset from center
    // must be divided by the camera zoom, then the camera center added.
    // (Before the camera got a zoom the division was a no-op — adding zoom
    // without dividing made every visible screen point map to the WRONG
    // side of the sling, so the bird only ever launched backwards, bug #15.)
    var z = (cam && cam.zoom) || 1;
    return { x: (sx - VW / 2) / z + cam.x, y: (sy - VH / 2) / z + cam.y };
  }

  function pointerDown(ev) {
    audio.init(); audio.resume();
    if (screen !== 'play' || paused) return;
    var b = CORE.activeBird(state);
    if (!b || b.state !== 'aiming') {
      // tap during flight = ability
      if (b && b.state === 'flying' && !b.abilityUsed) {
        if (CORE.triggerAbility(state)) audio.play({ type: b.kind === 'wren' ? 'ability_fury' : b.kind === 'zippy' ? 'ability_dive' : 'ability_quake' });
      }
      return;
    }
    var w = toWorld(ev);
    // allow grabbing anywhere near the sling zone or on the bird itself
    var sling = state.level.sling;
    var dSling = Math.hypot(w.x - sling.x, w.y - sling.y);
    if (dSling < 220) {
      aiming = true;
      drag = w;
      ev.preventDefault();
    }
  }

  function pointerMove(ev) {
    if (!aiming || !drag) return;
    var w = toWorld(ev);
    var sling = state.level.sling;
    // clamp the pull to MAX_PULL
    var dx = w.x - sling.x, dy = w.y - sling.y;
    var len = Math.hypot(dx, dy);
    if (len > CORE.MAX_PULL) { dx = dx / len * CORE.MAX_PULL; dy = dy / len * CORE.MAX_PULL; }
    drag = { x: sling.x + dx, y: sling.y + dy };
    ev.preventDefault();
  }

  function pointerUp() {
    if (!aiming || !drag) return;
    aiming = false;
    var b = CORE.activeBird(state);
    if (b && b.state === 'aiming' && CORE.launch(state, drag)) {
      audio.play({ type: 'launch' });
    }
    drag = null;
    updateHud();
  }

  canvas.addEventListener('mousedown', pointerDown);
  window.addEventListener('mousemove', pointerMove);
  window.addEventListener('mouseup', pointerUp);
  canvas.addEventListener('touchstart', function (ev) { pointerDown(ev.touches[0]); ev.preventDefault(); }, { passive: false });
  canvas.addEventListener('touchmove', function (ev) { pointerMove(ev.touches[0]); ev.preventDefault(); }, { passive: false });
  canvas.addEventListener('touchend', function (ev) { pointerUp(); ev.preventDefault(); }, { passive: false });

  window.addEventListener('keydown', function (ev) {
    if (ev.repeat) return;
    var k = ev.key.toLowerCase();
    if (screen === 'play' || screen === 'pause') {
      if (k === 'p') togglePause();
      if (k === 'r') restartLevel();
      if (k === 'm') toMenu();
    } else if (screen === 'select') {
      if (k === 'escape') show('start');
      for (var i = 0; i < 5; i++) if (k === String(i + 1) && i + 1 <= progress.unlocked) startLevel(i);
    } else if (screen === 'start') {
      if (k === 'enter' || k === ' ') { ev.preventDefault(); toSelect(); }
    } else if (screen === 'win') {
      if (k === 'enter') (state.level.id < LEVELS.length ? startLevel(levelIndex + 1) : show('select'));
    } else if (screen === 'lose') {
      if (k === 'enter' || k === 'r') restartLevel();
    }
  });

  function togglePause() {
    if (screen === 'play') { paused = true; show('pause'); }
    else if (screen === 'pause') { paused = false; show('play'); lastT = null; }
  }
  function toMenu() {
    paused = false;
    renderSelect();
    show('select');
  }

  // -------------------------------------------------------------- buttons

  document.getElementById('btn-play').addEventListener('click', function () { audio.init(); audio.play({ type: 'ui' }); toSelect(); });
  function toSelect() { renderSelect(); show('select'); }
  el.select.querySelector('#btn-back-start').addEventListener('click', function () { audio.play({ type: 'ui' }); show('start'); });
  // NOTE: no generic btn-replay/btn-menu — every screen ships its own
  // role-specific pair (btn-win-retry/menu, btn-lose-retry/menu,
  // btn-pause-restart/menu); the old generic pair ids never made it into
  // index.html and their wiring crashed the page boot (see test 1b).
  el.nextBtn.addEventListener('click', function () { if (state.level.id < LEVELS.length) startLevel(levelIndex + 1); });
  document.getElementById('btn-win-retry').addEventListener('click', restartLevel);
  document.getElementById('btn-win-menu').addEventListener('click', toMenu);
  document.getElementById('btn-lose-retry').addEventListener('click', restartLevel);
  document.getElementById('btn-lose-menu').addEventListener('click', toMenu);
  document.getElementById('btn-pause-resume').addEventListener('click', togglePause);
  document.getElementById('btn-pause-restart').addEventListener('click', restartLevel);
  document.getElementById('btn-pause-menu').addEventListener('click', toMenu);
  el.pauseBtn.addEventListener('click', function (ev) { ev.stopPropagation(); togglePause(); });
  el.muteBtn.addEventListener('click', function (ev) {
    ev.stopPropagation();
    audio.init();
    audio.setMuted(!audio.muted);
    el.muteBtn.textContent = audio.muted ? '🔇' : '🔊';
  });

  // test/debug handle: the headless page harness (test/page.test.mjs)
  // reads the live state through this to assert what the player actually
  // sees (launch direction, bird spend, band drawing). Never used by the
  // page itself.
  window.ISLE_PAGE = { getState: function () { return state; } };

  // --------------------------------------------------------------- loop

  function frame(t) {
    requestAnimationFrame(frame);
    if (lastT === null) lastT = t;
    var dt = Math.min(0.05, (t - lastT) / 1000);
    lastT = t;

    if (screen === 'play' && !paused && state) {
      acc += dt;
      var steps = 0;
      while (acc >= fixedDt && steps < 12) {
        CORE.step(state, fixedDt);
        acc -= fixedDt;
        steps++;
      }
      updateHud();
      if (state.status === 'won' && !winShownAt) { winShownAt = state.time; onWon(); }
      if (state.status === 'lost' && !loseShownAt) { loseShownAt = state.time; onLost(); }
      renderer.handleEvents(state.events.splice(0));
    } else if (state) {
      // keep the world gently settling behind menus (win/lose screens)
      if (screen === 'win' || screen === 'lose') {
        CORE.step(state, fixedDt);
        renderer.handleEvents(state.events.splice(0));
      }
    }

    var view = {
      drag: drag,
      activeBird: CORE.activeBird(state),
      traj: null
    };
    if (aiming && drag && state) {
      var ab = CORE.activeBird(state);
      if (ab && ab.state === 'aiming') {
        var v = CORE.aimVector(state, state.level.sling, drag);
        if (v) view.traj = CORE.trajectory(state, ab.x, ab.y, v.vx, v.vy, 46);
      }
    }
    if (state) renderer.draw(state, view);
  }

  // --------------------------------------------------------------- boot

  (function boot() {
    // title screen with an idle demo state behind it
    state = CORE.createGame(LEVELS[0]);
    show('start');
    requestAnimationFrame(frame);
  })();
})();