/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var facekit = LK.import("@upit/facekit.v1");

/**** 
* Classes
****/ 
// Note class
var Note = Container.expand(function () {
	var self = Container.call(this);
	self.direction = 'up'; // will be set after creation
	self.speed = 12; // pixels per frame, reduced for easier gameplay
	self.hit = false;
	self.active = true;
	// Attach asset
	self.noteAsset = null; // will be set after direction is set
	// For hit animation
	self.flashTween = null;
	// Called every tick
	self.update = function () {
		if (!self.active) {
			return;
		}
		var vec = getNoteTravelVec(self.direction);
		self.x += vec.x * self.speed;
		self.y += vec.y * self.speed;
	};
	// Animate on hit
	self.animateHit = function () {
		self.active = false;
		if (self.flashTween) {
			tween.stop(self, {
				alpha: true,
				scaleX: true,
				scaleY: true
			});
		}
		tween(self, {
			alpha: 0,
			scaleX: 1.5,
			scaleY: 1.5
		}, {
			duration: 180,
			easing: tween.cubicOut,
			onFinish: function onFinish() {
				self.destroy();
			}
		});
	};
	// Animate on miss
	self.animateMiss = function () {
		self.active = false;
		if (self.flashTween) {
			tween.stop(self, {
				alpha: true,
				scaleX: true,
				scaleY: true
			});
		}
		tween(self, {
			alpha: 0.2
		}, {
			duration: 180,
			easing: tween.cubicOut,
			onFinish: function onFinish() {
				self.destroy();
			}
		});
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x181c20
});

/**** 
* Game Code
****/ 
// Note directions
// Music (placeholder, actual music asset id will be auto-loaded)
// Sounds for hit and miss
// Four note shapes for each direction
// Center of play area
var NOTE_DIRECTIONS = ['left', 'right'];
var NOTE_ASSET = {
	left: 'noteLeft',
	right: 'noteRight'
};
// Note spawn positions (offscreen, moving toward center)
function getNoteSpawnPos(direction) {
	var centerX = 2048 / 2,
		centerY = 2732 / 2;
	var offset = 900; // How far from center to spawn
	if (direction === 'left') {
		return {
			x: centerX - offset,
			y: centerY
		};
	}
	if (direction === 'right') {
		return {
			x: centerX + offset,
			y: centerY
		};
	}
	return {
		x: centerX,
		y: centerY
	};
}
// Note travel vector (unit vector toward center)
function getNoteTravelVec(direction) {
	if (direction === 'left') {
		return {
			x: 1,
			y: 0
		};
	}
	if (direction === 'right') {
		return {
			x: -1,
			y: 0
		};
	}
	return {
		x: 0,
		y: 0
	};
}
var centerX = 2048 / 2,
	centerY = 2732 / 2;
// Add center target
var centerTarget = LK.getAsset('centerTarget', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: centerX,
	y: centerY,
	scaleX: 1,
	scaleY: 1
});
game.addChild(centerTarget);
// Score display
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: '#fff'
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Combo display
var combo = 0;
var comboTxt = new Text2('', {
	size: 70,
	fill: '#ffe082'
});
comboTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(comboTxt);
comboTxt.y = 130;
// Remaining life display (top right)
var lifeTxt = new Text2('', {
	size: 90,
	fill: '#ff8a65'
});
lifeTxt.anchor.set(1, 0); // right-top
LK.gui.topRight.addChild(lifeTxt);
lifeTxt.x = 0;
lifeTxt.y = 20;
// Miss feedback
var missTxt = new Text2('', {
	size: 100,
	fill: '#e57373'
});
missTxt.anchor.set(0.5, 0.5);
LK.gui.center.addChild(missTxt);
// Notes array
var notes = [];
// Timing
var noteInterval = 38; // frames between notes (about 1.5 notes/sec at 60fps)
var noteTimer = 0;
// Game state
var isGameOver = false;
var isYouWin = false;
var maxMisses = 8;
var misses = 0;
var targetScore = 15;
// Face direction detection
function getFaceDirection() {
	// Use noseTip and chin to estimate tilt
	// If facekit is not ready, return null
	if (!facekit.noseTip || !facekit.chin || !facekit.leftEye || !facekit.rightEye) {
		return null;
	}
	var dx = facekit.rightEye.x - facekit.leftEye.x;
	var dy = facekit.rightEye.y - facekit.leftEye.y;
	var angle = Math.atan2(dy, dx) * 180 / Math.PI; // horizontal head tilt
	// Left/right: compare noseTip.x to center
	var horizontal = facekit.noseTip.x - centerX;
	// Heuristics: prioritize strong tilts
	if (horizontal < -80) {
		return 'left';
	}
	if (horizontal > 80) {
		return 'right';
	}
	// If head is turned, use angle
	if (angle < -25) {
		return 'right';
	}
	if (angle > 25) {
		return 'left';
	}
	return null;
}
// Show combo
function showCombo() {
	if (combo > 1) {
		comboTxt.setText(combo + 'x Combo!');
	} else {
		comboTxt.setText('');
	}
}
// Show miss
function showMiss() {
	missTxt.setText('Miss!');
	tween(missTxt, {
		alpha: 0
	}, {
		duration: 600,
		onFinish: function onFinish() {
			missTxt.setText('');
			missTxt.alpha = 1;
		}
	});
}
// Spawn a note
function spawnNote() {
	var dir = NOTE_DIRECTIONS[Math.floor(Math.random() * NOTE_DIRECTIONS.length)];
	var note = new Note();
	note.direction = dir;
	var spawn = getNoteSpawnPos(dir);
	note.x = spawn.x;
	note.y = spawn.y;
	note.noteAsset = note.attachAsset(NOTE_ASSET[dir], {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Rotate asset to point toward center
	if (dir === 'left') {
		note.noteAsset.rotation = -Math.PI / 2;
	}
	if (dir === 'right') {
		note.noteAsset.rotation = Math.PI / 2;
	}
	notes.push(note);
	game.addChild(note);
}
// Check if note is in hit window (distance to center)
function isNoteHittable(note) {
	var dx = note.x - centerX;
	var dy = note.y - centerY;
	var dist = Math.sqrt(dx * dx + dy * dy);
	return dist < 180; // hit window radius (increased for easier hits)
}
// Check if note is missed (passed center)
function isNoteMissed(note) {
	var dx = note.x - centerX;
	var dy = note.y - centerY;
	var dist = Math.sqrt(dx * dx + dy * dy);
	return dist < 20; // too close, missed (smaller, so player has more time to hit)
}
// Main update loop
game.update = function () {
	if (isGameOver || isYouWin) {
		return;
	}
	// Spawn notes
	noteTimer++;
	if (noteTimer >= noteInterval) {
		spawnNote();
		noteTimer = 0;
	}
	// Get current face direction
	var faceDir = getFaceDirection();
	// For each note: move, check for hit/miss
	for (var i = notes.length - 1; i >= 0; i--) {
		var note = notes[i];
		note.update();
		if (!note.active) {
			notes.splice(i, 1);
			continue;
		}
		// If note is in hit window and faceDir matches, hit!
		if (!note.hit && isNoteHittable(note) && faceDir === note.direction) {
			note.hit = true;
			note.animateHit();
			// Increase background music volume to 1 on hit
			LK.playMusic('bgmusic', {
				fade: {
					start: 0.1,
					end: 1,
					duration: 200,
					volume: 1
				}
			});
			score++;
			combo++;
			showCombo();
			scoreTxt.setText(score);
			if (score >= targetScore) {
				isYouWin = true;
				LK.showYouWin();
				return;
			}
			continue;
		}
		// If note passes center and not hit, miss
		// Only trigger miss the moment the note crosses the miss threshold (not repeatedly)
		if (!note.hit && note.lastMissed !== true && isNoteMissed(note)) {
			note.hit = true;
			note.lastMissed = true;
			note.animateMiss();
			// Lower background music volume to 0.1 on miss
			LK.playMusic('bgmusic', {
				fade: {
					start: 1,
					end: 0.1,
					duration: 200,
					volume: 0.1
				}
			});
			misses++;
			combo = 0;
			showCombo();
			showMiss();
			lifeTxt.setText('Life: ' + (maxMisses - misses));
			if (misses >= maxMisses) {
				isGameOver = true;
				LK.effects.flashScreen(0xff0000, 800);
				LK.showGameOver();
				return;
			}
			continue;
		} else if (!note.hit && note.lastMissed !== true) {
			// Track that note is not yet missed
			note.lastMissed = false;
		}
	}
};
LK.playMusic('bgmusic', {
	fade: {
		start: 0.1,
		end: 1,
		duration: 100,
		volume: 1
	}
});
// Reset state on game restart
game.on('reset', function () {
	score = 0;
	combo = 0;
	misses = 0;
	isGameOver = false;
	isYouWin = false;
	notes = [];
	scoreTxt.setText('0');
	comboTxt.setText('');
	missTxt.setText('');
	noteTimer = 0;
	lifeTxt.setText('Life: ' + (maxMisses - misses));
});
// No touch controls needed; game is face-only
// Make sure all elements are visible and not in top left 100x100
centerTarget.x = centerX;
centerTarget.y = centerY;
scoreTxt.x = LK.gui.top.width / 2;
scoreTxt.y = 10;
comboTxt.x = LK.gui.top.width / 2;
comboTxt.y = 130;
missTxt.x = LK.gui.center.width / 2;
missTxt.y = LK.gui.center.height / 2;
;
// Set initial value for life display
lifeTxt.setText('Life: ' + (maxMisses - misses));

===================================================================
--- original.js
+++ change.js
@@ -300,9 +300,14 @@
 			note.hit = true;
 			note.animateHit();
 			// Increase background music volume to 1 on hit
 			LK.playMusic('bgmusic', {
-				volume: 1
+				fade: {
+					start: 0.1,
+					end: 1,
+					duration: 200,
+					volume: 1
+				}
 			});
 			score++;
 			combo++;
 			showCombo();
@@ -321,9 +326,14 @@
 			note.lastMissed = true;
 			note.animateMiss();
 			// Lower background music volume to 0.1 on miss
 			LK.playMusic('bgmusic', {
-				volume: 0.1
+				fade: {
+					start: 1,
+					end: 0.1,
+					duration: 200,
+					volume: 0.1
+				}
 			});
 			misses++;
 			combo = 0;
 			showCombo();