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

/**** 
* Classes
****/ 
// Note class: represents a falling note
var Note = Container.expand(function () {
	var self = Container.call(this);
	// Properties: keyIndex (0-3), speed, hit, missed
	self.keyIndex = 0;
	self.speed = 12; // px per frame
	self.hit = false;
	self.missed = false;
	self.noteAsset = null;
	// Set up note asset
	self.setType = function (keyIndex) {
		self.keyIndex = keyIndex;
		var assetId = 'note' + (keyIndex + 1);
		self.noteAsset = self.attachAsset(assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	// Called every tick
	self.update = function () {
		self.y += self.speed;
	};
	// Flash feedback (hit/miss)
	self.flash = function (type) {
		var flashId = type === 'hit' ? 'hitFlash' : 'missFlash';
		var flash = LK.getAsset(flashId, {
			anchorX: 0.5,
			anchorY: 0.5,
			x: 0,
			y: 0
		});
		flash.alpha = 0.7;
		self.addChild(flash);
		tween(flash, {
			alpha: 0
		}, {
			duration: 300,
			onFinish: function onFinish() {
				flash.destroy();
			}
		});
	};
	return self;
});

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

/**** 
* Game Code
****/ 
var NUM_KEYS = 4;
var KEY_WIDTH = 400;
var KEY_HEIGHT = 300;
var KEY_GAP = 12;
var NOTE_WIDTH = 320;
var NOTE_HEIGHT = 120;
var GAME_W = 2048;
var GAME_H = 2732;
var KEY_Y = 120; // distance from bottom
// Add background image (fills the screen, behind all elements)
var background = LK.getAsset('background', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: 0,
	width: GAME_W,
	height: GAME_H
});
game.addChild(background);
// Music
// Sound for hit/miss
// Feedback flash
// Notes: colored ellipses
// Piano keys: white rectangles
// 4 piano keys (white), 4 note shapes (colored), 1 background music
// Piano key layout: 4 keys, bottom of screen, evenly spaced
// Key positions (centered)
var keyPositions = [];
var totalWidth = NUM_KEYS * KEY_WIDTH + (NUM_KEYS - 1) * KEY_GAP;
var startX = (GAME_W - totalWidth) / 2 + KEY_WIDTH / 2;
for (var i = 0; i < NUM_KEYS; i++) {
	keyPositions[i] = {
		x: startX + i * (KEY_WIDTH + KEY_GAP),
		y: GAME_H - KEY_HEIGHT / 2 - KEY_Y
	};
}
// Create piano keys
var pianoKeys = [];
for (var i = 0; i < NUM_KEYS; i++) {
	var keyAssetId = 'pianoKey' + (i + 1);
	var key = new Container();
	var keyShape = key.attachAsset(keyAssetId, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	key.x = keyPositions[i].x;
	key.y = keyPositions[i].y;
	key.keyIndex = i;
	game.addChild(key);
	pianoKeys.push(key);
}
// Score display
var score = 0;
var bestScore = storage.bestScore || 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Best score display (smaller, top right)
var bestScoreTxt = new Text2('Rekor: ' + bestScore, {
	size: 60,
	fill: "#fff"
});
bestScoreTxt.anchor.set(1, 0);
LK.gui.topRight.addChild(bestScoreTxt);
// Notes array
var notes = [];
// Note spawn timing
var noteInterval = 38; // frames between notes (approx 1.5 notes/sec)
var noteTimer = 0;
// Feedback for key press (flash)
function flashKey(keyIndex, type) {
	var key = pianoKeys[keyIndex];
	var flashId = type === 'hit' ? 'hitFlash' : 'missFlash';
	var flash = LK.getAsset(flashId, {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 0
	});
	flash.alpha = 0.7;
	key.addChild(flash);
	tween(flash, {
		alpha: 0
	}, {
		duration: 250,
		onFinish: function onFinish() {
			flash.destroy();
		}
	});
}
// Touch handling
game.down = function (x, y, obj) {
	// Check if touch is on a key
	for (var i = 0; i < pianoKeys.length; i++) {
		var key = pianoKeys[i];
		// Rectangle hit test
		var left = key.x - KEY_WIDTH / 2;
		var right = key.x + KEY_WIDTH / 2;
		var top = key.y - KEY_HEIGHT / 2;
		var bottom = key.y + KEY_HEIGHT / 2;
		if (x >= left && x <= right && y >= top && y <= bottom) {
			// Find the lowest note in this column that is hittable
			var hitNote = null;
			var hitWindow = 120; // px, how close to key to count as hit
			for (var j = 0; j < notes.length; j++) {
				var note = notes[j];
				if (note.keyIndex === i && !note.hit && !note.missed) {
					// Note is in this column
					var noteBottom = note.y + NOTE_HEIGHT / 2;
					var keyTop = key.y - KEY_HEIGHT / 2;
					var keyBottom = key.y + KEY_HEIGHT / 2;
					// If note is within hit window above the key (falling down)
					if (noteBottom >= keyTop - hitWindow && noteBottom <= keyBottom + hitWindow) {
						// For falling notes, prefer the lowest note (closest to the key)
						if (!hitNote || note.y > hitNote.y) {
							hitNote = note;
						}
					}
				}
			}
			if (hitNote) {
				// Hit!
				hitNote.hit = true;
				hitNote.flash('hit');
				flashKey(i, 'hit');
				LK.getSound('hit').play();
				score += 1;
				if (score > bestScore) {
					bestScore = score;
					storage.bestScore = bestScore;
					bestScoreTxt.setText('Rekor: ' + bestScore);
				}
				scoreTxt.setText(score);
			} else {
				// Miss (touched key but no note in window)
				flashKey(i, 'miss');
				LK.getSound('miss').play();
				// Optionally, penalize or just give feedback
			}
			break;
		}
	}
};
// No drag or move needed for this game
game.move = function (x, y, obj) {};
game.up = function (x, y, obj) {};
// Game update loop
game.update = function () {
	// Adjust note speed based on score
	var baseSpeed = 6; // much slower than before
	var speedStep = 2.5; // how much to increase per step
	var stepScore = 10; // every 10 points after 20, increase speed
	var minScore = 20;
	var maxSpeed = 22; // cap speed so it doesn't get too fast
	var currentSpeed = baseSpeed;
	if (score >= minScore) {
		// For every stepScore after minScore, increase speed by speedStep
		var steps = Math.floor((score - minScore) / stepScore) + 1;
		currentSpeed = baseSpeed + steps * speedStep;
		if (currentSpeed > maxSpeed) currentSpeed = maxSpeed;
	}
	// Spawn notes according to music rhythm
	if (typeof musicBeats === "undefined") {
		// Initialize beat array and pointer on first update
		var musicBeats = [];
		var beatPtr = 0;
		// Use plugin to extract beats from the music asset
		// This will fill musicBeats with beat times in seconds
		musicBeats = LK.music.getBeats('piano', {
			sensitivity: 0.7
		}); // sensitivity can be tuned
		// Convert to frame numbers for easy comparison
		for (var b = 0; b < musicBeats.length; b++) {
			musicBeats[b] = Math.floor(musicBeats[b] * 60); // 60 FPS
		}
		beatPtr = 0;
	}
	if (typeof musicStartTick === "undefined") {
		// Track when music started (in ticks)
		var musicStartTick = LK.ticks;
	}
	var musicTick = LK.ticks - musicStartTick;
	while (beatPtr < musicBeats.length && musicBeats[beatPtr] <= musicTick) {
		// Spawn a note at this beat
		var keyIndex = Math.floor(Math.random() * NUM_KEYS);
		var note = new Note();
		note.setType(keyIndex);
		note.x = keyPositions[keyIndex].x;
		note.y = 0 - NOTE_HEIGHT / 2; // Spawn at the very top
		note.lastY = note.y;
		note.lastHit = false;
		note.speed = currentSpeed; // set speed based on score
		notes.push(note);
		game.addChild(note);
		beatPtr++;
	}
	// Update notes
	for (var i = notes.length - 1; i >= 0; i--) {
		var note = notes[i];
		note.update();
		// If note is hit, remove after short delay
		if (note.hit) {
			note.destroy();
			notes.splice(i, 1);
			continue;
		}
		// If note passes below the key and not hit, mark as missed
		var key = pianoKeys[note.keyIndex];
		var keyBottom = key.y + KEY_HEIGHT / 2;
		if (!note.missed && note.y - NOTE_HEIGHT / 2 > keyBottom + 40) {
			note.missed = true;
			note.flash('miss');
			flashKey(note.keyIndex, 'miss');
			LK.getSound('miss').play();
			// End game on miss
			LK.effects.flashScreen(0xe57373, 600);
			if (score > bestScore) {
				bestScore = score;
				storage.bestScore = bestScore;
			}
			LK.stopMusic();
			LK.showGameOver();
			return;
		}
		// Remove notes that are far off screen
		if (note.y - NOTE_HEIGHT / 2 > GAME_H + 200) {
			note.destroy();
			notes.splice(i, 1);
		}
	}
};
// Start music
game.onStart = function () {
	LK.stopMusic();
	LK.playMusic('piano');
	musicStartTick = LK.ticks;
	if (typeof musicBeats !== "undefined") {
		beatPtr = 0;
	}
};
// Stop music when game ends
game.onGameOver = function () {
	LK.stopMusic();
	musicStartTick = undefined;
	beatPtr = 0;
};

===================================================================
--- original.js
+++ change.js
@@ -225,13 +225,31 @@
 		var steps = Math.floor((score - minScore) / stepScore) + 1;
 		currentSpeed = baseSpeed + steps * speedStep;
 		if (currentSpeed > maxSpeed) currentSpeed = maxSpeed;
 	}
-	// Spawn notes
-	noteTimer++;
-	if (noteTimer >= noteInterval) {
-		noteTimer = 0;
-		// Random key
+	// Spawn notes according to music rhythm
+	if (typeof musicBeats === "undefined") {
+		// Initialize beat array and pointer on first update
+		var musicBeats = [];
+		var beatPtr = 0;
+		// Use plugin to extract beats from the music asset
+		// This will fill musicBeats with beat times in seconds
+		musicBeats = LK.music.getBeats('piano', {
+			sensitivity: 0.7
+		}); // sensitivity can be tuned
+		// Convert to frame numbers for easy comparison
+		for (var b = 0; b < musicBeats.length; b++) {
+			musicBeats[b] = Math.floor(musicBeats[b] * 60); // 60 FPS
+		}
+		beatPtr = 0;
+	}
+	if (typeof musicStartTick === "undefined") {
+		// Track when music started (in ticks)
+		var musicStartTick = LK.ticks;
+	}
+	var musicTick = LK.ticks - musicStartTick;
+	while (beatPtr < musicBeats.length && musicBeats[beatPtr] <= musicTick) {
+		// Spawn a note at this beat
 		var keyIndex = Math.floor(Math.random() * NUM_KEYS);
 		var note = new Note();
 		note.setType(keyIndex);
 		note.x = keyPositions[keyIndex].x;
@@ -240,8 +258,9 @@
 		note.lastHit = false;
 		note.speed = currentSpeed; // set speed based on score
 		notes.push(note);
 		game.addChild(note);
+		beatPtr++;
 	}
 	// Update notes
 	for (var i = notes.length - 1; i >= 0; i--) {
 		var note = notes[i];
@@ -280,9 +299,15 @@
 // Start music
 game.onStart = function () {
 	LK.stopMusic();
 	LK.playMusic('piano');
+	musicStartTick = LK.ticks;
+	if (typeof musicBeats !== "undefined") {
+		beatPtr = 0;
+	}
 };
 // Stop music when game ends
 game.onGameOver = function () {
 	LK.stopMusic();
+	musicStartTick = undefined;
+	beatPtr = 0;
 };
\ No newline at end of file