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

/**** 
* Classes
****/ 
// LetterBubble: A bubble with a letter inside, touchable
var LetterBubble = Container.expand(function () {
	var self = Container.call(this);
	// Properties to be set after creation:
	// self.letter (string, e.g. "A")
	// self.isTarget (bool, is this the correct letter to pop?)
	// We'll assign a color randomly from the available bubble assets
	var bubbleColors = ['bubbleBlue', 'bubbleGreen', 'bubbleRed', 'bubbleYellow', 'bubblePurple', 'bubbleOrange'];
	var colorIdx = Math.floor(Math.random() * bubbleColors.length);
	var bubbleAsset = self.attachAsset(bubbleColors[colorIdx], {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Letter text
	self.letterText = new Text2('A', {
		size: 120,
		fill: 0xFFFFFF,
		font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
	});
	self.letterText.anchor.set(0.5, 0.5);
	self.addChild(self.letterText);
	// Animate in (pop effect)
	self.scale.set(0.1, 0.1);
	tween(self.scale, {
		x: 1,
		y: 1
	}, {
		duration: 300,
		easing: tween.elasticOut
	});
	// Touch event
	self.down = function (x, y, obj) {
		// Only allow popping if not already popped
		if (self.popped) return;
		self.popped = true;
		onBubbleTapped(self);
	};
	// Pop animation
	self.pop = function (_onFinish) {
		// Play pop sound
		LK.getSound('pop').play();
		// Animate: scale up, fade out, then destroy
		tween(self.scale, {
			x: 1.3,
			y: 1.3
		}, {
			duration: 120,
			easing: tween.easeOut
		});
		tween(self, {
			alpha: 0
		}, {
			duration: 180,
			delay: 100,
			onFinish: function onFinish() {
				if (_onFinish) _onFinish();
				self.destroy();
			}
		});
	};
	// Gentle shake for incorrect
	self.shake = function () {
		// Animate left-right shake
		var origX = self.x;
		tween(self, {
			x: origX - 20
		}, {
			duration: 60,
			easing: tween.easeIn,
			onFinish: function onFinish() {
				tween(self, {
					x: origX + 20
				}, {
					duration: 60,
					easing: tween.easeOut,
					onFinish: function onFinish() {
						tween(self, {
							x: origX
						}, {
							duration: 60
						});
					}
				});
			}
		});
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0xE3F6FD // Light blue background for kid-friendly look
});

/**** 
* Game Code
****/ 
// Alphabet array
// Letter bubbles: We'll use colored ellipses for bubbles, and overlay Text2 for letters.
// We'll use 26 different colors for variety, but for MVP, 5-6 colors are enough and can be reused.
// Sounds for correct/incorrect feedback
// Simple celebratory sound for win
var alphabet = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"];
// Game state
var currentLetterIdx = 0; // Index in alphabet for the current target letter
var bubbles = []; // Array of LetterBubble instances
var lettersPerRound = 4; // Start with 4, will increase as player gets correct answers
var correctInARow = 0; // Track correct answers in a row for difficulty
var roundActive = false; // Is a round currently active?
var score = 0; // Number of correct letters popped
// Endless mode: after all letters, reshuffle and continue
var endlessMode = true;
// Timer variables
var timerActive = false;
var timerValue = 0; // seconds left
var timerInterval = null;
var TIMER_START = 15; // seconds to start with when timer mode begins
var TIMER_ADD = 3; // seconds to add per correct answer
// High score
var highScore = storage.letterpop_highscore || 0;
// UI elements
var promptText = new Text2('', {
	size: 110,
	fill: 0x333333,
	font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
});
promptText.anchor.set(0.5, 0);
LK.gui.top.addChild(promptText);
var scoreText = new Text2('0', {
	size: 110,
	fill: 0x4A90E2,
	font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
});
scoreText.anchor.set(0.5, 1);
scoreText.y = -40; // Raise it a bit above the very bottom
LK.gui.bottom.addChild(scoreText);
// High score text (top center, under prompt)
var highScoreText = new Text2('High: ' + highScore, {
	size: 60,
	fill: 0x888888,
	font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
});
highScoreText.anchor.set(0.5, 0);
highScoreText.y = 100;
LK.gui.top.addChild(highScoreText);
// Timer text (top center, under high score)
var timerText = new Text2('', {
	size: 80,
	fill: 0xD0021B,
	font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
});
timerText.anchor.set(0.5, 0);
timerText.y = 180;
LK.gui.top.addChild(timerText);
// Feedback text (centered, fades in/out)
var feedbackText = new Text2('', {
	size: 130,
	fill: 0x43A047,
	font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
});
feedbackText.anchor.set(0.5, 0.5);
feedbackText.alpha = 0;
LK.gui.center.addChild(feedbackText);
// Helper: Shuffle array (Fisher-Yates)
function shuffleArray(arr) {
	var a = arr.slice();
	for (var i = a.length - 1; i > 0; i--) {
		var j = Math.floor(Math.random() * (i + 1));
		var t = a[i];
		a[i] = a[j];
		a[j] = t;
	}
	return a;
}
// Helper: Start a new round
function startRound() {
	// Remove old bubbles
	for (var i = 0; i < bubbles.length; i++) {
		bubbles[i].destroy();
	}
	bubbles = [];
	if (currentLetterIdx >= alphabet.length) {
		if (endlessMode) {
			// Reshuffle for endless play, keep score and difficulty
			currentLetterIdx = 0;
			// Shuffle alphabet for next endless cycle
			alphabet = shuffleArray(alphabet);
		} else {
			// All letters done!
			showCelebration();
			return;
		}
	}
	roundActive = true;
	// Set prompt
	var targetLetter = alphabet[currentLetterIdx];
	promptText.setText("Find: " + targetLetter);
	// Pick distractor letters (not the target)
	var distractors = [];
	var pool = [];
	for (var i = 0; i < alphabet.length; i++) {
		if (i !== currentLetterIdx) pool.push(alphabet[i]);
	}
	pool = shuffleArray(pool);
	for (var i = 0; i < lettersPerRound - 1; i++) {
		distractors.push(pool[i]);
	}
	// Combine and shuffle
	var roundLetters = distractors.concat([targetLetter]);
	roundLetters = shuffleArray(roundLetters);
	// Dynamically arrange bubbles in a centered grid or row depending on count
	var numBubbles = roundLetters.length;
	var bubbleSize = 300; // match asset size
	var margin = 60;
	var positions = [];
	if (numBubbles <= 5) {
		// Arrange in a single centered row
		var totalWidth = numBubbles * bubbleSize + (numBubbles - 1) * margin;
		var startX = (2048 - totalWidth) / 2 + bubbleSize / 2;
		var y = 2732 / 2;
		for (var i = 0; i < numBubbles; i++) {
			positions.push({
				x: startX + i * (bubbleSize + margin),
				y: y
			});
		}
	} else {
		// Arrange in two rows, centered
		var rowCount = 2;
		var perRow = Math.ceil(numBubbles / rowCount);
		var totalWidth = perRow * bubbleSize + (perRow - 1) * margin;
		var startY = 2732 / 2 - (bubbleSize + margin) / 2;
		for (var row = 0; row < rowCount; row++) {
			var y = startY + row * (bubbleSize + margin);
			var bubblesInThisRow = row === 0 ? Math.min(perRow, numBubbles) : numBubbles - perRow;
			var rowStartX = (2048 - (bubblesInThisRow * bubbleSize + (bubblesInThisRow - 1) * margin)) / 2 + bubbleSize / 2;
			for (var col = 0; col < bubblesInThisRow; col++) {
				positions.push({
					x: rowStartX + col * (bubbleSize + margin),
					y: y
				});
			}
		}
	}
	for (var i = 0; i < roundLetters.length; i++) {
		var bubble = new LetterBubble();
		bubble.letter = roundLetters[i];
		bubble.letterText.setText(bubble.letter);
		bubble.isTarget = bubble.letter === targetLetter;
		// Position
		bubble.x = positions[i].x;
		bubble.y = positions[i].y;
		// Add to game
		game.addChild(bubble);
		bubbles.push(bubble);
	}
}
// Handle bubble tap
function onBubbleTapped(bubble) {
	if (!roundActive) return;
	if (bubble.isTarget) {
		// Correct!
		roundActive = false;
		score++;
		scoreText.setText(score);
		// Update high score if needed
		if (score > highScore) {
			highScore = score;
			highScoreText.setText('High: ' + highScore);
			storage.letterpop_highscore = highScore;
		}
		// Start timer mode after 10 points
		if (!timerActive && score >= 10) {
			timerActive = true;
			timerValue = TIMER_START;
			timerText.setText('Time: ' + timerValue);
			if (timerInterval) LK.clearInterval(timerInterval);
			timerInterval = LK.setInterval(function () {
				if (!timerActive) return;
				timerValue--;
				timerText.setText('Time: ' + timerValue);
				if (timerValue <= 0) {
					timerValue = 0;
					timerText.setText('Time: 0');
					endGameTimeout();
				}
			}, 1000);
		}
		// Add time for correct answer if timer is active
		if (timerActive) {
			timerValue += TIMER_ADD;
			timerText.setText('Time: ' + timerValue);
		}
		// Track correct answers in a row for difficulty increase
		if (typeof correctInARow === "undefined") {
			correctInARow = 0;
		}
		correctInARow++;
		// After every two correct answers, increase number of options (up to 20)
		if (correctInARow % 2 === 0) {
			if (typeof lettersPerRound === "undefined") lettersPerRound = 4;
			lettersPerRound = Math.min(lettersPerRound + 1, 20);
		}
		// Feedback
		showFeedback("Great!", "#43A047");
		LK.getSound('ding').play();
		// Pop animation, then next round
		bubble.pop(function () {
			// Remove other bubbles with fade out
			for (var i = 0; i < bubbles.length; i++) {
				if (bubbles[i] !== bubble) {
					tween(bubbles[i], {
						alpha: 0
					}, {
						duration: 200,
						onFinish: function (bub) {
							return function () {
								bub.destroy();
							};
						}(bubbles[i])
					});
				}
			}
			// Next letter after short delay
			LK.setTimeout(function () {
				currentLetterIdx++;
				startRound();
			}, 600);
		});
	} else {
		// Reset streak on incorrect answer
		correctInARow = 0;
		// Incorrect
		showFeedback("Try again!", "#D0021B");
		LK.getSound('oops').play();
		bubble.shake();
		// Allow another try (do not end round)
	}
}
// Show feedback text in center, fade in/out
function showFeedback(msg, color) {
	feedbackText.setText(msg);
	// Use setStyle to update fill color safely
	feedbackText.setStyle({
		fill: color
	});
	feedbackText.alpha = 0;
	tween(feedbackText, {
		alpha: 1
	}, {
		duration: 120,
		onFinish: function onFinish() {
			LK.setTimeout(function () {
				tween(feedbackText, {
					alpha: 0
				}, {
					duration: 200
				});
			}, 500);
		}
	});
}
// End game due to timer running out
function endGameTimeout() {
	timerActive = false;
	if (timerInterval) {
		LK.clearInterval(timerInterval);
		timerInterval = null;
	}
	// Remove any remaining bubbles
	for (var i = 0; i < bubbles.length; i++) {
		bubbles[i].destroy();
	}
	bubbles = [];
	promptText.setText("Time's up!");
	feedbackText.setText("Score: " + score);
	feedbackText.setStyle({
		fill: 0xD0021B
	});
	feedbackText.alpha = 0;
	tween(feedbackText, {
		alpha: 1
	}, {
		duration: 300
	});
	// Play oops sound
	LK.getSound('oops').play();
	// Show game over after a short delay (triggers LK's game over popup)
	LK.setTimeout(function () {
		LK.showGameOver();
	}, 1200);
}
// Show celebration screen
function showCelebration() {
	// Remove any remaining bubbles
	for (var i = 0; i < bubbles.length; i++) {
		bubbles[i].destroy();
	}
	bubbles = [];
	promptText.setText("All done!");
	feedbackText.setText("You did it!");
	// Use setStyle to update fill color safely
	feedbackText.setStyle({
		fill: 0xF5A623
	});
	feedbackText.alpha = 0;
	tween(feedbackText, {
		alpha: 1
	}, {
		duration: 300
	});
	// Play cheer sound
	LK.getSound('cheer').play();
	// Show "You Win" after a short delay (triggers LK's win popup)
	LK.setTimeout(function () {
		LK.showYouWin();
	}, 1200);
}
// Start game
function startGame() {
	// Show a visually appealing home screen before the first round
	if (typeof startGame.hasRun === "undefined") {
		// Only show on first load, not after game over
		startGame.hasRun = true;
		// Create a custom home screen container
		var homeScreen = new Container();
		// Big colorful title
		var title = new Text2("Letter Pop!", {
			size: 220,
			fill: ["#4A90E2", "#F5A623", "#7ED321", "#D0021B"],
			font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
		});
		title.anchor.set(0.5, 0.5);
		title.x = 2048 / 2;
		title.y = 700;
		homeScreen.addChild(title);
		// Fun subtitle
		var subtitle = new Text2("Pop the right letter bubbles!", {
			size: 90,
			fill: 0x9013FE,
			font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
		});
		subtitle.anchor.set(0.5, 0.5);
		subtitle.x = 2048 / 2;
		subtitle.y = 900;
		homeScreen.addChild(subtitle);
		// Show a few sample bubbles for visual appeal
		var sampleLetters = ["A", "B", "C"];
		var bubbleColors = ['bubbleBlue', 'bubbleGreen', 'bubbleRed'];
		for (var i = 0; i < sampleLetters.length; i++) {
			var sampleBubble = LK.getAsset(bubbleColors[i], {
				anchorX: 0.5,
				anchorY: 0.5,
				x: 2048 / 2 - 200 + i * 200,
				y: 1200,
				scaleX: 1.1,
				scaleY: 1.1
			});
			homeScreen.addChild(sampleBubble);
			var letter = new Text2(sampleLetters[i], {
				size: 110,
				fill: "#fff",
				font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
			});
			letter.anchor.set(0.5, 0.5);
			letter.x = sampleBubble.x;
			letter.y = sampleBubble.y;
			homeScreen.addChild(letter);
		}
		// Play button
		var playBtn = LK.getAsset('bubbleOrange', {
			anchorX: 0.5,
			anchorY: 0.5,
			x: 2048 / 2,
			y: 1550,
			scaleX: 1.3,
			scaleY: 1.3
		});
		homeScreen.addChild(playBtn);
		var playText = new Text2("Play", {
			size: 110,
			fill: "#fff",
			font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
		});
		playText.anchor.set(0.5, 0.5);
		playText.x = playBtn.x;
		playText.y = playBtn.y;
		homeScreen.addChild(playText);
		// Show high score on home screen
		var homeHighScore = new Text2("High Score: " + (storage.letterpop_highscore || 0), {
			size: 80,
			fill: 0x888888,
			font: "GillSans-Bold,Impact,'Arial Black',Tahoma"
		});
		homeHighScore.anchor.set(0.5, 0.5);
		homeHighScore.x = 2048 / 2;
		homeHighScore.y = 1750;
		homeScreen.addChild(homeHighScore);
		// Add homeScreen to game
		game.addChild(homeScreen);
		// Play button interaction
		playBtn.down = function () {
			stage.removeChild(homeScreen);
			actuallyStartGame();
		};
		playText.down = playBtn.down; // Make text also clickable
		// Don't start the game yet!
		return;
	}
	actuallyStartGame();
	function actuallyStartGame() {
		currentLetterIdx = 0;
		score = 0;
		scoreText.setText(score);
		feedbackText.alpha = 0;
		correctInARow = 0;
		lettersPerRound = 4;
		// Reset timer
		timerActive = false;
		timerValue = 0;
		timerText.setText('');
		if (timerInterval) {
			LK.clearInterval(timerInterval);
			timerInterval = null;
		}
		// Reload high score from storage
		highScore = storage.letterpop_highscore || 0;
		highScoreText.setText('High: ' + highScore);
		startRound();
	}
}
// Start on load
startGame();
// No need for update loop, as all logic is event-driven
// Touchscreen: No drag/move needed, only tap (down) on bubbles
// Make sure no elements are in top-left 100x100 (all UI is top/center/right)

===================================================================
--- original.js
+++ change.js
@@ -506,10 +506,10 @@
 		homeHighScore.anchor.set(0.5, 0.5);
 		homeHighScore.x = 2048 / 2;
 		homeHighScore.y = 1750;
 		homeScreen.addChild(homeHighScore);
-		// Add homeScreen to stage
-		stage.addChild(homeScreen);
+		// Add homeScreen to game
+		game.addChild(homeScreen);
 		// Play button interaction
 		playBtn.down = function () {
 			stage.removeChild(homeScreen);
 			actuallyStartGame();