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

/**** 
* Classes
****/ 
// Enemy class
// Bullet class
var Bullet = Container.expand(function (startX, startY, targetEnemy, damage, speed) {
	var self = Container.call(this);
	// Bullet properties
	self.targetEnemy = targetEnemy;
	self.damage = damage || 10;
	self.speed = speed || 5;
	self.x = startX;
	self.y = startY;
	self.isTracking = true; // Flag to indicate if bullet is actively tracking target
	self.flightTime = 0; // Track how long the bullet has been flying
	self.maxFlightTime = 180; // 3 seconds at 60fps
	// Visual representation of bullet
	var bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Initialize any active tweens to null
	self.moveTween = null;
	// Method to predict where enemy will be
	self.predictTargetPosition = function (timeToImpact) {
		if (!self.targetEnemy || !self.targetEnemy.parent) {
			return null;
		}
		// Calculate current enemy velocity vectors based on their movement
		var enemyVelocityX = Math.cos(Math.atan2(self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.y - self.targetEnemy.currentCellY : 0, self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.x - self.targetEnemy.currentCellX : 0)) * self.targetEnemy.speed;
		var enemyVelocityY = Math.sin(Math.atan2(self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.y - self.targetEnemy.currentCellY : 0, self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.x - self.targetEnemy.currentCellX : 0)) * self.targetEnemy.speed;
		// Predict where enemy will be
		return {
			x: self.targetEnemy.x + enemyVelocityX * timeToImpact * CELL_SIZE,
			y: self.targetEnemy.y + enemyVelocityY * timeToImpact * CELL_SIZE
		};
	};
	// Method to update bullet trajectory with tweening
	self.updateTrajectory = function () {
		// If we already have an active tween, stop it
		if (self.moveTween) {
			tween.stop(self, {
				x: true,
				y: true
			});
		}
		if (!self.targetEnemy || !self.targetEnemy.parent) {
			return false;
		}
		// Calculate base distance to current enemy position
		var dx = self.targetEnemy.x - self.x;
		var dy = self.targetEnemy.y - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		// Calculate time to impact based on bullet speed
		var timeToImpact = distance / (self.speed * CELL_SIZE / 60); // Convert to frames
		// Get predicted position
		var targetPos = self.predictTargetPosition(timeToImpact);
		if (!targetPos) {
			return false;
		}
		// Calculate adjusted distance to predicted position
		dx = targetPos.x - self.x;
		dy = targetPos.y - self.y;
		distance = Math.sqrt(dx * dx + dy * dy);
		// Calculate adjusted time to impact
		timeToImpact = Math.min(distance / (self.speed * CELL_SIZE / 60), 60); // Cap at 1 second
		// Create tween to fly to predicted position
		self.moveTween = tween(self, {
			x: targetPos.x,
			y: targetPos.y
		}, {
			duration: timeToImpact * 16.67,
			// Convert frames to ms
			easing: tween.linear,
			onFinish: function onFinish() {
				// Check if we're close enough to target to hit it
				if (self.targetEnemy && self.targetEnemy.parent) {
					var finalDx = self.targetEnemy.x - self.x;
					var finalDy = self.targetEnemy.y - self.y;
					var finalDistance = Math.sqrt(finalDx * finalDx + finalDy * finalDy);
					if (finalDistance < CELL_SIZE / 2) {
						// We've hit the target
						self.hitTarget();
					} else {
						// Still need to track
						self.updateTrajectory();
					}
				} else {
					// Target is gone
					self.destroy();
				}
			}
		});
		return true;
	};
	// Method when bullet hits target
	self.hitTarget = function () {
		if (!self.targetEnemy || !self.targetEnemy.parent) {
			self.destroy();
			return;
		}
		// Deal damage to enemy
		self.targetEnemy.health -= self.damage;
		// Update health bar visual
		if (self.targetEnemy.health <= 0) {
			// Enemy is defeated
			self.targetEnemy.health = 0;
		} else {
			// Update health bar width based on remaining health percentage
			self.targetEnemy.healthBar.width = self.targetEnemy.health / self.targetEnemy.maxHealth * 70;
		}
		// Remove this bullet
		self.destroy();
	};
	// Update method - called every frame
	self.update = function () {
		// Increment flight time
		self.flightTime++;
		// If target is gone or bullet has been flying too long, destroy it
		if (!self.targetEnemy || !self.targetEnemy.parent || self.flightTime > self.maxFlightTime) {
			self.destroy();
			return;
		}
		// If actively tracking, update trajectory periodically
		if (self.isTracking && self.flightTime % 20 === 0) {
			// Update every 1/3 second
			self.updateTrajectory();
		}
		// Check if we've hit the target
		var dx = self.targetEnemy.x - self.x;
		var dy = self.targetEnemy.y - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		// If we hit the target
		if (distance < CELL_SIZE / 3) {
			self.hitTarget();
		}
	};
	// Start tracking immediately when created
	self.updateTrajectory();
	return self;
});
// DebugCell class
var DebugCell = Container.expand(function () {
	var self = Container.call(this);
	var cellGraphics = self.attachAsset('cell', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	cellGraphics.tint = Math.random() * 0xffffff;
	// Add a debug arrow to the debug cells
	var debugArrows = [];
	// Add a number label to the debug cells
	var numberLabel = new Text2('0', {
		size: 30,
		fill: 0xFFFFFF,
		weight: 800
	});
	numberLabel.anchor.set(.5, .5);
	self.addChild(numberLabel);
	self.update = function () {};
	self.down = function () {
		return;
		if (self.cell.type == 0 || self.cell.type == 1) {
			self.cell.type = self.cell.type == 1 ? 0 : 1;
			if (grid.pathFind()) {
				self.cell.type = self.cell.type == 1 ? 0 : 1;
				grid.pathFind();
				var notification = game.addChild(new Notification("Path is blocked!"));
				notification.x = 2048 / 2;
				notification.y = grid.height - 50;
			}
			grid.renderDebug();
		}
	};
	self.removeArrows = function () {
		while (debugArrows.length) {
			self.removeChild(debugArrows.pop());
		}
	};
	self.render = function (data) {
		switch (data.type) {
			case 0:
			case 2:
				{
					if (data.pathId != pathId) {
						self.removeArrows();
						numberLabel.setText("-");
						cellGraphics.tint = 0x880000;
						return;
					}
					numberLabel.visible = true;
					var tint = Math.floor(data.score / maxScore * 0x88);
					cellGraphics.tint = 0x88 - tint << 8 | tint;
					while (debugArrows.length > data.targets.length) {
						self.removeChild(debugArrows.pop());
					}
					for (var a = 0; a < data.targets.length; a++) {
						var destination = data.targets[a];
						var ox = destination.x - data.x;
						var oy = destination.y - data.y;
						var angle = Math.atan2(oy, ox);
						if (!debugArrows[a]) {
							debugArrows[a] = LK.getAsset('arrow', {
								anchorX: -.5,
								anchorY: 0.5
							});
							debugArrows[a].alpha = .5;
							self.addChildAt(debugArrows[a], 1);
							//							debugArrows = 
						}
						debugArrows[a].rotation = angle;
						//	debugArrow.rotation = angle;
					}
					break;
				}
			case 1:
				{
					self.removeArrows();
					cellGraphics.tint = 0xaaaaaa;
					numberLabel.visible = false;
					break;
				}
			case 3:
				{
					self.removeArrows();
					cellGraphics.tint = 0x008800;
					numberLabel.visible = false;
					break;
				}
		}
		numberLabel.setText(Math.floor(data.score / 1000) / 10);
	};
});
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = Math.random() * .2 + .03;
	self.cellX = 0;
	self.cellY = 0;
	self.currentCellX = 0;
	self.currentCellY = 0;
	self.currentTarget = undefined;
	self.lastCellX = 0; // Track previous position for velocity calculation
	self.lastCellY = 0; // Track previous position for velocity calculation
	self.velocityX = 0; // Store calculated x velocity
	self.velocityY = 0; // Store calculated y velocity
	self.maxHealth = 100; // Starting max health
	self.health = self.maxHealth; // Current health
	self.bulletsTargetingThis = []; // Track bullets targeting this enemy
	// Add health bar to the enemy
	var healthBarOutline = self.attachAsset('healthBarOutline', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	var healthBar = self.attachAsset('healthBar', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	healthBarOutline.y = healthBar.y = -enemyGraphics.height / 2 - 10; // Position the health bar above the enemy
	self.healthBar = healthBar;
	// Method to update velocity based on movement
	self.updateVelocity = function () {
		if (self.currentTarget) {
			self.velocityX = self.currentTarget.x - self.currentCellX;
			self.velocityY = self.currentTarget.y - self.currentCellY;
			// Normalize velocity vector
			var length = Math.sqrt(self.velocityX * self.velocityX + self.velocityY * self.velocityY);
			if (length > 0) {
				self.velocityX /= length;
				self.velocityY /= length;
			}
		}
		// Store current position for next update
		self.lastCellX = self.currentCellX;
		self.lastCellY = self.currentCellY;
	};
	// Method for bullet prediction calculations
	self.getPredictedPosition = function (timeSteps) {
		if (!self.currentTarget) {
			return {
				x: self.x,
				y: self.y
			};
		}
		var predictedX = self.currentCellX + self.velocityX * self.speed * timeSteps;
		var predictedY = self.currentCellY + self.velocityY * self.speed * timeSteps;
		return {
			x: grid.x + predictedX * CELL_SIZE,
			y: grid.y + predictedY * CELL_SIZE
		};
	};
});
//Class for the grid, handles all logic related to grid movement and interaction
var Grid = Container.expand(function (gridWidth, gridHeight) {
	var self = Container.call(this);
	self.cells = [];
	self.spawns = [];
	self.goals = [];
	for (var i = 0; i < gridWidth; i++) {
		self.cells[i] = [];
		for (var j = 0; j < gridHeight; j++) {
			self.cells[i][j] = {
				score: 0,
				pathId: 0,
				towersInRange: [] // Cache for towers in range
			};
		}
	}
	/*
				Cell Types
				0: Transparent floor
				1: Wall
				2: Spawn
				3: Goal
	*/
	for (var i = 0; i < gridWidth; i++) {
		for (var j = 0; j < gridHeight; j++) {
			// Set the type to 1 (wall) if the cell is on the edge of the grid, otherwise set it to 0 (ground)
			var cell = self.cells[i][j];
			var cellType = i === 0 || i === gridWidth - 1 || j <= 4 || j >= gridHeight - 4 ? 1 : 0;
			if (i > 11 - 3 && i <= 11 + 3) {
				if (j === 0) {
					cellType = 2;
					self.spawns.push(cell);
				} else if (j <= 4) {
					cellType = 0;
				} else if (j === gridHeight - 1) {
					cellType = 3;
					self.goals.push(cell);
				} else if (j >= gridHeight - 4) {
					cellType = 0;
				}
			}
			cell.type = cellType;
			cell.x = i;
			cell.y = j;
			/*if (cell.type == 0) {
				if (Math.random() > .5) {
					cell.type = 1;
				}
			}*/
			//Cache neighbours for speed
			cell.upLeft = self.cells[i - 1] && self.cells[i - 1][j - 1];
			cell.up = self.cells[i - 1] && self.cells[i - 1][j];
			cell.upRight = self.cells[i - 1] && self.cells[i - 1][j + 1];
			cell.left = self.cells[i][j - 1];
			cell.right = self.cells[i][j + 1];
			cell.downLeft = self.cells[i + 1] && self.cells[i + 1][j - 1];
			cell.down = self.cells[i + 1] && self.cells[i + 1][j];
			cell.downRight = self.cells[i + 1] && self.cells[i + 1][j + 1];
			cell.neighbors = [cell.upLeft, cell.up, cell.upRight, cell.right, cell.downRight, cell.down, cell.downLeft, cell.left];
			cell.targets = [];
			if (j > 3 && j <= gridHeight - 4) {
				var debugCell = new DebugCell();
				self.addChild(debugCell);
				debugCell.cell = cell;
				debugCell.x = i * CELL_SIZE;
				debugCell.y = j * CELL_SIZE;
				cell.debugCell = debugCell;
			}
		}
	}
	self.getCell = function (x, y) {
		return self.cells[x] && self.cells[x][y];
	};
	self.pathFind = function () {
		var before = new Date().getTime();
		var toProcess = self.goals.concat([]);
		maxScore = 0;
		pathId += 1;
		for (var a = 0; a < toProcess.length; a++) {
			toProcess[a].pathId = pathId;
		}
		function processNode(node, targetValue, targetNode) {
			if (node && node.type != 1) {
				if (node.pathId < pathId || targetValue < node.score) {
					node.targets = [targetNode];
				} else if (node.pathId == pathId && targetValue == node.score) {
					node.targets.push(targetNode);
				}
				if (node.pathId < pathId || targetValue < node.score) {
					node.score = targetValue;
					if (node.pathId != pathId) {
						toProcess.push(node);
					}
					node.pathId = pathId;
					if (targetValue > maxScore) {
						maxScore = targetValue;
					}
				}
			}
		}
		while (toProcess.length) {
			var nodes = toProcess;
			toProcess = [];
			for (var a = 0; a < nodes.length; a++) {
				var node = nodes[a];
				var targetScore = node.score + 14142;
				// Check for diagonal movement and ensure both adjacent cells are not walls
				if (node.up && node.left && node.up.type != 1 && node.left.type != 1) {
					processNode(node.upLeft, targetScore, node);
				}
				if (node.up && node.right && node.up.type != 1 && node.right.type != 1) {
					processNode(node.upRight, targetScore, node);
				}
				if (node.down && node.right && node.down.type != 1 && node.right.type != 1) {
					processNode(node.downRight, targetScore, node);
				}
				if (node.down && node.left && node.down.type != 1 && node.left.type != 1) {
					processNode(node.downLeft, targetScore, node);
				}
				targetScore = node.score + 10000;
				processNode(node.up, targetScore, node);
				processNode(node.right, targetScore, node);
				processNode(node.down, targetScore, node);
				processNode(node.left, targetScore, node);
			}
		}
		for (var a = 0; a < self.spawns.length; a++) {
			if (self.spawns[a].pathId != pathId) {
				console.warn("Spawn blocked");
				return true;
			}
		}
		for (var a = 0; a < enemies.length; a++) {
			var enemy = enemies[a];
			var target = self.getCell(enemy.cellX, enemy.cellY);
			if (enemy.currentTarget) {
				if (enemy.currentTarget.pathId != pathId) {
					if (!target || target.pathId != pathId) {
						console.warn("Enemy blocked");
						return true;
					}
				}
			} else if (!target || target.pathId != pathId) {
				console.warn("Enemy blocked");
				return true;
			}
		}
		console.log("Speed", new Date().getTime() - before);
	};
	self.renderDebug = function () {
		for (var i = 0; i < gridWidth; i++) {
			for (var j = 0; j < gridHeight; j++) {
				var debugCell = self.cells[i][j].debugCell;
				if (debugCell) {
					debugCell.render(self.cells[i][j]);
				}
			}
		}
	};
	self.updateEnemy = function (enemy) {
		var cell = grid.getCell(enemy.cellX, enemy.cellY);
		if (cell.type == 3) {
			return true;
		}
		if (!enemy.currentTarget) {
			enemy.currentTarget = cell.targets[0];
		}
		// Store velocity data for bullet prediction
		enemy.lastCellX = enemy.currentCellX;
		enemy.lastCellY = enemy.currentCellY;
		if (enemy.currentTarget) {
			//Allows enemies to change direction right away.
			if (cell.score < enemy.currentTarget.score) {
				enemy.currentTarget = cell;
			}
			var ox = enemy.currentTarget.x - enemy.currentCellX;
			var oy = enemy.currentTarget.y - enemy.currentCellY;
			var dist = Math.sqrt(ox * ox + oy * oy);
			if (dist < enemy.speed) {
				enemy.cellX = Math.round(enemy.currentCellX);
				enemy.cellY = Math.round(enemy.currentCellY);
				enemy.currentTarget = undefined;
				return;
			}
			var angle = Math.atan2(oy, ox);
			enemy.currentCellX += Math.cos(angle) * enemy.speed;
			enemy.currentCellY += Math.sin(angle) * enemy.speed;
			// Update enemy velocity for bullet prediction
			enemy.velocityX = Math.cos(angle);
			enemy.velocityY = Math.sin(angle);
		}
		enemy.x = grid.x + enemy.currentCellX * CELL_SIZE;
		enemy.y = grid.y + enemy.currentCellY * CELL_SIZE;
		// If enemy has the method, call it to update velocity
		if (enemy.updateVelocity) {
			enemy.updateVelocity();
		}
	};
});
// Notification class
var Notification = Container.expand(function (message) {
	var self = Container.call(this);
	var notificationGraphics = self.attachAsset('notification', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	var notificationText = new Text2(message, {
		size: 50,
		fill: 0x000000,
		weight: 800
	});
	notificationText.anchor.set(0.5, 0.5);
	notificationGraphics.width = notificationText.width + 30;
	self.addChild(notificationText);
	self.alpha = 1;
	var fadeOutTime = 120; // 2 seconds at 60FPS
	self.update = function () {
		if (fadeOutTime > 0) {
			fadeOutTime--;
			self.alpha = Math.min(fadeOutTime / 120 * 2, 1);
		} else {
			self.destroy();
		}
	};
	return self;
});
// Tower class that can be placed on the grid
var Tower = Container.expand(function (id) {
	var self = Container.call(this);
	// Tower attributes
	self.id = id || 'default';
	self.level = 1;
	self.maxLevel = 6;
	self.gridX = 0;
	self.gridY = 0;
	self.range = 3 * CELL_SIZE; // initial range (3 grid cells)
	self.cellsInRange = []; // Cache for cells in range
	self.fireRate = 60; // frames between shots
	self.bulletSpeed = 5;
	self.damage = 10;
	self.lastFired = 0;
	self.targetEnemy = null;
	// Create the tower base (a square)
	var baseGraphics = self.attachAsset('tower', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Level indicators (dots at bottom of tower)
	var levelIndicators = [];
	var maxDots = self.maxLevel;
	var dotSpacing = baseGraphics.width / (maxDots + 1);
	var dotSize = CELL_SIZE / 6;
	for (var i = 0; i < maxDots; i++) {
		var dot = new Container();
		var towerLevelIndicator = dot.attachAsset('towerLevelIndicator', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		towerLevelIndicator.width = dotSize;
		towerLevelIndicator.height = dotSize;
		towerLevelIndicator.tint = 0xCCCCCC; // Gray dots by default
		// Position dot at bottom of tower
		dot.x = -CELL_SIZE + dotSpacing * (i + 1);
		dot.y = CELL_SIZE * 0.7;
		self.addChild(dot);
		levelIndicators.push(dot);
	}
	// Create the gun turret that will rotate
	var gunContainer = new Container();
	self.addChild(gunContainer);
	var gunGraphics = gunContainer.attachAsset('defense', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	//gunGraphics.y = -CELL_SIZE * 0.3; // Position the gun slightly up from center
	// Update the level indicators
	self.updateLevelIndicators = function () {
		for (var i = 0; i < maxDots; i++) {
			var dot = levelIndicators[i];
			var towerLevelIndicator = dot.children[0];
			// Light up dots up to current level
			if (i < self.level) {
				towerLevelIndicator.tint = 0xFFFF00; // Yellow for active levels
			} else {
				towerLevelIndicator.tint = 0xCCCCCC; // Gray for inactive levels
			}
		}
	};
	// Initialize level indicators
	self.updateLevelIndicators();
	// Method to upgrade the tower
	self.upgrade = function () {
		if (self.level < self.maxLevel) {
			self.level++;
			// Increase stats based on level
			self.range = (3 + self.level * 0.5) * CELL_SIZE;
			self.fireRate = Math.max(20, 60 - self.level * 8); // Faster firing rate
			self.damage = 10 + self.level * 5;
			self.bulletSpeed = 5 + self.level * 0.5;
			// Update level indicators
			self.updateLevelIndicators();
			return true;
		}
		return false;
	};
	// Method to find the nearest enemy within range
	self.findTarget = function () {
		var closestEnemy = null;
		var closestDistance = self.range;
		for (var i = 0; i < self.cellsInRange.length; i++) {
			var cell = self.cellsInRange[i];
			for (var j = 0; j < enemies.length; j++) {
				var enemy = enemies[j];
				if (enemy.cellX === cell.x && enemy.cellY === cell.y) {
					var dx = enemy.x - self.x;
					var dy = enemy.y - self.y;
					var distance = Math.sqrt(dx * dx + dy * dy);
					if (distance < closestDistance) {
						closestDistance = distance;
						closestEnemy = enemy;
					}
				}
			}
		}
		return closestEnemy;
	};
	// Update method
	self.update = function () {
		// Find target if we don't have one or if current target is out of range
		if (!self.targetEnemy || !self.isInRange(self.targetEnemy)) {
			self.targetEnemy = self.findTarget();
		}
		// Rotate gun toward target
		if (self.targetEnemy) {
			var dx = self.targetEnemy.x - self.x;
			var dy = self.targetEnemy.y - self.y;
			var angle = Math.atan2(dy, dx);
			// Rotate the gun container
			gunContainer.rotation = angle;
			// Fire at target if cooldown is complete
			if (LK.ticks - self.lastFired >= self.fireRate) {
				self.fire();
				self.lastFired = LK.ticks;
			}
		}
	};
	// Check if enemy is in range
	self.isInRange = function (enemy) {
		if (!enemy) {
			return false;
		}
		var dx = enemy.x - self.x;
		var dy = enemy.y - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		return distance <= self.range;
	};
	// Fire at the current target
	self.fire = function () {
		if (self.targetEnemy) {
			// Verify the target is alive and calculate damage including future damage
			var potentialDamage = 0;
			for (var i = 0; i < self.targetEnemy.bulletsTargetingThis.length; i++) {
				potentialDamage += self.targetEnemy.bulletsTargetingThis[i].damage;
			}
			// Only shoot if enemy would still be alive after all current bullets hit
			if (self.targetEnemy.health > potentialDamage) {
				// Calculate bullet starting position from the gun barrel
				var bulletX = self.x + Math.cos(gunContainer.rotation) * 40;
				var bulletY = self.y + Math.sin(gunContainer.rotation) * 40;
				// Create a new bullet with increased speed based on tower level
				// Higher level towers get faster bullets to catch faster enemies
				var adjustedSpeed = self.bulletSpeed * (1 + self.level * 0.2);
				// Create a new bullet
				var bullet = new Bullet(bulletX, bulletY, self.targetEnemy, self.damage, adjustedSpeed);
				game.addChild(bullet);
				// Add bullet to global bullets array and to enemy's tracking array
				bullets.push(bullet);
				self.targetEnemy.bulletsTargetingThis.push(bullet);
				// Apply visual effect to show bullet launching
				LK.effects.flashObject(bullet, 0xFFFFFF, 200);
			}
		}
	};
	// Place tower on the grid
	self.placeOnGrid = function (gridX, gridY) {
		self.gridX = gridX;
		self.gridY = gridY;
		// Adjust by half a cell size to align with grid cell centers
		self.x = grid.x + gridX * CELL_SIZE + CELL_SIZE / 2;
		self.y = grid.y + gridY * CELL_SIZE + CELL_SIZE / 2;
		// Mark these grid cells as occupied
		for (var i = 0; i < 2; i++) {
			for (var j = 0; j < 2; j++) {
				var cell = grid.getCell(gridX + i, gridY + j);
				if (cell) {
					cell.type = 1; // Mark as wall/occupied
				}
			}
		}
		// Calculate cells in range
		self.cellsInRange = [];
		for (var i = -Math.floor(self.range / CELL_SIZE); i <= Math.floor(self.range / CELL_SIZE); i++) {
			for (var j = -Math.floor(self.range / CELL_SIZE); j <= Math.floor(self.range / CELL_SIZE); j++) {
				var cell = grid.getCell(gridX + i, gridY + j);
				if (cell) {
					self.cellsInRange.push(cell);
					cell.towersInRange.push(self);
				}
			}
		}
	};
	return self;
});
// TowerPreview class for showing where towers can be placed
var TowerPreview = Container.expand(function () {
	var self = Container.call(this);
	// Define tower range (in grid cells)
	var towerRange = 3;
	var rangeInPixels = towerRange * CELL_SIZE;
	// Create the range indicator (circle)
	var rangeIndicator = new Container();
	self.addChild(rangeIndicator);
	// Since we don't have direct access to Graphics,
	// we'll create a white semi-transparent circle shape asset
	var rangeGraphics = rangeIndicator.attachAsset('rangeCircle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	rangeGraphics.alpha = 0.3; // Make it semi-transparent
	// Create the preview square (2x2 grid cells)
	var previewGraphics = self.attachAsset('towerpreview', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Set the size to cover 2x2 grid cells
	previewGraphics.width = CELL_SIZE * 2;
	previewGraphics.height = CELL_SIZE * 2;
	// Initial state
	self.canPlace = false;
	self.gridX = 0;
	self.gridY = 0;
	self.blockedByEnemy = false; // Track if placement is blocked by enemy
	// Update the preview color based on placement possibility
	self.updatePlacementStatus = function () {
		// First check if placement is valid from a grid perspective
		var validGridPlacement = true;
		// Check if we're in the valid placement area (main square of the board)
		if (self.gridY <= 4 || self.gridY + 1 >= grid.cells[0].length - 4) {
			validGridPlacement = false;
		} else {
			// Check each of the 2x2 cells
			for (var i = 0; i < 2; i++) {
				for (var j = 0; j < 2; j++) {
					var cell = grid.getCell(self.gridX + i, self.gridY + j);
					// Can't place if any cell is undefined or not of type 0 (empty ground)
					if (!cell || cell.type !== 0) {
						validGridPlacement = false;
						break;
					}
				}
				if (!validGridPlacement) {
					break;
				}
			}
		}
		// Now check if any enemy is occupying the space where the tower would be placed
		self.blockedByEnemy = false;
		if (validGridPlacement) {
			for (var i = 0; i < enemies.length; i++) {
				var enemy = enemies[i];
				if (enemy.cellX >= self.gridX && enemy.cellX < self.gridX + 2 && enemy.cellY >= self.gridY && enemy.cellY < self.gridY + 2) {
					self.blockedByEnemy = true;
					break;
				}
			}
		}
		// Set final placement status
		self.canPlace = validGridPlacement && !self.blockedByEnemy;
		// If we can place, tint green, otherwise red
		previewGraphics.tint = self.canPlace ? 0x00FF00 : 0xFF0000;
	};
	// Check if the tower can be placed at the current position
	self.checkPlacement = function () {
		self.updatePlacementStatus();
	};
	// Snap the preview to the grid
	self.snapToGrid = function (x, y) {
		// Convert screen coordinates to grid coordinates
		// Offset by the grid's position
		var gridPosX = x - grid.x;
		var gridPosY = y - grid.y;
		// Convert to grid coordinates and round down to get the top-left cell
		self.gridX = Math.floor(gridPosX / CELL_SIZE);
		self.gridY = Math.floor(gridPosY / CELL_SIZE);
		// Position the preview at the intersection of the four cells
		// Adding CELL_SIZE to gridX and gridY gives us the center point
		// Adjust by half a cell size to align with grid cell centers
		self.x = grid.x + self.gridX * CELL_SIZE + CELL_SIZE / 2; // Center of the 2x2 grid
		self.y = grid.y + self.gridY * CELL_SIZE + CELL_SIZE / 2; // Center of the 2x2 grid
		// Check if we can place the tower here
		self.checkPlacement();
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x333333 //Init game with black background 
});

/**** 
* Game Code
****/ 
// Define cell size as a global constant
// Import tween plugin
var CELL_SIZE = 76;
var pathId = 1;
var maxScore = 0;
var enemies = [];
var towers = [];
var bullets = []; // Array to store active bullets
var defenses = [];
// Create separate layers for debug tiles, towers, and enemies
var debugLayer = new Container();
var towerLayer = new Container();
var enemyLayer = new Container();
var grid = new Grid(24, 29 + 6);
grid.x = 150;
grid.y = 112 - CELL_SIZE * 4;
grid.pathFind();
grid.renderDebug();
debugLayer.addChild(grid);
// Add layers to the game in the correct order
game.addChild(debugLayer);
game.addChild(towerLayer);
game.addChild(enemyLayer);
var offset = 0;
// Create tower preview
var towerPreview = new TowerPreview();
game.addChild(towerPreview);
towerPreview.visible = false;
// Handle drag events for tower placement
var isDragging = false;
// Check if placing a tower would block the path
function wouldBlockPath(gridX, gridY) {
	// Temporarily mark cells as walls
	var cells = [];
	for (var i = 0; i < 2; i++) {
		for (var j = 0; j < 2; j++) {
			var cell = grid.getCell(gridX + i, gridY + j);
			if (cell) {
				cells.push({
					cell: cell,
					originalType: cell.type
				});
				cell.type = 1; // Mark as wall
			}
		}
	}
	// Check if path is still valid
	var blocked = grid.pathFind();
	// Restore original cell types
	for (var i = 0; i < cells.length; i++) {
		cells[i].cell.type = cells[i].originalType;
	}
	// Re-find path with original cells
	grid.pathFind();
	grid.renderDebug();
	return blocked;
}
// Place a tower at the grid position
function placeTower(gridX, gridY) {
	var tower = new Tower('default');
	tower.placeOnGrid(gridX, gridY);
	towerLayer.addChild(tower);
	towers.push(tower);
	// Update grid pathing
	grid.pathFind();
	grid.renderDebug();
}
game.down = function (x, y, obj) {
	towerPreview.visible = true;
	isDragging = true;
	towerPreview.snapToGrid(x, y);
};
game.move = function (x, y, obj) {
	if (isDragging) {
		towerPreview.snapToGrid(x, y);
	}
};
game.up = function (x, y, obj) {
	isDragging = false;
	// Check placement possibilities
	if (towerPreview.canPlace) {
		// Check if placing here would block the path
		if (!wouldBlockPath(towerPreview.gridX, towerPreview.gridY)) {
			// Place the tower
			placeTower(towerPreview.gridX, towerPreview.gridY);
		} else {
			// Show notification that we can't place here
			var notification = game.addChild(new Notification("Tower would block the path!"));
			notification.x = 2048 / 2;
			notification.y = grid.height - 50;
		}
	} else if (towerPreview.blockedByEnemy) {
		// Show notification that an enemy is in the way
		var notification = game.addChild(new Notification("Cannot build: Enemy in the way!"));
		notification.x = 2048 / 2;
		notification.y = grid.height - 50;
	} else if (towerPreview.visible) {
		// Generic notification for other reasons
		var notification = game.addChild(new Notification("Cannot build here!"));
		notification.x = 2048 / 2;
		notification.y = grid.height - 50;
	}
	towerPreview.visible = false;
};
game.update = function () {
	// Spawn enemies periodically
	if (++offset % 100 == 0) {
		var target = grid.spawns[Math.random() * grid.spawns.length >> 0];
		var enemy = enemyLayer.addChild(new Enemy());
		enemy.currentCellX = enemy.cellX = target.x;
		enemy.currentCellY = enemy.cellY = target.y;
		enemies.push(enemy);
	}
	// Update enemies
	for (var a = enemies.length - 1; a >= 0; a--) {
		var enemy = enemies[a];
		// Check if enemy is defeated
		if (enemy.health <= 0) {
			// Clear bullet targeting references
			for (var i = 0; i < enemy.bulletsTargetingThis.length; i++) {
				var bullet = enemy.bulletsTargetingThis[i];
				bullet.targetEnemy = null; // This will cause bullet to destroy itself on next update
			}
			// Remove enemy
			enemyLayer.removeChild(enemy);
			enemies.splice(a, 1);
			continue;
		}
		// Update enemy movement
		if (grid.updateEnemy(enemy)) {
			// Enemy reached goal
			enemyLayer.removeChild(enemy);
			enemies.splice(a, 1);
		}
	}
	// Update towers
	for (var i = 0; i < towers.length; i++) {
		towers[i].update();
	}
	// Update bullets
	for (var i = bullets.length - 1; i >= 0; i--) {
		bullets[i].update();
		// Remove destroyed bullets
		if (!bullets[i].parent) {
			// If this bullet has a target, remove the bullet from the target's tracking array
			if (bullets[i].targetEnemy) {
				var targetEnemy = bullets[i].targetEnemy;
				var bulletIndex = targetEnemy.bulletsTargetingThis.indexOf(bullets[i]);
				if (bulletIndex !== -1) {
					targetEnemy.bulletsTargetingThis.splice(bulletIndex, 1);
				}
			}
			bullets.splice(i, 1);
		}
	}
	// Update tower preview placement status on every frame
	// This ensures the placement status updates in real-time as enemies move
	if (towerPreview.visible) {
		towerPreview.checkPlacement();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -1,5 +1,10 @@
 /**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
 * Classes
 ****/ 
 // Enemy class
 // Bullet class
@@ -10,45 +15,134 @@
 	self.damage = damage || 10;
 	self.speed = speed || 5;
 	self.x = startX;
 	self.y = startY;
+	self.isTracking = true; // Flag to indicate if bullet is actively tracking target
+	self.flightTime = 0; // Track how long the bullet has been flying
+	self.maxFlightTime = 180; // 3 seconds at 60fps
 	// Visual representation of bullet
 	var bulletGraphics = self.attachAsset('bullet', {
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
+	// Initialize any active tweens to null
+	self.moveTween = null;
+	// Method to predict where enemy will be
+	self.predictTargetPosition = function (timeToImpact) {
+		if (!self.targetEnemy || !self.targetEnemy.parent) {
+			return null;
+		}
+		// Calculate current enemy velocity vectors based on their movement
+		var enemyVelocityX = Math.cos(Math.atan2(self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.y - self.targetEnemy.currentCellY : 0, self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.x - self.targetEnemy.currentCellX : 0)) * self.targetEnemy.speed;
+		var enemyVelocityY = Math.sin(Math.atan2(self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.y - self.targetEnemy.currentCellY : 0, self.targetEnemy.currentTarget ? self.targetEnemy.currentTarget.x - self.targetEnemy.currentCellX : 0)) * self.targetEnemy.speed;
+		// Predict where enemy will be
+		return {
+			x: self.targetEnemy.x + enemyVelocityX * timeToImpact * CELL_SIZE,
+			y: self.targetEnemy.y + enemyVelocityY * timeToImpact * CELL_SIZE
+		};
+	};
+	// Method to update bullet trajectory with tweening
+	self.updateTrajectory = function () {
+		// If we already have an active tween, stop it
+		if (self.moveTween) {
+			tween.stop(self, {
+				x: true,
+				y: true
+			});
+		}
+		if (!self.targetEnemy || !self.targetEnemy.parent) {
+			return false;
+		}
+		// Calculate base distance to current enemy position
+		var dx = self.targetEnemy.x - self.x;
+		var dy = self.targetEnemy.y - self.y;
+		var distance = Math.sqrt(dx * dx + dy * dy);
+		// Calculate time to impact based on bullet speed
+		var timeToImpact = distance / (self.speed * CELL_SIZE / 60); // Convert to frames
+		// Get predicted position
+		var targetPos = self.predictTargetPosition(timeToImpact);
+		if (!targetPos) {
+			return false;
+		}
+		// Calculate adjusted distance to predicted position
+		dx = targetPos.x - self.x;
+		dy = targetPos.y - self.y;
+		distance = Math.sqrt(dx * dx + dy * dy);
+		// Calculate adjusted time to impact
+		timeToImpact = Math.min(distance / (self.speed * CELL_SIZE / 60), 60); // Cap at 1 second
+		// Create tween to fly to predicted position
+		self.moveTween = tween(self, {
+			x: targetPos.x,
+			y: targetPos.y
+		}, {
+			duration: timeToImpact * 16.67,
+			// Convert frames to ms
+			easing: tween.linear,
+			onFinish: function onFinish() {
+				// Check if we're close enough to target to hit it
+				if (self.targetEnemy && self.targetEnemy.parent) {
+					var finalDx = self.targetEnemy.x - self.x;
+					var finalDy = self.targetEnemy.y - self.y;
+					var finalDistance = Math.sqrt(finalDx * finalDx + finalDy * finalDy);
+					if (finalDistance < CELL_SIZE / 2) {
+						// We've hit the target
+						self.hitTarget();
+					} else {
+						// Still need to track
+						self.updateTrajectory();
+					}
+				} else {
+					// Target is gone
+					self.destroy();
+				}
+			}
+		});
+		return true;
+	};
+	// Method when bullet hits target
+	self.hitTarget = function () {
+		if (!self.targetEnemy || !self.targetEnemy.parent) {
+			self.destroy();
+			return;
+		}
+		// Deal damage to enemy
+		self.targetEnemy.health -= self.damage;
+		// Update health bar visual
+		if (self.targetEnemy.health <= 0) {
+			// Enemy is defeated
+			self.targetEnemy.health = 0;
+		} else {
+			// Update health bar width based on remaining health percentage
+			self.targetEnemy.healthBar.width = self.targetEnemy.health / self.targetEnemy.maxHealth * 70;
+		}
+		// Remove this bullet
+		self.destroy();
+	};
 	// Update method - called every frame
 	self.update = function () {
-		// If target is gone, destroy this bullet
-		if (!self.targetEnemy || !self.targetEnemy.parent) {
+		// Increment flight time
+		self.flightTime++;
+		// If target is gone or bullet has been flying too long, destroy it
+		if (!self.targetEnemy || !self.targetEnemy.parent || self.flightTime > self.maxFlightTime) {
 			self.destroy();
 			return;
 		}
-		// Move toward target
+		// If actively tracking, update trajectory periodically
+		if (self.isTracking && self.flightTime % 20 === 0) {
+			// Update every 1/3 second
+			self.updateTrajectory();
+		}
+		// Check if we've hit the target
 		var dx = self.targetEnemy.x - self.x;
 		var dy = self.targetEnemy.y - self.y;
 		var distance = Math.sqrt(dx * dx + dy * dy);
 		// If we hit the target
-		if (distance < self.speed) {
-			// Deal damage to enemy
-			self.targetEnemy.health -= self.damage;
-			// Update health bar visual
-			if (self.targetEnemy.health <= 0) {
-				// Enemy is defeated
-				self.targetEnemy.health = 0;
-			} else {
-				// Update health bar width based on remaining health percentage
-				self.targetEnemy.healthBar.width = self.targetEnemy.health / self.targetEnemy.maxHealth * 70;
-			}
-			// Remove this bullet
-			self.destroy();
-		} else {
-			// Move toward target
-			var angle = Math.atan2(dy, dx);
-			self.x += Math.cos(angle) * self.speed;
-			self.y += Math.sin(angle) * self.speed;
+		if (distance < CELL_SIZE / 3) {
+			self.hitTarget();
 		}
 	};
+	// Start tracking immediately when created
+	self.updateTrajectory();
 	return self;
 });
 // DebugCell class
 var DebugCell = Container.expand(function () {
@@ -153,8 +247,12 @@
 	self.cellY = 0;
 	self.currentCellX = 0;
 	self.currentCellY = 0;
 	self.currentTarget = undefined;
+	self.lastCellX = 0; // Track previous position for velocity calculation
+	self.lastCellY = 0; // Track previous position for velocity calculation
+	self.velocityX = 0; // Store calculated x velocity
+	self.velocityY = 0; // Store calculated y velocity
 	self.maxHealth = 100; // Starting max health
 	self.health = self.maxHealth; // Current health
 	self.bulletsTargetingThis = []; // Track bullets targeting this enemy
 	// Add health bar to the enemy
@@ -167,8 +265,39 @@
 		anchorY: 0.5
 	});
 	healthBarOutline.y = healthBar.y = -enemyGraphics.height / 2 - 10; // Position the health bar above the enemy
 	self.healthBar = healthBar;
+	// Method to update velocity based on movement
+	self.updateVelocity = function () {
+		if (self.currentTarget) {
+			self.velocityX = self.currentTarget.x - self.currentCellX;
+			self.velocityY = self.currentTarget.y - self.currentCellY;
+			// Normalize velocity vector
+			var length = Math.sqrt(self.velocityX * self.velocityX + self.velocityY * self.velocityY);
+			if (length > 0) {
+				self.velocityX /= length;
+				self.velocityY /= length;
+			}
+		}
+		// Store current position for next update
+		self.lastCellX = self.currentCellX;
+		self.lastCellY = self.currentCellY;
+	};
+	// Method for bullet prediction calculations
+	self.getPredictedPosition = function (timeSteps) {
+		if (!self.currentTarget) {
+			return {
+				x: self.x,
+				y: self.y
+			};
+		}
+		var predictedX = self.currentCellX + self.velocityX * self.speed * timeSteps;
+		var predictedY = self.currentCellY + self.velocityY * self.speed * timeSteps;
+		return {
+			x: grid.x + predictedX * CELL_SIZE,
+			y: grid.y + predictedY * CELL_SIZE
+		};
+	};
 });
 //Class for the grid, handles all logic related to grid movement and interaction
 var Grid = Container.expand(function (gridWidth, gridHeight) {
 	var self = Container.call(this);
@@ -335,8 +464,11 @@
 		}
 		if (!enemy.currentTarget) {
 			enemy.currentTarget = cell.targets[0];
 		}
+		// Store velocity data for bullet prediction
+		enemy.lastCellX = enemy.currentCellX;
+		enemy.lastCellY = enemy.currentCellY;
 		if (enemy.currentTarget) {
 			//Allows enemies to change direction right away.
 			if (cell.score < enemy.currentTarget.score) {
 				enemy.currentTarget = cell;
@@ -352,11 +484,18 @@
 			}
 			var angle = Math.atan2(oy, ox);
 			enemy.currentCellX += Math.cos(angle) * enemy.speed;
 			enemy.currentCellY += Math.sin(angle) * enemy.speed;
+			// Update enemy velocity for bullet prediction
+			enemy.velocityX = Math.cos(angle);
+			enemy.velocityY = Math.sin(angle);
 		}
 		enemy.x = grid.x + enemy.currentCellX * CELL_SIZE;
 		enemy.y = grid.y + enemy.currentCellY * CELL_SIZE;
+		// If enemy has the method, call it to update velocity
+		if (enemy.updateVelocity) {
+			enemy.updateVelocity();
+		}
 	};
 });
 // Notification class
 var Notification = Container.expand(function (message) {
@@ -524,17 +663,22 @@
 				potentialDamage += self.targetEnemy.bulletsTargetingThis[i].damage;
 			}
 			// Only shoot if enemy would still be alive after all current bullets hit
 			if (self.targetEnemy.health > potentialDamage) {
-				// Calculate bullet starting position
+				// Calculate bullet starting position from the gun barrel
 				var bulletX = self.x + Math.cos(gunContainer.rotation) * 40;
 				var bulletY = self.y + Math.sin(gunContainer.rotation) * 40;
+				// Create a new bullet with increased speed based on tower level
+				// Higher level towers get faster bullets to catch faster enemies
+				var adjustedSpeed = self.bulletSpeed * (1 + self.level * 0.2);
 				// Create a new bullet
-				var bullet = new Bullet(bulletX, bulletY, self.targetEnemy, self.damage, self.bulletSpeed);
+				var bullet = new Bullet(bulletX, bulletY, self.targetEnemy, self.damage, adjustedSpeed);
 				game.addChild(bullet);
 				// Add bullet to global bullets array and to enemy's tracking array
 				bullets.push(bullet);
 				self.targetEnemy.bulletsTargetingThis.push(bullet);
+				// Apply visual effect to show bullet launching
+				LK.effects.flashObject(bullet, 0xFFFFFF, 200);
 			}
 		}
 	};
 	// Place tower on the grid
@@ -669,8 +813,9 @@
 /**** 
 * Game Code
 ****/ 
 // Define cell size as a global constant
+// Import tween plugin
 var CELL_SIZE = 76;
 var pathId = 1;
 var maxScore = 0;
 var enemies = [];