===================================================================
--- original.js
+++ change.js
@@ -242,11 +242,14 @@
 	});
 	self.asset.x = self.x;
 	self.asset.y = self.y;
 	self.buildingQueue = [];
+	self.lastAttackTime = 0;
+	self.lastHitTime = 0;
 	self.damage = function (points) {
 		console.log("Building " + self.name + " hit! " + points);
 		self.health -= points;
+		self.lastHitTime = LK.getTime();
 		self.asset.tint = 0xff0000;
 		LK.setTimeout(function () {
 			self.asset.tint = 0xFFFFFF;
 		}, 500);
@@ -868,8 +871,9 @@
 	self.attackDamage = unitInfo.attackDamage;
 	self.attackSpeed = unitInfo.attackSpeed; // Speed of attack (time between attacks)
 	self.attackMode = 0; // 0 = not attacking, 1 = attacking, 2 = moving to target
 	self.lastAttackTime = 0;
+	self.lastHitTime = 0;
 	self.actions = unitInfo.actions;
 	self.asset = self.attachAsset(type, {
 		anchorX: 0.5,
 		anchorY: 0.5,
@@ -1055,8 +1059,9 @@
 	};
 	self.damage = function (points) {
 		console.log("Unit " + self.name + " hit! " + points);
 		self.asset.tint = 0xff0000;
+		self.lastHitTime = LK.getTime();
 		LK.setTimeout(function () {
 			self.asset.tint = getPlayerTint(self.playerId);
 		}, 300);
 		self.health -= points;
@@ -1804,12 +1809,29 @@
 var rockIlot1Center = {
 	x: 0,
 	y: 0
 };
-// AI
+/* ***************************************************************************************************** */ 
+/* ********************************************* AI FUNCTIONS ****************************************** */
+/* ***************************************************************************************************** */ 
+var AI_LEVEL = {
+	EASY: {
+		acttingDelay: 1000,
+		thinkingDelay: 1000
+	},
+	NORMAL: {
+		acttingDelay: 300,
+		thinkingDelay: 600
+	},
+	HARD: {
+		acttingDelay: 100,
+		thinkingDelay: 200
+	}
+};
+var aiCurrentLevel = AI_LEVEL.EASY;
 var aiBaseUnitList = {
 	'unitHarvester': 1,
-	'unitQuad ': 1,
+	'unitQuad': 1,
 	'unitLightTank': 2,
 	'unitHeavyTank': 4
 };
 var aiBaseBuildingList = {
@@ -1819,8 +1841,85 @@
 	'heavyFactory': 1
 };
 var aiCurrentUnitConstruction = null;
 var aiCurrentBuildingConstruction = null;
+var aiNeededBuildingList = null;
+var aiNeededUnitsList = null;
+// Think of what AI must do
+function aiThinking() {
+	if (LK.ticks % aiCurrentLevel.thinkingDelay !== 0) {
+		return;
+	}
+	console.log("aiThinking...");
+	// Check buildings requirements
+	aiNeededBuildingList = checkBuildingRequirements();
+	// Check units requirements
+	aiNeededUnitsList = checkUnitRequirements();
+	// Check defense needs
+	// Check attack opportunities
+}
+function checkBuildingRequirements() {
+	console.log("checkBuildingRequirements...");
+	console.log("player2 buildings:", player2.buildings);
+	// 1) Count currently owned buildings
+	var aiCurrentBuildingList = {
+		'windTrap': 0,
+		'spiceRefinery': 0,
+		'lightFactory': 0,
+		'heavyFactory': 0
+	};
+	player2.buildings.forEach(function (building) {
+		aiCurrentBuildingList[building.type] = (aiCurrentBuildingList[building.type] || 0) + 1;
+	});
+	console.log("aiCurrentBuildingList:", aiCurrentBuildingList);
+	// 2) Check if all requirements are met
+	var tempNeededBuildingList = {};
+	// Compare aiBaseBuildingList and aiCurrentBuildingList
+	for (var building in aiBaseBuildingList) {
+		if (aiBaseBuildingList[building] > aiCurrentBuildingList[building]) {
+			tempNeededBuildingList[building] = aiBaseBuildingList[building] - aiCurrentBuildingList[building];
+		}
+	}
+	return tempNeededBuildingList;
+}
+function checkUnitRequirements() {
+	console.log("checkUnitRequirements...");
+	console.log("player2 units:", player2.units);
+	// 1) Count currently owned units
+	var aiCurrentUnitList = {
+		'unitHarvester': 0,
+		'unitQuad': 0,
+		'unitLightTank': 0,
+		'unitHeavyTank': 0
+	};
+	player2.units.forEach(function (unit) {
+		aiCurrentUnitList[unit.type] = (aiCurrentUnitList[unit.type] || 0) + 1;
+	});
+	console.log("aiCurrentUnitList:", aiCurrentUnitList);
+	// 2) Check if all requirements are met
+	var tempNeededUnitList = {};
+	// Compare aiBaseUnitList and aiCurrentUnitList
+	for (var unit in aiBaseUnitList) {
+		if (aiBaseUnitList[unit] > aiCurrentUnitList[unit]) {
+			tempNeededUnitList[unit] = aiBaseUnitList[unit] - aiCurrentUnitList[unit];
+		}
+	}
+	return tempNeededUnitList;
+}
+// Do what AI thought about
+function aiActing() {
+	if (LK.ticks % aiCurrentLevel.acttingDelay !== 0) {
+		return;
+	}
+	console.log("aiActing...");
+	// 1) Meet buildings requirements
+	console.log("aiNeededBuildingList:", aiNeededBuildingList);
+	// 2) Meet units requirements
+	console.log("aiNeededUnitsList:", aiNeededUnitsList);
+}
+/* ***************************************************************************************************** */ 
+/* ********************************************* INIT FUNCTIONS ****************************************** */
+/* ***************************************************************************************************** */ 
 // Prepare the map
 function prepareMap() {
 	globalTerrain = new Array(mapXSize).fill(0).map(function () {
 		return new Array(mapYSize).fill(0);
@@ -2420,12 +2519,8 @@
 		// Update the FPS text on the screen
 		fpsText.setText('FPS: ' + fps);
 	}, 1000); // 1000 milliseconds = 1 second
 };
-function aiUpdate() {
-	console.log("aiUpdate...");
-	// Check units requirements
-}
 function checkGameEnd() {
 	console.log("checkGameEnd...");
 	// Check if either player1 or player2 has no more buildings
 	if (player1.buildings.length === 0 || player2.buildings.length === 0) {
@@ -2508,8 +2603,10 @@
 			if (unit.assetEffect) {
 				game.addChild(unit.assetEffect);
 			}
 		});
+		aiThinking();
+		aiActing();
 	}
 	tickCounter++;
 });
 // Start the game with Player 1 construction yard preselected