[bot] fixes

src/common/haxe/ru/m/tankz/bot/Bot.hx

@@ -14,6 +14,7 @@ class Bot implements EngineListener {
     private var engine:Engine;
 
     private var shotTimer:Timer;
+    private var turnTimer:Timer;
 
     public function new(engine:Engine, tankId:Int) {
         this.engine = engine;
@@ -34,6 +35,8 @@ class Bot implements EngineListener {
         engine.action(tankId, TankAction.MOVE(Direction.BOTTOM));
         shotTimer = new Timer(1000);
         shotTimer.run = shot;
+        turnTimer = new Timer(3000);
+        turnTimer.run = turn;
     }
 
     public function shot():Void {
@@ -41,7 +44,16 @@ class Bot implements EngineListener {
     }
 
     public function turn():Void {
-        engine.action(tankId, TankAction.MOVE(Direction.TOP));
+        engine.action(tankId, TankAction.MOVE(randomDirection()));
+    }
+
+    private function randomDirection():Direction {
+        return [
+            Direction.TOP,
+            Direction.BOTTOM,
+            Direction.LEFT,
+            Direction.RIGHT,
+        ][Math.floor(Math.random() * 4)];
     }
 
     public function dispose():Void {
@@ -49,6 +61,10 @@ class Bot implements EngineListener {
             shotTimer.stop();
             shotTimer = null;
         }
+        if (turnTimer != null) {
+            turnTimer.stop();
+            turnTimer = null;
+        }
         engine = null;
     }
 }

src/common/haxe/ru/m/tankz/engine/Engine.hx

@@ -91,6 +91,7 @@ class Engine {
     }
 
     public function action(tankId:Int, action:TankAction):Void {
+        if (!entities.exists(tankId)) return;
         var tank:Tank = cast entities.get(tankId);
         switch (action) {
             case TankAction.MOVE(direction):
@@ -184,7 +185,7 @@ class Engine {
             removedEntities.push(entity.key);
             if (Std.is(entity, Bullet)) {
                 var tank:Tank = cast entities.get(cast(entity, Bullet).tankId);
-                tank.onDestroyBullet();
+                if (tank != null) tank.onDestroyBullet();
             }
         }
         if (bots.exists(entity.id)) {