合并来自UQcsse3200/Team08的拉取请求#49

Create SystemClockTimer

source/core/src/main/com/csse3200/game/services/SystemClockTimer

@@ -0,0 +1,38 @@
+package com.csse3200.game.services;
+
+public class SystemClockTimer {
+    private final long durationMillis;
+    private long startTimeMillis;
+    private boolean isRunning = false;
+    private boolean isTriggered = false;
+
+    public SystemClockTimer(long durationMillis) {
+        this.durationMillis = durationMillis;
+    }
+
+    public void start() {
+        startTimeMillis = System.currentTimeMillis();
+        isRunning = true;
+        isTriggered = false;
+    }
+
+    public void update() {
+        if (isRunning && !isTriggered) {
+            long currentTimeMillis = System.currentTimeMillis();
+            if (currentTimeMillis - startTimeMillis >= durationMillis) {
+                triggerAction();
+                isTriggered = true;
+                isRunning = false;
+            }
+        }
+    }
+
+    private void triggerAction() {
+        System.out.println("Timer is over! Triggering action...");
+    }
+
+    public boolean isRunning() {
+        return isRunning;
+    }
+}
+