1 files changed, 116 insertions, 0 deletions
diff --git a/src/main/java/simulator/engine/HeadlessSimulationEngine.java b/src/main/java/simulator/engine/HeadlessSimulationEngine.java
new file mode 100644
index 0000000..36a64a7
--- /dev/null
+++ b/src/main/java/simulator/engine/HeadlessSimulationEngine.java
@@ -0,0 +1,116 @@
+package simulator.engine;
+
+import core.*;
+import prefs.VSPrefs;
+import events.internal.VSMessageReceiveEvent;
+import simulator.VSLogging;
+
+/**
+ * Headless implementation of the simulation engine that runs without any GUI dependencies.
+ * This engine focuses purely on simulation logic without any visualization concerns.
+ */
+public class HeadlessSimulationEngine extends AbstractSimulationEngine {
+    
+    public HeadlessSimulationEngine(VSPrefs prefs, VSLogging loging) {
+        super(prefs, loging);
+    }
+    
+    @Override
+    protected long calculateDeliveryTime(VSMessage message) {
+        // Get source process
+        VSInternalProcess source = (VSInternalProcess) message.getSendingProcess();
+        
+        if (source == null) {
+            return time; // Deliver immediately if process not found
+        }
+        
+        // Calculate network delay
+        long networkDelay = prefs.getLong("sim.network.delay");
+        long variability = prefs.getLong("sim.network.variability");
+        
+        // Add random variability
+        if (variability > 0) {
+            long variance = (long)(Math.random() * variability * 2) - variability;
+            networkDelay += variance;
+        }
+        
+        // Ensure minimum delay
+        if (networkDelay < 0) {
+            networkDelay = 0;
+        }
+        
+        // Calculate delivery time based on source process time
+        return source.getTime() + networkDelay;
+    }
+    
+    @Override
+    protected void scheduleMessageDelivery(VSMessage message, long deliveryTime) {
+        // In DS-Sim, messages are broadcast to all processes
+        VSInternalProcess sendingProcess = (VSInternalProcess) message.getSendingProcess();
+        boolean recvOwn = prefs.getBoolean("sim.message.own.recv");
+        
+        // Schedule delivery to all processes
+        for (VSInternalProcess receiverProcess : processes) {
+            if (receiverProcess.equals(sendingProcess)) {
+                // Only deliver to self if configured
+                if (!recvOwn) {
+                    continue;
+                }
+            }
+            
+            // Create receive event for this process
+            VSMessageReceiveEvent receiveEvent = new VSMessageReceiveEvent(message);
+            VSTask task = new VSTask(deliveryTime, receiverProcess, receiveEvent, VSTask.GLOBAL);
+            taskManager.addTask(task);
+            
+            if (loging != null) {
+                loging.log("Message scheduled for delivery to process " + 
+                          receiverProcess.getProcessNum() + "; ID: " + 
+                          message.getMessageID() + "; Time: " + deliveryTime);
+            }
+        }
+    }
+    
+    /**
+     * Run one simulation step.
+     * This method advances time and executes all tasks scheduled for the current time.
+     */
+    public void runStep() {
+        if (isPaused || hasFinished) {
+            return;
+        }
+        
+        // Sync all process times
+        for (VSInternalProcess process : processes) {
+            process.syncTime(time);
+        }
+        
+        // Run tasks for current time
+        taskManager.runTasks(time, 0, time - 1);
+        
+        // Check if simulation has finished
+        // TODO: Implement proper finish detection
+        // For now, rely on external control or time limits
+    }
+    
+    /**
+     * Run the simulation for a specified duration.
+     * @param duration Duration in milliseconds
+     */
+    public void runFor(long duration) {
+        long endTime = time + duration;
+        
+        while (time < endTime && !hasFinished) {
+            runStep();
+            time++;
+        }
+    }
+    
+    /**
+     * Check if any protocols are still active.
+     * TODO: Implement this when protocol tracking is available
+     */
+    private boolean hasActiveProtocols() {
+        return false; // For now, assume no active protocols
+    }
+}
+\ No newline at end of file