complete code

src/main/java/DownloadWorker.java

@@ -1,12 +1,5 @@
 import java.util.Random;
 
-/**
- * Simulates downloading a single chunk of a file.
- *
- * <p>This class is intentionally provided as a skeleton for students.
- * The main multithreading and simulation logic should be completed
- * in the run() method.</p>
- */
 public class DownloadWorker implements Runnable {
 
     private final ChunkStatus chunkStatus;
@@ -21,23 +14,43 @@ public class DownloadWorker implements Runnable {
 
     @Override
     public void run() {
-        // TODO: Record the chunk start time in chunkStatus.
-        double downloaded = 0.0;
+        chunkStatus.setStartTimeMs(System.currentTimeMillis());
 
-        // TODO: Print a message that this chunk has started downloading.
+        double downloaded = 0;
+
+        System.out.println("Chunk " + chunkStatus.getChunkId() + " started.");
 
         while (downloaded < chunkStatus.getChunkSizeMB()) {
-            // TODO: Generate a random sleep delay between min and max delay.
-            // TODO: Sleep for that delay.
-            // TODO: Generate a random download amount for this step.
-            // TODO: Increase downloaded, but do not go beyond chunk size.
-            // TODO: Save the updated downloaded value into chunkStatus.
-            // TODO: Optionally print step-by-step progress.
+
+            int delay = random.nextInt(
+                    config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1
+            ) + config.getMinStepDelayMs();
+
+            try {
+                Thread.sleep(delay);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+
+            double amount = random.nextDouble() *
+                    (config.getMaxStepDownloadMB() - config.getMinStepDownloadMB())
+                    + config.getMinStepDownloadMB();
+
+            downloaded = downloaded + amount;
+
+            if (downloaded > chunkStatus.getChunkSizeMB()) {
+                downloaded = chunkStatus.getChunkSizeMB();
+            }
+
+            chunkStatus.setDownloadedMB(downloaded);
+
+            System.out.println("Chunk " + chunkStatus.getChunkId()
+                    + ": " + downloaded + "/" + chunkStatus.getChunkSizeMB() + " MB");
         }
 
-        // TODO: Mark the chunk as completed.
-        // TODO: Record the chunk end time in chunkStatus.
-        // TODO: Print a message that this chunk has finished downloading.
-    }
+        chunkStatus.setCompleted(true);
+        chunkStatus.setEndTimeMs(System.currentTimeMillis());
 
-}
+        System.out.println("Chunk " + chunkStatus.getChunkId() + " finished.");
+    }
+}