address comment

Signed-off-by: Abhishek Kumar <abhishek.mrt22@gmail.com>

Author: shwstppr

server/src/main/java/com/cloud/network/as/AutoScaleManagerImpl.java

@@ -1960,6 +1960,23 @@ public void updateVmDetails(Map<String, String> deployParams, Map<String, String
         }
     }
 
+    protected String getTrimmedHostNameForWindows(String name) {
+        String valid = name.replaceAll("[^a-zA-Z0-9-]", "");
+        String hostName = valid.length() > 15 ? valid.substring(valid.length() - 15) : valid;
+        if (!hostName.isEmpty() && !Character.isLetter(hostName.charAt(0))) {
+            for (int i = 0; i < hostName.length(); i++) {
+                if (Character.isLetter(hostName.charAt(i))) {
+                    hostName = hostName.charAt(i) + hostName.substring(i + 1);
+                    break;
+                }
+            }
+            if (!Character.isLetter(hostName.charAt(0))) {
+                hostName = hostName.length() < 15 ? "a" + hostName : "a" + hostName.substring(1);
+            }
+        }
+        return hostName;
+    }
+
     protected Pair<String, String> getNextVmHostAndDisplayName(AutoScaleVmGroupVO asGroup, VirtualMachineTemplate template) {
         template.getGuestOSId();
         GuestOSVO guestOSVO = guestOSDao.findById(template.getGuestOSId());
@@ -1972,15 +1989,7 @@ protected Pair<String, String> getNextVmHostAndDisplayName(AutoScaleVmGroupVO as
         if (!isWindows || name.length() <= 15) {
             return new Pair<>(name, name);
         }
-        String hostName = name.substring(Math.max(0, name.length() - 15));
-        if (Character.isLetterOrDigit(hostName.charAt(0))) {
-            return new Pair<>(hostName, name);
-        }
-        String temp = name.substring(0, Math.max(0, name.length() - 15)).replaceAll("[^a-zA-Z0-9]", "");
-        if (!temp.isEmpty()) {
-            return new Pair<>(temp.charAt(temp.length() - 1) + hostName.substring(1), name);
-        }
-        return new Pair<>('a' + hostName.substring(1), name);
+        return new Pair<>(getTrimmedHostNameForWindows(name), name);
     }
 
     @Override

server/src/test/java/com/cloud/network/as/AutoScaleManagerImplTest.java

@@ -2552,4 +2552,53 @@ public void getNextVmHostAndDisplayNameHandlesNullGuestOS() {
         Assert.assertTrue(result.first().matches(vmHostNamePattern));
         Assert.assertEquals(result.first(), result.second());
     }
+
+    @Test
+    public void trimsValidWindowsHostName() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("ValidVMName1234");
+        Assert.assertEquals("ValidVMName1234", result);
+    }
+
+    @Test
+    public void trimsInvalidCharactersFromHostName() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("Invalid@Host#Name!");
+        Assert.assertEquals("InvalidHostName", result);
+    }
+
+    @Test
+    public void ensuresHostNameStartsWithLetter() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("123456789012345");
+        Assert.assertTrue(Character.isLetter(result.charAt(0)));
+    }
+
+    @Test
+    public void prefixesWithLetterIfNoLetterExists() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("1234567890-12345");
+        Assert.assertEquals("a34567890-12345", result);
+    }
+
+    @Test
+    public void trimsHostNameToLast15Characters() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("ThisIsAReallyLongHost-Name_1234");
+        Assert.assertEquals("ngHost-Name1234", result);
+    }
+
+    @Test
+    public void handlesEmptyHostName() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("");
+        Assert.assertEquals("", result);
+    }
+
+    @Test
+    public void handlesHostNameWithOnlyMostlyInvalidCharacters() {
+        AutoScaleManagerImpl manager = new AutoScaleManagerImpl();
+        String result = manager.getTrimmedHostNameForWindows("@#$%^&*()   1");
+        Assert.assertEquals("a1", result);
+    }
 }