chore: Regional API domain processing

src/main/java/com/twilio/Twilio.java

@@ -11,13 +11,17 @@
 import com.twilio.http.Request;
 import com.twilio.http.Response;
 import com.twilio.http.TwilioRestClient;
+import com.twilio.type.RegionEndpoints;
+import java.util.Map;
 import lombok.Getter;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Singleton class to initialize Twilio environment.
@@ -40,6 +44,11 @@ public class Twilio {
 
     private static CredentialProvider credentialProvider;
 
+    private static Map<String, String> regionMap = RegionEndpoints.getRegions();
+    private static final Logger logger = LoggerFactory.getLogger(Twilio.class);
+
+
+
     private Twilio() {
     }
 
@@ -234,7 +243,12 @@ private static TwilioRestClient buildRestClient() {
         if (userAgentExtensions != null) {
             builder.userAgentExtensions(Twilio.userAgentExtensions);
         }
-
+        if (Twilio.edge == null && Twilio.region != null) {
+            logger.warn(
+                "Setting default `Edge` for the provided `region`. For regional processing, DNS is of format product.<city>.<region>.twilio.com; otherwise use product.twilio.com."
+            );
+            Twilio.edge = regionMap.get(Twilio.region);
+        }
         builder.region(Twilio.region);
         builder.edge(Twilio.edge);
 

src/main/java/com/twilio/http/TwilioRestClient.java

@@ -2,8 +2,10 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.twilio.Twilio;
 import com.twilio.auth_strategy.AuthStrategy;
 import com.twilio.constant.EnumConstants;
+import com.twilio.type.RegionEndpoints;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -69,14 +71,22 @@
     @Getter
     private final List<String> userAgentExtensions;
     private static final Logger logger = LoggerFactory.getLogger(TwilioRestClient.class);
+    private static Map<String, String> regionMap = RegionEndpoints.getRegions();
 
     protected TwilioRestClient(Builder b) {
         this.username = b.username;
         this.password = b.password;
         this.authStrategy = b.authStrategy;
         this.accountSid = b.accountSid;
         this.region = b.region;
-        this.edge = b.edge;
+        if(b.edge == null && b.region != null) {
+            logger.warn(
+                "Setting default `Edge` for the provided `region`. For regional processing, DNS is of format product.<city>.<region>.twilio.com; otherwise use product.twilio.com."
+            );
+            this.edge = regionMap.get(this.region);
+        }
+        else
+            this.edge = b.edge;
         this.httpClient = b.httpClient;
         this.objectMapper = b.objectMapper;
         this.userAgentExtensions = b.userAgentExtensions;
@@ -89,7 +99,7 @@
      * @return Response object
      */
     public Response request(final Request request) {
-        // If authStrategy is passed from NoAuth API, no need to set authStrategy (ex TokenCreator). 
+        // If authStrategy is passed from NoAuth API, no need to set authStrategy (ex TokenCreator).
         if (request.getAuthStrategy() == null) {
             if (username != null && password != null) {
                 request.setAuth(username, password);

src/main/java/com/twilio/type/RegionEndpoints.java

@@ -0,0 +1,30 @@
+package com.twilio.type;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Provides region-to-edge mappings for Twilio's regional processing.
+ * <p>
+ * This class is part of the transition away from direct edge configuration,
+ * allowing clients to use region identifiers that are mapped to the appropriate edge endpoints.
+ * It is intended to centralize and simplify region-to-edge lookups for Twilio services.
+ */
+public class RegionEndpoints {
+  private static Map<String, String> regionMap = new HashMap<>();
+  static {
+    regionMap.put("au1", "sydney");
+    regionMap.put("br1", "sao-paulo");
+    regionMap.put("ie1", "dublin");
+    regionMap.put("de1", "frankfurt");
+    regionMap.put("jp1", "tokyo");
+    regionMap.put("jp2", "osaka");
+    regionMap.put("sg1", "singapore");
+    regionMap.put("us1", "ashburn");
+    regionMap.put("us2", "umatilla");
+  }
+  public static Map<String, String> getRegions() {
+    return Collections.unmodifiableMap(regionMap);
+  }
+}

src/test/java/com/twilio/TwilioTest.java

@@ -9,8 +9,11 @@
 import com.twilio.http.Response;
 import com.twilio.http.TwilioRestClient;
 
+import com.twilio.type.RegionEndpoints;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
@@ -158,4 +161,28 @@
 
         Twilio.validateSslCertificate(networkHttpClient);
     }
+
+    @Test
+    public void testEdge() {
+        Twilio.setUsername("testUser");
+        Twilio.setPassword("testToken");
+        Twilio.setRegion("br1");
+        Twilio.setEdge("someEdge");
+        TwilioRestClient client = Twilio.getRestClient();
+        assertEquals("someEdge", client.getEdge());
+        Twilio.setEdge(null);
+        Twilio.setRegion(null);
+    }
+
+    @Test
+    public void testEdgeIsSetFromRegionMap() {
+        Map<String, String> regionMap = RegionEndpoints.getRegions();
+        Twilio.setUsername("testUser");
+        Twilio.setPassword("testToken");
+        Twilio.setRegion("br1");
+        TwilioRestClient client = Twilio.getRestClient();
+        assertEquals(regionMap.get("br1"), client.getEdge());
+        Twilio.setRegion(null);
+    }
+
 }

src/test/java/com/twilio/http/TwilioRestClientTest.java

@@ -8,12 +8,16 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.twilio.Twilio;
 import com.twilio.auth_strategy.BasicAuthStrategy;
 import com.twilio.auth_strategy.NoAuthStrategy;
 import com.twilio.rest.Domains;
+import com.twilio.type.RegionEndpoints;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
@@ -161,4 +165,19 @@
         // AuthStrategy of Request not changing by TwilioRestClient
         assertEquals(NoAuthStrategy.getInstance(), request.getAuthStrategy());
     }
+
+    @Test
+    public void testEdgeIsSetFromRegionMap() {
+        Map<String, String> regionMap = RegionEndpoints.getRegions();
+        for( String key: regionMap.keySet() ) {
+            TwilioRestClient client = new TwilioRestClient.Builder(USER_NAME, TOKEN).region(key).build();
+            assertEquals(regionMap.get(key), client.getEdge());
+        }
+    }
+
+    @Test
+    public void testEdge() {
+        TwilioRestClient client = new TwilioRestClient.Builder(USER_NAME, TOKEN).region("us1").edge("someEdge").build();
+        assertEquals("someEdge", client.getEdge());
+    }
 }