Extract part of GerritGlobalModule into AuthModule

Programs that want part but not all of GerritGlobalModule currently
have to copy just the bindings they want into their modules; this is
occasionally painful but basically doable.

However, the logic for switching on the auth type is a bit too much to
copy and paste, so extract a reusable module.

Change-Id: I3dfac672919ede56f1db02bdf24de9a374335b4e
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/config/AuthModule.java b/gerrit-server/src/main/java/com/google/gerrit/server/config/AuthModule.java
new file mode 100644
index 0000000..f9e9949
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/config/AuthModule.java
@@ -0,0 +1,54 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.package com.google.gerrit.server.git;
+
+package com.google.gerrit.server.config;
+
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.reviewdb.client.AuthType;
+import com.google.gerrit.server.account.DefaultRealm;
+import com.google.gerrit.server.account.Realm;
+import com.google.gerrit.server.auth.AuthBackend;
+import com.google.gerrit.server.auth.InternalAuthBackend;
+import com.google.gerrit.server.auth.ldap.LdapModule;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+
+public class AuthModule extends AbstractModule {
+  private final AuthType loginType;
+
+  @Inject
+  AuthModule(AuthConfig authConfig) {
+    loginType = authConfig.getAuthType();
+  }
+
+  @Override
+  protected void configure() {
+    switch (loginType) {
+      case HTTP_LDAP:
+      case LDAP:
+      case LDAP_BIND:
+      case CLIENT_SSL_CERT_LDAP:
+        install(new LdapModule());
+        break;
+
+      case CUSTOM_EXTENSION:
+        break;
+
+      default:
+        bind(Realm.class).to(DefaultRealm.class);
+        DynamicSet.bind(binder(), AuthBackend.class).to(InternalAuthBackend.class);
+        break;
+    }
+  }
+}
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java b/gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java
index e45ef21..3f7acf6 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java
@@ -26,7 +26,6 @@
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.registration.DynamicSet;
-import com.google.gerrit.reviewdb.client.AuthType;
 import com.google.gerrit.rules.PrologModule;
 import com.google.gerrit.rules.RulesCache;
 import com.google.gerrit.server.AnonymousUser;
@@ -47,7 +46,6 @@
 import com.google.gerrit.server.account.AccountVisibilityProvider;
 import com.google.gerrit.server.account.CapabilityControl;
 import com.google.gerrit.server.account.ChangeUserName;
-import com.google.gerrit.server.account.DefaultRealm;
 import com.google.gerrit.server.account.EmailExpander;
 import com.google.gerrit.server.account.GroupBackend;
 import com.google.gerrit.server.account.GroupCacheImpl;
@@ -60,12 +58,9 @@
 import com.google.gerrit.server.account.InternalGroupBackend;
 import com.google.gerrit.server.account.PerformCreateGroup;
 import com.google.gerrit.server.account.PerformRenameGroup;
-import com.google.gerrit.server.account.Realm;
 import com.google.gerrit.server.account.UniversalGroupBackend;
 import com.google.gerrit.server.auth.AuthBackend;
-import com.google.gerrit.server.auth.InternalAuthBackend;
 import com.google.gerrit.server.auth.UniversalAuthBackend;
-import com.google.gerrit.server.auth.ldap.LdapModule;
 import com.google.gerrit.server.avatar.AvatarProvider;
 import com.google.gerrit.server.cache.CacheRemovalListener;
 import com.google.gerrit.server.events.EventFactory;
@@ -119,45 +114,27 @@
 import com.google.inject.TypeLiteral;
 
 import org.apache.velocity.runtime.RuntimeInstance;
-import org.eclipse.jgit.lib.Config;
 
 import java.util.List;
 
 
 /** Starts global state with standard dependencies. */
 public class GerritGlobalModule extends FactoryModule {
-  private final AuthType loginType;
+  private final AuthModule authModule;
 
   @Inject
-  GerritGlobalModule(final AuthConfig authConfig,
-      @GerritServerConfig final Config config) {
-    loginType = authConfig.getAuthType();
+  GerritGlobalModule(AuthModule authModule) {
+    this.authModule = authModule;
   }
 
   @Override
   protected void configure() {
-    switch (loginType) {
-      case HTTP_LDAP:
-      case LDAP:
-      case LDAP_BIND:
-      case CLIENT_SSL_CERT_LDAP:
-        install(new LdapModule());
-        break;
-
-      case CUSTOM_EXTENSION:
-        break;
-
-      default:
-        bind(Realm.class).to(DefaultRealm.class);
-        DynamicSet.bind(binder(), AuthBackend.class).to(InternalAuthBackend.class);
-        break;
-    }
-
     bind(EmailExpander.class).toProvider(EmailExpanderProvider.class).in(
         SINGLETON);
 
     bind(IdGenerator.class);
     bind(RulesCache.class);
+    install(authModule);
     install(AccountByEmailCacheImpl.module());
     install(AccountCacheImpl.module());
     install(GroupCacheImpl.module());