Implementation for Fetching and Caching Server Side Remote Config

src/main/java/com/google/firebase/remoteconfig/AndCondition.java

@@ -0,0 +1,63 @@
+
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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.firebase.remoteconfig;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.collect.ImmutableList;
+import com.google.firebase.internal.NonNull;
+import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.AndConditionResponse;
+import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.OneOfConditionResponse;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+final class AndCondition {
+  private final ImmutableList<OneOfCondition> conditions;
+
+  AndCondition(@NonNull List<OneOfCondition> conditions) {
+    checkNotNull(conditions, "List of conditions for AND operation must not be null.");
+    checkArgument(!conditions.isEmpty(), 
+        "List of conditions for AND operation must not be empty.");
+    this.conditions = ImmutableList.copyOf(conditions);
+  }
+
+  AndCondition(AndConditionResponse andConditionResponse) {
+    List<OneOfConditionResponse> conditionList = andConditionResponse.getConditions();
+    checkNotNull(conditionList, "List of conditions for AND operation must not be null.");
+    checkArgument(!conditionList.isEmpty(), 
+        "List of conditions for AND operation must not be empty");
+    this.conditions = conditionList.stream()
+                                  .map(OneOfCondition::new) 
+                                  .collect(ImmutableList.toImmutableList());
+  }
+
+  @NonNull
+  List<OneOfCondition> getConditions() {
+    return new ArrayList<>(conditions);
+  }
+
+  AndConditionResponse toAndConditionResponse() {
+    return new AndConditionResponse()
+                   .setConditions(this.conditions.stream()
+                                                 .map(OneOfCondition::toOneOfConditionResponse)
+                                                 .collect(Collectors.toList()));    
+  }
+}

src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java

@@ -101,6 +101,73 @@ protected Template execute() throws FirebaseRemoteConfigException {
     };
   }
 
+  /**
+   * Alternative to {@link #getServerTemplate} where developers can initialize with a pre-cached
+   * template or config.
+   */
+  public ServerTemplateImpl.Builder serverTemplateBuilder() {
+    return new ServerTemplateImpl.Builder(this.remoteConfigClient);
+  }
+
+  /**
+   * Initializes a template instance and loads the latest template data.
+   *
+   * @param defaultConfig Default parameter values to use if a getter references a parameter not
+   *     found in the template.
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ServerTemplate getServerTemplate(KeysAndValues defaultConfig)
+      throws FirebaseRemoteConfigException {
+    return getServerTemplateOp(defaultConfig).call();
+  }
+
+  /**
+   * Initializes a template instance without any defaults and loads the latest template data.
+   *
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ServerTemplate getServerTemplate() throws FirebaseRemoteConfigException {
+    return getServerTemplate(null);
+  }
+
+  /**
+   * Initializes a template instance and asynchronously loads the latest template data.
+   *
+   * @param defaultConfig Default parameter values to use if a getter references a parameter not
+   *     found in the template.
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ApiFuture<ServerTemplate> getServerTemplateAsync(KeysAndValues defaultConfig) {
+    return getServerTemplateOp(defaultConfig).callAsync(app);
+  }
+
+  /**
+   * Initializes a template instance without any defaults and asynchronously loads the latest
+   * template data.
+   *
+   * @return A {@link Template} instance with the latest template data.
+   */
+  public ApiFuture<ServerTemplate> getServerTemplateAsync() {
+    return getServerTemplateAsync(null);
+  }
+
+  private CallableOperation<ServerTemplate, FirebaseRemoteConfigException> getServerTemplateOp(
+      KeysAndValues defaultConfig) {
+    return new CallableOperation<ServerTemplate, FirebaseRemoteConfigException>() {
+      @Override
+      protected ServerTemplate execute() throws FirebaseRemoteConfigException {
+        String serverTemplateData = remoteConfigClient.getServerTemplate();
+        ServerTemplate template =
+                serverTemplateBuilder()
+                .defaultConfig(defaultConfig)
+                .cachedTemplate(serverTemplateData)
+                .build();
+
+        return template;
+      }
+    };
+  }
+
   /**
    * Gets the requested version of the of the Remote Config template.
    *

src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigClient.java

@@ -40,4 +40,7 @@ Template publishTemplate(Template template, boolean validateOnly,
 
   ListVersionsResponse listVersions(
           ListVersionsOptions options) throws FirebaseRemoteConfigException;
-}
+
+  String getServerTemplate() throws FirebaseRemoteConfigException;
+
+}