Add Remote Config Pubish, Validate, and GetTemplateAtVersion operations (#496)

* Add Pubish, Validate, and GetTemplateAtVersion operations

* Clean up tests

* Move PublishOptions to parent package

Author: lahirumaramba

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

@@ -24,6 +24,7 @@
 import com.google.firebase.ImplFirebaseTrampolines;
 import com.google.firebase.internal.CallableOperation;
 import com.google.firebase.internal.FirebaseService;
+import com.google.firebase.internal.NonNull;
 
 /**
  * This class is the entry point for all server-side Firebase Remote Config actions.
@@ -100,6 +101,160 @@ protected Template execute() throws FirebaseRemoteConfigException {
     };
   }
 
+  /**
+   * Gets the requested version of the of the Remote Config template.
+   *
+   * @param versionNumber The version number of the Remote Config template to look up.
+   * @return A {@link Template}.
+   * @throws FirebaseRemoteConfigException If an error occurs while getting the template.
+   */
+  public Template getTemplateAtVersion(
+          @NonNull String versionNumber) throws FirebaseRemoteConfigException {
+    return getTemplateAtVersionOp(versionNumber).call();
+  }
+
+  /**
+   * Gets the requested version of the of the Remote Config template.
+   *
+   * @param versionNumber The version number of the Remote Config template to look up.
+   * @return A {@link Template}.
+   * @throws FirebaseRemoteConfigException If an error occurs while getting the template.
+   */
+  public Template getTemplateAtVersion(long versionNumber) throws FirebaseRemoteConfigException {
+    String versionNumberString = String.valueOf(versionNumber);
+    return getTemplateAtVersionOp(versionNumberString).call();
+  }
+
+  /**
+   * Similar to {@link #getTemplateAtVersion(String versionNumber)} but performs the operation
+   * asynchronously.
+   *
+   * @param versionNumber The version number of the Remote Config template to look up.
+   * @return An {@code ApiFuture} that completes with a {@link Template} when
+   *     the requested template is available.
+   */
+  public ApiFuture<Template> getTemplateAtVersionAsync(@NonNull String versionNumber) {
+    return getTemplateAtVersionOp(versionNumber).callAsync(app);
+  }
+
+  /**
+   * Similar to {@link #getTemplateAtVersion(long versionNumber)} but performs the operation
+   * asynchronously.
+   *
+   * @param versionNumber The version number of the Remote Config template to look up.
+   * @return An {@code ApiFuture} that completes with a {@link Template} when
+   *     the requested template is available.
+   */
+  public ApiFuture<Template> getTemplateAtVersionAsync(long versionNumber) {
+    String versionNumberString = String.valueOf(versionNumber);
+    return getTemplateAtVersionOp(versionNumberString).callAsync(app);
+  }
+
+  private CallableOperation<Template, FirebaseRemoteConfigException> getTemplateAtVersionOp(
+          final String versionNumber) {
+    final FirebaseRemoteConfigClient remoteConfigClient = getRemoteConfigClient();
+    return new CallableOperation<Template, FirebaseRemoteConfigException>() {
+      @Override
+      protected Template execute() throws FirebaseRemoteConfigException {
+        return remoteConfigClient.getTemplateAtVersion(versionNumber);
+      }
+    };
+  }
+
+  /**
+   * Publishes a Remote Config template.
+   *
+   * @param template The Remote Config template to be published.
+   * @return The published {@link Template}.
+   * @throws FirebaseRemoteConfigException If an error occurs while publishing the template.
+   */
+  public Template publishTemplate(@NonNull Template template) throws FirebaseRemoteConfigException {
+    return publishTemplateOp(template).call();
+  }
+
+  /**
+   * Similar to {@link #publishTemplate(Template template)} but performs the operation
+   * asynchronously.
+   *
+   * @param template The Remote Config template to be published.
+   * @return An {@code ApiFuture} that completes with a {@link Template} when
+   *     the provided template is published.
+   */
+  public ApiFuture<Template> publishTemplateAsync(@NonNull Template template) {
+    return publishTemplateOp(template).callAsync(app);
+  }
+
+  /**
+   * Validates a Remote Config template.
+   *
+   * @param template The Remote Config template to be validated.
+   * @return The validated {@link Template}.
+   * @throws FirebaseRemoteConfigException If an error occurs while validating the template.
+   */
+  public Template validateTemplate(
+          @NonNull Template template) throws FirebaseRemoteConfigException {
+    return publishTemplateOp(template, new PublishOptions().setValidateOnly(true)).call();
+  }
+
+  /**
+   * Similar to {@link #validateTemplate(Template template)} but performs the operation
+   * asynchronously.
+   *
+   * @param template The Remote Config template to be validated.
+   * @return An {@code ApiFuture} that completes with a {@link Template} when
+   *     the provided template is validated.
+   */
+  public ApiFuture<Template> validateTemplateAsync(@NonNull Template template) {
+    return publishTemplateOp(template, new PublishOptions().setValidateOnly(true)).callAsync(app);
+  }
+
+  /**
+   * Force publishes a Remote Config template.
+   *
+   * <p>This method forces the Remote Config template to be updated and circumvent the ETag.
+   * This approach is not recommended because it risks causing the loss of updates to your
+   * Remote Config template if multiple clients are updating the Remote Config template.
+   * See <a href="https://firebase.google.com/docs/remote-config/use-config-rest#etag_usage_and_forced_updates">
+   * ETag usage and forced updates</a>.
+   *
+   * @param template The Remote Config template to be forcefully published.
+   * @return The published {@link Template}.
+   * @throws FirebaseRemoteConfigException If an error occurs while publishing the template.
+   */
+  public Template forcePublishTemplate(
+          @NonNull Template template) throws FirebaseRemoteConfigException {
+    return publishTemplateOp(template, new PublishOptions().setForcePublish(true)).call();
+  }
+
+  /**
+   * Similar to {@link #forcePublishTemplate(Template template)} but performs the operation
+   * asynchronously.
+   *
+   * @param template The Remote Config template to be forcefully published.
+   * @return An {@code ApiFuture} that completes with a {@link Template} when
+   *     the provided template is published.
+   */
+  public ApiFuture<Template> forcePublishTemplateAsync(@NonNull Template template) {
+    return publishTemplateOp(template, new PublishOptions().setForcePublish(true)).callAsync(app);
+  }
+
+  private CallableOperation<Template, FirebaseRemoteConfigException> publishTemplateOp(
+          final Template template) {
+    return publishTemplateOp(template, new PublishOptions());
+  }
+
+  private CallableOperation<Template, FirebaseRemoteConfigException> publishTemplateOp(
+          final Template template, final PublishOptions options) {
+    final FirebaseRemoteConfigClient remoteConfigClient = getRemoteConfigClient();
+    return new CallableOperation<Template, FirebaseRemoteConfigException>() {
+      @Override
+      protected Template execute() throws FirebaseRemoteConfigException {
+        return remoteConfigClient
+                .publishTemplate(template, options.isValidateOnly(), options.isForcePublish());
+      }
+    };
+  }
+
   @VisibleForTesting
   FirebaseRemoteConfigClient getRemoteConfigClient() {
     return remoteConfigClient;

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

@@ -28,4 +28,9 @@ interface FirebaseRemoteConfigClient {
    * @throws FirebaseRemoteConfigException If an error occurs while getting the template.
    */
   Template getTemplate() throws FirebaseRemoteConfigException;
+
+  Template getTemplateAtVersion(String versionNumber) throws FirebaseRemoteConfigException;
+
+  Template publishTemplate(Template template, boolean validateOnly,
+                                  boolean forcePublish) throws FirebaseRemoteConfigException;
 }

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

@@ -22,6 +22,7 @@
 
 import com.google.api.client.http.HttpRequestFactory;
 import com.google.api.client.http.HttpResponseInterceptor;
+import com.google.api.client.http.json.JsonHttpContent;
 import com.google.api.client.json.JsonFactory;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
@@ -34,6 +35,7 @@
 import com.google.firebase.internal.ApiClientUtils;
 import com.google.firebase.internal.ErrorHandlingHttpClient;
 import com.google.firebase.internal.HttpRequestInfo;
+import com.google.firebase.internal.NonNull;
 import com.google.firebase.internal.SdkUtils;
 import com.google.firebase.remoteconfig.internal.RemoteConfigServiceErrorResponse;
 import com.google.firebase.remoteconfig.internal.TemplateResponse;
@@ -100,6 +102,42 @@ public Template getTemplate() throws FirebaseRemoteConfigException {
     return template.setETag(getETag(response));
   }
 
+  @Override
+  public Template getTemplateAtVersion(String versionNumber) throws FirebaseRemoteConfigException {
+    checkArgument(isValidVersionNumber(versionNumber),
+            "Version number must be a non-empty string in int64 format.");
+    HttpRequestInfo request = HttpRequestInfo.buildGetRequest(remoteConfigUrl)
+            .addAllHeaders(COMMON_HEADERS)
+            .addParameter("versionNumber", versionNumber);
+    IncomingHttpResponse response = httpClient.send(request);
+    TemplateResponse templateResponse = httpClient.parse(response, TemplateResponse.class);
+    Template template = new Template(templateResponse);
+    return template.setETag(getETag(response));
+  }
+
+  @Override
+  public Template publishTemplate(@NonNull Template template, boolean validateOnly,
+                                  boolean forcePublish) throws FirebaseRemoteConfigException {
+    checkArgument(template != null, "Template must not be null.");
+    HttpRequestInfo request = HttpRequestInfo.buildRequest("PUT", remoteConfigUrl,
+            new JsonHttpContent(jsonFactory, template.toTemplateResponse()))
+            .addAllHeaders(COMMON_HEADERS)
+            .addHeader("If-Match", forcePublish ? "*" : template.getETag());
+    if (validateOnly) {
+      request.addParameter("validateOnly", true);
+    }
+    IncomingHttpResponse response = httpClient.send(request);
+    TemplateResponse templateResponse = httpClient.parse(response, TemplateResponse.class);
+    Template publishedTemplate = new Template(templateResponse);
+    if (validateOnly) {
+      // validating a template returns an etag with the suffix -0 means that the provided template
+      // was successfully validated. We set the etag back to the original etag of the template
+      // to allow subsequent operations.
+      return publishedTemplate.setETag(template.getETag());
+    }
+    return publishedTemplate.setETag(getETag(response));
+  }
+
   private String getETag(IncomingHttpResponse response) {
     List<String> etagList = (List<String>) response.getHeaders().get("etag");
     checkState(etagList != null && !etagList.isEmpty(),
@@ -112,6 +150,10 @@ private String getETag(IncomingHttpResponse response) {
     return etag;
   }
 
+  private boolean isValidVersionNumber(String versionNumber) {
+    return !Strings.isNullOrEmpty(versionNumber) && versionNumber.matches("^\\d+$");
+  }
+
   static FirebaseRemoteConfigClientImpl fromApp(FirebaseApp app) {
     String projectId = ImplFirebaseTrampolines.getProjectId(app);
     checkArgument(!Strings.isNullOrEmpty(projectId),

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

@@ -0,0 +1,33 @@
+package com.google.firebase.remoteconfig;
+
+/**
+ * An internal class for publish template options.
+ */
+final class PublishOptions {
+
+  private boolean validateOnly;
+  private boolean forcePublish;
+
+  PublishOptions() {
+    validateOnly = false;
+    forcePublish = false;
+  }
+
+  public PublishOptions setForcePublish(boolean forcePublish) {
+    this.forcePublish = forcePublish;
+    return this;
+  }
+
+  public PublishOptions setValidateOnly(boolean validateOnly) {
+    this.validateOnly = validateOnly;
+    return this;
+  }
+
+  public boolean isForcePublish() {
+    return forcePublish;
+  }
+
+  public boolean isValidateOnly() {
+    return validateOnly;
+  }
+}