Add toJSON and fromJSON to Remote Config Template

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

@@ -69,9 +69,7 @@ public Condition(@NonNull String name, @NonNull String expression, @Nullable Tag
     checkNotNull(conditionResponse);
     this.name = conditionResponse.getName();
     this.expression = conditionResponse.getExpression();
-    if (conditionResponse.getTagColor() == null) {
-      this.tagColor = TagColor.UNSPECIFIED;
-    } else {
+    if (!Strings.isNullOrEmpty(conditionResponse.getTagColor())) {
       this.tagColor = TagColor.valueOf(conditionResponse.getTagColor());
     }
   }
@@ -168,4 +166,9 @@ public boolean equals(Object o) {
     return Objects.equals(name, condition.name)
             && Objects.equals(expression, condition.expression) && tagColor == condition.tagColor;
   }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(name, expression, tagColor);
+  }
 }

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

@@ -121,7 +121,7 @@ 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()))
+            new JsonHttpContent(jsonFactory, template.toTemplateResponse(false)))
             .addAllHeaders(COMMON_HEADERS)
             .addHeader("If-Match", forcePublish ? "*" : template.getETag());
     if (validateOnly) {

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

@@ -20,20 +20,74 @@
 
 import com.google.common.base.Strings;
 
+import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.TimeZone;
 
 final class RemoteConfigUtil {
 
+  // SimpleDateFormat cannot handle fractional seconds in timestamps
+  // (example: "2014-10-02T15:01:23.045123456Z"). Therefore, we strip fractional seconds
+  // from the date string (example: "2014-10-02T15:01:23") when parsing Zulu timestamp strings.
+  // The backend API expects timestamps in Zulu format with fractional seconds. To generate correct
+  // timestamps in payloads we use ".SSS000000'Z'" suffix.
+  // Hence, two Zulu date patterns are used below.
+  private static final String ZULU_DATE_PATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSS000000'Z'";
+  private static final String ZULU_DATE_NO_FRAC_SECS_PATTERN = "yyyy-MM-dd'T'HH:mm:ss";
+  private static final String UTC_DATE_PATTERN = "EEE, dd MMM yyyy HH:mm:ss z";
+  private static final TimeZone UTC_TIME_ZONE = TimeZone.getTimeZone("UTC");
+
   static boolean isValidVersionNumber(String versionNumber) {
     return !Strings.isNullOrEmpty(versionNumber) && versionNumber.matches("^\\d+$");
   }
 
+  static long convertToMilliseconds(String dateString) throws ParseException {
+    try {
+      return convertFromUtcZuluFormat(dateString);
+    } catch (ParseException e) {
+      return convertFromUtcDateFormat(dateString);
+    }
+  }
+
   static String convertToUtcZuluFormat(long millis) {
+    // sample output date string: 2020-11-12T22:12:02.000000000Z
     checkArgument(millis >= 0, "Milliseconds duration must not be negative");
-    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS000000'Z'");
-    dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    SimpleDateFormat dateFormat = new SimpleDateFormat(ZULU_DATE_PATTERN);
+    dateFormat.setTimeZone(UTC_TIME_ZONE);
     return dateFormat.format(new Date(millis));
   }
+
+  static String convertToUtcDateFormat(long millis) {
+    // sample output date string: Tue, 08 Dec 2020 15:49:51 GMT
+    checkArgument(millis >= 0, "Milliseconds duration must not be negative");
+    SimpleDateFormat dateFormat = new SimpleDateFormat(UTC_DATE_PATTERN);
+    dateFormat.setTimeZone(UTC_TIME_ZONE);
+    return dateFormat.format(new Date(millis));
+  }
+
+  static long convertFromUtcZuluFormat(String dateString) throws ParseException {
+    checkArgument(!Strings.isNullOrEmpty(dateString), "Date string must not be null or empty");
+    // Input timestamp is in RFC3339 UTC "Zulu" format, accurate to
+    // nanoseconds (up to 9 fractional seconds digits).
+    // SimpleDateFormat cannot handle fractional seconds, therefore we strip fractional seconds
+    // from the input date string before parsing.
+    // example: input -> "2014-10-02T15:01:23.045123456Z"
+    // formatted -> "2014-10-02T15:01:23"
+    int indexOfPeriod = dateString.indexOf(".");
+    if (indexOfPeriod != -1) {
+      dateString = dateString.substring(0, indexOfPeriod);
+    }
+    SimpleDateFormat dateFormat = new SimpleDateFormat(ZULU_DATE_NO_FRAC_SECS_PATTERN);
+    dateFormat.setTimeZone(UTC_TIME_ZONE);
+    return dateFormat.parse(dateString).getTime();
+  }
+
+  static long convertFromUtcDateFormat(String dateString) throws ParseException {
+    // sample input date string: Tue, 08 Dec 2020 15:49:51 GMT
+    checkArgument(!Strings.isNullOrEmpty(dateString), "Date string must not be null or empty");
+    SimpleDateFormat dateFormat = new SimpleDateFormat(UTC_DATE_PATTERN);
+    dateFormat.setTimeZone(UTC_TIME_ZONE);
+    return dateFormat.parse(dateString).getTime();
+  }
 }

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

@@ -16,11 +16,17 @@
 
 package com.google.firebase.remoteconfig;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.api.client.googleapis.util.Utils;
+import com.google.api.client.json.JsonFactory;
+import com.google.common.base.Strings;
+import com.google.firebase.ErrorCode;
 import com.google.firebase.internal.NonNull;
 import com.google.firebase.remoteconfig.internal.TemplateResponse;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -40,11 +46,18 @@ public final class Template {
 
   /**
    * Creates a new {@link Template}.
+   *
+   * @param etag The ETag of this template.
    */
-  public Template() {
-    parameters = new HashMap<>();
-    conditions = new ArrayList<>();
-    parameterGroups = new HashMap<>();
+  public Template(String etag) {
+    this.parameters = new HashMap<>();
+    this.conditions = new ArrayList<>();
+    this.parameterGroups = new HashMap<>();
+    this.etag = etag;
+  }
+
+  Template() {
+    this((String) null);
   }
 
   Template(@NonNull TemplateResponse templateResponse) {
@@ -73,6 +86,29 @@ public Template() {
     if (templateResponse.getVersion() != null) {
       this.version = new Version(templateResponse.getVersion());
     }
+    this.etag = templateResponse.getEtag();
+  }
+
+  /**
+   * Creates and returns a new Remote Config template from a JSON string.
+   * Input JSON string must contain an {@code etag} property to create a valid template.
+   *
+   * @param json A non-null JSON string to populate a Remote Config template.
+   * @return A new {@link Template} instance.
+   * @throws FirebaseRemoteConfigException If the input JSON string is not parsable.
+   */
+  public static Template fromJSON(@NonNull String json) throws FirebaseRemoteConfigException {
+    checkArgument(!Strings.isNullOrEmpty(json), "JSON String must not be null or empty.");
+    // using the default json factory as no rpc calls are made here
+    JsonFactory jsonFactory = Utils.getDefaultJsonFactory();
+    try {
+      TemplateResponse templateResponse = jsonFactory.createJsonParser(json)
+              .parseAndClose(TemplateResponse.class);
+      return new Template(templateResponse);
+    } catch (IOException e) {
+      throw new FirebaseRemoteConfigException(ErrorCode.INVALID_ARGUMENT,
+              "Unable to parse JSON string.");
+    }
   }
 
   /**
@@ -177,12 +213,26 @@ public Template setVersion(Version version) {
     return this;
   }
 
+  /**
+   * Gets the JSON-serializable representation of this template.
+   *
+   * @return A JSON-serializable representation of this {@link Template} instance.
+   */
+  public String toJSON() {
+    JsonFactory jsonFactory = Utils.getDefaultJsonFactory();
+    try {
+      return jsonFactory.toString(this.toTemplateResponse(true));
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
   Template setETag(String etag) {
     this.etag = etag;
     return this;
   }
 
-  TemplateResponse toTemplateResponse() {
+  TemplateResponse toTemplateResponse(boolean includeAll) {
     Map<String, TemplateResponse.ParameterResponse> parameterResponses = new HashMap<>();
     for (Map.Entry<String, Parameter> entry : this.parameters.entrySet()) {
       parameterResponses.put(entry.getKey(), entry.getValue().toParameterResponse());
@@ -196,12 +246,16 @@ TemplateResponse toTemplateResponse() {
       parameterGroupResponse.put(entry.getKey(), entry.getValue().toParameterGroupResponse());
     }
     TemplateResponse.VersionResponse versionResponse = (this.version == null) ? null
-            : this.version.toVersionResponse();
-    return new TemplateResponse()
+            : this.version.toVersionResponse(includeAll);
+    TemplateResponse templateResponse = new TemplateResponse()
             .setParameters(parameterResponses)
             .setConditions(conditionResponses)
             .setParameterGroups(parameterGroupResponse)
             .setVersion(versionResponse);
+    if (includeAll) {
+      return templateResponse.setEtag(this.etag);
+    }
+    return templateResponse;
   }
 
   @Override

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

@@ -88,4 +88,11 @@ public boolean equals(Object o) {
   public int hashCode() {
     return Objects.hash(email, name, imageUrl);
   }
+
+  UserResponse toUserResponse() {
+    return new UserResponse()
+            .setEmail(this.email)
+            .setImageUrl(this.imageUrl)
+            .setName(this.name);
+  }
 }

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

@@ -25,11 +25,7 @@
 import com.google.firebase.remoteconfig.internal.TemplateResponse.VersionResponse;
 
 import java.text.ParseException;
-import java.text.SimpleDateFormat;
 import java.util.Objects;
-import java.util.TimeZone;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 /**
  * Represents a Remote Config template version.
@@ -64,18 +60,8 @@ private Version() {
     this.versionNumber = versionResponse.getVersionNumber();
 
     if (!Strings.isNullOrEmpty(versionResponse.getUpdateTime())) {
-      // Update Time is a timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds.
-      // example: "2014-10-02T15:01:23.045123456Z"
-      // SimpleDateFormat cannot handle nanoseconds, therefore we strip nanoseconds from the string.
-      String updateTime = versionResponse.getUpdateTime();
-      int indexOfPeriod = updateTime.indexOf(".");
-      if (indexOfPeriod != -1) {
-        updateTime = updateTime.substring(0, indexOfPeriod);
-      }
-      SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
-      dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
       try {
-        this.updateTime = dateFormat.parse(updateTime).getTime();
+        this.updateTime = RemoteConfigUtil.convertToMilliseconds(versionResponse.getUpdateTime());
       } catch (ParseException e) {
         throw new IllegalStateException("Unable to parse update time.", e);
       }
@@ -196,9 +182,19 @@ public Version setDescription(String description) {
     return this;
   }
 
-  VersionResponse toVersionResponse() {
-    return new VersionResponse()
-            .setDescription(this.description);
+  VersionResponse toVersionResponse(boolean includeAll) {
+    VersionResponse versionResponse = new VersionResponse().setDescription(this.description);
+    if (includeAll) {
+      versionResponse.setUpdateTime(this.updateTime > 0L
+              ? RemoteConfigUtil.convertToUtcDateFormat(this.updateTime) : null)
+              .setLegacy(this.legacy)
+              .setRollbackSource(this.rollbackSource)
+              .setUpdateOrigin(this.updateOrigin)
+              .setUpdateType(this.updateType)
+              .setUpdateUser((this.updateUser == null) ? null : this.updateUser.toUserResponse())
+              .setVersionNumber(this.versionNumber);
+    }
+    return versionResponse;
   }
 
   @Override

src/main/java/com/google/firebase/remoteconfig/internal/TemplateResponse.java

@@ -39,6 +39,11 @@ public final class TemplateResponse {
   @Key("version")
   private VersionResponse version;
 
+  // For local JSON serialization and deserialization purposes only.
+  // ETag in response type is never set by the HTTP response.
+  @Key("etag")
+  private String etag;
+
   public Map<String, ParameterResponse> getParameters() {
     return parameters;
   }
@@ -55,6 +60,10 @@ public VersionResponse getVersion() {
     return version;
   }
 
+  public String getEtag() {
+    return etag;
+  }
+
   public TemplateResponse setParameters(
           Map<String, ParameterResponse> parameters) {
     this.parameters = parameters;
@@ -78,6 +87,11 @@ public TemplateResponse setVersion(VersionResponse version) {
     return this;
   }
 
+  public TemplateResponse setEtag(String etag) {
+    this.etag = etag;
+    return this;
+  }
+
   /**
    * The Data Transfer Object for parsing Remote Config parameter responses from the
    * Remote Config service.

src/test/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigClientImplTest.java

@@ -105,7 +105,6 @@ public class FirebaseRemoteConfigClientImplTest {
                   .setTagColor(TagColor.INDIGO),
           new Condition("android_en",
                   "device.os == 'android' && device.country in ['us', 'uk']")
-                  .setTagColor(TagColor.UNSPECIFIED)
   );
 
   private static final Version EXPECTED_VERSION = new Version(new TemplateResponse.VersionResponse()