/* Copyright (c) 2009 Google Inc.
 *
 * 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.wave.api;

import com.google.wave.api.JsonRpcConstant.ParamsProperty;

import java.util.Map;

/**
 * Encapsulates the response of a JSON-RPC call.
 *
 * @author douwe@google.com (Douwe Osinga)
 */
public class JsonRpcResponse {

  private final String id;
  private final Map<ParamsProperty, Object> data;
  private final String errorMessage;

  /**
   * Construct a JSON-RPC error response.
   *
   * @param id the id of the operation request.
   * @param errorMessage the error message.
   * @return an instance of {@link JsonRpcResponse} that represents an error.
   */
  public static JsonRpcResponse error(String id, String errorMessage) {
    return new JsonRpcResponse(id, null, errorMessage);
  }

  /**
   * Construct a JSON-RPC response.
   *
   * @param id the id of the operation request.
   * @param data a key value pairs of data that was returned as a result of
   *     operation.
   * @return an instance of {@link JsonRpcResponse} that represents a success
   *     case.
   */
  public static JsonRpcResponse result(String id, Map<ParamsProperty, Object> data) {
    return new JsonRpcResponse(id, data, null);
  }

  private JsonRpcResponse(String id, Map<ParamsProperty, Object> result, String errorMessage) {
    this.id = id;
    this.data = result;
    this.errorMessage = errorMessage;
  }

  public Map<ParamsProperty, Object> getData() {
    return data;
  }

  public String getErrorMessage() {
    return errorMessage;
  }

  public String getId() {
    return id;
  }

  public boolean isError() {
    return data == null;
  }
}