/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.ambari.server.api.services.stackadvisor.commands;

import static org.apache.ambari.server.api.services.stackadvisor.recommendations.RecommendationResponse.BindingHostGroup;
import static org.apache.ambari.server.api.services.stackadvisor.recommendations.RecommendationResponse.HostGroup;

import java.io.File;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.ambari.server.api.services.AmbariMetaInfo;
import org.apache.ambari.server.api.services.stackadvisor.StackAdvisorException;
import org.apache.ambari.server.api.services.stackadvisor.StackAdvisorRequest;
import org.apache.ambari.server.api.services.stackadvisor.StackAdvisorRunner;
import org.apache.ambari.server.api.services.stackadvisor.recommendations.RecommendationResponse;

/**
 * {@link org.apache.ambari.server.api.services.stackadvisor.commands.StackAdvisorCommand} implementation for
 * configuration recommendation.
 */
public class ConfigurationRecommendationCommand extends
    StackAdvisorCommand<RecommendationResponse> {

  public ConfigurationRecommendationCommand(File recommendationsDir, String recommendationsArtifactsLifetime, String stackAdvisorScript, int requestId,
                                            StackAdvisorRunner saRunner, AmbariMetaInfo metaInfo) {
    super(recommendationsDir, recommendationsArtifactsLifetime, stackAdvisorScript, requestId, saRunner, metaInfo);
  }

  @Override
  protected StackAdvisorCommandType getCommandType() {
    return StackAdvisorCommandType.RECOMMEND_CONFIGURATIONS;
  }

  @Override
  protected void validate(StackAdvisorRequest request) throws StackAdvisorException {
    if (request.getHosts() == null || request.getHosts().isEmpty() || request.getServices() == null
        || request.getServices().isEmpty()) {
      throw new StackAdvisorException("Hosts and services must not be empty");
    }
  }

  @Override
  protected RecommendationResponse updateResponse(StackAdvisorRequest request, RecommendationResponse response) {
    response.getRecommendations().getBlueprint().setHostGroups(processHostGroups(request));
    response.getRecommendations().getBlueprintClusterBinding().setHostGroups(processHostGroupBindings(request));
    return response;
  }

  protected Set<HostGroup> processHostGroups(StackAdvisorRequest request) {
    Set<HostGroup> resultSet = new HashSet<>();
    for (Map.Entry<String, Set<String>> componentHost : request.getHostComponents().entrySet()) {
      String hostGroupName = componentHost.getKey();
      Set<String> components = componentHost.getValue();
      if (hostGroupName != null && components != null) {
        HostGroup hostGroup = new HostGroup();
        Set<Map<String, String>> componentsSet = new HashSet<>();
        for (String component : components) {
          Map<String, String> componentMap = new HashMap<>();
          componentMap.put("name", component);
          componentsSet.add(componentMap);
        }
        hostGroup.setComponents(componentsSet);
        hostGroup.setName(hostGroupName);
        resultSet.add(hostGroup);
      }
    }
    return resultSet;
  }

  private Set<BindingHostGroup> processHostGroupBindings(StackAdvisorRequest request) {
    Set<BindingHostGroup> resultSet = new HashSet<>();
    for (Map.Entry<String, Set<String>> hostBinding : request.getHostGroupBindings().entrySet()) {
      String hostGroupName = hostBinding.getKey();
      Set<String> hosts = hostBinding.getValue();
      if (hostGroupName != null && hosts != null) {
        BindingHostGroup bindingHostGroup = new BindingHostGroup();
        Set<Map<String, String>> hostsSet = new HashSet<>();
        for (String host : hosts) {
          Map<String, String> hostMap = new HashMap<>();
          hostMap.put("name", host);
          hostsSet.add(hostMap);
        }
        bindingHostGroup.setHosts(hostsSet);
        bindingHostGroup.setName(hostGroupName);
        resultSet.add(bindingHostGroup);
      }
    }
    return resultSet;
  }

  @Override
  protected String getResultFileName() {
    return "configurations.json";
  }

}