package org.apache.helix.model;

/*
 * 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.
 */

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.helix.model.HelixConfigScope.ConfigScopeProperty;
import org.apache.helix.model.builder.ConfigScopeBuilder;
import org.apache.helix.util.StringTemplate;
import org.apache.log4j.Logger;

/**
 * @deprecated replaced by {@link HelixConfigScope}
 */
@Deprecated
public class ConfigScope {
  private static Logger LOG = Logger.getLogger(ConfigScope.class);

  private static final List<ConfigScopeProperty> scopePriority =
      new ArrayList<ConfigScopeProperty>();
  private static final Map<ConfigScopeProperty, Map<ConfigScopeProperty, ConfigScopeProperty>> scopeTransition =
      new HashMap<ConfigScopeProperty, Map<ConfigScopeProperty, ConfigScopeProperty>>();
  private static final StringTemplate template = new StringTemplate();
  static {
    // scope priority: CLUSTER > PARTICIPANT > RESOURCE > PARTITION
    scopePriority.add(ConfigScopeProperty.CLUSTER);
    scopePriority.add(ConfigScopeProperty.PARTICIPANT);
    scopePriority.add(ConfigScopeProperty.RESOURCE);
    scopePriority.add(ConfigScopeProperty.PARTITION);

    // scope transition table to check valid inputs
    scopeTransition.put(ConfigScopeProperty.CLUSTER,
        new HashMap<ConfigScopeProperty, ConfigScopeProperty>());
    scopeTransition.get(ConfigScopeProperty.CLUSTER).put(ConfigScopeProperty.PARTICIPANT,
        ConfigScopeProperty.PARTICIPANT);
    scopeTransition.get(ConfigScopeProperty.CLUSTER).put(ConfigScopeProperty.RESOURCE,
        ConfigScopeProperty.RESOURCE);
    scopeTransition.put(ConfigScopeProperty.RESOURCE,
        new HashMap<ConfigScopeProperty, ConfigScopeProperty>());
    scopeTransition.get(ConfigScopeProperty.RESOURCE).put(ConfigScopeProperty.PARTITION,
        ConfigScopeProperty.PARTITION);

    // string templates to generate znode path/index
    // @formatter:off
    template.addEntry(ConfigScopeProperty.CLUSTER, 2,
        "/{clusterName}/CONFIGS/CLUSTER/{clusterName}");
    template.addEntry(ConfigScopeProperty.PARTICIPANT, 2,
        "/{clusterName}/CONFIGS/PARTICIPANT/{participantName}");
    template.addEntry(ConfigScopeProperty.RESOURCE, 2,
        "/{clusterName}/CONFIGS/RESOURCE/{resourceName}");
    template.addEntry(ConfigScopeProperty.PARTITION, 3,
        "/{clusterName}/CONFIGS/RESOURCE/{resourceName}|{partitionName}");
    // @formatter:on
  }

  private final String _clusterName;
  private final ConfigScopeProperty _scope;

  /**
   * _scopeStr is like:
   * "/ClusterName/CONFIGS/{CLUSTER|PARTICIPANT|RESOURCE|PARTITION}/{clusterName|instanceName|resourceName}{|partitionName}"
   */
  private final String _scopeStr;

  public ConfigScope(ConfigScopeBuilder configScopeBuilder) {
    Map<ConfigScopeProperty, String> scopeMap = configScopeBuilder.getScopeMap();
    List<String> keys = new ArrayList<String>();

    ConfigScopeProperty curScope = null;
    for (ConfigScopeProperty scope : scopePriority) {
      if (scopeMap.containsKey(scope)) {
        if (curScope == null && scope == ConfigScopeProperty.CLUSTER) {
          keys.add(scopeMap.get(scope));
          curScope = ConfigScopeProperty.CLUSTER;
        } else if (curScope == null) {
          throw new IllegalArgumentException("Missing CLUSTER scope. Can't build scope using "
              + configScopeBuilder);
        } else {
          if (!scopeTransition.containsKey(curScope)
              || !scopeTransition.get(curScope).containsKey(scope)) {
            throw new IllegalArgumentException("Can't build scope using " + configScopeBuilder);
          }
          keys.add(scopeMap.get(scope));
          curScope = scopeTransition.get(curScope).get(scope);
        }
      }
    }

    if (curScope == ConfigScopeProperty.CLUSTER) {
      // append one more {clusterName}
      keys.add(scopeMap.get(ConfigScopeProperty.CLUSTER));
    }

    String scopeStr = template.instantiate(curScope, keys.toArray(new String[0]));

    _clusterName = keys.get(0);
    _scopeStr = scopeStr;
    _scope = curScope;
  }

  public ConfigScopeProperty getScope() {
    return _scope;
  }

  public String getClusterName() {
    return _clusterName;
  }

  public String getScopeStr() {
    return _scopeStr;
  }

  @Override
  public String toString() {
    return super.toString() + ": " + _scopeStr;
  }
}
