/**
 * 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.controller.metrics;

import static org.apache.ambari.server.controller.metrics.MetricsPaddingMethod.ZERO_PADDING_PARAM;

import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;

import org.apache.ambari.server.configuration.ComponentSSLConfiguration;
import org.apache.ambari.server.controller.internal.AbstractPropertyProvider;
import org.apache.ambari.server.controller.internal.PropertyInfo;
import org.apache.ambari.server.controller.internal.URLStreamProvider;
import org.apache.ambari.server.controller.metrics.timeline.cache.TimelineMetricCacheProvider;
import org.apache.ambari.server.controller.spi.Predicate;
import org.apache.ambari.server.controller.spi.Request;
import org.apache.ambari.server.controller.spi.Resource;
import org.apache.ambari.server.controller.spi.SystemException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class MetricsPropertyProvider extends AbstractPropertyProvider {
  protected final static Logger LOG =
    LoggerFactory.getLogger(MetricsPropertyProvider.class);

  protected static final Pattern questionMarkPattern = Pattern.compile("\\?");

  protected final URLStreamProvider streamProvider;

  protected final MetricHostProvider hostProvider;

  protected final String clusterNamePropertyId;

  protected final String hostNamePropertyId;

  protected final String componentNamePropertyId;

  protected final ComponentSSLConfiguration configuration;

  protected MetricsPaddingMethod metricsPaddingMethod;

  private static final MetricsPaddingMethod DEFAULT_PADDING_METHOD =
    new MetricsPaddingMethod(MetricsPaddingMethod.PADDING_STRATEGY.ZEROS);

  protected MetricsPropertyProvider(Map<String, Map<String,
       PropertyInfo>> componentPropertyInfoMap,
       URLStreamProvider streamProvider,
       ComponentSSLConfiguration configuration,
       MetricHostProvider hostProvider,
       String clusterNamePropertyId,
       String hostNamePropertyId,
       String componentNamePropertyId) {

    super(componentPropertyInfoMap);

    this.streamProvider           = streamProvider;
    this.configuration            = configuration;
    this.hostProvider             = hostProvider;
    this.clusterNamePropertyId    = clusterNamePropertyId;
    this.hostNamePropertyId       = hostNamePropertyId;
    this.componentNamePropertyId  = componentNamePropertyId;
  }

  public static MetricsPropertyProviderProxy createInstance(
        Resource.Type type,
        Map<String, Map<String, PropertyInfo>> componentPropertyInfoMap,
        URLStreamProvider streamProvider,
        ComponentSSLConfiguration configuration,
        TimelineMetricCacheProvider cacheProvider,
        MetricHostProvider hostProvider,
        MetricsServiceProvider serviceProvider,
        String clusterNamePropertyId,
        String hostNamePropertyId,
        String componentNamePropertyId) {

    if (type.isInternalType()) {
      return new MetricsPropertyProviderProxy(
        type.getInternalType(),
        componentPropertyInfoMap,
        streamProvider,
        configuration,
        cacheProvider,
        hostProvider,
        serviceProvider,
        clusterNamePropertyId,
        hostNamePropertyId,
        componentNamePropertyId
      );
    }

    return null;
  }

  /**
   * Get the host name for the given resource.
   *
   * @param resource  the resource
   *
   * @return the host name
   */
  protected abstract String getHostName(Resource resource);

  /**
   * Get the component name for the given resource.
   *
   * @param resource  the resource
   *
   * @return the component name
   */
  protected abstract String getComponentName(Resource resource);

  @Override
  public Set<Resource> populateResources(Set<Resource> resources,
                Request request, Predicate predicate) throws SystemException {
    Set<String> ids = getRequestPropertyIds(request, predicate);
    if (ids.isEmpty()) {
      return resources;
    }

    if (!checkAuthorizationForMetrics(resources, clusterNamePropertyId)) {
      return resources;
    }

    // Re-initialize in case of reuse.
    metricsPaddingMethod = DEFAULT_PADDING_METHOD;

    Set<String> requestPropertyIds = request.getPropertyIds();
    if (requestPropertyIds != null && !requestPropertyIds.isEmpty()) {
      for (String propertyId : requestPropertyIds) {
        if (propertyId.startsWith(ZERO_PADDING_PARAM)) {
          String paddingStrategyStr = propertyId.substring(ZERO_PADDING_PARAM.length() + 1);
          metricsPaddingMethod = new MetricsPaddingMethod(
            MetricsPaddingMethod.PADDING_STRATEGY.valueOf(paddingStrategyStr));
        }
      }
    }

    return populateResourcesWithProperties(resources, request, ids);
  }

  /**
   * Delegate implementation of populating resources to concrete providers.
   *
   * @param resources @Resource
   * @param request @Request
   * @param propertyIds Set of ids
   * @return @Set of resources
   * @throws SystemException
   */
  protected abstract Set<Resource> populateResourcesWithProperties(Set<Resource> resources,
      Request request, Set<String> propertyIds) throws SystemException;

  /**
   * Get a comma delimited string from the given set of strings or
   * an empty string if the size of the given set is greater than
   * the given limit.
   *
   * @param set    the set of strings
   * @param limit  the upper size limit for the list
   *
   * @return a comma delimited string of strings
   */
  public static String getSetString(Set<String> set, int limit) {
    StringBuilder sb = new StringBuilder();

    if (limit == -1 || set.size() <= limit) {
      for (String cluster : set) {
        if (sb.length() > 0) {
          sb.append(',');
        }
        sb.append(cluster);
      }
    }
    return sb.toString();
  }

}