content: /*
   * 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.state.alert;
  
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  
  import org.apache.ambari.server.controller.jmx.JMXMetricHolder;
  import org.apache.ambari.server.state.UriInfo;
  import org.springframework.expression.spel.standard.SpelExpressionParser;
  import org.springframework.expression.spel.support.SimpleEvaluationContext;
  
  import com.fasterxml.jackson.annotation.JsonAutoDetect;
  import com.fasterxml.jackson.annotation.JsonInclude;
  import com.fasterxml.jackson.annotation.JsonProperty;
  import com.google.gson.annotations.SerializedName;
  
  /**
   * Alert when the source type is defined as {@link SourceType#METRIC}
   * <p/>
   * Equality checking for instances of this class should be executed on every
   * member to ensure that reconciling stack differences is correct.
   */
  @JsonInclude(JsonInclude.Include.NON_EMPTY)
  public class MetricSource extends Source {
  
    @SerializedName("uri")
    private UriInfo uri = null;
  
    @SerializedName("jmx")
    private JmxInfo jmxInfo = null;
  
    @SerializedName("ganglia")
    private String gangliaInfo = null;
  
    /**
     * @return the jmx info, if this metric is jmx-based
     */
    @JsonProperty("jmx")
    public JmxInfo getJmxInfo() {
      return jmxInfo;
    }
  
    /**
     * @return the ganglia info, if this metric is ganglia-based
     */
    @JsonProperty("ganglia")
    public String getGangliaInfo() {
      return gangliaInfo;
    }
  
    /**
     * @return the uri info, which may include port information
     */
    @JsonProperty("uri")
    public UriInfo getUri() {
      return uri;
    }
  
    @Override
    public int hashCode() {
      return Objects.hash(super.hashCode(), gangliaInfo, uri, jmxInfo);
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj) {
        return true;
      }
  
      if (!super.equals(obj)) {
        return false;
      }
  
      if (getClass() != obj.getClass()) {
        return false;
      }
  
      MetricSource other = (MetricSource) obj;
      return Objects.equals(gangliaInfo, other.gangliaInfo) &&
        Objects.equals(uri, other.uri) &&
        Objects.equals(jmxInfo, other.jmxInfo);
    }
  
    /**
     * Represents the {@code jmx} element in a Metric alert.
     */
    @JsonInclude(JsonInclude.Include.NON_EMPTY)
    @JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY, getterVisibility = JsonAutoDetect.Visibility.NONE, setterVisibility = JsonAutoDetect.Visibility.NONE)
    public static class JmxInfo {
      @JsonProperty("property_list")
      @SerializedName("property_list")
      private List<String> propertyList;
  
      @SerializedName("value")
      private String value = "{0}";
  
      @JsonProperty("url_suffix")
      @SerializedName("url_suffix")
      private String urlSuffix = "/jmx";
  
      public List<String> getPropertyList() {
        return propertyList;
      }
  
      public void setPropertyList(List<String> propertyList) {
        this.propertyList = propertyList;
      }
  
      public void setValue(String value) {
        this.value = value;
      }
  
      public Value getValue() {
        return new Value(value);
      }
  
      @Override
      public boolean equals(Object object) {
        if (!JmxInfo.class.isInstance(object)) {
          return false;
        }
  
        JmxInfo other = (JmxInfo)object;
  
        List<String> list1 = new ArrayList<>(propertyList);
        List<String> list2 = new ArrayList<>(other.propertyList);
  
        // !!! even if out of order, this is enough to fail
        return list1.equals(list2);
      }
  
      @Override
      public int hashCode() {
        return Objects.hashCode(propertyList);
      }
  
      public String getUrlSuffix() {
        return urlSuffix;
      }
  
      public Optional<Number> eval(JMXMetricHolder jmxMetricHolder) {
        List<Object> metrics = jmxMetricHolder.findAll(propertyList);
        if (metrics.isEmpty()) {
          return Optional.empty();
        } else {
          Object value = getValue().eval(metrics);
          return value instanceof Number ? Optional.of((Number)value) : Optional.empty();
        }
      }
    }
  
    public static class Value {
      private final String value;
  
      public Value(String value) {
        this.value = value;
      }
  
      /**
       * Evaluate an expression like "{0}/({0} + {1}) * 100.0" where each positional argument represent a metrics value.
       * The value is converted to SpEL syntax:
       *  #var0/(#var0 + #var1) * 100.0
       * then it is evaluated in the context of the metrics parameters.
       */
      public Object eval(List<Object> metrics) {
        SimpleEvaluationContext context = SimpleEvaluationContext.forReadWriteDataBinding().build();
        for(int i = 0; i < metrics.size(); i++) {
          context.setVariable("var" + i, metrics.get(i));
        }
        return new SpelExpressionParser()
          .parseExpression(value.replaceAll("(\\{(\\d+)\\})", "#var$2"))
          .getValue(context);
      }
  
      @Override
      public String toString() {
        return value;
      }
    }
  }
  