code: /*
   * 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.skywalking.oal.rt.parser;
  
  import org.apache.skywalking.oal.rt.util.ClassMethodUtil;
  import org.apache.skywalking.oal.rt.util.TypeCastUtil;
  import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.Arg;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.ConstOne;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.Entrance;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.SourceFrom;
  import org.apache.skywalking.oap.server.core.storage.annotation.Column;
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Field;
  import java.lang.reflect.Method;
  import java.lang.reflect.Parameter;
  import java.util.List;
  import static java.util.Objects.isNull;
  
  public class DeepAnalysis {
      public AnalysisResult analysis(AnalysisResult result) {
          // 1. Set sub package name by source.metrics
          Class<? extends Metrics> metricsClass = MetricsHolder.find(result.getAggregationFuncStmt().getAggregationFunctionName());
          String metricsClassSimpleName = metricsClass.getSimpleName();
  
          result.setMetricsClassName(metricsClassSimpleName);
  
          // Optional for filter
          List<ConditionExpression> expressions = result.getFilters().getFilterExpressionsParserResult();
          if (expressions != null && expressions.size() > 0) {
              for (ConditionExpression expression : expressions) {
                  final FilterMatchers.MatcherInfo matcherInfo = FilterMatchers.INSTANCE.find(
                      expression.getExpressionType());
  
                  final String getter = matcherInfo.isBooleanType()
                      ? ClassMethodUtil.toIsMethod(expression.getAttributes())
                      : ClassMethodUtil.toGetMethod(expression.getAttributes());
  
                  final Expression filterExpression = new Expression();
                  filterExpression.setExpressionObject(matcherInfo.getMatcher().getName());
                  filterExpression.setLeft(TypeCastUtil.withCast(expression.getCastType(), "source." + getter));
                  filterExpression.setRight(expression.getValue());
                  result.getFilters().addFilterExpressions(filterExpression);
              }
          }
  
          // 3. Find Entrance method of this metrics
          Class<?> c = metricsClass;
          Method entranceMethod = null;
          SearchEntrance:
          while (!c.equals(Object.class)) {
              for (Method method : c.getMethods()) {
                  Entrance annotation = method.getAnnotation(Entrance.class);
                  if (annotation != null) {
                      entranceMethod = method;
                      break SearchEntrance;
                  }
              }
              c = c.getSuperclass();
          }
          if (entranceMethod == null) {
              throw new IllegalArgumentException("Can't find Entrance method in class: " + metricsClass.getName());
          }
          EntryMethod entryMethod = new EntryMethod();
          result.setEntryMethod(entryMethod);
          entryMethod.setMethodName(entranceMethod.getName());
  
          // 4. Use parameter's annotation of entrance method to generate aggregation entrance.
          for (Parameter parameter : entranceMethod.getParameters()) {
              Class<?> parameterType = parameter.getType();
              Annotation[] parameterAnnotations = parameter.getAnnotations();
              if (parameterAnnotations == null || parameterAnnotations.length == 0) {
                  throw new IllegalArgumentException(
                      "Entrance method:" + entranceMethod + " doesn't include the annotation.");
              }
              Annotation annotation = parameterAnnotations[0];
              if (annotation instanceof SourceFrom) {
                  entryMethod.addArg(
                      parameterType,
                      TypeCastUtil.withCast(
                          result.getFrom().getSourceCastType(),
                          "source." + ClassMethodUtil.toGetMethod(result.getFrom().getSourceAttribute())
                      )
                  );
              } else if (annotation instanceof ConstOne) {
                  entryMethod.addArg(parameterType, "1");
              } else if (annotation instanceof org.apache.skywalking.oap.server.core.analysis.metrics.annotation.Expression) {
                  if (isNull(result.getAggregationFuncStmt().getFuncConditionExpressions())
                      || result.getAggregationFuncStmt().getFuncConditionExpressions().isEmpty()) {
                      throw new IllegalArgumentException(
                          "Entrance method:" + entranceMethod + " argument can't find funcParamExpression.");
                  } else {
                      ConditionExpression expression = result.getAggregationFuncStmt().getNextFuncConditionExpression();
                      final FilterMatchers.MatcherInfo matcherInfo = FilterMatchers.INSTANCE.find(
                          expression.getExpressionType());
  
                      final String getter = matcherInfo.isBooleanType()
                          ? ClassMethodUtil.toIsMethod(expression.getAttributes())
                          : ClassMethodUtil.toGetMethod(expression.getAttributes());
  
                      final Expression argExpression = new Expression();
                      argExpression.setRight(expression.getValue());
                      argExpression.setExpressionObject(matcherInfo.getMatcher().getName());
                      argExpression.setLeft(TypeCastUtil.withCast(expression.getCastType(), "source." + getter));
  
                      entryMethod.addArg(argExpression);
                  }
              } else if (annotation instanceof Arg) {
                  entryMethod.addArg(parameterType, result.getAggregationFuncStmt().getNextFuncArg());
              } else {
                  throw new IllegalArgumentException(
                      "Entrance method:" + entranceMethod + " doesn't the expected annotation.");
              }
          }
  
          // 5. Get all column declared in MetricsHolder class.
          c = metricsClass;
          while (!c.equals(Object.class)) {
              for (Field field : c.getDeclaredFields()) {
                  Column column = field.getAnnotation(Column.class);
                  if (column != null) {
                      result.addPersistentField(
                          field.getName(),
                          column.name(),
                          field.getType());
                  }
              }
              c = c.getSuperclass();
          }
  
          // 6. Based on Source, generate default columns
          List<SourceColumn> columns = SourceColumnsFactory.getColumns(result.getFrom().getSourceName());
          result.setFieldsFromSource(columns);
  
          result.generateSerializeFields();
  
          return result;
      }
  
  }
  