/*
    * 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.bcel.classfile;
  
  import java.io.DataInput;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * represents one parameter annotation in the parameter annotation table
   *
   * @since 6.0
   */
  public class ParameterAnnotationEntry implements Node {
  
      static final ParameterAnnotationEntry[] EMPTY_ARRAY = {};
  
      public static ParameterAnnotationEntry[] createParameterAnnotationEntries(final Attribute[] attributes) {
          if (attributes == null) {
              return EMPTY_ARRAY;
          }
          // Find attributes that contain parameter annotation data
          final List<ParameterAnnotationEntry> accumulatedAnnotations = new ArrayList<>(attributes.length);
          for (final Attribute attribute : attributes) {
              if (attribute instanceof ParameterAnnotations) {
                  final ParameterAnnotations runtimeAnnotations = (ParameterAnnotations) attribute;
                  final ParameterAnnotationEntry[] parameterAnnotationEntries = runtimeAnnotations.getParameterAnnotationEntries();
                  if (parameterAnnotationEntries != null) {
                      Collections.addAll(accumulatedAnnotations, parameterAnnotationEntries);
                  }
              }
          }
          return accumulatedAnnotations.toArray(EMPTY_ARRAY);
      }
  
      private final AnnotationEntry[] annotationTable;
  
      /**
       * Constructs object from input stream.
       *
       * @param input Input stream
       * @throws IOException if an I/O error occurs.
       */
      ParameterAnnotationEntry(final DataInput input, final ConstantPool constantPool) throws IOException {
          final int annotationTableLength = input.readUnsignedShort();
          annotationTable = new AnnotationEntry[annotationTableLength];
          for (int i = 0; i < annotationTableLength; i++) {
              // TODO isRuntimeVisible
              annotationTable[i] = AnnotationEntry.read(input, constantPool, false);
          }
      }
  
      /**
       * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
       * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
       *
       * @param v Visitor object
       */
      @Override
      public void accept(final Visitor v) {
          v.visitParameterAnnotationEntry(this);
      }
  
      public void dump(final DataOutputStream dos) throws IOException {
          dos.writeShort(annotationTable.length);
          for (final AnnotationEntry entry : annotationTable) {
              entry.dump(dos);
          }
      }
  
      /**
       * returns the array of annotation entries in this annotation
       */
      public AnnotationEntry[] getAnnotationEntries() {
          return annotationTable;
      }
  }