// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
package org.apache.tapestry5.internal.plastic.asm.tree;

import java.util.ArrayList;
import java.util.List;

import org.apache.tapestry5.internal.plastic.asm.AnnotationVisitor;
import org.apache.tapestry5.internal.plastic.asm.Opcodes;

/**
 * A node that represents an annotation.
 *
 * @author Eric Bruneton
 */
public class AnnotationNode extends AnnotationVisitor {

  /** The class descriptor of the annotation class. */
  public String desc;

  /**
   * The name value pairs of this annotation. Each name value pair is stored as two consecutive
   * elements in the list. The name is a {@link String}, and the value may be a {@link Byte}, {@link
   * Boolean}, {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Float},
   * {@link Double}, {@link String} or {@link org.apache.tapestry5.internal.plastic.asm.Type}, or a two elements String
   * array (for enumeration values), an {@link AnnotationNode}, or a {@link List} of values of one
   * of the preceding types. The list may be {@literal null} if there is no name value pair.
   */
  public List<Object> values;

  /**
   * Constructs a new {@link AnnotationNode}. <i>Subclasses must not use this constructor</i>.
   * Instead, they must use the {@link #AnnotationNode(int, String)} version.
   *
   * @param descriptor the class descriptor of the annotation class.
   * @throws IllegalStateException If a subclass calls this constructor.
   */
  public AnnotationNode(final String descriptor) {
    this(/* latest api = */ Opcodes.ASM9, descriptor);
    if (getClass() != AnnotationNode.class) {
      throw new IllegalStateException();
    }
  }

  /**
   * Constructs a new {@link AnnotationNode}.
   *
   * @param api the ASM API version implemented by this visitor. Must be one of the {@code
   *     ASM}<i>x</i> values in {@link Opcodes}.
   * @param descriptor the class descriptor of the annotation class.
   */
  public AnnotationNode(final int api, final String descriptor) {
    super(api);
    this.desc = descriptor;
  }

  /**
   * Constructs a new {@link AnnotationNode} to visit an array value.
   *
   * @param values where the visited values must be stored.
   */
  AnnotationNode(final List<Object> values) {
    super(/* latest api = */ Opcodes.ASM9);
    this.values = values;
  }

  // ------------------------------------------------------------------------
  // Implementation of the AnnotationVisitor abstract class
  // ------------------------------------------------------------------------

  @Override
  public void visit(final String name, final Object value) {
    if (values == null) {
      values = new ArrayList<>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    if (value instanceof byte[]) {
      values.add(Util.asArrayList((byte[]) value));
    } else if (value instanceof boolean[]) {
      values.add(Util.asArrayList((boolean[]) value));
    } else if (value instanceof short[]) {
      values.add(Util.asArrayList((short[]) value));
    } else if (value instanceof char[]) {
      values.add(Util.asArrayList((char[]) value));
    } else if (value instanceof int[]) {
      values.add(Util.asArrayList((int[]) value));
    } else if (value instanceof long[]) {
      values.add(Util.asArrayList((long[]) value));
    } else if (value instanceof float[]) {
      values.add(Util.asArrayList((float[]) value));
    } else if (value instanceof double[]) {
      values.add(Util.asArrayList((double[]) value));
    } else {
      values.add(value);
    }
  }

  @Override
  public void visitEnum(final String name, final String descriptor, final String value) {
    if (values == null) {
      values = new ArrayList<>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    values.add(new String[] {descriptor, value});
  }

  @Override
  public AnnotationVisitor visitAnnotation(final String name, final String descriptor) {
    if (values == null) {
      values = new ArrayList<>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    AnnotationNode annotation = new AnnotationNode(descriptor);
    values.add(annotation);
    return annotation;
  }

  @Override
  public AnnotationVisitor visitArray(final String name) {
    if (values == null) {
      values = new ArrayList<>(this.desc != null ? 2 : 1);
    }
    if (this.desc != null) {
      values.add(name);
    }
    List<Object> array = new ArrayList<>();
    values.add(array);
    return new AnnotationNode(array);
  }

  @Override
  public void visitEnd() {
    // Nothing to do.
  }

  // ------------------------------------------------------------------------
  // Accept methods
  // ------------------------------------------------------------------------

  /**
   * Checks that this annotation node is compatible with the given ASM API version. This method
   * checks that this node, and all its children recursively, do not contain elements that were
   * introduced in more recent versions of the ASM API than the given version.
   *
   * @param api an ASM API version. Must be one of the {@code ASM}<i>x</i> values in {@link
   *     Opcodes}.
   */
  public void check(final int api) {
    // nothing to do
  }

  /**
   * Makes the given visitor visit this annotation.
   *
   * @param annotationVisitor an annotation visitor. Maybe {@literal null}.
   */
  public void accept(final AnnotationVisitor annotationVisitor) {
    if (annotationVisitor != null) {
      if (values != null) {
        for (int i = 0, n = values.size(); i < n; i += 2) {
          String name = (String) values.get(i);
          Object value = values.get(i + 1);
          accept(annotationVisitor, name, value);
        }
      }
      annotationVisitor.visitEnd();
    }
  }

  /**
   * Makes the given visitor visit a given annotation value.
   *
   * @param annotationVisitor an annotation visitor. Maybe {@literal null}.
   * @param name the value name.
   * @param value the actual value.
   */
  static void accept(
      final AnnotationVisitor annotationVisitor, final String name, final Object value) {
    if (annotationVisitor != null) {
      if (value instanceof String[]) {
        String[] typeValue = (String[]) value;
        annotationVisitor.visitEnum(name, typeValue[0], typeValue[1]);
      } else if (value instanceof AnnotationNode) {
        AnnotationNode annotationValue = (AnnotationNode) value;
        annotationValue.accept(annotationVisitor.visitAnnotation(name, annotationValue.desc));
      } else if (value instanceof List) {
        AnnotationVisitor arrayAnnotationVisitor = annotationVisitor.visitArray(name);
        if (arrayAnnotationVisitor != null) {
          List<?> arrayValue = (List<?>) value;
          for (int i = 0, n = arrayValue.size(); i < n; ++i) {
            accept(arrayAnnotationVisitor, null, arrayValue.get(i));
          }
          arrayAnnotationVisitor.visitEnd();
        }
      } else {
        annotationVisitor.visit(name, value);
      }
    }
  }
}
