/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 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
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * 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.mvel2.asm;

/**
 * An {@link AnnotationVisitor} that generates annotations in bytecode form.
 *
 * @author Eric Bruneton
 * @author Eugene Kuleshov
 */
final class AnnotationWriter implements AnnotationVisitor {

  /**
   * The class writer to which this annotation must be added.
   */
  private final ClassWriter cw;

  /**
   * The number of values in this annotation.
   */
  private int size;

  /**
   * <tt>true<tt> if values are named, <tt>false</tt> otherwise. Annotation
   * writers used for annotation default and annotation arrays use unnamed
   * values.
   */
  private final boolean named;

  /**
   * The annotation values in bytecode form. This byte vector only contains
   * the values themselves, i.e. the number of values must be stored as a
   * unsigned short just before these bytes.
   */
  private final ByteVector bv;

  /**
   * The byte vector to be used to store the number of values of this
   * annotation. See {@link #bv}.
   */
  private final ByteVector parent;

  /**
   * Where the number of values of this annotation must be stored in
   * {@link #parent}.
   */
  private final int offset;

  /**
   * Next annotation writer. This field is used to store annotation lists.
   */
  AnnotationWriter next;

  /**
   * Previous annotation writer. This field is used to store annotation lists.
   */
  AnnotationWriter prev;

  // ------------------------------------------------------------------------
  // Constructor
  // ------------------------------------------------------------------------

  /**
   * Constructs a new {@link AnnotationWriter}.
   *
   * @param cw     the class writer to which this annotation must be added.
   * @param named  <tt>true<tt> if values are named, <tt>false</tt> otherwise.
   * @param bv     where the annotation values must be stored.
   * @param parent where the number of annotation values must be stored.
   * @param offset where in <tt>parent</tt> the number of annotation values must
   *               be stored.
   */
  AnnotationWriter(
      final ClassWriter cw,
      final boolean named,
      final ByteVector bv,
      final ByteVector parent,
      final int offset) {
    this.cw = cw;
    this.named = named;
    this.bv = bv;
    this.parent = parent;
    this.offset = offset;
  }

  // ------------------------------------------------------------------------
  // Implementation of the AnnotationVisitor interface
  // ------------------------------------------------------------------------

  public void visit(final String name, final Object value) {
    ++size;
    if (named) {
      bv.putShort(cw.newUTF8(name));
    }
    if (value instanceof String) {
      bv.put12('s', cw.newUTF8((String) value));
    }
    else if (value instanceof Byte) {
      bv.put12('B', cw.newInteger(((Byte) value).byteValue()).index);
    }
    else if (value instanceof Boolean) {
      int v = ((Boolean) value).booleanValue() ? 1 : 0;
      bv.put12('Z', cw.newInteger(v).index);
    }
    else if (value instanceof Character) {
      bv.put12('C', cw.newInteger(((Character) value).charValue()).index);
    }
    else if (value instanceof Short) {
      bv.put12('S', cw.newInteger(((Short) value).shortValue()).index);
    }
    else if (value instanceof Type) {
      bv.put12('c', cw.newUTF8(((Type) value).getDescriptor()));
    }
    else if (value instanceof byte[]) {
      byte[] v = (byte[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('B', cw.newInteger(v[i]).index);
      }
    }
    else if (value instanceof boolean[]) {
      boolean[] v = (boolean[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('Z', cw.newInteger(v[i] ? 1 : 0).index);
      }
    }
    else if (value instanceof short[]) {
      short[] v = (short[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('S', cw.newInteger(v[i]).index);
      }
    }
    else if (value instanceof char[]) {
      char[] v = (char[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('C', cw.newInteger(v[i]).index);
      }
    }
    else if (value instanceof int[]) {
      int[] v = (int[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('I', cw.newInteger(v[i]).index);
      }
    }
    else if (value instanceof long[]) {
      long[] v = (long[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('J', cw.newLong(v[i]).index);
      }
    }
    else if (value instanceof float[]) {
      float[] v = (float[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('F', cw.newFloat(v[i]).index);
      }
    }
    else if (value instanceof double[]) {
      double[] v = (double[]) value;
      bv.put12('[', v.length);
      for (int i = 0; i < v.length; i++) {
        bv.put12('D', cw.newDouble(v[i]).index);
      }
    }
    else {
      Item i = cw.newConstItem(value);
      bv.put12(".s.IFJDCS".charAt(i.type), i.index);
    }
  }

  public void visitEnum(
      final String name,
      final String desc,
      final String value) {
    ++size;
    if (named) {
      bv.putShort(cw.newUTF8(name));
    }
    bv.put12('e', cw.newUTF8(desc)).putShort(cw.newUTF8(value));
  }

  public AnnotationVisitor visitAnnotation(
      final String name,
      final String desc) {
    ++size;
    if (named) {
      bv.putShort(cw.newUTF8(name));
    }
    // write tag and type, and reserve space for values count
    bv.put12('@', cw.newUTF8(desc)).putShort(0);
    return new AnnotationWriter(cw, true, bv, bv, bv.length - 2);
  }

  public AnnotationVisitor visitArray(final String name) {
    ++size;
    if (named) {
      bv.putShort(cw.newUTF8(name));
    }
    // write tag, and reserve space for array size
    bv.put12('[', 0);
    return new AnnotationWriter(cw, false, bv, bv, bv.length - 2);
  }

  public void visitEnd() {
    if (parent != null) {
      byte[] data = parent.data;
      data[offset] = (byte) (size >>> 8);
      data[offset + 1] = (byte) size;
    }
  }

  // ------------------------------------------------------------------------
  // Utility methods
  // ------------------------------------------------------------------------

  /**
   * Returns the size of this annotation writer list.
   *
   * @return the size of this annotation writer list.
   */
  int getSize() {
    int size = 0;
    AnnotationWriter aw = this;
    while (aw != null) {
      size += aw.bv.length;
      aw = aw.next;
    }
    return size;
  }

  /**
   * Puts the annotations of this annotation writer list into the given byte
   * vector.
   *
   * @param out where the annotations must be put.
   */
  void put(final ByteVector out) {
    int n = 0;
    int size = 2;
    AnnotationWriter aw = this;
    AnnotationWriter last = null;
    while (aw != null) {
      ++n;
      size += aw.bv.length;
      aw.visitEnd(); // in case user forgot to call visitEnd
      aw.prev = last;
      last = aw;
      aw = aw.next;
    }
    out.putInt(size);
    out.putShort(n);
    aw = last;
    while (aw != null) {
      out.putByteArray(aw.bv.data, 0, aw.bv.length);
      aw = aw.prev;
    }
  }

  /**
   * Puts the given annotation lists into the given byte vector.
   *
   * @param panns an array of annotation writer lists.
   * @param out   where the annotations must be put.
   */
  static void put(final AnnotationWriter[] panns, final ByteVector out) {
    int size = 1 + 2 * panns.length;
    for (int i = 0; i < panns.length; ++i) {
      size += panns[i] == null ? 0 : panns[i].getSize();
    }
    out.putInt(size).putByte(panns.length);
    for (int i = 0; i < panns.length; ++i) {
      AnnotationWriter aw = panns[i];
      AnnotationWriter last = null;
      int n = 0;
      while (aw != null) {
        ++n;
        aw.visitEnd(); // in case user forgot to call visitEnd
        aw.prev = last;
        last = aw;
        aw = aw.next;
      }
      out.putShort(n);
      aw = last;
      while (aw != null) {
        out.putByteArray(aw.bv.data, 0, aw.bv.length);
        aw = aw.prev;
      }
    }
  }
}
