/***
 * 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.util;

import org.mvel2.asm.AnnotationVisitor;
import org.mvel2.asm.Attribute;

/**
 * An abstract trace visitor.
 *
 * @author Eric Bruneton
 */
public abstract class TraceAbstractVisitor extends AbstractVisitor {

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for internal
   * type names in bytecode notation.
   */
  public final static int INTERNAL_NAME = 0;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for field
   * descriptors, formatted in bytecode notation
   */
  public final static int FIELD_DESCRIPTOR = 1;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for field
   * signatures, formatted in bytecode notation
   */
  public final static int FIELD_SIGNATURE = 2;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for method
   * descriptors, formatted in bytecode notation
   */
  public final static int METHOD_DESCRIPTOR = 3;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for method
   * signatures, formatted in bytecode notation
   */
  public final static int METHOD_SIGNATURE = 4;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for class
   * signatures, formatted in bytecode notation
   */
  public final static int CLASS_SIGNATURE = 5;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for field or
   * method return value signatures, formatted in default Java notation
   * (non-bytecode)
   */
  public final static int TYPE_DECLARATION = 6;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for class
   * signatures, formatted in default Java notation (non-bytecode)
   */
  public final static int CLASS_DECLARATION = 7;

  /**
   * Constant used in {@link #appendDescriptor appendDescriptor} for method
   * parameter signatures, formatted in default Java notation (non-bytecode)
   */
  public final static int PARAMETERS_DECLARATION = 8;

  /**
   * Tab for class members.
   */
  protected String tab = "  ";

  /**
   * Prints a disassembled view of the given annotation.
   *
   * @param desc    the class descriptor of the annotation class.
   * @param visible <tt>true</tt> if the annotation is visible at runtime.
   * @return a visitor to visit the annotation values.
   */
  public AnnotationVisitor visitAnnotation(
      final String desc,
      final boolean visible) {
    buf.setLength(0);
    buf.append(tab).append('@');
    appendDescriptor(FIELD_DESCRIPTOR, desc);
    buf.append('(');
    text.add(buf.toString());
    TraceAnnotationVisitor tav = createTraceAnnotationVisitor();
    text.add(tav.getText());
    text.add(visible ? ")\n" : ") // invisible\n");
    return tav;
  }

  /**
   * Prints a disassembled view of the given attribute.
   *
   * @param attr an attribute.
   */
  public void visitAttribute(final Attribute attr) {
    buf.setLength(0);
    buf.append(tab).append("ATTRIBUTE ");
    appendDescriptor(-1, attr.type);

    if (attr instanceof Traceable) {
      ((Traceable) attr).trace(buf, null);
    }
    else {
      buf.append(" : unknown\n");
    }

    text.add(buf.toString());
  }

  /**
   * Does nothing.
   */
  public void visitEnd() {
    // does nothing
  }

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

  protected TraceAnnotationVisitor createTraceAnnotationVisitor() {
    return new TraceAnnotationVisitor();
  }

  /**
   * Appends an internal name, a type descriptor or a type signature to
   * {@link #buf buf}.
   *
   * @param type indicates if desc is an internal name, a field descriptor, a
   *             method descriptor, a class signature, ...
   * @param desc an internal name, type descriptor, or type signature. May be
   *             <tt>null</tt>.
   */
  protected void appendDescriptor(final int type, final String desc) {
    if (type == CLASS_SIGNATURE || type == FIELD_SIGNATURE
        || type == METHOD_SIGNATURE) {
      if (desc != null) {
        buf.append("// signature ").append(desc).append('\n');
      }
    }
    else {
      buf.append(desc);
    }
  }

}
