/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 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 alterrs.asm.util;

import alterrs.asm.AnnotationVisitor;
import alterrs.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 static final int INTERNAL_NAME = 0;

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

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

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

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

	/**
	 * Constant used in {@link #appendDescriptor appendDescriptor} for class
	 * signatures, formatted in bytecode notation
	 */
	public static final 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 static final int TYPE_DECLARATION = 6;

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

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