/***
 * ASM XML Adapter
 * Copyright (c) 2004, Eugene Kuleshov
 * 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.objectweb.asm.xml;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Label;
import org.objectweb.asm.Type;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * A {@link org.xml.sax.ContentHandler ContentHandler} that transforms XML
 * document into Java class file. This class can be feeded by any kind of SAX
 * 2.0 event producers, e.g. XML parser, XSLT or XPath engines, or custom code.
 * 
 * @see org.objectweb.asm.xml.SAXClassAdapter
 * @see org.objectweb.asm.xml.Processor
 * 
 * @author Eugene Kuleshov
 */
public class ASMContentHandler extends DefaultHandler implements Opcodes {
    /**
     * Stack of the intermediate processing contexts.
     */
    private List stack = new ArrayList();

    /**
     * Complete name of the current element.
     */
    private String match = "";

    /**
     * <tt>true</tt> if the maximum stack size and number of local variables
     * must be automatically computed.
     */
    protected boolean computeMax;

    /**
     * Output stream to write result bytecode.
     */
    protected OutputStream os;

    /**
     * Current instance of the {@link ClassWriter ClassWriter} used to write
     * class bytecode.
     */
    protected ClassWriter cw;

    /**
     * Map of the active {@link Label Label} instances for current method.
     */
    protected Map labels;

    private static final String BASE = "class";

    private final RuleSet RULES = new RuleSet();
    {
        RULES.add(BASE, new ClassRule());
        RULES.add(BASE + "/interfaces/interface", new InterfaceRule());
        RULES.add(BASE + "/interfaces", new InterfacesRule());
        RULES.add(BASE + "/outerclass", new OuterClassRule());
        RULES.add(BASE + "/innerclass", new InnerClassRule());
        RULES.add(BASE + "/source", new SourceRule());
        RULES.add(BASE + "/field", new FieldRule());

        RULES.add(BASE + "/method", new MethodRule());
        RULES.add(BASE + "/method/exceptions/exception", new ExceptionRule());
        RULES.add(BASE + "/method/exceptions", new ExceptionsRule());

        RULES.add(BASE + "/method/annotationDefault",
                new AnnotationDefaultRule());

        RULES.add(BASE + "/method/code/*", new OpcodesRule()); // opcodes

        RULES.add(BASE + "/method/code/TABLESWITCH", new TableSwitchRule());
        RULES.add(BASE + "/method/code/TABLESWITCH/label",
                new TableSwitchLabelRule());
        RULES.add(BASE + "/method/code/LOOKUPSWITCH", new LookupSwitchRule());
        RULES.add(BASE + "/method/code/LOOKUPSWITCH/label",
                new LookupSwitchLabelRule());

        RULES.add(BASE + "/method/code/Label", new LabelRule());
        RULES.add(BASE + "/method/code/TryCatch", new TryCatchRule());
        RULES.add(BASE + "/method/code/LineNumber", new LineNumberRule());
        RULES.add(BASE + "/method/code/LocalVar", new LocalVarRule());
        RULES.add(BASE + "/method/code/Max", new MaxRule());

        RULES.add("*/annotation", new AnnotationRule());
        RULES.add("*/parameterAnnotation", new AnnotationParameterRule());
        RULES.add("*/annotationValue", new AnnotationValueRule());
        RULES.add("*/annotationValueAnnotation",
                new AnnotationValueAnnotationRule());
        RULES.add("*/annotationValueEnum", new AnnotationValueEnumRule());
        RULES.add("*/annotationValueArray", new AnnotationValueArrayRule());
    }

    private static interface OpcodeGroup {
        public static final int INSN = 0;
        public static final int INSN_INT = 1;
        public static final int INSN_VAR = 2;
        public static final int INSN_TYPE = 3;
        public static final int INSN_FIELD = 4;
        public static final int INSN_METHOD = 5;
        public static final int INSN_JUMP = 6;
        public static final int INSN_LDC = 7;
        public static final int INSN_IINC = 8;
        public static final int INSN_MULTIANEWARRAY = 9;
    }

    /**
     * Map of the opcode names to opcode and opcode group
     */
    static final Map OPCODES = new HashMap();
    static {
        OPCODES.put("NOP", new Opcode(NOP, OpcodeGroup.INSN));
        OPCODES.put("ACONST_NULL", new Opcode(ACONST_NULL, OpcodeGroup.INSN));
        OPCODES.put("ICONST_M1", new Opcode(ICONST_M1, OpcodeGroup.INSN));
        OPCODES.put("ICONST_0", new Opcode(ICONST_0, OpcodeGroup.INSN));
        OPCODES.put("ICONST_1", new Opcode(ICONST_1, OpcodeGroup.INSN));
        OPCODES.put("ICONST_2", new Opcode(ICONST_2, OpcodeGroup.INSN));
        OPCODES.put("ICONST_3", new Opcode(ICONST_3, OpcodeGroup.INSN));
        OPCODES.put("ICONST_4", new Opcode(ICONST_4, OpcodeGroup.INSN));
        OPCODES.put("ICONST_5", new Opcode(ICONST_5, OpcodeGroup.INSN));
        OPCODES.put("LCONST_0", new Opcode(LCONST_0, OpcodeGroup.INSN));
        OPCODES.put("LCONST_1", new Opcode(LCONST_1, OpcodeGroup.INSN));
        OPCODES.put("FCONST_0", new Opcode(FCONST_0, OpcodeGroup.INSN));
        OPCODES.put("FCONST_1", new Opcode(FCONST_1, OpcodeGroup.INSN));
        OPCODES.put("FCONST_2", new Opcode(FCONST_2, OpcodeGroup.INSN));
        OPCODES.put("DCONST_0", new Opcode(DCONST_0, OpcodeGroup.INSN));
        OPCODES.put("DCONST_1", new Opcode(DCONST_1, OpcodeGroup.INSN));
        OPCODES.put("BIPUSH", new Opcode(BIPUSH, OpcodeGroup.INSN_INT));
        OPCODES.put("SIPUSH", new Opcode(SIPUSH, OpcodeGroup.INSN_INT));
        OPCODES.put("LDC", new Opcode(LDC, OpcodeGroup.INSN_LDC));
        OPCODES.put("ILOAD", new Opcode(ILOAD, OpcodeGroup.INSN_VAR));
        OPCODES.put("LLOAD", new Opcode(LLOAD, OpcodeGroup.INSN_VAR));
        OPCODES.put("FLOAD", new Opcode(FLOAD, OpcodeGroup.INSN_VAR));
        OPCODES.put("DLOAD", new Opcode(DLOAD, OpcodeGroup.INSN_VAR));
        OPCODES.put("ALOAD", new Opcode(ALOAD, OpcodeGroup.INSN_VAR));
        OPCODES.put("IALOAD", new Opcode(IALOAD, OpcodeGroup.INSN));
        OPCODES.put("LALOAD", new Opcode(LALOAD, OpcodeGroup.INSN));
        OPCODES.put("FALOAD", new Opcode(FALOAD, OpcodeGroup.INSN));
        OPCODES.put("DALOAD", new Opcode(DALOAD, OpcodeGroup.INSN));
        OPCODES.put("AALOAD", new Opcode(AALOAD, OpcodeGroup.INSN));
        OPCODES.put("BALOAD", new Opcode(BALOAD, OpcodeGroup.INSN));
        OPCODES.put("CALOAD", new Opcode(CALOAD, OpcodeGroup.INSN));
        OPCODES.put("SALOAD", new Opcode(SALOAD, OpcodeGroup.INSN));
        OPCODES.put("ISTORE", new Opcode(ISTORE, OpcodeGroup.INSN_VAR));
        OPCODES.put("LSTORE", new Opcode(LSTORE, OpcodeGroup.INSN_VAR));
        OPCODES.put("FSTORE", new Opcode(FSTORE, OpcodeGroup.INSN_VAR));
        OPCODES.put("DSTORE", new Opcode(DSTORE, OpcodeGroup.INSN_VAR));
        OPCODES.put("ASTORE", new Opcode(ASTORE, OpcodeGroup.INSN_VAR));
        OPCODES.put("IASTORE", new Opcode(IASTORE, OpcodeGroup.INSN));
        OPCODES.put("LASTORE", new Opcode(LASTORE, OpcodeGroup.INSN));
        OPCODES.put("FASTORE", new Opcode(FASTORE, OpcodeGroup.INSN));
        OPCODES.put("DASTORE", new Opcode(DASTORE, OpcodeGroup.INSN));
        OPCODES.put("AASTORE", new Opcode(AASTORE, OpcodeGroup.INSN));
        OPCODES.put("BASTORE", new Opcode(BASTORE, OpcodeGroup.INSN));
        OPCODES.put("CASTORE", new Opcode(CASTORE, OpcodeGroup.INSN));
        OPCODES.put("SASTORE", new Opcode(SASTORE, OpcodeGroup.INSN));
        OPCODES.put("POP", new Opcode(POP, OpcodeGroup.INSN));
        OPCODES.put("POP2", new Opcode(POP2, OpcodeGroup.INSN));
        OPCODES.put("DUP", new Opcode(DUP, OpcodeGroup.INSN));
        OPCODES.put("DUP_X1", new Opcode(DUP_X1, OpcodeGroup.INSN));
        OPCODES.put("DUP_X2", new Opcode(DUP_X2, OpcodeGroup.INSN));
        OPCODES.put("DUP2", new Opcode(DUP2, OpcodeGroup.INSN));
        OPCODES.put("DUP2_X1", new Opcode(DUP2_X1, OpcodeGroup.INSN));
        OPCODES.put("DUP2_X2", new Opcode(DUP2_X2, OpcodeGroup.INSN));
        OPCODES.put("SWAP", new Opcode(SWAP, OpcodeGroup.INSN));
        OPCODES.put("IADD", new Opcode(IADD, OpcodeGroup.INSN));
        OPCODES.put("LADD", new Opcode(LADD, OpcodeGroup.INSN));
        OPCODES.put("FADD", new Opcode(FADD, OpcodeGroup.INSN));
        OPCODES.put("DADD", new Opcode(DADD, OpcodeGroup.INSN));
        OPCODES.put("ISUB", new Opcode(ISUB, OpcodeGroup.INSN));
        OPCODES.put("LSUB", new Opcode(LSUB, OpcodeGroup.INSN));
        OPCODES.put("FSUB", new Opcode(FSUB, OpcodeGroup.INSN));
        OPCODES.put("DSUB", new Opcode(DSUB, OpcodeGroup.INSN));
        OPCODES.put("IMUL", new Opcode(IMUL, OpcodeGroup.INSN));
        OPCODES.put("LMUL", new Opcode(LMUL, OpcodeGroup.INSN));
        OPCODES.put("FMUL", new Opcode(FMUL, OpcodeGroup.INSN));
        OPCODES.put("DMUL", new Opcode(DMUL, OpcodeGroup.INSN));
        OPCODES.put("IDIV", new Opcode(IDIV, OpcodeGroup.INSN));
        OPCODES.put("LDIV", new Opcode(LDIV, OpcodeGroup.INSN));
        OPCODES.put("FDIV", new Opcode(FDIV, OpcodeGroup.INSN));
        OPCODES.put("DDIV", new Opcode(DDIV, OpcodeGroup.INSN));
        OPCODES.put("IREM", new Opcode(IREM, OpcodeGroup.INSN));
        OPCODES.put("LREM", new Opcode(LREM, OpcodeGroup.INSN));
        OPCODES.put("FREM", new Opcode(FREM, OpcodeGroup.INSN));
        OPCODES.put("DREM", new Opcode(DREM, OpcodeGroup.INSN));
        OPCODES.put("INEG", new Opcode(INEG, OpcodeGroup.INSN));
        OPCODES.put("LNEG", new Opcode(LNEG, OpcodeGroup.INSN));
        OPCODES.put("FNEG", new Opcode(FNEG, OpcodeGroup.INSN));
        OPCODES.put("DNEG", new Opcode(DNEG, OpcodeGroup.INSN));
        OPCODES.put("ISHL", new Opcode(ISHL, OpcodeGroup.INSN));
        OPCODES.put("LSHL", new Opcode(LSHL, OpcodeGroup.INSN));
        OPCODES.put("ISHR", new Opcode(ISHR, OpcodeGroup.INSN));
        OPCODES.put("LSHR", new Opcode(LSHR, OpcodeGroup.INSN));
        OPCODES.put("IUSHR", new Opcode(IUSHR, OpcodeGroup.INSN));
        OPCODES.put("LUSHR", new Opcode(LUSHR, OpcodeGroup.INSN));
        OPCODES.put("IAND", new Opcode(IAND, OpcodeGroup.INSN));
        OPCODES.put("LAND", new Opcode(LAND, OpcodeGroup.INSN));
        OPCODES.put("IOR", new Opcode(IOR, OpcodeGroup.INSN));
        OPCODES.put("LOR", new Opcode(LOR, OpcodeGroup.INSN));
        OPCODES.put("IXOR", new Opcode(IXOR, OpcodeGroup.INSN));
        OPCODES.put("LXOR", new Opcode(LXOR, OpcodeGroup.INSN));
        OPCODES.put("IINC", new Opcode(IINC, OpcodeGroup.INSN_IINC));
        OPCODES.put("I2L", new Opcode(I2L, OpcodeGroup.INSN));
        OPCODES.put("I2F", new Opcode(I2F, OpcodeGroup.INSN));
        OPCODES.put("I2D", new Opcode(I2D, OpcodeGroup.INSN));
        OPCODES.put("L2I", new Opcode(L2I, OpcodeGroup.INSN));
        OPCODES.put("L2F", new Opcode(L2F, OpcodeGroup.INSN));
        OPCODES.put("L2D", new Opcode(L2D, OpcodeGroup.INSN));
        OPCODES.put("F2I", new Opcode(F2I, OpcodeGroup.INSN));
        OPCODES.put("F2L", new Opcode(F2L, OpcodeGroup.INSN));
        OPCODES.put("F2D", new Opcode(F2D, OpcodeGroup.INSN));
        OPCODES.put("D2I", new Opcode(D2I, OpcodeGroup.INSN));
        OPCODES.put("D2L", new Opcode(D2L, OpcodeGroup.INSN));
        OPCODES.put("D2F", new Opcode(D2F, OpcodeGroup.INSN));
        OPCODES.put("I2B", new Opcode(I2B, OpcodeGroup.INSN));
        OPCODES.put("I2C", new Opcode(I2C, OpcodeGroup.INSN));
        OPCODES.put("I2S", new Opcode(I2S, OpcodeGroup.INSN));
        OPCODES.put("LCMP", new Opcode(LCMP, OpcodeGroup.INSN));
        OPCODES.put("FCMPL", new Opcode(FCMPL, OpcodeGroup.INSN));
        OPCODES.put("FCMPG", new Opcode(FCMPG, OpcodeGroup.INSN));
        OPCODES.put("DCMPL", new Opcode(DCMPL, OpcodeGroup.INSN));
        OPCODES.put("DCMPG", new Opcode(DCMPG, OpcodeGroup.INSN));
        OPCODES.put("IFEQ", new Opcode(IFEQ, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFNE", new Opcode(IFNE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFLT", new Opcode(IFLT, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFGE", new Opcode(IFGE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFGT", new Opcode(IFGT, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFLE", new Opcode(IFLE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPEQ", new Opcode(IF_ICMPEQ, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPNE", new Opcode(IF_ICMPNE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPLT", new Opcode(IF_ICMPLT, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPGE", new Opcode(IF_ICMPGE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPGT", new Opcode(IF_ICMPGT, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ICMPLE", new Opcode(IF_ICMPLE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ACMPEQ", new Opcode(IF_ACMPEQ, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IF_ACMPNE", new Opcode(IF_ACMPNE, OpcodeGroup.INSN_JUMP));
        OPCODES.put("GOTO", new Opcode(GOTO, OpcodeGroup.INSN_JUMP));
        OPCODES.put("JSR", new Opcode(JSR, OpcodeGroup.INSN_JUMP));
        OPCODES.put("RET", new Opcode(RET, OpcodeGroup.INSN_VAR));
        // OPCODES.put( "TABLESWITCH", new Opcode( TABLESWITCH,
        // "visiTableSwitchInsn"));
        // OPCODES.put( "LOOKUPSWITCH", new Opcode( LOOKUPSWITCH,
        // "visitLookupSwitch"));
        OPCODES.put("IRETURN", new Opcode(IRETURN, OpcodeGroup.INSN));
        OPCODES.put("LRETURN", new Opcode(LRETURN, OpcodeGroup.INSN));
        OPCODES.put("FRETURN", new Opcode(FRETURN, OpcodeGroup.INSN));
        OPCODES.put("DRETURN", new Opcode(DRETURN, OpcodeGroup.INSN));
        OPCODES.put("ARETURN", new Opcode(ARETURN, OpcodeGroup.INSN));
        OPCODES.put("RETURN", new Opcode(RETURN, OpcodeGroup.INSN));
        OPCODES.put("GETSTATIC", new Opcode(GETSTATIC, OpcodeGroup.INSN_FIELD));
        OPCODES.put("PUTSTATIC", new Opcode(PUTSTATIC, OpcodeGroup.INSN_FIELD));
        OPCODES.put("GETFIELD", new Opcode(GETFIELD, OpcodeGroup.INSN_FIELD));
        OPCODES.put("PUTFIELD", new Opcode(PUTFIELD, OpcodeGroup.INSN_FIELD));
        OPCODES.put("INVOKEVIRTUAL", new Opcode(INVOKEVIRTUAL,
                OpcodeGroup.INSN_METHOD));
        OPCODES.put("INVOKESPECIAL", new Opcode(INVOKESPECIAL,
                OpcodeGroup.INSN_METHOD));
        OPCODES.put("INVOKESTATIC", new Opcode(INVOKESTATIC,
                OpcodeGroup.INSN_METHOD));
        OPCODES.put("INVOKEINTERFACE", new Opcode(INVOKEINTERFACE,
                OpcodeGroup.INSN_METHOD));
        OPCODES.put("NEW", new Opcode(NEW, OpcodeGroup.INSN_TYPE));
        OPCODES.put("NEWARRAY", new Opcode(NEWARRAY, OpcodeGroup.INSN_INT));
        OPCODES.put("ANEWARRAY", new Opcode(ANEWARRAY, OpcodeGroup.INSN_TYPE));
        OPCODES.put("ARRAYLENGTH", new Opcode(ARRAYLENGTH, OpcodeGroup.INSN));
        OPCODES.put("ATHROW", new Opcode(ATHROW, OpcodeGroup.INSN));
        OPCODES.put("CHECKCAST", new Opcode(CHECKCAST, OpcodeGroup.INSN_TYPE));
        OPCODES.put("INSTANCEOF", new Opcode(INSTANCEOF, OpcodeGroup.INSN_TYPE));
        OPCODES.put("MONITORENTER", new Opcode(MONITORENTER, OpcodeGroup.INSN));
        OPCODES.put("MONITOREXIT", new Opcode(MONITOREXIT, OpcodeGroup.INSN));
        OPCODES.put("MULTIANEWARRAY", new Opcode(MULTIANEWARRAY,
                OpcodeGroup.INSN_MULTIANEWARRAY));
        OPCODES.put("IFNULL", new Opcode(IFNULL, OpcodeGroup.INSN_JUMP));
        OPCODES.put("IFNONNULL", new Opcode(IFNONNULL, OpcodeGroup.INSN_JUMP));
    }

    /**
     * Constructs a new {@link ASMContentHandler ASMContentHandler} object.
     * 
     * @param os output stream to write generated class.
     * @param computeMax <tt>true</tt> if the maximum stack size and the
     *        maximum number of local variables must be automatically computed.
     *        This value is passed to {@link ClassWriter ClassWriter} instance.
     */
    public ASMContentHandler(OutputStream os, boolean computeMax) {
        this.os = os;
        this.computeMax = computeMax;
    }

    /**
     * Returns the bytecode of the class that was build with underneath class
     * writer.
     * 
     * @return the bytecode of the class that was build with underneath class
     *         writer or null if there are no classwriter created.
     */
    public byte[] toByteArray() {
        return cw == null ? null : cw.toByteArray();
    }

    /**
     * Process notification of the start of an XML element being reached.
     * 
     * @param ns - The Namespace URI, or the empty string if the element has no
     *        Namespace URI or if Namespace processing is not being performed.
     * @param localName - The local name (without prefix), or the empty string
     *        if Namespace processing is not being performed.
     * @param qName - The qualified name (with prefix), or the empty string if
     *        qualified names are not available.
     * @param list - The attributes attached to the element. If there are no
     *        attributes, it shall be an empty Attributes object.
     * @exception SAXException if a parsing error is to be reported
     */
    public final void startElement(
        String ns,
        String localName,
        String qName,
        Attributes list) throws SAXException
    {
        // the actual element name is either in localName or qName, depending
        // on whether the parser is namespace aware
        String name = localName;
        if (name == null || name.length() < 1) {
            name = qName;
        }

        // Compute the current matching rule
        StringBuffer sb = new StringBuffer(match);
        if (match.length() > 0) {
            sb.append('/');
        }
        sb.append(name);
        match = sb.toString();

        // Fire "begin" events for all relevant rules
        Rule r = (Rule) RULES.match(match);
        if (r != null)
            r.begin(name, list);
    }

    /**
     * Process notification of the end of an XML element being reached.
     * 
     * @param ns - The Namespace URI, or the empty string if the element has no
     *        Namespace URI or if Namespace processing is not being performed.
     * @param localName - The local name (without prefix), or the empty string
     *        if Namespace processing is not being performed.
     * @param qName - The qualified XML 1.0 name (with prefix), or the empty
     *        string if qualified names are not available.
     * 
     * @exception SAXException if a parsing error is to be reported
     */
    public final void endElement(String ns, String localName, String qName)
            throws SAXException
    {
        // the actual element name is either in localName or qName, depending
        // on whether the parser is namespace aware
        String name = localName;
        if (name == null || name.length() < 1) {
            name = qName;
        }

        // Fire "end" events for all relevant rules in reverse order
        Rule r = (Rule) RULES.match(match);
        if (r != null)
            r.end(name);

        // Recover the previous match expression
        int slash = match.lastIndexOf('/');
        if (slash >= 0) {
            match = match.substring(0, slash);
        } else {
            match = "";
        }
    }

    /**
     * Process notification of the end of a document and write generated
     * bytecode into output stream.
     * 
     * @exception SAXException if parsing or writing error is to be reported.
     */
    public final void endDocument() throws SAXException {
        try {
            os.write(cw.toByteArray());
        } catch (IOException ex) {
            throw new SAXException(ex.toString(), ex);
        }
    }

    /**
     * Return the top object on the stack without removing it. If there are no
     * objects on the stack, return <code>null</code>.
     * 
     * @return the top object on the stack without removing it.
     */
    final Object peek() {
        return stack.size() == 0 ? null : stack.get(stack.size() - 1);
    }

    /**
     * Return the n'th object down the stack, where 0 is the top element and
     * [getCount()-1] is the bottom element. If the specified index is out of
     * range, return <code>null</code>.
     * 
     * @param n Index of the desired element, where 0 is the top of the stack, 1
     *        is the next element down, and so on.
     * @return the n'th object down the stack.
     */
    final Object peek(int n) {
        return stack.size() < (n + 1) ? null : stack.get(n);
    }

    /**
     * Pop the top object off of the stack, and return it. If there are no
     * objects on the stack, return <code>null</code>.
     * 
     * @return the top object off of the stack.
     */
    final Object pop() {
        return stack.size() == 0 ? null : stack.remove(stack.size() - 1);
    }

    /**
     * Push a new object onto the top of the object stack.
     * 
     * @param object The new object
     */
    final void push(Object object) {
        stack.add(object);
    }

    private static final class RuleSet {
        private Map rules = new HashMap();

        private List lpatterns = new ArrayList();

        private List rpatterns = new ArrayList();

        public void add(String path, Object rule) {
            String pattern = path;
            if (path.startsWith("*/")) {
                pattern = path.substring(1);
                lpatterns.add(pattern);
            } else if (path.endsWith("/*")) {
                pattern = path.substring(0, path.length() - 1);
                rpatterns.add(pattern);
            }
            rules.put(pattern, rule);
        }

        public Object match(String path) {
            if (rules.containsKey(path)) {
                return rules.get(path);
            }

            int n = path.lastIndexOf('/');
            for (Iterator it = lpatterns.iterator(); it.hasNext();) {
                String pattern = (String) it.next();
                if (path.substring(n).endsWith(pattern)) {
                    return rules.get(pattern);
                }
            }

            for (Iterator it = rpatterns.iterator(); it.hasNext();) {
                String pattern = (String) it.next();
                if (path.startsWith(pattern)) {
                    return rules.get(pattern);
                }
            }

            return null;
        }

    }

    /**
     * Rule
     */
    protected abstract class Rule {

        public void begin(String name, Attributes attrs) {
        }

        public void end(String name) {
        }

        protected final Object getValue(String desc, String val) {
            Object value = null;
            if (val != null) {
                if (desc.equals("Ljava/lang/String;")) {
                    value = decode(val);
                } else if ("Ljava/lang/Integer;".equals(desc)
                        || "I".equals(desc) || "S".equals(desc)
                        || "B".equals(desc) || "C".equals(desc)
                        || desc.equals("Z"))
                {
                    value = new Integer(val);

                } else if ("Ljava/lang/Short;".equals(desc)) {
                    value = new Short(val);

                } else if ("Ljava/lang/Byte;".equals(desc)) {
                    value = new Byte(val);

                } else if ("Ljava/lang/Character;".equals(desc)) {
                    value = new Character(decode(val).charAt(0));

                } else if ("Ljava/lang/Boolean;".equals(desc)) {
                    value = Boolean.valueOf(val);

                    // } else if ("Ljava/lang/Integer;".equals(desc)
                    // || desc.equals("I"))
                    // {
                    // value = new Integer(val);
                    // } else if ("Ljava/lang/Character;".equals(desc)
                    // || desc.equals("C"))
                    // {
                    // value = new Character(decode(val).charAt(0));
                    // } else if ("Ljava/lang/Short;".equals(desc) ||
                    // desc.equals("S"))
                    // {
                    // value = Short.valueOf(val);
                    // } else if ("Ljava/lang/Byte;".equals(desc) ||
                    // desc.equals("B"))
                    // {
                    // value = Byte.valueOf(val);

                } else if ("Ljava/lang/Long;".equals(desc) || desc.equals("J"))
                {
                    value = new Long(val);
                } else if ("Ljava/lang/Float;".equals(desc) || desc.equals("F"))
                {
                    value = new Float(val);
                } else if ("Ljava/lang/Double;".equals(desc)
                        || desc.equals("D"))
                {
                    value = new Double(val);
                } else if (Type.getDescriptor(Type.class).equals(desc)) {
                    value = Type.getType(val);

                    // } else if ("[I".equals(desc)) {
                    // value = new int[0]; // TODO
                    // } else if ("[C".equals(desc)) {
                    // value = new char[0]; // TODO
                    // } else if ("[Z".equals(desc)) {
                    // value = new boolean[0]; // TODO
                    // } else if ("[S".equals(desc)) {
                    // value = new short[0]; // TODO
                    // } else if ("[B".equals(desc)) {
                    // value = new byte[0]; // TODO
                    // } else if ("[J".equals(desc)) {
                    // value = new long[0]; // TODO
                    // } else if ("[F".equals(desc)) {
                    // value = new float[0]; // TODO
                    // } else if ("[D".equals(desc)) {
                    // value = new double[0]; // TODO

                } else {
                    throw new RuntimeException("Invalid value:" + val
                            + " desc:" + desc + " ctx:" + this);
                }
            }
            return value;
        }

        private final String decode(String val) {
            StringBuffer sb = new StringBuffer(val.length());
            try {
                int n = 0;
                while (n < val.length()) {
                    char c = val.charAt(n);
                    if (c == '\\') {
                        n++;
                        c = val.charAt(n);
                        if (c == '\\') {
                            sb.append('\\');
                        } else {
                            n++; // skip 'u'
                            sb.append((char) Integer.parseInt(val.substring(n,
                                    n + 4), 16));
                            n += 3;
                        }
                    } else {
                        sb.append(c);
                    }
                    n++;
                }

            } catch (RuntimeException ex) {
                System.err.println(val + "\n" + ex.toString());
                ex.printStackTrace();
                throw ex;
            }
            return sb.toString();
        }

        protected final Label getLabel(Object label) {
            Label lbl = (Label) labels.get(label);
            if (lbl == null) {
                lbl = new Label();
                labels.put(label, lbl);
            }
            return lbl;
        }

        // TODO verify move to stack
        protected final MethodVisitor getCodeVisitor() {
            return (MethodVisitor) peek();
        }
        
        protected final int getAccess(String s) {
            int access = 0;
            if (s.indexOf("public") != -1)
                access |= Opcodes.ACC_PUBLIC;
            if (s.indexOf("private") != -1)
                access |= Opcodes.ACC_PRIVATE;
            if (s.indexOf("protected") != -1)
                access |= Opcodes.ACC_PROTECTED;
            if (s.indexOf("static") != -1)
                access |= Opcodes.ACC_STATIC;
            if (s.indexOf("final") != -1)
                access |= Opcodes.ACC_FINAL;
            if (s.indexOf("super") != -1)
                access |= Opcodes.ACC_SUPER;
            if (s.indexOf("synchronized") != -1)
                access |= Opcodes.ACC_SYNCHRONIZED;
            if (s.indexOf("volatile") != -1)
                access |= Opcodes.ACC_VOLATILE;
            if (s.indexOf("bridge") != -1)
                access |= Opcodes.ACC_BRIDGE;
            if (s.indexOf("varargs") != -1)
                access |= Opcodes.ACC_VARARGS;
            if (s.indexOf("transient") != -1)
                access |= Opcodes.ACC_TRANSIENT;
            if (s.indexOf("native") != -1)
                access |= Opcodes.ACC_NATIVE;
            if (s.indexOf("interface") != -1)
                access |= Opcodes.ACC_INTERFACE;
            if (s.indexOf("abstract") != -1)
                access |= Opcodes.ACC_ABSTRACT;
            if (s.indexOf("strict") != -1)
                access |= Opcodes.ACC_STRICT;
            if (s.indexOf("synthetic") != -1)
                access |= Opcodes.ACC_SYNTHETIC;
            if (s.indexOf("annotation") != -1)
                access |= Opcodes.ACC_ANNOTATION;
            if (s.indexOf("enum") != -1)
                access |= Opcodes.ACC_ENUM;
            if (s.indexOf("deprecated") != -1)
                access |= Opcodes.ACC_DEPRECATED;
            return access;
        }

    }

    /**
     * ClassRule
     */
    private final class ClassRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            int major = Integer.parseInt(attrs.getValue("major"));
            int minor = Integer.parseInt(attrs.getValue("minor"));
            cw = new ClassWriter(computeMax);
            Map vals = new HashMap();
            vals.put("version", new Integer(minor << 16 | major));
            vals.put("access", attrs.getValue("access"));
            vals.put("name", attrs.getValue("name"));
            vals.put("parent", attrs.getValue("parent"));
            vals.put("source", attrs.getValue("source"));
            vals.put("signature", attrs.getValue("signature"));
            vals.put("interfaces", new ArrayList());
            push(vals);
            // values will be extracted in InterfacesRule.end();
        }

    }

    private final class SourceRule extends Rule {

        public void begin(String name, Attributes attrs) {
            String file = attrs.getValue("file");
            String debug = attrs.getValue("debug");
            cw.visitSource(file, debug);
        }

    }

    /**
     * InterfaceRule
     */
    private final class InterfaceRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            ((List) ((Map) peek()).get("interfaces")).add(attrs.getValue("name"));
        }

    }

    /**
     * InterfacesRule
     */
    private final class InterfacesRule extends Rule {

        public final void end(String element) {
            Map vals = (Map) pop();
            int version = ((Integer) vals.get("version")).intValue();
            int access = getAccess((String) vals.get("access"));
            String name = (String) vals.get("name");
            String signature = (String) vals.get("signature");
            String parent = (String) vals.get("parent");
            List infs = (List) vals.get("interfaces");
            String[] interfaces = (String[]) infs.toArray(new String[infs.size()]);
            cw.visit(version, access, name, signature, parent, interfaces);
            push(cw);
        }

    }

    /**
     * OuterClassRule
     */
    private final class OuterClassRule extends Rule {

        public final void begin(String element, Attributes attrs) {
            String owner = attrs.getValue("owner");
            String name = attrs.getValue("name");
            String desc = attrs.getValue("desc");
            cw.visitOuterClass(owner, name, desc);
        }

    }

    /**
     * InnerClassRule
     */
    private final class InnerClassRule extends Rule {

        public final void begin(String element, Attributes attrs) {
            int access = getAccess(attrs.getValue("access"));
            String name = attrs.getValue("name");
            String outerName = attrs.getValue("outerName");
            String innerName = attrs.getValue("innerName");
            cw.visitInnerClass(name, outerName, innerName, access);
        }

    }

    /**
     * FieldRule
     */
    private final class FieldRule extends Rule {

        public final void begin(String element, Attributes attrs) {
            int access = getAccess(attrs.getValue("access"));
            String name = attrs.getValue("name");
            String signature = attrs.getValue("signature");
            String desc = attrs.getValue("desc");
            Object value = getValue(desc, attrs.getValue("value"));
            push(cw.visitField(access, name, desc, signature, value));
        }

        public void end(String name) {
            ((FieldVisitor) pop()).visitEnd();
        }

    }

    /**
     * MethodRule
     */
    private final class MethodRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            labels = new HashMap();
            Map vals = new HashMap();
            vals.put("access", attrs.getValue("access"));
            vals.put("name", attrs.getValue("name"));
            vals.put("desc", attrs.getValue("desc"));
            vals.put("signature", attrs.getValue("signature"));
            vals.put("exceptions", new ArrayList());
            push(vals);
            // values will be extracted in ExceptionsRule.end();
        }

        public final void end(String name) {
            ((MethodVisitor) pop()).visitEnd();
            labels = null;
        }

    }

    /**
     * ExceptionRule
     */
    private final class ExceptionRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            ((List) ((Map) peek()).get("exceptions")).add(attrs.getValue("name"));
        }

    }

    /**
     * ExceptionsRule
     */
    private final class ExceptionsRule extends Rule {

        public final void end(String element) {
            Map vals = (Map) pop();
            int access = getAccess((String) vals.get("access"));
            String name = (String) vals.get("name");
            String desc = (String) vals.get("desc");
            String signature = (String) vals.get("signature");
            List excs = (List) vals.get("exceptions");
            String[] exceptions = (String[]) excs.toArray(new String[excs.size()]);

            push(cw.visitMethod(access, name, desc, signature, exceptions));
        }

    }

    /**
     * TableSwitchRule
     */
    private class TableSwitchRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            Map vals = new HashMap();
            vals.put("min", attrs.getValue("min"));
            vals.put("max", attrs.getValue("max"));
            vals.put("dflt", attrs.getValue("dflt"));
            vals.put("labels", new ArrayList());
            push(vals);
        }

        public final void end(String name) {
            Map vals = (Map) pop();
            int min = Integer.parseInt((String) vals.get("min"));
            int max = Integer.parseInt((String) vals.get("max"));
            Label dflt = getLabel(vals.get("dflt"));
            List lbls = (List) vals.get("labels");
            Label[] labels = (Label[]) lbls.toArray(new Label[lbls.size()]);
            getCodeVisitor().visitTableSwitchInsn(min, max, dflt, labels);
        }

    }

    /**
     * TableSwitchLabelRule
     */
    private final class TableSwitchLabelRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            ((List) ((Map) peek()).get("labels")).add(getLabel(attrs.getValue("name")));
        }

    }

    /**
     * LookupSwitchRule
     */
    private final class LookupSwitchRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            Map vals = new HashMap();
            vals.put("dflt", attrs.getValue("dflt"));
            vals.put("labels", new ArrayList());
            vals.put("keys", new ArrayList());
            push(vals);
        }

        public final void end(String name) {
            Map vals = (Map) pop();
            Label dflt = getLabel(vals.get("dflt"));
            List keyList = (List) vals.get("keys");
            List lbls = (List) vals.get("labels");
            Label[] labels = (Label[]) lbls.toArray(new Label[lbls.size()]);
            int[] keys = new int[keyList.size()];
            for (int i = 0; i < keys.length; i++) {
                keys[i] = Integer.parseInt((String) keyList.get(i));
            }
            getCodeVisitor().visitLookupSwitchInsn(dflt, keys, labels);
        }

    }

    /**
     * LookupSwitchLabelRule
     */
    private final class LookupSwitchLabelRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            Map vals = (Map) peek();
            ((List) vals.get("labels")).add(getLabel(attrs.getValue("name")));
            ((List) vals.get("keys")).add(attrs.getValue("key"));
        }

    }

    /**
     * LabelRule
     */
    private final class LabelRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            getCodeVisitor().visitLabel(getLabel(attrs.getValue("name")));
        }

    }

    /**
     * TryCatchRule
     */
    private final class TryCatchRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            Label start = getLabel(attrs.getValue("start"));
            Label end = getLabel(attrs.getValue("end"));
            Label handler = getLabel(attrs.getValue("handler"));
            String type = attrs.getValue("type");
            getCodeVisitor().visitTryCatchBlock(start, end, handler, type);
        }

    }

    /**
     * LineNumberRule
     */
    private final class LineNumberRule extends Rule {

        public final void begin(String name, Attributes attrs) {
            int line = Integer.parseInt(attrs.getValue("line"));
            Label start = getLabel(attrs.getValue("start"));
            getCodeVisitor().visitLineNumber(line, start);
        }

    }

    /**
     * LocalVarRule
     */
    private final class LocalVarRule extends Rule {

        public final void begin(String element, Attributes attrs) {
            String name = attrs.getValue("name");
            String desc = attrs.getValue("desc");
            String signature = attrs.getValue("signature");
            Label start = getLabel(attrs.getValue("start"));
            Label end = getLabel(attrs.getValue("end"));
            int var = Integer.parseInt(attrs.getValue("var"));
            getCodeVisitor().visitLocalVariable(name,
                    desc,
                    signature,
                    start,
                    end,
                    var);
        }

    }

    /**
     * OpcodesRule
     */
    private final class OpcodesRule extends Rule {

        // public boolean match( String match, String element) {
        // return match.startsWith( path) && OPCODES.containsKey( element);
        // }

        public final void begin(String element, Attributes attrs) {
            Opcode o = ((Opcode) OPCODES.get(element));
            if (o == null)
                return;

            switch (o.type) {
                case OpcodeGroup.INSN:
                    getCodeVisitor().visitInsn(o.opcode);
                    break;

                case OpcodeGroup.INSN_FIELD:
                    getCodeVisitor().visitFieldInsn(o.opcode,
                            attrs.getValue("owner"),
                            attrs.getValue("name"),
                            attrs.getValue("desc"));
                    break;

                case OpcodeGroup.INSN_INT:
                    getCodeVisitor().visitIntInsn(o.opcode,
                            Integer.parseInt(attrs.getValue("value")));
                    break;

                case OpcodeGroup.INSN_JUMP:
                    getCodeVisitor().visitJumpInsn(o.opcode,
                            getLabel(attrs.getValue("label")));
                    break;

                case OpcodeGroup.INSN_METHOD:
                    getCodeVisitor().visitMethodInsn(o.opcode,
                            attrs.getValue("owner"),
                            attrs.getValue("name"),
                            attrs.getValue("desc"));
                    break;

                case OpcodeGroup.INSN_TYPE:
                    getCodeVisitor().visitTypeInsn(o.opcode,
                            attrs.getValue("desc"));
                    break;

                case OpcodeGroup.INSN_VAR:
                    getCodeVisitor().visitVarInsn(o.opcode,
                            Integer.parseInt(attrs.getValue("var")));
                    break;

                case OpcodeGroup.INSN_IINC:
                    getCodeVisitor().visitIincInsn(Integer.parseInt(attrs.getValue("var")),
                            Integer.parseInt(attrs.getValue("inc")));
                    break;

                case OpcodeGroup.INSN_LDC:
                    getCodeVisitor().visitLdcInsn(getValue(attrs.getValue("desc"),
                            attrs.getValue("cst")));
                    break;

                case OpcodeGroup.INSN_MULTIANEWARRAY:
                    getCodeVisitor().visitMultiANewArrayInsn(attrs.getValue("desc"),
                            Integer.parseInt(attrs.getValue("dims")));
                    break;

                default:
                    throw new RuntimeException("Invalid element: " + element
                            + " at " + match);

            }
        }
    }

    /**
     * MaxRule
     */
    private final class MaxRule extends Rule {

        public final void begin(String element, Attributes attrs) {
            int maxStack = Integer.parseInt(attrs.getValue("maxStack"));
            int maxLocals = Integer.parseInt(attrs.getValue("maxLocals"));
            getCodeVisitor().visitMaxs(maxStack, maxLocals);
        }

    }

    private final class AnnotationRule extends Rule {

        public void begin(String name, Attributes attrs) {
            String desc = attrs.getValue("desc");
            boolean visible = Boolean.valueOf(attrs.getValue("visible"))
                    .booleanValue();

            Object v = peek();
            if (v instanceof ClassVisitor) {
                push(((ClassVisitor) v).visitAnnotation(desc, visible));
            } else if (v instanceof FieldVisitor) {
                push(((FieldVisitor) v).visitAnnotation(desc, visible));
            } else if (v instanceof MethodVisitor) {
                push(((MethodVisitor) v).visitAnnotation(desc, visible));
            }
        }

        public void end(String name) {
            ((AnnotationVisitor) pop()).visitEnd();
        }

    }

    private final class AnnotationParameterRule extends Rule {

        public void begin(String name, Attributes attrs) {
            int parameter = Integer.parseInt(attrs.getValue("parameter"));
            String desc = attrs.getValue("desc");
            boolean visible = Boolean.valueOf(attrs.getValue("visible"))
                    .booleanValue();

            push(((MethodVisitor) peek()).visitParameterAnnotation(parameter,
                    desc,
                    visible));
        }

        public void end(String name) {
            ((AnnotationVisitor) pop()).visitEnd();
        }

    }

    private final class AnnotationValueRule extends Rule {

        public void begin(String nm, Attributes attrs) {
            String name = attrs.getValue("name");
            String desc = attrs.getValue("desc");
            String value = attrs.getValue("value");
            ((AnnotationVisitor) peek()).visit(name, getValue(desc, value));
        }

    }

    private final class AnnotationValueEnumRule extends Rule {

        public void begin(String nm, Attributes attrs) {
            String name = attrs.getValue("name");
            String desc = attrs.getValue("desc");
            String value = attrs.getValue("value");
            ((AnnotationVisitor) peek()).visitEnum(name, desc, value);
        }

    }

    private final class AnnotationValueAnnotationRule extends Rule {

        public void begin(String nm, Attributes attrs) {
            String name = attrs.getValue("name");
            String desc = attrs.getValue("desc");
            push(((AnnotationVisitor) peek()).visitAnnotation(name, desc));
        }

        public void end(String name) {
            ((AnnotationVisitor) pop()).visitEnd();
        }

    }

    private final class AnnotationValueArrayRule extends Rule {

        public void begin(String nm, Attributes attrs) {
            String name = attrs.getValue("name");
            push(((AnnotationVisitor) peek()).visitArray(name));
        }

        public void end(String name) {
            ((AnnotationVisitor) pop()).visitEnd();
        }

    }

    private final class AnnotationDefaultRule extends Rule {

        public void begin(String nm, Attributes attrs) {
            push(((MethodVisitor) peek()).visitAnnotationDefault());
        }

        public void end(String name) {
            ((AnnotationVisitor) pop()).visitEnd();
        }

    }

    /**
     * Opcode
     */
    private final static class Opcode {
        public int opcode;

        public int type;

        public Opcode(int opcode, int type) {
            this.opcode = opcode;
            this.type = type;
        }

    }

}