/***
 * 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 org.eclipse.persistence.internal.libraries.asm.util;

import org.eclipse.persistence.internal.libraries.asm.AnnotationVisitor;
import org.eclipse.persistence.internal.libraries.asm.Label;
import org.eclipse.persistence.internal.libraries.asm.MethodVisitor;
import org.eclipse.persistence.internal.libraries.asm.Opcodes;

import java.util.HashMap;

/**
 * A {@link MethodVisitor} that prints the ASM code that generates the methods
 * it visits.
 * 
 * @author Eric Bruneton
 * @author Eugene Kuleshov
 */
public class ASMifierMethodVisitor extends ASMifierAbstractVisitor implements
        MethodVisitor
{

    /**
     * Constructs a new {@link ASMifierMethodVisitor} object.
     */
    public ASMifierMethodVisitor() {
        super("mv");
        this.labelNames = new HashMap();
    }

    public AnnotationVisitor visitAnnotationDefault() {
        buf.setLength(0);
        buf.append("{\n").append("av0 = mv.visitAnnotationDefault();\n");
        text.add(buf.toString());
        ASMifierAnnotationVisitor av = new ASMifierAnnotationVisitor(0);
        text.add(av.getText());
        text.add("}\n");
        return av;
    }

    public AnnotationVisitor visitParameterAnnotation(
        final int parameter,
        final String desc,
        final boolean visible)
    {
        buf.setLength(0);
        buf.append("{\n")
                .append("av0 = mv.visitParameterAnnotation(")
                .append(parameter)
                .append(", ");
        appendConstant(desc);
        buf.append(", ").append(visible).append(");\n");
        text.add(buf.toString());
        ASMifierAnnotationVisitor av = new ASMifierAnnotationVisitor(0);
        text.add(av.getText());
        text.add("}\n");
        return av;
    }

    public void visitCode() {
        text.add("mv.visitCode();\n");
    }

    public void visitFrame(
        final int type,
        final int nLocal,
        final Object[] local,
        final int nStack,
        final Object[] stack)
    {
        buf.setLength(0);
        switch (type) {
            case Opcodes.F_NEW:
            case Opcodes.F_FULL:
                declareFrameTypes(nLocal, local);
                declareFrameTypes(nStack, stack);
                if (type == Opcodes.F_NEW) {
                    buf.append("mv.visitFrame(Opcodes.F_NEW, ");
                } else {
                    buf.append("mv.visitFrame(Opcodes.F_FULL, ");
                }
                buf.append(nLocal).append(", new Object[] {");
                appendFrameTypes(nLocal, local);
                buf.append("}, ").append(nStack).append(", new Object[] {");
                appendFrameTypes(nStack, stack);
                buf.append('}');
                break;
            case Opcodes.F_APPEND:
                declareFrameTypes(nLocal, local);
                buf.append("mv.visitFrame(Opcodes.F_APPEND,")
                        .append(nLocal)
                        .append(", new Object[] {");
                appendFrameTypes(nLocal, local);
                buf.append("}, 0, null");
                break;
            case Opcodes.F_CHOP:
                buf.append("mv.visitFrame(Opcodes.F_CHOP,")
                        .append(nLocal)
                        .append(", null, 0, null");
                break;
            case Opcodes.F_SAME:
                buf.append("mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null");
                break;
            case Opcodes.F_SAME1:
                declareFrameTypes(1, stack);
                buf.append("mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] {");
                appendFrameTypes(1, stack);
                buf.append('}');
                break;
        }
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitInsn(final int opcode) {
        buf.setLength(0);
        buf.append("mv.visitInsn(").append(OPCODES[opcode]).append(");\n");
        text.add(buf.toString());
    }

    public void visitIntInsn(final int opcode, final int operand) {
        buf.setLength(0);
        buf.append("mv.visitIntInsn(")
                .append(OPCODES[opcode])
                .append(", ")
                .append(opcode == Opcodes.NEWARRAY
                        ? TYPES[operand]
                        : Integer.toString(operand))
                .append(");\n");
        text.add(buf.toString());
    }

    public void visitVarInsn(final int opcode, final int var) {
        buf.setLength(0);
        buf.append("mv.visitVarInsn(")
                .append(OPCODES[opcode])
                .append(", ")
                .append(var)
                .append(");\n");
        text.add(buf.toString());
    }

    public void visitTypeInsn(final int opcode, final String type) {
        buf.setLength(0);
        buf.append("mv.visitTypeInsn(").append(OPCODES[opcode]).append(", ");
        appendConstant(type);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitFieldInsn(
        final int opcode,
        final String owner,
        final String name,
        final String desc)
    {
        buf.setLength(0);
        buf.append("mv.visitFieldInsn(").append(OPCODES[opcode]).append(", ");
        appendConstant(owner);
        buf.append(", ");
        appendConstant(name);
        buf.append(", ");
        appendConstant(desc);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitMethodInsn(
        final int opcode,
        final String owner,
        final String name,
        final String desc)
    {
        buf.setLength(0);
        buf.append("mv.visitMethodInsn(").append(OPCODES[opcode]).append(", ");
        appendConstant(owner);
        buf.append(", ");
        appendConstant(name);
        buf.append(", ");
        appendConstant(desc);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitJumpInsn(final int opcode, final Label label) {
        buf.setLength(0);
        declareLabel(label);
        buf.append("mv.visitJumpInsn(").append(OPCODES[opcode]).append(", ");
        appendLabel(label);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitLabel(final Label label) {
        buf.setLength(0);
        declareLabel(label);
        buf.append("mv.visitLabel(");
        appendLabel(label);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitLdcInsn(final Object cst) {
        buf.setLength(0);
        buf.append("mv.visitLdcInsn(");
        appendConstant(cst);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitIincInsn(final int var, final int increment) {
        buf.setLength(0);
        buf.append("mv.visitIincInsn(")
                .append(var)
                .append(", ")
                .append(increment)
                .append(");\n");
        text.add(buf.toString());
    }

    public void visitTableSwitchInsn(
        final int min,
        final int max,
        final Label dflt,
        final Label[] labels)
    {
        buf.setLength(0);
        for (int i = 0; i < labels.length; ++i) {
            declareLabel(labels[i]);
        }
        declareLabel(dflt);

        buf.append("mv.visitTableSwitchInsn(")
                .append(min)
                .append(", ")
                .append(max)
                .append(", ");
        appendLabel(dflt);
        buf.append(", new Label[] {");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(i == 0 ? " " : ", ");
            appendLabel(labels[i]);
        }
        buf.append(" });\n");
        text.add(buf.toString());
    }

    public void visitLookupSwitchInsn(
        final Label dflt,
        final int[] keys,
        final Label[] labels)
    {
        buf.setLength(0);
        for (int i = 0; i < labels.length; ++i) {
            declareLabel(labels[i]);
        }
        declareLabel(dflt);

        buf.append("mv.visitLookupSwitchInsn(");
        appendLabel(dflt);
        buf.append(", new int[] {");
        for (int i = 0; i < keys.length; ++i) {
            buf.append(i == 0 ? " " : ", ").append(keys[i]);
        }
        buf.append(" }, new Label[] {");
        for (int i = 0; i < labels.length; ++i) {
            buf.append(i == 0 ? " " : ", ");
            appendLabel(labels[i]);
        }
        buf.append(" });\n");
        text.add(buf.toString());
    }

    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        buf.setLength(0);
        buf.append("mv.visitMultiANewArrayInsn(");
        appendConstant(desc);
        buf.append(", ").append(dims).append(");\n");
        text.add(buf.toString());
    }

    public void visitTryCatchBlock(
        final Label start,
        final Label end,
        final Label handler,
        final String type)
    {
        buf.setLength(0);
        declareLabel(start);
        declareLabel(end);
        declareLabel(handler);
        buf.append("mv.visitTryCatchBlock(");
        appendLabel(start);
        buf.append(", ");
        appendLabel(end);
        buf.append(", ");
        appendLabel(handler);
        buf.append(", ");
        appendConstant(type);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitLocalVariable(
        final String name,
        final String desc,
        final String signature,
        final Label start,
        final Label end,
        final int index)
    {
        buf.setLength(0);
        buf.append("mv.visitLocalVariable(");
        appendConstant(name);
        buf.append(", ");
        appendConstant(desc);
        buf.append(", ");
        appendConstant(signature);
        buf.append(", ");
        appendLabel(start);
        buf.append(", ");
        appendLabel(end);
        buf.append(", ").append(index).append(");\n");
        text.add(buf.toString());
    }

    public void visitLineNumber(final int line, final Label start) {
        buf.setLength(0);
        buf.append("mv.visitLineNumber(").append(line).append(", ");
        appendLabel(start);
        buf.append(");\n");
        text.add(buf.toString());
    }

    public void visitMaxs(final int maxStack, final int maxLocals) {
        buf.setLength(0);
        buf.append("mv.visitMaxs(")
                .append(maxStack)
                .append(", ")
                .append(maxLocals)
                .append(");\n");
        text.add(buf.toString());
    }

    private void declareFrameTypes(final int n, final Object[] o) {
        for (int i = 0; i < n; ++i) {
            if (o[i] instanceof Label) {
                declareLabel((Label) o[i]);
            }
        }
    }

    private void appendFrameTypes(final int n, final Object[] o) {
        for (int i = 0; i < n; ++i) {
            if (i > 0) {
                buf.append(", ");
            }
            if (o[i] instanceof String) {
                appendConstant(o[i]);
            } else if (o[i] instanceof Integer) {
                switch (((Integer) o[i]).intValue()) {
                    case 0:
                        buf.append("Opcodes.TOP");
                        break;
                    case 1:
                        buf.append("Opcodes.INTEGER");
                        break;
                    case 2:
                        buf.append("Opcodes.FLOAT");
                        break;
                    case 3:
                        buf.append("Opcodes.DOUBLE");
                        break;
                    case 4:
                        buf.append("Opcodes.LONG");
                        break;
                    case 5:
                        buf.append("Opcodes.NULL");
                        break;
                    case 6:
                        buf.append("Opcodes.UNINITIALIZED_THIS");
                        break;
                }
            } else {
                appendLabel((Label) o[i]);
            }
        }
    }

    /**
     * Appends a declaration of the given label to {@link #buf buf}. This
     * declaration is of the form "Label lXXX = new Label();". Does nothing if
     * the given label has already been declared.
     * 
     * @param l a label.
     */
    private void declareLabel(final Label l) {
        String name = (String) labelNames.get(l);
        if (name == null) {
            name = "l" + labelNames.size();
            labelNames.put(l, name);
            buf.append("Label ").append(name).append(" = new Label();\n");
        }
    }

    /**
     * Appends the name of the given label to {@link #buf buf}. The given label
     * <i>must</i> already have a name. One way to ensure this is to always
     * call {@link #declareLabel declared} before calling this method.
     * 
     * @param l a label.
     */
    private void appendLabel(final Label l) {
        buf.append((String) labelNames.get(l));
    }
}
