/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.jfr.internal;

import java.io.ByteArrayOutputStream;

import java.io.PrintWriter;

import java.util.List;

import jdk.internal.org.objectweb.asm.ClassReader;

import jdk.internal.org.objectweb.asm.MethodVisitor;

import jdk.internal.org.objectweb.asm.Opcodes;

import jdk.internal.org.objectweb.asm.Type;

import jdk.internal.org.objectweb.asm.commons.Method;

import jdk.internal.org.objectweb.asm.util.TraceClassVisitor;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.internal.EventInstrumentation.FieldInfo;

final class ASMToolkit {

    private static Type TYPE_STRING = Type.getType(String.class);

    private static Type Type_THREAD = Type.getType(Thread.class);

    private static Type TYPE_CLASS = Type.getType(Class.class);

    public static void invokeSpecial(MethodVisitor methodVisitor, String className, Method m) {

        methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, className, m.getName(), m.getDescriptor(), false);

    }

    public static void invokeStatic(MethodVisitor methodVisitor, String className, Method m) {

        methodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, className, m.getName(), m.getDescriptor(), false);

    }

    public static void invokeVirtual(MethodVisitor methodVisitor, String className, Method m) {

        methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, className, m.getName(), m.getDescriptor(), false);

    }

    public static Type toType(ValueDescriptor v) {

        String typeName = v.getTypeName();

        switch (typeName) {

        case "byte":

            return Type.BYTE_TYPE;

        case "short":

            return Type.SHORT_TYPE;

        case "int":

            return Type.INT_TYPE;

        case "long":

            return Type.LONG_TYPE;

        case "double":

            return Type.DOUBLE_TYPE;

        case "float":

            return Type.FLOAT_TYPE;

        case "char":

            return Type.CHAR_TYPE;

        case "boolean":

            return Type.BOOLEAN_TYPE;

        case "java.lang.String":

            return TYPE_STRING;

        case "java.lang.Thread":

            return Type_THREAD;

        case "java.lang.Class":

            return TYPE_CLASS;

        }

        // Add support for SettingControl?

       throw new Error("Not a valid type " + v.getTypeName());

    }

    /**

     * Converts "int" into "I" and "java.lang.String" into "Ljava/lang/String;"

     *

     * @param typeName

     *            type

     *

     * @return descriptor

     */

    public static String getDescriptor(String typeName) {

        if ("int".equals(typeName)) {

            return "I";

        }

        if ("long".equals(typeName)) {

            return "J";

        }

        if ("boolean".equals(typeName)) {

            return "Z";

        }

        if ("float".equals(typeName)) {

            return "F";

        }

        if ("double".equals(typeName)) {

            return "D";

        }

        if ("short".equals(typeName)) {

            return "S";

        }

        if ("char".equals(typeName)) {

            return "C";

        }

        if ("byte".equals(typeName)) {

            return "B";

        }

        String internal = getInternalName(typeName);

        return Type.getObjectType(internal).getDescriptor();

    }

    /**

     * Converts java.lang.String into java/lang/String

     *

     * @param className

     *

     * @return internal name

     */

    public static String getInternalName(String className) {

        return className.replace(".", "/");

    }

    public static Method makeWriteMethod(List<FieldInfo> fields) {

        StringBuilder sb = new StringBuilder();

        sb.append("(");

        for (FieldInfo v : fields) {

            if (!v.fieldName.equals(EventInstrumentation.FIELD_EVENT_THREAD) && !v.fieldName.equals(EventInstrumentation.FIELD_STACK_TRACE)) {

                sb.append(v.fieldDescriptor);

            }

        }

        sb.append(")V");

        return new Method("write", sb.toString());

    }

    public static void logASM(String className, byte[] bytes) {

        Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.INFO, "Generated bytecode for class " + className);

        Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.TRACE, () -> {

            ClassReader cr = new ClassReader(bytes);

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            PrintWriter w = new PrintWriter(baos);

            w.println("Bytecode:");

            cr.accept(new TraceClassVisitor(w), 0);

            return baos.toString();

        });

    }

}