/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012-2015 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 2 of the License.

 *

 * This program 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 for more details.

 *

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

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.vm4brwsr;

final class VarType {

    public static final int INTEGER = 0;

    public static final int LONG = 1;

    public static final int FLOAT = 2;

    public static final int DOUBLE = 3;

    public static final int REFERENCE = 4;

    public static final int LAST = REFERENCE;

    private VarType() {

    }

    public static boolean isCategory2(final int varType) {

        return (varType == LONG) || (varType == DOUBLE);

    }

    public static int fromStackMapType(final int smType) {

        switch (smType & 0xff) {

            case ByteCodeParser.ITEM_Integer:

                return VarType.INTEGER;

            case ByteCodeParser.ITEM_Float:

                return VarType.FLOAT;

            case ByteCodeParser.ITEM_Double:

                return VarType.DOUBLE;

            case ByteCodeParser.ITEM_Long:

                return VarType.LONG;

            case ByteCodeParser.ITEM_Null:

            case ByteCodeParser.ITEM_InitObject:

            case ByteCodeParser.ITEM_Object:

            case ByteCodeParser.ITEM_NewObject:

                return VarType.REFERENCE;

            case ByteCodeParser.ITEM_Bogus:

                /* unclear how to handle for now */

            default:

                throw new IllegalStateException("Unhandled stack map type");

        }

    }

    public static int fromConstantType(final byte constantTag) {

        switch (constantTag) {

            case ByteCodeParser.CONSTANT_INTEGER:

                return VarType.INTEGER;

            case ByteCodeParser.CONSTANT_FLOAT:

                return VarType.FLOAT;

            case ByteCodeParser.CONSTANT_LONG:

                return VarType.LONG;

            case ByteCodeParser.CONSTANT_DOUBLE:

                return VarType.DOUBLE;

            case ByteCodeParser.CONSTANT_CLASS:

            case ByteCodeParser.CONSTANT_UTF8:

            case ByteCodeParser.CONSTANT_UNICODE:

            case ByteCodeParser.CONSTANT_STRING:

                return VarType.REFERENCE;

            case ByteCodeParser.CONSTANT_FIELD:

            case ByteCodeParser.CONSTANT_METHOD:

            case ByteCodeParser.CONSTANT_INTERFACEMETHOD:

            case ByteCodeParser.CONSTANT_NAMEANDTYPE:

                /* unclear how to handle for now */

            default:

                throw new IllegalStateException("Unhandled constant tag");

        }

    }

    public static int fromFieldType(final char fieldType) {

        switch (fieldType) {

            case 'B':

            case 'C':

            case 'S':

            case 'Z':

            case 'I':

                return VarType.INTEGER;

            case 'J':

                return VarType.LONG;

            case 'F':

                return VarType.FLOAT;

            case 'D':

                return VarType.DOUBLE;

            case 'L':

            case '[':

                return VarType.REFERENCE;

            default:

                throw new IllegalStateException("Unhandled field type");

        }

    }

    public static String toString(final int varType) {

        switch (varType) {

            case VarType.INTEGER: return "int";

            case VarType.LONG: return "long";

            case VarType.FLOAT: return "float";

            case VarType.DOUBLE: return "double";

            case VarType.REFERENCE: return "ref";

            default:

                throw new IllegalStateException("Unhandled field type");

        }

    }

}