/*

 * Copyright (c) 2005, 2012, 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 com.sun.tools.javac.util;

import com.sun.tools.javac.code.Type;

/**

 * Utilities for operating on constant values.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own risk.

 * This code and its internal interfaces are subject to change or

 * deletion without notice.</b>

 */

public class Constants {

    /**

     * Converts a constant in internal representation (in which

     * boolean, char, byte, short, and int are each represented by an

     * Integer) into standard representation.  Other values (including

     * null) are returned unchanged.

     */

    public static Object decode(Object value, Type type) {

        if (value instanceof Integer) {

            int i = (Integer) value;

            switch (type.getTag()) {

            case BOOLEAN:  return i != 0;

            case CHAR:     return (char) i;

            case BYTE:     return (byte) i;

            case SHORT:    return (short) i;

            }

        }

        return value;

    }

    /**

     * Returns a string representation of a constant value (given in

     * internal representation), quoted and formatted as in Java source.

     */

    public static String format(Object value, Type type) {

        value = decode(value, type);

        switch (type.getTag()) {

        case BYTE:      return formatByte((Byte) value);

        case LONG:      return formatLong((Long) value);

        case FLOAT:     return formatFloat((Float) value);

        case DOUBLE:    return formatDouble((Double) value);

        case CHAR:      return formatChar((Character) value);

        }

        if (value instanceof String)

            return formatString((String) value);

        return value + "";

    }

    /**

     * Returns a string representation of a constant value (given in

     * standard wrapped representation), quoted and formatted as in

     * Java source.

     */

    public static String format(Object value) {

        if (value instanceof Byte)      return formatByte((Byte) value);

        if (value instanceof Short)     return formatShort((Short) value);

        if (value instanceof Long)      return formatLong((Long) value);

        if (value instanceof Float)     return formatFloat((Float) value);

        if (value instanceof Double)    return formatDouble((Double) value);

        if (value instanceof Character) return formatChar((Character) value);

        if (value instanceof String)    return formatString((String) value);

        if (value instanceof Integer ||

            value instanceof Boolean)   return value.toString();

        else

            throw new IllegalArgumentException("Argument is not a primitive type or a string; it " +

                                               ((value == null) ?

                                                "is a null value." :

                                                "has class " +

                                                value.getClass().getName()) + "." );

    }

    private static String formatByte(byte b) {

        return String.format("(byte)0x%02x", b);

    }

    private static String formatShort(short s) {

        return String.format("(short)%d", s);

    }

    private static String formatLong(long lng) {

        return lng + "L";

    }

    private static String formatFloat(float f) {

        if (Float.isNaN(f))

            return "0.0f/0.0f";

        else if (Float.isInfinite(f))

            return (f < 0) ? "-1.0f/0.0f" : "1.0f/0.0f";

        else

            return f + "f";

    }

    private static String formatDouble(double d) {

        if (Double.isNaN(d))

            return "0.0/0.0";

        else if (Double.isInfinite(d))

            return (d < 0) ? "-1.0/0.0" : "1.0/0.0";

        else

            return d + "";

    }

    private static String formatChar(char c) {

        return '\'' + Convert.quote(c) + '\'';

    }

    private static String formatString(String s) {

        return '"' + Convert.quote(s) + '"';

    }

}