/* ConstOperator Copyright (C) 1998-1999 Jochen Hoenicke.
 *
 * 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; either version 2, or (at your option)
 * any later version.
 *
 * 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id$
 */

package net.sf.jode.expr;
import net.sf.jode.type.Type;
import net.sf.jode.type.IntegerType;
import net.sf.jode.util.StringQuoter;
import net.sf.jode.decompiler.TabbedPrintWriter;

public class ConstOperator extends NoArgOperator {
    Object value;
    boolean isInitializer = false;

    private static final Type tBoolConstInt 
	= new IntegerType(IntegerType.IT_I | IntegerType.IT_C 
			  | IntegerType.IT_Z
			  | IntegerType.IT_S | IntegerType.IT_B);

    public ConstOperator(Object constant) {
	super(Type.tUnknown);
	if (constant instanceof Boolean) {
	    updateParentType(Type.tBoolean);
	    constant = new Integer(((Boolean)constant).booleanValue() ? 1 : 0);
	} else if (constant instanceof Integer) {
	    int intVal = ((Integer) constant).intValue();
	    updateParentType 
		((intVal == 0 || intVal == 1) ? tBoolConstInt
		 : (intVal < Short.MIN_VALUE 
		    || intVal > Character.MAX_VALUE) ? Type.tInt
		 : new IntegerType
		 ((intVal < Byte.MIN_VALUE) 
		  ?    IntegerType.IT_S|IntegerType.IT_I
		  : (intVal < 0)
		  ?    IntegerType.IT_S|IntegerType.IT_B|IntegerType.IT_I
		  : (intVal <= Byte.MAX_VALUE)
		  ?    (IntegerType.IT_S|IntegerType.IT_B
			|IntegerType.IT_C|IntegerType.IT_I)
		  : (intVal <= Short.MAX_VALUE)
		  ?    IntegerType.IT_S|IntegerType.IT_C|IntegerType.IT_I
		  :    IntegerType.IT_C|IntegerType.IT_I));
	} else if (constant instanceof Long)
	    updateParentType(Type.tLong);
	else if (constant instanceof Float)
	    updateParentType(Type.tFloat);
	else if (constant instanceof Double)
	    updateParentType(Type.tDouble);
	else if (constant instanceof String)
	    updateParentType(Type.tString);
	else if (constant == null)
	    updateParentType(Type.tUObject);
	else
	    throw new IllegalArgumentException("Illegal constant type: "
					       +constant.getClass());
	value = constant;
    }

    public Object getValue() {
        return value;
    }

    /**
     * Return true, if this value is a one of the given type.
     * This is used for ++ and -- instructions.
     * @param type the type for which this must be a one.  This may
     * be different from the type this value actually is.
     */
    public boolean isOne(Type type) {
	if (type instanceof IntegerType) {
	    return (value instanceof Integer
		    && ((Integer)value).intValue() == 1);
	} else if (type == Type.tLong) {
	    return (value instanceof Long
		    && ((Long)value).longValue() == 1L);
	} else if (type == Type.tFloat) {
	    return (value instanceof Float
		    && ((Float)value).floatValue() == 1.0f);
	} else if (type == Type.tDouble) {
	    return (value instanceof Double
		    && ((Double)value).doubleValue() == 1.0);
	}
	return false;
    }

    public int getPriority() {
        return 1000;
    }

    public boolean opEquals(Operator o) {
	if (o instanceof ConstOperator) {
	    Object otherValue = ((ConstOperator)o).value;
	    return value == null
		? otherValue == null : value.equals(otherValue);
	}
	return false;
    }

    public void makeInitializer(Type type) {
        isInitializer = true;
    }

    public String toString() {
        String strVal = String.valueOf(value);
        if (type.isOfType(Type.tBoolean)) {
	    int intVal = ((Integer)value).intValue();
            if (intVal == 0)
                return "false";
            else if (intVal == 1)
                return "true";
	    else 
		throw new InternalError
		    ("boolean is neither false nor true");
        } 
	if (type.getHint().equals(Type.tChar)) {
            char c = (char) ((Integer) value).intValue();
	    return StringQuoter.quote(c);
	} else if (type.equals(Type.tString)) {
	    return StringQuoter.quote(strVal);
        } else if (parent != null) {
            int opindex = parent.getOperatorIndex();
            if (opindex >= OPASSIGN_OP + ADD_OP
                && opindex <  OPASSIGN_OP + ASSIGN_OP)
                opindex -= OPASSIGN_OP;

            if (opindex >= AND_OP && opindex < AND_OP + 3) {
                /* For bit wise and/or/xor change representation.
                 */
                if (type.isOfType(Type.tUInt)) {
                    int i = ((Integer) value).intValue();
                    if (i < -1) 
                        strVal = "~0x"+Integer.toHexString(-i-1);
                    else
                        strVal = "0x"+Integer.toHexString(i);
                } else if (type.equals(Type.tLong)) {
                    long l = ((Long) value).longValue();
                    if (l < -1) 
                        strVal = "~0x"+Long.toHexString(-l-1);
                    else
                        strVal = "0x"+Long.toHexString(l);
                }
            }
        }
        if (type.isOfType(Type.tLong))
            return strVal+"L";
        if (type.isOfType(Type.tFloat)) {
	    if (strVal.equals("NaN"))
		return "Float.NaN";
	    if (strVal.equals("-Infinity"))
		return "Float.NEGATIVE_INFINITY";
	    if (strVal.equals("Infinity"))
		return "Float.POSITIVE_INFINITY";
            return strVal+"F";
	}
        if (type.isOfType(Type.tDouble)) {
	    if (strVal.equals("NaN"))
		return "Double.NaN";
	    if (strVal.equals("-Infinity"))
		return "Double.NEGATIVE_INFINITY";
	    if (strVal.equals("Infinity"))
		return "Double.POSITIVE_INFINITY";
            return strVal;
	}
        if (!type.isOfType(Type.tInt) 
	    && (type.getHint().equals(Type.tByte)
		|| type.getHint().equals(Type.tShort))
            && !isInitializer
	    && !(parent instanceof StoreInstruction
		 && parent.getOperatorIndex() != ASSIGN_OP
		 && parent.subExpressions[1] == this)) {
            /* One of the strange things in java.  All constants
             * are int and must be explicitly casted to byte,...,short.
             * But in assignments and initializers this cast is unnecessary.
	     * See JLS section 5.2
             */
            return "("+type.getHint()+") "+strVal;
	}

        return strVal;
    }

    public void dumpExpression(TabbedPrintWriter writer)
	throws java.io.IOException {
	writer.print(toString());
    }
}