package groovy;

import java.util.List;

/**
 * Groovy Category to verify overriding of the various operators (+, -, *, /,
 * %, |, &, ++, --, [] get/put, ==, != , <, <=, >, >=, <=>).
 * 
 * <p/>
 * The {@link MyNum} static nested class is defined at the bottom of this
 * class.
 */
public class OperatorCategory {
    private static final String CLASSNAME = OperatorCategory.class.getName();
    
    private static final boolean DEBUG = true;
    
    private static String lastOp;
    
    /** Get and clear last operation string. */
    public static String lastOp() {
        String ret = lastOp;
        lastOp = null;
        
        return ret;
    }
    
    public static Number plus( Number a, Number b ) {
        lastOp = "plus";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() + b.intValue();
    }

    public static Number minus( Number a, Number b ) {
        lastOp = "minus";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() - b.intValue();
    }

    public static Number multiply( Number a, Number b ) {
        lastOp = "multiply";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() * b.intValue();
    }

    public static Number div( Number a, Number b ) {
        lastOp = "div";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() / b.intValue();
    }

    public static Number mod( Number a, Number b ) {
        lastOp = "mod";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() % b.intValue();
    }

    public static Number or( Number a, Number b ) {
        lastOp = "or";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() | b.intValue();
    }

    public static Number and( Number a, Number b ) {
        lastOp = "and";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() & b.intValue();
    }

    public static Number next( Number a ) {
        lastOp = "next";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a)" );
        
        return a.intValue()+1;
    }

    public static int previous( Number a ) {
        lastOp = "previous";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a)" );
        
        return a.intValue()-1;
    }

    public static Object getAt( List a, Integer index ) {
        lastOp = "getAt";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(List a, Integer index)" );
        
        return ((List)a).get(index);
    }

    public static Object putAt( List a, Integer index, Object value ) {
        lastOp = "putAt";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(List a, Integer index, Object value)" );
        
        return a.set(index, value);
    }

    public static Number leftShift( Number a, Number b ) {
        lastOp = "leftShift";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() << b.intValue();
    }

    public static Number rightShift( Number a, Number b ) {
        lastOp = "rightShift";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() >> b.intValue();
    }

    public static Number rightShiftUnsigned( Number a, Number b ) {
        lastOp = "rightShiftUnsigned";
        
        if (DEBUG) System.out.println( CLASSNAME + "." + lastOp + "(Number a, Number b)" );
        
        return a.intValue() >> b.intValue();
    }

    public static boolean equals( Number a, Number b ) {
        lastOp = "equalsNumberNumber";
        
        if (DEBUG) System.out.println( CLASSNAME + ".equals(Number a, Number b)" );
        
        return a.equals(b);
    }

    public static boolean equals( MyNum a, MyNum b ) {
        lastOp = "equalsMyNumMyNum";
        
        if (DEBUG) System.out.println( CLASSNAME + ".equals(MyNum a, MyNum b)" );
        
        return a.equals(b);
    }

    public static boolean equals( MyNum a, Number b ) {
        lastOp = "equalsMyNumNumber";
        
        if (DEBUG) System.out.println( CLASSNAME + ".equals(MyNum a, Number b)" );
        
        return a.equals(b);
    }

    public static boolean equals( Number a, MyNum b ) {
        if (DEBUG) System.out.println( CLASSNAME + ".equals(Number a, MyNum b)" );
        
        boolean ret = equals(b,a);  // Yes the args are reversed intentionally

        lastOp = "equalsNumberMyNum";
        
        return ret;
    }

    public static Number compareTo( Number a, Number b ) {
        lastOp = "compareToNumberNumber";
        
        if (DEBUG) System.out.println( CLASSNAME + ".compareTo(Number a, Number b)" );
        
        if ((a instanceof Comparable) && (b instanceof Comparable)) {
          return ((Comparable)a).compareTo((Comparable)b);
        }
        else {
            double diff = a.doubleValue() - b.doubleValue();
            
            return (diff < 0) ? -1 : ((diff > 0) ? 1 : 0);
        }
    }

    public static int compareTo( MyNum a, MyNum b ) {
        lastOp = "compareToMyNumMyNum";
        
        if (DEBUG) System.out.println( CLASSNAME + ".compareTo(MyNum a, MyNum b)" );
        
        return a.compareTo(b);
    }

    public static int compareTo( MyNum a, Number b ) {
        lastOp = "compareToMyNumNumber";
        
        if (DEBUG) System.out.println( CLASSNAME + ".compareTo(MyNum a, Number b)" );
        
        return a.compareTo(b);
    }

    public static int compareTo( Number a, MyNum b ) {
        if (DEBUG) System.out.println( CLASSNAME + ".compareTo(Number a, MyNum b)" );
        
        int ret = -compareTo(b,a);  // Yes the args are reversed intentionally

        lastOp = "compareToNumberMyNum";
        
        return ret;
    }
    
    public static class MyNum implements Comparable<Object> {
        Comparable _value;
        
        public MyNum( Number num ) {
            if (num == null) throw new NullPointerException( "num can not be null" );
            if (!(num instanceof Comparable)) {
                throw new NullPointerException( "num is not a Comparable (" + num.getClass().getName() + ")" );
            }
            
            _value = (Comparable) num;
        }
        
        public boolean equals( Object other ) {
            if      (this == other) return true;
            else if (other == null) return false;
            else if (getClass() == other.getClass()) {
                return _value.equals( ((MyNum)other)._value );
            }
            else if (other instanceof Number) {
                return _value.equals( other );
            }

            return false;
        }
        
        public int hashCode() { return _value.hashCode(); }

        public int compareTo(Object other) {
            if      (this == other) return 0;
            else if (other == null) return 1;
            else if (getClass() == other.getClass()) {
                return _value.compareTo( ((MyNum)other)._value );
            }
            else if (other instanceof Number) {
                return _value.compareTo( other );
            }
            
            throw new IllegalArgumentException( getClass() + " and "
                + other.getClass() + " are not Comparable" );
        }
    }
}