/*
    * Copyright 2004-2006 the Seasar Foundation and the Others.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
   * either express or implied. See the License for the specific language
   * governing permissions and limitations under the License.
   */
  package org.seasar.tuigwaa.util.functor;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  import com.isenshi.util.functor.BinaryFunction;
  import com.isenshi.util.functor.BinaryPredicate;
  import com.isenshi.util.functor.UnaryFunction;
  
  public class Op {
  
  	public static final BinaryFunction SUM = new BinaryFunction(){
  		public Object evaluate(Object left, Object right) {
  			if(left instanceof Long && right instanceof Long){
  				return new Long(((Long)left).longValue() + ((Long)right).longValue());
  			}else if(left instanceof Double && right instanceof Double){
  				return new Double(((Double)left).doubleValue() + ((Double)right).doubleValue());
  			}else if(left instanceof Integer && right instanceof Integer){
  				return new Integer(((Integer)left).intValue() + ((Integer)right).intValue());
  			}else if(left instanceof Float && right instanceof Float){
  				return new Float(((Float)left).floatValue() + ((Float)right).floatValue());
  			}
  			return null;//"" + left + right;
  		}
  	};
  	
  	public static final BinaryFunction MAX = new BinaryFunction(){
  		public Object evaluate(Object left, Object right) {
  			return (GT.test(left, right))?left:right;
  		}
  	};
  		
  	public static final BinaryPredicate EQ = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			return (null == left ? null == right : left.equals(right));
  		}
  	};
  
  	public static final BinaryPredicate NE = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			return (null == left ? null != right : !left.equals(right));
  		}
  	};
  
  	public static final BinaryPredicate LT = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			if (left == null) {
  				return false;
  			}
  			return ((Comparable) left).compareTo(right) < 0;
  		}
  	};
  
  	public static final BinaryPredicate LE = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			if (left == null) {
  				return false;
  			}
  			return ((Comparable) left).compareTo(right) <= 0;
  		}
  	};
  
  	public static final BinaryPredicate GT = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			if (left == null) {
  				return false;
  			}
  			return ((Comparable) left).compareTo(right) > 0;
  		}
  	};
  
  	public static final BinaryPredicate GE = new BinaryPredicate() {
  		public boolean test(Object left, Object right) {
  			if (left == null) {
  				return false;
  			}
  			return ((Comparable) left).compareTo(right) >= 0;
  		}
  	};
  	
  	public static Map OP_MAP;
  
 	static{
 		Map tmp = new HashMap();
 		tmp.put("eq", EQ);
 		tmp.put("ne", NE);
 		tmp.put("lt", LT);
 		tmp.put("le", LE);
 		tmp.put("gt", GT);
 		tmp.put("ge", GE);
 		OP_MAP = Collections.unmodifiableMap(tmp);
 	}
 	
 	public static BinaryPredicate getInstance(String opcode){
 		return (BinaryPredicate)OP_MAP.get(opcode);
 	}
 	
 	public static final BinaryFunction NOTHING_BINARY_FUNCTION = new BinaryFunction(){
 		public Object evaluate(Object left, Object right) {
 			return left;
 		}
 	};
 	
 	public static final UnaryFunction COLLECTIONSIZE_FUNCTION = new UnaryFunction(){
 	
 		public Object evaluate(Object obj) {
 			Collection col = (Collection)obj;
 			if(col == null){
 				return new Integer(0);
 			}
 			return new Integer(col.size());
 		}
 	};
 }