/*
 * Copyright (c) 2011-2015 EPFL DATA Laboratory
 * Copyright (c) 2014-2015 The Squall Collaboration (see NOTICE)
 *
 * All rights reserved.
 *
 * 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 ch.epfl.data.squall.expressions;

import java.util.ArrayList;
import java.util.List;

import ch.epfl.data.squall.types.NumericType;
import ch.epfl.data.squall.types.Type;
import ch.epfl.data.squall.visitors.ValueExpressionVisitor;

/*
 * Having different T types in the constructor arguments
 *   does not result in exception in the constructor,
 *   but rather in evalString method.
 */
public class ValueSpecification<T extends Comparable<T>> implements
	ValueExpression<T> {
    private static final long serialVersionUID = 1L;

    private T _constant;
    private final Type<T> _wrapper;

    public ValueSpecification(Type<T> wrapper, T constant) {
	_constant = constant;
	_wrapper = wrapper;
    }

    @Override
    public void accept(ValueExpressionVisitor vev) {
	vev.visit(this);
    }

    @Override
    public void changeValues(int i, ValueExpression<T> newExpr) {

    }

    @Override
    public T eval(List<String> tuple) {
	return _constant;
    }

    @Override
    public String evalString(List<String> tuple) {
	final T value = eval(tuple);
	return _wrapper.toString(value);
    }

    @Override
    public List<ValueExpression> getInnerExpressions() {
	return new ArrayList<ValueExpression>();
    }

    @Override
    public Type getType() {
	return _wrapper;
    }

    @Override
    public void inverseNumber() {
	if (_wrapper instanceof NumericType) {
	    final NumericType makis = (NumericType) _wrapper;
	    // double temp = makis.toDouble((Number) _constant);
	    final double val = ((Number) _constant).doubleValue();
	    final double temp = makis.toDouble(new Double(val));
	    _constant = (T) makis.fromDouble(1.0 / temp);
	}
    }

    @Override
    public boolean isNegative() {
	if (_wrapper instanceof NumericType) {
	    final NumericType makis = (NumericType) _wrapper;
	    final double temp = makis.toDouble(_constant);
	    return (temp < 0);
	}
	return false;
    }

    @Override
    public String toString() {
	final StringBuilder sb = new StringBuilder();
	sb.append("Constant ").append(_constant.toString());
	return sb.toString();
    }
}