/*
 * 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.Arrays;
import java.util.List;

import ch.epfl.data.squall.types.StringType;
import ch.epfl.data.squall.types.Type;
import ch.epfl.data.squall.utilities.MyUtilities;
import ch.epfl.data.squall.visitors.ValueExpressionVisitor;

public class StringConcatenate implements ValueExpression<String> {
    private static final long serialVersionUID = 1L;

    private final List<ValueExpression<String>> _strList = new ArrayList<ValueExpression<String>>();

    public StringConcatenate(ValueExpression<String> str1,
	    ValueExpression<String> str2, ValueExpression<String>... strArray) {
	_strList.add(str1);
	_strList.add(str2);
	_strList.addAll(Arrays.asList(strArray));
    }

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

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

    }

    @Override
    public String eval(List<String> tuple) {
	String result = "";
	for (final ValueExpression<String> str : _strList)
	    result += str;
	return result;
    }

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

    @Override
    public List<ValueExpression> getInnerExpressions() {
	return MyUtilities.listTypeErasure(_strList);
    }

    @Override
    public Type getType() {
	return new StringType();
    }

    @Override
    public void inverseNumber() {

    }

    @Override
    public boolean isNegative() {
	return false;
    }

    @Override
    public String toString() {
	final StringBuilder sb = new StringBuilder();
	for (int i = 0; i < _strList.size(); i++) {
	    sb.append("(").append(_strList.get(i)).append(")");
	    if (i != _strList.size() - 1)
		sb.append(" STR_CONCAT ");
	}
	return sb.toString();
    }

}