/**
 *
 * The MIT License
 *
 * Copyright (c) 2011 the original author or authors.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package com.googlecode.charts4j.parameters;

import java.util.List;

import com.googlecode.charts4j.collect.Lists;

/**
 * Class for building bar chart zero line parameter string for the Google Chart
 * API.
 *
 * @author Julien Chastang (julien.c.chastang at gmail dot com)
 */
final class BarChartZeroLinesParameter extends AbstractParameter {

    /** The Google Chart API bar chart zero line parameter. */
    private static final String URL_PARAMETER_KEY = "chp";

    /** The doubles. */
    private final List<Double>  zeroLines         = Lists.newLinkedList();

    /**
     * Adds the zero line.
     *
     * @param zeroLine
     *            the bar chart zeroLine
     */

    void addZeroLine(final double zeroLine) {
        zeroLines.add(zeroLine);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getKey() {
        return URL_PARAMETER_KEY;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getValue() {
        final StringBuilder sb = new StringBuilder();

        int cnt = 0;
        for (Double d : zeroLines) {
            sb.append(cnt++ > 0 ? "," : "").append(d);
        }
        return !zeroLines.isEmpty() ? sb.toString() : "";
    }
}