/*
 * Copyright 2000-2014 Vaadin Ltd.
 * 
 * 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 com.vaadin.ui.renderers;

import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;

import com.vaadin.ui.Grid.AbstractRenderer;

import elemental.json.JsonValue;

/**
 * A renderer for presenting date values.
 * 
 * @since 7.4
 * @author Vaadin Ltd
 */
public class DateRenderer extends AbstractRenderer<Date> {
    private final Locale locale;
    private final String formatString;
    private final DateFormat dateFormat;

    /**
     * Creates a new date renderer.
     * <p>
     * The renderer is configured to render with the {@link Date#toString()}
     * representation for the default locale.
     */
    public DateRenderer() {
        this(Locale.getDefault());
    }

    /**
     * Creates a new date renderer.
     * <p>
     * The renderer is configured to render with the {@link Date#toString()}
     * representation for the given locale.
     * 
     * @param locale
     *            the locale in which to present dates
     * @throws IllegalArgumentException
     *             if {@code locale} is {@code null}
     */
    public DateRenderer(Locale locale) throws IllegalArgumentException {
        this("%s", locale);
    }

    /**
     * Creates a new date renderer.
     * <p>
     * The renderer is configured to render with the given string format, as
     * displayed in the default locale.
     * 
     * @param formatString
     *            the format string with which to format the date
     * @throws IllegalArgumentException
     *             if {@code formatString} is {@code null}
     * @see <a
     *      href="http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax">Format
     *      String Syntax</a>
     */
    public DateRenderer(String formatString) throws IllegalArgumentException {
        this(formatString, Locale.getDefault());
    }

    /**
     * Creates a new date renderer.
     * <p>
     * The renderer is configured to render with the given string format, as
     * displayed in the given locale.
     * 
     * @param formatString
     *            the format string to format the date with
     * @param locale
     *            the locale to use
     * @throws IllegalArgumentException
     *             if either argument is {@code null}
     * @see <a
     *      href="http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax">Format
     *      String Syntax</a>
     */
    public DateRenderer(String formatString, Locale locale)
            throws IllegalArgumentException {
        super(Date.class);

        if (formatString == null) {
            throw new IllegalArgumentException("format string may not be null");
        }

        if (locale == null) {
            throw new IllegalArgumentException("locale may not be null");
        }

        this.locale = locale;
        this.formatString = formatString;
        dateFormat = null;
    }

    /**
     * Creates a new date renderer.
     * <p>
     * The renderer is configured to render with he given date format.
     * 
     * @param dateFormat
     *            the date format to use when rendering dates
     * @throws IllegalArgumentException
     *             if {@code dateFormat} is {@code null}
     */
    public DateRenderer(DateFormat dateFormat) throws IllegalArgumentException {
        super(Date.class);
        if (dateFormat == null) {
            throw new IllegalArgumentException("date format may not be null");
        }

        locale = null;
        formatString = null;
        this.dateFormat = dateFormat;
    }

    @Override
    public JsonValue encode(Date value) {
        String dateString;
        if (dateFormat != null) {
            dateString = dateFormat.format(value);
        } else {
            dateString = String.format(locale, formatString, value);
        }
        return encode(dateString, String.class);
    }

    @Override
    public String toString() {
        final String fieldInfo;
        if (dateFormat != null) {
            fieldInfo = "dateFormat: " + dateFormat.toString();
        } else {
            fieldInfo = "locale: " + locale + ", formatString: " + formatString;
        }

        return String.format("%s [%s]", getClass().getSimpleName(), fieldInfo);
    }
}