/***
 * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
 * 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 br.com.caelum.vraptor.converter.l10n;

import static com.google.common.base.Strings.isNullOrEmpty;

import java.text.DecimalFormat;
import java.text.MessageFormat;
import java.text.ParseException;
import java.util.Locale;
import java.util.ResourceBundle;

import br.com.caelum.vraptor.Convert;
import br.com.caelum.vraptor.Converter;
import br.com.caelum.vraptor.converter.ConversionError;
import br.com.caelum.vraptor.core.Localization;
import br.com.caelum.vraptor.ioc.RequestScoped;

/**
 * Localized version of VRaptor's Double converter. This component is optional and must be declared in web.xml before
 * using. If the input value if empty or a null string, null values are returned. If the input string is not a number a
 * {@link ConversionError} will be throw.
 *
 * @author Rafael Dipold
 * @author Otávio Scherer Garcia
 * @since 3.4
 */
@Convert(double.class)
@RequestScoped
public class LocaleBasedPrimitiveDoubleConverter implements Converter<Double> {

	private final Localization localization;

	public LocaleBasedPrimitiveDoubleConverter(Localization localization) {
		this.localization = localization;
	}

	public Double convert(String value, Class<? extends Double> type, ResourceBundle bundle) {
		if (isNullOrEmpty(value)) {
			return 0d;
		}

		try {
			final Locale locale = localization.getLocale();
			DecimalFormat fmt = (DecimalFormat) DecimalFormat.getInstance(locale);

			return fmt.parse(value).doubleValue();
		} catch (ParseException e) {
			throw new ConversionError(MessageFormat.format(bundle.getString("is_not_a_valid_number"), value));
		}
	}
}