/***
 * 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.serialization.gson;

import java.lang.reflect.Type;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.annotation.Priority;
import javax.enterprise.context.Dependent;
import javax.enterprise.inject.Alternative;
import javax.interceptor.Interceptor;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import com.google.gson.JsonSyntaxException;

/**
 * Deserialize {@link Date} using ISO8601 format. 
 * This class must be in {@link Dependent} to allow us to discover generic type.
 * 
 * @author Rodrigo Turini
 * @since 4.0.0
 */
@Dependent
@Alternative
@Priority(Interceptor.Priority.LIBRARY_BEFORE)
public class DateGsonConverter implements JsonDeserializer<Date>, JsonSerializer<Date>{

	@Override
	public JsonElement serialize(Date date, Type typeOfSrc, JsonSerializationContext context) {
		String dateString = getFormat().format(date);
		return new JsonPrimitive(dateString);
	}

	@Override
	public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
		try {
			return getFormat().parse(json.getAsString());
		} catch (ParseException e) {
			throw new JsonSyntaxException(json.getAsString(), e);
		}
	}	

	protected DateFormat getFormat(){
		return new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
	}

}