/*
 * 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.types;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Random;

import org.apache.log4j.Logger;

import ch.epfl.data.squall.utilities.MyUtilities;

public class DateType implements Type<Date> {
    private static final long serialVersionUID = 1L;
    private static Logger LOG = Logger.getLogger(DateType.class);

    private static final String STRING_DATE_FORMAT = "yyyy-MM-dd";

    private static DateIntegerType _dt = new DateIntegerType();

    private final Random _rnd = new Random();

    // this cannot be static, because a static field with a constructor cannot
    // be serialized
    private final SimpleDateFormat string_format = new SimpleDateFormat(
	    STRING_DATE_FORMAT);

    private static final String INT_DATE_FORMAT = "yyyyMMdd";

    // this cannot be static, because a static field with a constructor cannot
    // be serialized
    private final SimpleDateFormat int_format = new SimpleDateFormat(
	    INT_DATE_FORMAT);

    public Date addDays(Date date, int days) {
	final Calendar c = Calendar.getInstance();
	final int unit = Calendar.DAY_OF_MONTH;
	c.setTime(date);
	c.add(unit, days);
	return c.getTime();
    }

    public Integer addDays(Integer dateLong, int days) {
	Date base = fromInteger(dateLong);
	Date result = addDays(base, days);
	return toInteger(result);
    }

    public Date fromInteger(Integer dateInt) {
	return fromString(String.valueOf(dateInt), int_format);
    }

    public Date fromLong(Long dateLong) {
	return fromString(String.valueOf(dateLong), int_format);
    }

    @Override
    public Date fromString(String str) {
	return fromString(str, string_format);
    }

    private Date fromString(String str, SimpleDateFormat format) {
	Date date = null;
	try {
	    date = format.parse(str);
	} catch (final ParseException pe) {
	    final String error = MyUtilities.getStackTrace(pe);
	    LOG.info(error);
	    throw new RuntimeException("Invalid Date Format for " + str);
	}
	return date;
    }

    @Override
    public double getDistance(Date bigger, Date smaller) {
	/*
	 * final DateTime smallerDT = new DateTime(smaller); final DateTime
	 * biggerDT = new DateTime(bigger); return Days.daysBetween(smallerDT,
	 * biggerDT).getDays();
	 */
	long diff = bigger.getTime() - smaller.getTime();
	return (diff / (24 * 1000 * 60 * 60));
    }

    @Override
    public Date getInitialValue() {
	return new Date();
    }

    public Integer toInteger(Date obj) {
	return Integer.valueOf(int_format.format(obj));
    }

    public Long toLong(Date obj) {
	return Long.valueOf(int_format.format(obj));
    }

    // for printing(debugging) purposes
    @Override
    public String toString() {
	return "DATE";
    }

    @Override
    public String toString(Date obj) {
	return string_format.format(obj);
    }

    @Override
    public Date generateRandomInstance() {
	int intDate = 0;
	return fromString(_dt.toStringWithDashes(_dt.generateRandomInstance()));
    }
}