package mobvista.dmp.util;

import org.apache.commons.lang.StringUtils;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class DateUtil {
	
	
	public static String format (Date date, String pattern) {
		if (date == null) {
			return null;
		}
		SimpleDateFormat sdf = new SimpleDateFormat(pattern);
		return sdf.format(date);
	}
	
	public static String format(String date, String pattern) {
		Date now = parse(date, pattern);
		return format(now, pattern);
	}
	
	public static Date parse (String date, String pattern) {
		try {
			if (date == null) {
				return null;
			}
			SimpleDateFormat sdf = new SimpleDateFormat(pattern);
			return sdf.parse(date);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	
	
	/**
	 * 获取指定日期，前n天或后n天
	 * @param date  指定日期
	 * @param days  指定天数，负数为前n天，整数位后n天
	 * @return
	 */
	public static Date getDay(Date date, int days) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.set(Calendar.DATE, calendar.get(Calendar.DATE) + days);
		return calendar.getTime();
	}
	
	
	/**
	 * 获取指定日期，前n天或后n天
	 * @param date  指定日期
	 * @param pattern 时间格式表达式
	 * @param days  指定天数，负数为前n天，整数位后n天
	 * @return
	 */
	public static String getDay(Date date, String pattern, int days) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.set(Calendar.DATE, calendar.get(Calendar.DATE) + days);
		return format(calendar.getTime(), pattern);
	}
	
	
	/**
	 * 获取指定日期，前n天或后n天
	 * @param date  指定日期
	 * @param pattern 时间格式表达式
	 * @param days  指定天数，负数为前n天，整数位后n天
	 * @return
	 */
	public static Date getDay(String date, String pattern, int days) {
		Date now = parse(date, pattern);
		return getDay(now, days);
	}
	
	/**
	 * 获取指定日期，前n天或后n天
	 * @param date  指定日期
	 * @param pattern 时间格式表达式
	 * @param days  指定天数，负数为前n天，整数位后n天
	 * @return
	 */
	public static String getDayByString(String date, String pattern, int days) {
		Date now = parse(date, pattern);
		return format(getDay(now, days), pattern);
	}


    /**
     * 获取指定日期前n月或后n月日期
     * @param date
     * @param pattern
     * @param months
     * @return
     */
	public static String getMonthDay(Date date , String pattern, int months) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) + months);
		return format(calendar.getTime(), pattern);
	}


    /**
     * 获取指定日期前n月或后n月日期
     * @param date
     * @param pattern
     * @param months
     * @return
     */
	public static String getMongthDay(String date, String pattern, int months) {
	    Date now = parse(date, pattern);
	    return getMonthDay(now, pattern, months);
    }
	
	/**
	 * 替换路径中的日期表达式
	 * <p>
	 * 例如：<br/>
	 * 原字符串：/dw_mkt/auto/ods/event/[yyyy/MM/dd/HH]/table/[yyyy/MM/dd/]<br/>
	 * 转换后字符串： /dw_mkt/auto/ods/event/2015/12/23/18/table//2015/12/23/
	 * </p>
	 * @param path
	 * @param date
	 * @param datePattern
	 * @return
	 */
	public static String replaceDateFormat(String path, String date, String datePattern) {
		if (!StringUtils.isEmpty(path)) {
			Date now = DateUtil.parse(date, datePattern);
			Pattern pattern = Pattern.compile("\\[[^\\]]*\\]");
			Matcher matcher = pattern.matcher(path);
			while (matcher.find()) {
				String dateStr = matcher.group();
				String dateFormat = dateStr.replaceAll("\\[","").replaceAll("\\]", "");
				path = path.replace(dateStr, DateUtil.format(now, dateFormat));
			}
		}
		return path;
	}

	/**
	 * 获取两个日期之间的所有日期，包含开始和结束时间
	 * @param startDay 
	 * @param stopDay 
	 * @param pattern 
	 * @param step
	 * @return
	 */
	public static List<String> getRangeDay(String startDay, String stopDay, String pattern, int step) {
		return getRangeDay(startDay, stopDay,  null, pattern, step);
	}
	
	/**
	 * 获取两个日期之间的所有日期，包含开始和结束时间
	 * @param startDay 
	 * @param stopDay 
	 * @param pattern 
	 * @param step
	 * @return
	 */
	public static List<String> getRangeDay(String startDay, String stopDay, String maxDay, String pattern, int step) {
		step = step == 0 ? 1 : step;
		if (!StringUtils.isEmpty(maxDay)) {
			stopDay = stopDay.compareTo(maxDay) < 0 ? stopDay : maxDay;
		}
		List<String> days = new ArrayList<String>();
		while (startDay.compareTo(stopDay) <= 0) {
			days.add(startDay);
			startDay = getDayByString(startDay, pattern, step);
		}
		return days;
	}
}