package com.nq.utils;

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

public class DateUtil {
    /**
     *
     * @return 返回xx天前的日期
     */
    public static String lastWeek(int dayNum) {
        Date date = new	Date();
        int year = Integer.parseInt(new SimpleDateFormat("yyyy").format(date));
        int month = Integer.parseInt(new SimpleDateFormat("MM").format(date));
        int day	= Integer.parseInt(new SimpleDateFormat("dd").format(date)) - dayNum;

        if (day	< 1) {
            month -= 1;
            if (month == 0)	{
                year -=	1;
                month =	12;
            }
            if (month == 4 || month	== 6 ||	month == 9 || month == 11) {
                day = 30 + day;
            } else if (month == 1 || month == 3 || month ==	5 || month == 7
                    || month == 8 || month == 10 ||	month == 12) {
                day = 31 + day;
            } else if (month == 2) {
                if (year % 400 == 0 || (year % 4 == 0 && year %	100 != 0))
                    day = 29 + day;
                else
                    day = 28 + day;
            }
        }
        String y = year	+ "";
        String m = "";
        String d = "";
        if (month < 10)
            m = "0"	+ month;
        else
            m = month + "";
        if (day	< 10)
            d = "0"	+ day;
        else
            d = day	+ "";
        return y + "-" + m + "-" + d;
    }
    public static String nextDay(String date) {
        DateFormat dft = new SimpleDateFormat("yyyy-MM-dd");
        String nextDay = "";
        try {
            Date temp = dft.parse(date);
            Calendar cld = Calendar.getInstance();
            cld.setTime(temp);
            cld.add(Calendar.DATE, 1);
            temp = cld.getTime();
            //获得下一天日期字符串
             nextDay = dft.format(temp);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return nextDay;
    }

    public static String lastManyDays(int dayNum){
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
        Date date=new Date();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DAY_OF_MONTH, -dayNum);
        date = calendar.getTime();
        return sdf.format(date);
    }

    public static String afterManyDays(int dayNum){
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
        Date date=new Date();
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DAY_OF_MONTH, +dayNum);
        date = calendar.getTime();
        return sdf.format(date);
    }
    public static String lastManyDays(String appointDate,int dayNum){
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
        SimpleDateFormat resultSdf=new SimpleDateFormat("MM-dd");
        Date date = null;
        try {
            date = sdf.parse(appointDate);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DAY_OF_MONTH, -dayNum);
        date = calendar.getTime();
        return resultSdf.format(date);
    }

    // 根据year年的第week周，查询本周的起止时间
    public static String weekToDayFormate(String weekDays){
        int weekDaysLength = weekDays.length();
        int year = 0;
        int week = 0;
        String resultDay = "";
        if (weekDays==null){
            weekDays=new Date().toString();
        }else {
            if (weekDays.substring(weekDaysLength-2,weekDaysLength-1).equals("1")){
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-2,weekDaysLength));
            }else {
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-1,weekDaysLength));
            }
        }


        Calendar calendar = Calendar.getInstance();
        // ①.设置该年份的开始日期：第一个月的第一天
        calendar.set(year,0,1);
        // ②.计算出第一周还剩几天：+1是因为1号是1天
        int dayOfWeek = 7 - calendar.get(Calendar.DAY_OF_WEEK) + 1;
        // ③.周数减去第一周再减去要得到的周
        week = week - 2;
        // ④.计算起止日期
        calendar.add(Calendar.DAY_OF_YEAR,week * 7 + dayOfWeek);
        resultDay+=new SimpleDateFormat("MM/dd").format(calendar.getTime());
        calendar.add(Calendar.DAY_OF_YEAR, 6);
        resultDay+="-"+new SimpleDateFormat("MM/dd").format(calendar.getTime());
        return resultDay;
    }
    /**
     * 根据具体年的周数算出日期范围
     * @param weekDays '%Y%u'  202106
     * @param targetNum 往后推的周数
     * @return MM-dd/MM-dd
     */
    public static String getWeekDays(String weekDays,int targetNum) {
        int weekDaysLength = weekDays.length();
        int year = 0;
        int week = 0;
        String resultDay = "";
        if (weekDays==null){
            weekDays=new Date().toString();
        }else {
            if (weekDays.substring(weekDaysLength-2,weekDaysLength-1).equals("1")){
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-2,weekDaysLength));
            }else {
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-1,weekDaysLength));
            }
        }
        // 计算目标周数
        if (week + targetNum > 52) {
            year++;
            week += targetNum - 52;
        } else if (week + targetNum <= 0) {
            year--;
            week += targetNum + 52;
        } else {
            week += targetNum;
        }

        SimpleDateFormat sdf = new SimpleDateFormat("MM-dd");
        Calendar cal = Calendar.getInstance();

        // 设置每周的开始日期
        cal.setFirstDayOfWeek(Calendar.SUNDAY);

        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.WEEK_OF_YEAR, week);

        cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
        String beginDate = sdf.format(cal.getTime());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        String endDate = sdf.format(cal.getTime());
        return beginDate + "~" + endDate;
    }

    /**
     * 根据具体年的周数算出日期范围
     * @param weekDays '%Y%u'  202106
     * @return MM-dd/MM-dd
     */
    public static String getWeekDays(String weekDays) {
        int weekDaysLength = weekDays.length();
        int year = 0;
        int week = 0;
        String resultDay = "";
        if (weekDays==null){
            weekDays=new Date().toString();
        }else {
            if (weekDays.substring(weekDaysLength-2,weekDaysLength-1).equals("1")){
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-2,weekDaysLength));
            }else {
                year = Integer.parseInt(weekDays.substring(0,weekDaysLength-2));
                week = Integer.parseInt(weekDays.substring(weekDaysLength-1,weekDaysLength));
            }
        }
        SimpleDateFormat sdf = new SimpleDateFormat("MM-dd");
        Calendar cal = Calendar.getInstance();
        // 设置每周的开始日期
        cal.setFirstDayOfWeek(Calendar.SUNDAY);
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.WEEK_OF_YEAR, week);
        cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
        String beginDate = sdf.format(cal.getTime());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        String endDate = sdf.format(cal.getTime());
        return beginDate + "/" + endDate;
    }

    /**
     * 时间戳转换成日期格式字符串
     * @param seconds 精确到秒的字符串
     * @return
     */
    public static String timeStamp2Date(String seconds,String format) {
        if(seconds == null || seconds.isEmpty() || seconds.equals("null")){
            return "";
        }
        if(format == null || format.isEmpty()){
            format = "yyyy-MM-dd HH:mm:ss";
        }
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        return sdf.format(new Date(Long.valueOf(seconds+"000")));
    }



}