# -*- coding: utf-8 -*-
from datetime import timedelta
from math import ceil

from . import ExactDate, Solar
from .util import SolarUtil


class SolarWeek:
 """
 阳历周
 """

 def __init__(self, year, month, day, start):
 """
 通过年月日初始化
 :param year: 年
 :param month: 月,1到12
 :param day: 日,1到31
 :param start: 星期几作为一周的开始,1234560分别代表星期一至星期天
 """
 self.__year = year
 self.__month = month
 self.__day = day
 self.__start = start

 @staticmethod
 def fromDate(date, start):
 return SolarWeek(date.year, date.month, date.day, start)

 @staticmethod
 def fromYmd(year, month, day, start):
 return SolarWeek(year, month, day, start)

 def getYear(self):
 return self.__year

 def getMonth(self):
 return self.__month

 def getDay(self):
 return self.__day

 def getStart(self):
 return self.__start

 def toString(self):
 return "%d.%d.%d" % (self.__year, self.__month, self.getIndex())

 def toFullString(self):
 return "%d年%d月第%d周" % (self.__year, self.__month, self.getIndex())

 def __str__(self):
 return self.toString()

 def getIndex(self):
 """
 获取当前日期是在当月第几周
 :return: 周序号,从1开始
 """
 first_day = ExactDate.fromYmd(self.__year, self.__month, 1)
 first_day_week = first_day.isoweekday()
 if 7 == first_day_week:
 first_day_week = 0
 offset = first_day_week - self.__start
 if offset < 0:
 offset += 7
 return int(ceil((self.__day + offset) * 1.0 / 7))

 def getFirstDay(self):
 """
 获取本周第一天的阳历日期(可能跨月)
 :return: 本周第一天的阳历日期
 """
 date = ExactDate.fromYmd(self.__year, self.__month, self.__day)
 week = date.isoweekday()
 if week == 7:
 week = 0
 prev = week - self.__start
 if prev < 0:
 prev += 7
 date = date + timedelta(days=-prev)
 return Solar.fromDate(date)

 def getFirstDayInMonth(self):
 """
 获取本周第一天的阳历日期(仅限当月)
 :return: 本周第一天的阳历日期
 """
 for day in self.getDays():
 if self.__month == day.getMonth():
 return day
 return None

 def getDays(self):
 """
 获取本周的阳历日期列表(可能跨月)
 :return: 本周的阳历日期列表
 """
 days = []
 first = self.getFirstDay()
 days.append(first)
 for i in range(1, 7):
 days.append(first.next(i))
 return days

 def getDaysInMonth(self):
 """
 获取本周的阳历日期列表(仅限当月)
 :return: 本周的阳历日期列表(仅限当月)
 """
 days = []
 for day in self.getDays():
 if self.__month == day.getMonth():
 days.append(day)
 return days

 def next(self, weeks, separate_month):
 """
 周推移
 :param weeks: 推移的周数,负数为倒推
 :param separate_month: 是否按月单独计算
 :return: 推移后的阳历周
 """
 if 0 == weeks:
 return SolarWeek.fromYmd(self.__year, self.__month, self.__day, self.__start)
 if separate_month:
 n = weeks
 c = ExactDate.fromYmd(self.__year, self.__month, self.__day)
 week = SolarWeek.fromDate(c, self.__start)
 month = self.__month
 plus = n > 0
 days = 7 if plus else -7
 while 0 != n:
 c = c + timedelta(days=days)
 week = SolarWeek.fromDate(c, self.__start)
 week_month = week.getMonth()
 if month != week_month:
 index = week.getIndex()
 if plus:
 if 1 == index:
 first_day = week.getFirstDay()
 week = SolarWeek.fromYmd(first_day.getYear(), first_day.getMonth(), first_day.getDay(), self.__start)
 week_month = week.getMonth()
 else:
 c = ExactDate.fromYmd(week.getYear(), week.getMonth(), 1)
 week = SolarWeek.fromDate(c, self.__start)
 else:
 size = SolarUtil.getWeeksOfMonth(week.getYear(), week.getMonth(), self.__start)
 if size == index:
 first_day = week.getFirstDay()
 last_day = first_day.next(6)
 week = SolarWeek.fromYmd(last_day.getYear(), last_day.getMonth(), last_day.getDay(), self.__start)
 week_month = week.getMonth()
 else:
 c = ExactDate.fromYmd(week.getYear(), week.getMonth(), SolarUtil.getDaysOfMonth(week.getYear(), week.getMonth()))
 week = SolarWeek.fromDate(c, self.__start)
 month = week_month
 n -= 1 if plus else -1
 return week
 else:
 c = ExactDate.fromYmd(self.__year, self.__month, self.__day)
 c = c + timedelta(days=weeks * 7)
 return SolarWeek.fromDate(c, self.__start)