# coding=utf8

from __future__ import unicode_literals, absolute_import, print_function

import datetime
import time

import pytz
from django.conf import settings
from django.utils import timezone


def get_timestamp_epoch(the_time):
    if the_time is None:
        return None

    if isinstance(the_time, str):
        try:
            the_time = datetime.datetime.strptime(the_time, "%Y-%m-%d %H:%M:%S")
        except ValueError:
            raise ValueError('time string must in <%Y-%m-%d %H:%M:%S> format')

    if isinstance(the_time, datetime.datetime):
        pass
    elif isinstance(the_time, datetime.date):
        # TODO: 是这样算的么？
        the_time = datetime.datetime(
            the_time.year, the_time.month, the_time.day)
    else:
        raise TypeError(
            "datetime.datetime or datetime.date expected. [%s]" % type(the_time))
    return int((the_time - datetime.datetime.fromtimestamp(0)).total_seconds())


def get_timestamp(the_time):
    if the_time is None:
        return None
    return get_timestamp_epoch(the_time) + 8 * 3600


def get_datetime(the_time):
    return datetime.datetime.utcfromtimestamp(the_time)


def get_timestamp_or_none(the_time):
    return get_timestamp(the_time) if the_time is not None else None


def week_monday(date):
    """
    返回date所属周的周一
    """
    return add_day(date, -date.isoweekday() + 1)


def get_monday(day=None):
    """
    返回输入日期的当星期的星期一的日期
    :param day: 输入日期
    :return: 输入日期的星期的星期一
    """
    if not day:
        day = datetime.date.today()
    return week_monday(day)


def get_humanize_datetime(d):
    """humanize datetime
    """
    now = datetime.datetime.now()

    if d.year == now.year:
        if d.month == now.month:
            if d.day == now.day:
                return u'今天'
            else:
                return u'{}天前'.format(now.day - d.day)
        else:
            return d.strftime('%m-%d')
    else:
        return d.strftime('%Y-%m-%d')


def get_seconds_left_to_end_of_day():
    now = timezone.now()
    end_of_day = datetime.datetime.combine(now, datetime.time.max)
    time_delta = end_of_day - now
    return int(time_delta.total_seconds())


def add_month(dt, n):
    return datetime.date(
        dt.year + (dt.month + n - 1) / 12,
        (dt.month + n) % 12 or 12,
        dt.day,
    )


def add_day(dt, n):
    return dt + datetime.timedelta(days=n)


def tzlc(dt, truncate_to_sec=True):
    if dt is None:
        return None
    if truncate_to_sec:
        dt = dt.replace(microsecond=0)
    return pytz.timezone(settings.TIME_ZONE).localize(dt)


def ts_now_as_score():
    return int(time.mktime(timezone.now().timetuple()))


MIN_TIME = tzlc(datetime.datetime.utcfromtimestamp(0))
MAX_TIME = tzlc(datetime.datetime.utcfromtimestamp(2147483647))