#
# Copyright 2016 Quantopian, Inc.
#
# 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.

from datetime import time
from pandas.tseries.holiday import(
    Holiday,
    DateOffset,
    MO,
    weekend_to_monday,
    GoodFriday,
    EasterMonday,
)
from pytz import timezone

from .trading_calendar import (
    TradingCalendar,
    MONDAY,
    TUESDAY,
    HolidayCalendar)

# New Year's Day
LSENewYearsDay = Holiday(
    "New Year's Day",
    month=1,
    day=1,
    observance=weekend_to_monday,
)
# Early May bank holiday
MayBank = Holiday(
    "Early May Bank Holiday",
    month=5,
    offset=DateOffset(weekday=MO(1)),
    day=1,
)
# Spring bank holiday
SpringBank = Holiday(
    "Spring Bank Holiday",
    month=5,
    day=31,
    offset=DateOffset(weekday=MO(-1)),
)
# Summer bank holiday
SummerBank = Holiday(
    "Summer Bank Holiday",
    month=8,
    day=31,
    offset=DateOffset(weekday=MO(-1)),
)
# Christmas
Christmas = Holiday(
    "Christmas",
    month=12,
    day=25,
)
# If christmas day is Saturday Monday 27th is a holiday
# If christmas day is sunday the Tuesday 27th is a holiday
WeekendChristmas = Holiday(
    "Weekend Christmas",
    month=12,
    day=27,
    days_of_week=(MONDAY, TUESDAY),
)
# Boxing day
BoxingDay = Holiday(
    "Boxing Day",
    month=12,
    day=26,
)
# If boxing day is saturday then Monday 28th is a holiday
# If boxing day is sunday then Tuesday 28th is a holiday
WeekendBoxingDay = Holiday(
    "Weekend Boxing Day",
    month=12,
    day=28,
    days_of_week=(MONDAY, TUESDAY),
)


class LSEExchangeCalendar(TradingCalendar):
    """
    Exchange calendar for the London Stock Exchange

    Open Time: 8:00 AM, GMT
    Close Time: 4:30 PM, GMT

    Regularly-Observed Holidays:
    - New Years Day (observed on first business day on/after)
    - Good Friday
    - Easter Monday
    - Early May Bank Holiday (first Monday in May)
    - Spring Bank Holiday (last Monday in May)
    - Summer Bank Holiday (last Monday in May)
    - Christmas Day
    - Dec. 27th (if Christmas is on a weekend)
    - Boxing Day
    - Dec. 28th (if Boxing Day is on a weekend)
    """

    @property
    def name(self):
        return "LSE"

    @property
    def tz(self):
        return timezone('Europe/London')

    @property
    def open_time(self):
        return time(8, 1)

    @property
    def close_time(self):
        return time(16, 30)

    @property
    def regular_holidays(self):
        return HolidayCalendar([
            LSENewYearsDay,
            GoodFriday,
            EasterMonday,
            MayBank,
            SpringBank,
            SummerBank,
            Christmas,
            WeekendChristmas,
            BoxingDay,
            WeekendBoxingDay
        ])
