#!/usr/bin/env python

# Synopsys:
#   Print the last business days in one year.
#
# Example:
#   $ last-business-days 2024
#   2024-01-31
#   2024-02-29
#   2024-03-29
#   2024-04-30
#   2024-05-31
#   2024-06-28
#   2024-07-31
#   2024-08-30
#   2024-09-30
#   2024-10-31
#   2024-11-29
#   2024-12-27
#
# References:
#   * Generate last business day of the month variable in Python for US Calendar - Stack Overflow
#     <https://stackoverflow.com/questions/62557373/generate-last-business-day-of-the-month-variable-in-python-for-us-calendar>
#   * Get the last day of the month - Stack Overflow
#     <https://stackoverflow.com/questions/42950/get-the-last-day-of-the-month>
#   * Lalcs/jpholiday: 日本の祝日を取得するライブラリ
#     <https://github.com/Lalcs/jpholiday>

import calendar
import datetime
import sys

# pip install jpholiday
import jpholiday

ONEDAY = datetime.timedelta(days=1)

def is_weekend(d):
    return d.weekday() >= 5

def last_business_day(year):
    for m in range(1, 13):
        _, last = calendar.monthrange(year, m)
        d = datetime.datetime(year, m, last)
        while is_weekend(d) or is_holiday(d):
            d -= ONEDAY
        yield d

class TestHoliday(jpholiday.OriginalHoliday):
    def _is_holiday(self, d):
        match d.month:
            case 1:
                return d.day in (2, 3)
            case 12:
                return d.day in (29, 30, 31)
            case _:
                return False

def is_holiday(d):
    return jpholiday.is_holiday(d)

def main(args=sys.argv[1:]):
    year = int(args[0])
    for d in last_business_day(year):
        print(d.isoformat().split('T')[0])

if __name__ == '__main__':
    main()