#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2022, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Calendar file of US Holidays from Mozilla provided by `icalendar`_.

License `CC BY-SA 3.0`_

Sourced from: https://www.mozilla.org/en-US/projects/calendar/holidays/

This module contains one list: ``us_holidays``.

.. rubric:: ``us_holidays``

.. code-block::

    [
        (datetime.date(1966, 12, 26), 'Kwanzaa'),
        (datetime.date(2000, 1, 1), "New Year's Day"),
        ...
        (datetime.date(2020, 12, 25), 'Christmas Day (US-OPM)')
    ]

.. bokeh-sampledata-xref:: us_holidays

.. _icalendar: https://pypi.org/project/icalendar/
'''

#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

# Standard library imports
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from datetime import datetime

# Bokeh imports
from ..util.dependencies import import_required
from ..util.sampledata import package_path

#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------

__all__ = (
    'us_holidays',
)

#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------

def _read_data() -> list[tuple[datetime, str]]:
    '''

    '''
    ic = import_required('icalendar', "us_holidays data requires icalendar (http://icalendar.readthedocs.org) to be installed")

    with open(package_path("USHolidays.ics")) as f:
        data = ic.Calendar.from_ical(f.read())

    return sorted((comp.get("dtstart").dt, str(comp.get("summary"))) for comp in data.walk() if comp.name == "VEVENT")

#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------

us_holidays = _read_data()