#!/usr/bin/env python3

###############################################################################
#
# Copyright 2016, 2018 - 2022, Gothenburg Bit Factory
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# SOFTWARE.
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# https://www.opensource.org/licenses/mit-license.php
#
###############################################################################

import argparse
import datetime
import json
import os
import re
from textwrap import dedent
from urllib.error import HTTPError
from urllib.request import urlopen


def gather_locale_files(path):
    """Enumerate all holiday files in the current directory."""

    locale_file_map = {}
    re_holiday_file = re.compile(r"/holidays.([a-z]{2}-[A-Z]{2})$")

    for file in enumerate(path):
        result = re_holiday_file.search(file)
        if result:
            # Extract the locale name.
            locale_file_map[result.group(1)] = file

    return locale_file_map


def enumerate(path):
    if not os.path.exists(path):
        raise Exception(f"Directory '{path}' does not exist")

    found = []

    for path, dirs, files in os.walk(path, topdown=True, onerror=None, followlinks=False):
        found.extend([os.path.join(path, x) for x in files])

    return found


def create_locale_files(path, locales):
    locale_file_map = {}

    for locale in locales:
        locale_file_map[locale] = os.path.join(path, f"holidays.{locale}")

    return locale_file_map


def update_locale_files(locales, regions, years):
    now = datetime.datetime.now()

    if not years:
        years = [now.year, now.year + 1]

    for locale, file in locales.items():
        with open(file, "w") as fh:
            fh.write(dedent(f"""\
            # Holiday data provided by holidata.net
            #   Generated {now:%Y-%m-%dT%H:%M:%S}
            
            define holidays:
              {locale}:
            """))

            for year in years:
                try:
                    holidays = get_holidata(locale, regions, year)

                    for date, desc in holidays.items():
                        fh.write(f"    {date} = {desc}\n")

                    fh.write("\n")

                except HTTPError as e:
                    if e.code == 404:
                        print(f"holidata.net does not have data for {locale}, for {year}.")
                    else:
                        print(e.code, e.read())


def get_holidata(locale, regions, year):
    url = f"https://holidata.net/{locale}/{year}.json"
    print(url)
    holidays = dict()
    lines = urlopen(url).read().decode("utf-8")

    for line in lines.split("\n"):
        if line:
            j = json.loads(line)

            if not j["region"] or not regions or j["region"] in regions:
                day = j["date"].replace("-", "_")
                desc = j["description"]
                holidays[day] = desc

    return holidays


def main(args):
    locale_files = create_locale_files(args.path, args.locale) if args.locale else gather_locale_files(args.path)
    update_locale_files(locale_files, args.region, args.year)


if __name__ == "__main__":
    usage = """See https://holidata.net for details of supported locales and regions."""
    parser = argparse.ArgumentParser(
        description="Update holiday data files. Simply run 'refresh' to update all of them.",
        usage="refresh [-h] [path] [--locale LOCALE [LOCALE ...]] [--region REGION [REGION ...]] [--year YEAR [YEAR ...]]"
    )
    parser.add_argument("--locale", nargs="+", help="specify locale to update")
    parser.add_argument("--region", nargs="+", help="specify locale region to update", default=[])
    parser.add_argument("--year", nargs="+", help="specify year to fetch (defaults to current and next year)", type=int, default=[])
    parser.add_argument("path", nargs="?", help="base path to search for locales (defaults to current directory)", default=".")

    try:
        main(parser.parse_args())
    except Exception as msg:
        print("Error:", msg)