date_replace.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Copyright (c) 2017 Renat Nasridinov
# This software may be freely distributed under the MIT license.
# https://opensource.org/licenses/MIT The MIT License (MIT)

import argparse
import json
import os
import sys
import calendar
from datetime import datetime as dt, timedelta, date, timezone


class Error(Exception):
    pass


class TargetDirectoryIsNotExists(Error):
    def __init__(self):
        print('Вказана цільова директорія не існує, встановлено поточну.\n')


DATE_FORMAT = "%d.%m.%Y %H:%M:%S"
DATE_KEYS = ['DocTime', 'GLTime']


parser = argparse.ArgumentParser()

parser.add_argument('-d', '--directory', dest='json_dir', default='.',
                    help='цільова директорія, що містить JSON-файли з '
                    'результатами голосувань')


def last_sun(year_, month_):
    c = calendar.Calendar(6)
    weeks = c.monthdays2calendar(year_, month_)
    last_week = weeks[-1]
    sunday = last_week[0][0]
    return date(year_, month_, sunday)


def is_dst(date_: str) -> timezone:
    date_instance = dt.strptime(date_, DATE_FORMAT).date()
    dst_start = last_sun(date_instance.year, 3)
    dst_start += timedelta(6 - dst_start.weekday())
    dst_end = last_sun(date_instance.year, 10)
    dst_end += timedelta(6 - dst_end.weekday())
    if dst_start <= date_instance < dst_end:
        dst = 3
    else:
        dst = 2
    return timezone(timedelta(hours=dst))


def convert_date(date_: str, tz: timezone) -> str:
    p_date = dt.strptime(date_, DATE_FORMAT)
    year, month, day, hour, minute, second = p_date.year, p_date.month, \
        p_date.day, p_date.hour, p_date.minute, p_date.second
    date2 = dt(year, month, day, hour, minute, second, tzinfo=tz)
    iso8601_date = date2.strftime('%Y-%m-%dT%H:%M:%S%z',)
    return iso8601_date


def check_dir(dir_: str) -> str:
    try:
        if not os.path.isdir(args.json_dir):
            raise TargetDirectoryIsNotExists
        return dir_
    except TargetDirectoryIsNotExists:
        return '.'


def get_jsondir_content(dir_: str) -> list:
    try:
        return [y for y in [f.path for f in os.scandir(dir_) if f.is_file()]
                if os.path.splitext(y)[1].lower() == '.json']
    except:
        print('Неможливо прочтати каталог.\n')
        sys.exit(1)


def date_replace(json_filename: str):
    try:
        with open(json_filename, encoding='utf-8') as f:
            json_data = json.load(f)
    except json.decoder.JSONDecodeError:
        print("Помилка парсингу файлу '{}', пропуск...\n".format(json_filename))
        return
    for key in DATE_KEYS:
        if key in json_data:
            tz = is_dst(json_data[key])
            json_data[key] = convert_date(json_data[key], tz)
    try:
        with open(json_filename, 'w', encoding='utf-8',) as f:
            json.dump(json_data, f, ensure_ascii=False,)
    except:
        raise
    return 0


def main(args_):
    json_dir = args_.json_dir
    if json_dir != '.':
        json_dir = check_dir(json_dir)
    dir_content = get_jsondir_content(json_dir)
    if not dir_content:
        print('JSON-файли у цільовій директорії відсутні.\n')
        sys.exit(0)
    for json_filename in dir_content:
        date_replace(json_filename)


if __name__ == "__main__":
    args = parser.parse_args()
    main(args)