Cron Job Scheduler Syntax Parser

schedule.py

"""
"""
import calendar
import locale
import yaml
import nltk
import re
import datetime
locale.setlocale(locale.LC_ALL, 'en_US.UTF-8')

# schedule = {
#     "schedule": "every monday, tuesday, wednesday, thursday, friday 09:00"
# }

# print(yaml.dump(schedule))

"""
tasks:
    - clone: ...
    - install: ...
    - 

check folde existence?

"""


configuration_str = """
schedule: every Monday,Tuesday, Thursday, Friday 20:00
---
schedule: next Friday 20:00
---
schedule: 2020-05-02 10:00

"""

weekdays = list(calendar.day_name)

# print(list(calendar.day_abbr))

PREFIX = "every"

def schedule_parser(schedule_str):
    parts = {
        "type": r"^every|^next",
        # "date": r"([12]\d{3}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01]))",
        "comma": r",",
        "day": "|".join(weekdays),
        "time": r"([0-1][0-9]|[2][0-3]):([0-5][0-9])",
        "whitespace": r"\s+",
        "missmatch": r"."
    }
    expr = re.compile('|'.join(f"(?P<{name}>{expr})" for name, expr in parts.items()))
    tokens = expr.finditer(schedule_str)

    # Schedule type A every day at time
    schedule_type = None
    days = []
    time = None

    for token in tokens:
        kind = token.lastgroup
        value = token.group()
        column = token.start()

        # print(kind, value, column)
        # if token.isspace():
            # continue
        # if schedule_type is None:
        if kind in ("whitespace", "comma", "date"):
            continue
        elif kind == "type":
            schedule_type = value
        elif kind == "day":
            days.append(value)
        elif kind == "time":
            time = value

            # print(kind, value, column)
        else:
            raise Exception(f"Invalid token \"{value}\" ({kind}) found at column {column}")
            # print(kind, value, column)

    return schedule_type, days, time


def next_date(day, time):
    today = datetime.datetime.today()
    date = today + datetime.timedelta(days=7 - today.weekday() + weekdays.index(day))

    hour, minute = map(int, time.split(":"))
    date = date.replace(hour=hour, minute=minute, second=0, microsecond=0)

    return date



if __name__ == "__main__":
    for configuration in yaml.safe_load_all(configuration_str):
        schedule = configuration["schedule"]
        schedule_type, days, time = schedule_parser(schedule)
        break


    today = datetime.datetime.today()

    last_monday = today - datetime.timedelta(days=today.weekday())
    coming_monday = today + datetime.timedelta(days=-today.weekday(), weeks=1)
    # print("Today:", today)
    # print("Weekday:", today.weekday())
    # print("Last Monday:", last_monday)
    # print("Coming Monday:", coming_monday)

    # print(calendar.day_name._days)
    for day in days:
        date = next_date(day, time)
        print(day, date)

        print(today < date)

        # print(date)