#!/usr/bin/env python3


import datetime
from mailbox import mbox, mboxMessage
import re
from typing import Tuple


class Parser:
    INFO_REGEX = re.compile(r"(\d{6}) \| (x\S*)\s*")
    SUBMISSION_REGEX = re.compile(r"adresář:\s+\S*\/(\S*)\s*")
    POINTS_REGEX = re.compile(r"\*\scelkový počet bodů\s+((\d|\.)*)\s*")
    DATE_FORMAT = "%Y_%m%d_%H%M%S"
    OFFSET_FOR_CORRECTION = datetime.timedelta(days=8)

    @staticmethod
    def get_match_from_mail(regex: re.Pattern, mail: mboxMessage) -> re.Match:
        body = mail.get_payload()
        match = regex.search(body)
        if not match:
            raise ValueError("invalid mail has been given")

        return match

    @staticmethod
    def parse_info(mail: mboxMessage) -> Tuple[str, str]:
        match = Parser.get_match_from_mail(Parser.INFO_REGEX, mail)
        return match.group(1), match.group(2)

    @staticmethod
    def parse_submission(mail: mboxMessage) -> str:
        match = Parser.get_match_from_mail(Parser.SUBMISSION_REGEX, mail)
        return match.group(1)

    @staticmethod
    def parse_points(mail: mboxMessage) -> float:
        match = Parser.get_match_from_mail(Parser.POINTS_REGEX, mail)
        return float(match.group(1))

    def submitted_before_deadline(self, submission: str) -> bool:
        submitted = datetime.datetime.strptime(
            submission.split("/")[-1][-16:], Parser.DATE_FORMAT
        )
        return self.deadline > submitted

    def __init__(self, path: str, deadline: str, correction: bool = False) -> None:
        self.box = mbox(path)
        self.deadline = datetime.datetime.strptime(deadline, Parser.DATE_FORMAT)
        if correction:
            # in case of correction pass the date of
            # submitting review to IS for automatic computation
            self.deadline = self.deadline.replace(hour=0, minute=0, second=0)
            self.deadline += Parser.OFFSET_FOR_CORRECTION


if __name__ == "__main__":
    mails = mbox("~/xyz.mbox")
    _, mail = mails.popitem()
    print(Parser.parse_info(mail))
    print(Parser.parse_submission(mail))
    print(Parser.parse_points(mail))