from datetime import datetime

import RawMail
import User
from DBConn import DBConn, get_unix_timestamp


class Mail:
    """Class for holding the data in the mail table of the database"""
    def __init__(self):
        self.__mail_id = None
        self.__raw_id = None
        self.__from_id = None
        self.__to_id = None
        self.__mail_subject = None
        self.__mail_body = None
        self.__mail_read = None
        self.__mail_date_sent = None

        # Holding variables for the from, to and raw mail class objects
        self.__from_user: User.User or None = None
        self.__to_user: User.User or None = None
        self.__raw_mail: RawMail.RawMail or None = None

        self.__is_valid = False

    def load_mail(self, mail_id: int):
        """Method to load the mail with the id given"""
        self.__mail_id = mail_id
        self.__load_mail()

    def __load_mail(self) -> None:
        """Private method to load the mail from the database using the mail_id"""
        db_connection = DBConn()
        mail_details = db_connection.do_select("mail_store", "row", "*", "mail_id = :mail_id",
                                               [
                                                   {
                                                       "field": "mail_id",
                                                       "value": self.__mail_id
                                                   }
                                               ])

        if mail_details is not None and len(mail_details) > 0:
            self.__mail_id = mail_details['mail_id']
            self.__raw_id = mail_details['raw_id']
            self.__from_id = mail_details['from_id']
            self.__to_id = mail_details['to_id']
            self.__mail_subject = mail_details['mail_subject']
            self.__mail_body = mail_details['mail_body']
            self.__mail_read = mail_details['mail_read']
            self.__mail_date_sent = mail_details['mail_date_sent']
            self.__is_valid = True

    def mail_is_valid(self):
        """Method to check if we have loaded a valid mail from the DB"""
        return self.__is_valid

    def get_mail_id(self):
        """Method to return the mail id"""
        return self.__mail_id

    def get_subject(self, trim_len: int = 0):
        """Method to return the subject line, if given a number it will truncate the string to that len"""
        if trim_len > 0:
            return self.__mail_subject[0:trim_len]
        else:
            return self.__mail_subject

    def get_date_sent(self, format_string: str = "%d/%m/%y %H:%M"):
        """Method to get the sent date with the given date format"""
        date_time_string = datetime.utcfromtimestamp(self.__mail_date_sent).strftime(format_string)
        return date_time_string

    def get_from_user(self) -> User.User or None:
        """Method to load a user object into the from user variable"""
        if self.__from_id:
            # Preload the user into the object if not loaded beforehand
            if not self.__from_user:
                self.__from_user = User.User(self.__from_id)
            return self.__from_user
        else:
            return None

    def get_to_user(self) -> User.User or None:
        """Method to load a user object into the to user variable"""
        if self.__to_id:
            # Preload the user into the object if not loaded beforehand
            if not self.__to_user:
                self.__to_user = User.User(self.__to_id)
            return self.__to_user
        else:
            return None

    def get_raw_mail(self):
        """Method to load a raw mail object into the variable"""
        if not self.__raw_mail:
            self.__raw_mail = RawMail.RawMail()
            self.__raw_mail.load_raw_mail(self.__raw_id)
        return self.__raw_mail

    def create_mail(self, raw_id: int, from_id: int, to_id: int, subject: str, body: str) -> bool:
        """Method to add the mail to the database"""
        result = False
        if not self.__is_valid:
            if raw_id and from_id and to_id and len(subject) > 0 or len(body) > 0:
                db_connection = DBConn()
                self.__mail_id = db_connection.do_insert("mail_store",
                                                         [{"field": "raw_id", "value": raw_id},
                                                          {"field": "from_id", "value": from_id},
                                                          {"field": "to_id", "value": to_id},
                                                          {"field": "mail_subject", "value": subject},
                                                          {"field": "mail_body", "value": body},
                                                          {"field": "mail_read", "value": 0},
                                                          {"field": "mail_date_sent", "value": get_unix_timestamp()}],
                                                         True)
                if self.__mail_id:
                    self.__load_mail()
                    result = True

        return result