# -*- encoding: utf-8 -*-
from datetime import datetime
from email import encoders
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import logging
import smtplib
import ssl
import typing as T


RETRIES = 3
logger = logging.getLogger(__name__)


def retry_and_log(func: T.Callable[..., T.Any]) -> T.Callable[..., T.Any]:
    """
    This decorator wraps a function, logs at info in case of success and logs
    error in case an exception is raised.
    """
    def inner(*args, **kwargs):
        for i in range(RETRIES):
            try:
                func(*args, **kwargs)
                logger.info(f"Success ({i+1} tentative): {func.__name__}(args={args}, kwargs={kwargs})")  # noqa: E501
                return
            except Exception as e:
                logger.error(f"Failure ({i+1} tentative): {e}")

    return inner


class Notifier(object):
    def __init__(
        self,
        smtp_addr: T.Text,
        smtp_port: int,
        smtp_starttls: bool,
        smtp_user: T.Text,
        smtp_pass: T.Text,
        smtp_from: T.Optional[T.Text] = None,
    ) -> None:
        context = ssl.create_default_context()
        if smtp_starttls:
            self._conn = smtplib.SMTP_SSL(smtp_addr, smtp_port)
            self._greet = self._conn.ehlo
        else:
            self._conn = smtplib.SMTP(smtp_addr, smtp_port)
            self._greet = lambda: self._conn.starttls(context=context)

        self._addr = smtp_addr
        self._port = smtp_port
        self._user = smtp_user
        self._pass = smtp_pass
        self._from = smtp_from if smtp_from else smtp_user
        logger.info("%s initialized", self)

    def __str__(self) -> T.Text:
        return f"Notifier<{self._addr}:{self._port},from={self._from}>"

    def send(self, to: T.List[T.Text], email: T.Text) -> None:
        self._greet()
        self._conn.login(self._user, self._pass)
        self._conn.sendmail(self._from, to, email)
        self._conn.close()

    @retry_and_log
    def send_result(self, to: T.List[T.Text], result: bytes) -> None:
        date = datetime.now().strftime("%Y-%m-%d")
        body = f"Resoconto dei voli dal sito di AdR per l'aereoporto di Ciampino in data {date}"  # noqa: E501

        message = MIMEMultipart()
        message["From"] = self._from
        message["To"] = ",".join(to)
        message["Subject"] = f"[{date}] Resoconto CIA da AdR"

        message.attach(MIMEText(body, "plain"))

        payload = MIMEBase("application", "octet-stream")
        payload.set_payload(result)
        encoders.encode_base64(payload)
        payload.add_header(
            "Content-Disposition",
            f"attachment; filename={date}.xlsx",
        )

        message.attach(payload)

        email = message.as_string()

        self.send(to, email)