import asyncio
import logging
import ssl

import aiosmtplib
from email.mime.base import MIMEBase
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from fastapi.responses import RedirectResponse
from typing import Union, List


async def send_email(
    host: str,
    port: int,
    message: str,
    timeout: int,
    sender: str,
    recipient: str,
    subject: str,
    login_email: str,
    password: str,
    attachments: List[MIMEBase] = tuple(),
    use_tls: bool = True,
    check_hostname: bool = True,
) -> Union[bool, aiosmtplib.SMTPException]:
    """
    Sends an email with the given details. Returns True on success
    or an exception object upon failure
    """

    try:
        async with aiosmtplib.SMTP(host, port, timeout=timeout) as srv:
            msg = MIMEMultipart()
            msg["From"] = sender
            msg["To"] = recipient
            msg["Subject"] = subject
            msg.attach(MIMEText(message, "html"))
            for attachment in attachments:
                msg.attach(attachment)
            await srv.ehlo()  # We identify ourselves
            if use_tls:
                context = ssl.create_default_context()
                context.check_hostname = check_hostname
                await srv.starttls(tls_context=context)
                await srv.ehlo()  # We do it again, but encrypted!
            await srv.login(login_email, password)
            await srv.sendmail(sender, recipient, msg.as_string())
    except (aiosmtplib.SMTPException, asyncio.TimeoutError) as error:
        logging.error(f"An error occurred while dealing with {host}:{port} (SMTP): {type(error).__name__}: {error}")
        return error
    return True


async def test_smtp(
    host: str,
    port: int,
    login_email: str,
    password: str,
    timeout: int,
    use_tls: bool = True,
    check_hostname: bool = True,
):
    """
    Attempts login to the given SMTP server with the given credentials.
    Used upon startup, raises an exception upon failure. This will
    fail if the server does not support TLS encryption for login
    """

    async with aiosmtplib.SMTP(host, port, timeout=timeout) as srv:
        await srv.ehlo()
        if use_tls:
            context = ssl.create_default_context()
            context.check_hostname = check_hostname
            await srv.starttls(tls_context=context)
            await srv.ehlo()
        await srv.login(login_email, password)


def redirect(url: str) -> RedirectResponse:
    """
    Returns a redirect response to the given url
    """

    return RedirectResponse(url=url)