# Copyright (C) 2020 by Maike <maike@systemli.org>
# Copyright (C) 2020 by Cathy Hu <cathy.hu@fau.de>
# Copyright (C) 2020 by Thomas Lindner <tom@dl6tom.de>
#
# SPDX-License-Identifier: 0BSD

from fastapi import APIRouter, Depends, HTTPException, Response, status
from kibicara.platforms.email.bot import spawner
from kibicara.platforms.email.model import Email, EmailSubscribers
from kibicara.platformapi import Message
from kibicara.config import config
from kibicara.email import send_email
from kibicara.webapi.admin import from_token, to_token
from kibicara.webapi.hoods import get_hood, get_hood_unauthorized
from logging import getLogger
from ormantic.exceptions import NoMatch
from os import urandom
from pydantic import BaseModel
from smtplib import SMTPException
from sqlite3 import IntegrityError


logger = getLogger(__name__)


class BodyEmail(BaseModel):
    name: str


class BodyMessage(BaseModel):
    """ This model shows which values are supplied by the MDA listener script. """

    text: str
    secret: str


class BodySubscriber(BaseModel):
    """ This model holds the email address of a fresh subscriber. """

    email: str


async def get_email(email_id: int, hood=Depends(get_hood)):
    """ Get Email row by hood.
    You can specify an email_id to nail it down, but it works without as well.

    :param hood: Hood the Email bot belongs to.
    :return: Email row of the found email bot.
    """
    try:
        return await Email.objects.get(id=email_id, hood=hood)
    except NoMatch:
        return HTTPException(status_code=status.HTTP_404_NOT_FOUND)


async def get_subscriber(subscriber_id: int, hood=Depends(get_hood)):
    try:
        return await EmailSubscriber.objects.get(id=subscriber_id, hood=hood)
    except NoMatch:
        return HTTPException(status_code=status.HTTP_404_NOT_FOUND)


# registers the routes, gets imported in /kibicara/webapi/__init__.py
router = APIRouter()


@router.get('/')
async def email_read_all(hood=Depends(get_hood)):
    return await Email.objects.filter(hood=hood).all()


@router.post('/', status_code=status.HTTP_201_CREATED)
async def email_create(values: BodyEmail, response: Response, hood=Depends(get_hood)):
    """ Create an Email bot. Call this when creating a hood.

    :param hood: Hood row of the hood the Email bot is supposed to belong to.
    :return: Email row of the new email bot.
    """
    if not values.name.startswith('kibicara-'):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail='Recipient address didn\'t start with kibicara-',
        )
    try:
        email = await Email.objects.create(
            hood=hood, secret=urandom(32).hex(), **values.__dict__
        )
        spawner.start(email)
        response.headers['Location'] = '%d' % hood.id
        return email
    except IntegrityError:
        raise HTTPException(status_code=status.HTTP_409_CONFLICT)


@router.get('/{email_id}')
async def email_read(email=Depends(get_email)):
    return email


@router.put('/{email_id}', status_code=status.HTTP_204_NO_CONTENT)
async def email_update(email=Depends(get_email)):
    await email.update()


@router.delete('/{email_id}', status_code=status.HTTP_204_NO_CONTENT)
async def email_delete(email=Depends(get_email)):
    """ Delete an Email bot.
    Stops and deletes the Email bot.

    :param hood: Hood the Email bot belongs to.
    """
    await email.delete()


@router.post('/subscribe/', status_code=status.HTTP_202_ACCEPTED)
async def email_subscribe(
    subscriber: BodySubscriber, hood=Depends(get_hood_unauthorized)
):
    """ Send a confirmation mail to subscribe to messages via email.

    :param subscriber: Subscriber object, holds the email address.
    :param hood: Hood the Email bot belongs to.
    :return: Returns status code 200 after sending confirmation email.
    """
    token = to_token(hood=hood.id, email=subscriber.email)
    confirm_link = '%s/api/%d/email/subscribe/confirm/%s' % (
        config['root_url'],
        hood.id,
        token,
    )
    try:
        send_email(
            subscriber.email,
            "Subscribe to Kibicara " + hood.name,
            sender=hood.name,
            body='To confirm your subscription, follow this link: ' + confirm_link,
        )
        return {}
    except ConnectionRefusedError:
        logger.info(token)
        logger.error("Sending subscription confirmation email failed.", exc_info=True)
        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY)
    except SMTPException:
        logger.info(token)
        logger.error("Sending subscription confirmation email failed.", exc_info=True)
        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY)


@router.post('/subscribe/confirm/{token}', status_code=status.HTTP_201_CREATED)
async def email_subscribe_confirm(token, hood=Depends(get_hood_unauthorized)):
    """ Confirm a new subscriber and add them to the database.

    :param token: encrypted JSON token, holds the email of the subscriber.
    :param hood: Hood the Email bot belongs to.
    :return: Returns status code 200 after adding the subscriber to the database.
    """
    payload = from_token(token)
    # If token.hood and url.hood are different, raise an error:
    if hood.id is not payload['hood']:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST)
    try:
        await EmailSubscribers.objects.create(hood=hood.id, email=payload['email'])
        return {}
    except IntegrityError:
        raise HTTPException(status_code=status.HTTP_409_CONFLICT)


@router.delete('/unsubscribe/{token}', status_code=status.HTTP_204_NO_CONTENT)
async def email_unsubscribe(token, hood=Depends(get_hood_unauthorized)):
    """ Remove a subscriber from the database when they click on an unsubscribe link.

    :param token: encrypted JSON token, holds subscriber email + hood.id.
    :param hood: Hood the Email bot belongs to.
    """
    logger.warning("token is: " + token)
    payload = from_token(token)
    # If token.hood and url.hood are different, raise an error:
    if hood.id is not payload['hood']:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST)
    await EmailSubscribers.objects.delete(hood=payload['hood'], email=payload['email'])


@router.get('/subscribers/')
async def subscribers_read_all(hood=Depends(get_hood)):
    return await EmailSubscribers.objects.filter(hood=hood).all()


@router.get('/subscribers/{subscriber_id}')
async def subscribers_read(subscriber=Depends(get_subscriber)):
    return subscriber


@router.post('/messages/', status_code=status.HTTP_201_CREATED)
async def email_message_create(
    message: BodyMessage, hood=Depends(get_hood_unauthorized)
):
    """ Receive a message from the MDA and pass it to the censor.

    :param message: BodyMessage object, holds the message.
    :param hood: Hood the Email bot belongs to.
    :return: returns status code 201 if the message is accepted by the censor.
    """
    for email in await Email.objects.filter(hood=hood).all():
        if message.secret == email.secret:
            # check API secret
            logger.warning(str(message))
            logger.warning(str(email))
            # pass message.text to bot.py
            if await spawner.get(hood).publish(Message(message.text)):
                logger.warning("Message was accepted: " + message.text)
                return {}
            else:
                logger.warning("Message was't accepted: " + message.text)
                raise HTTPException(
                    status_code=status.HTTP_451_UNAVAILABLE_FOR_LEGAL_REASONS
                )
    logger.warning(
        "Someone is trying to submit an email without the correct API secret"
    )
    raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED)