# -*- coding: utf-8 -*-
import logging
from django.core.mail import EmailMessage
from django.template.loader import get_template

from . import config
from .utils import get_group_members

logger = logging.getLogger(__name__)


def get_recipients(task, sport=None):
    users = []
    if task == 'accept':
        group_var_name = 'MANAGE_ALL_GROUP'
        group_name = getattr(config, group_var_name, None)
        if group_name:
            users.extend(get_group_members(group_name, ignore_missing=True))

        if sport:
            group_var_name = 'MANAGE_{}_GROUP'.format(sport)
            group_name = getattr(config, group_var_name, None)
            if group_name:
                users.extend(get_group_members(group_name, ignore_missing=True))

    elif task == 'publish':
        group_var_name = 'INCREMENTAL_PUBLISHER_GROUP'
        group_name = getattr(config, group_var_name, None)
        if group_name:
            users.extend(get_group_members(group_name, ignore_missing=True))
    else:
        raise ValueError('utils.get_recipients(): invalid value for task')

    for u in users:
        yield '{name} <{addr}>'.format(name=u.get_full_name(), addr=u.email)


class AbstractMail(object):
    _sender = config.EMAIL_SENDER
    _subject = 'Generic Mail'

    def _get_subject(self, **kwargs):
        return self._subject.format(**kwargs)

    def _get_body(self):
        raise NotImplementedError()

    def _get_recipients(self):
        raise NotImplementedError()

    def send(self):
        if not config.ENABLE_EMAIL_NOTIFICATIONS:
            return None
        subject = self._get_subject()
        body = self._get_body()
        sender = self._sender
        recipients = self._get_recipients()

        emo = EmailMessage(subject=subject, body=body, from_email=sender, to=recipients)
        emo.send()


class AbstractEventMail(AbstractMail):
    _subject = u'[DAV Veranstaltungen]'
    _template_name = 'dav_events/emails/default.txt'

    def __init__(self, event):
        self._event = event

    def _get_body(self):
        template_name = self._template_name
        template = get_template(template_name)
        context = {
            'base_url': config.BASE_URL,
        }
        context.update(self._event.get_template_context())
        return template.render(context)


class NewEventMail(AbstractEventMail):
    _template_name = 'dav_events/emails/new_event.txt'

    def _get_subject(self, **kwargs):
        s = super(NewEventMail, self)._get_subject(**kwargs)
        s += u' Neue Veranstaltung angelegt'
        return s

    def _get_recipients(self):
        r = '{fullname} <{email}>'.format(fullname=self._event.owner.get_full_name(),
                                          email=self._event.owner.email)
        return [r]


class EventToAcceptMail(AbstractEventMail):
    _template_name = 'dav_events/emails/event_to_accept.txt'

    def _get_subject(self, **kwargs):
        s = super(EventToAcceptMail, self)._get_subject(**kwargs)
        s += u' Neue Veranstaltung freigeben'
        return s

    def _get_recipients(self):
        return get_recipients('accept', self._event.sport)


class EventAcceptedMail(AbstractEventMail):
    _template_name = 'dav_events/emails/event_accepted.txt'

    def _get_subject(self, **kwargs):
        s = super(EventAcceptedMail, self)._get_subject(**kwargs)
        s += u' Veranstaltung wurde freigegeben'
        return s

    def _get_recipients(self):
        r = '{fullname} <{email}>'.format(fullname=self._event.owner.get_full_name(),
                                          email=self._event.owner.email)
        return [r]


class EventToPublishMail(AbstractEventMail):
    _template_name = 'dav_events/emails/event_to_publish.txt'

    def _get_subject(self, **kwargs):
        s = super(EventToPublishMail, self)._get_subject(**kwargs)
        s += u' Veranstaltung veröffentlichen'
        return s

    def _get_recipients(self):
        return get_recipients('publish', self._event.sport)


class PasswordSetEmail(AbstractMail):
    _subject = u'[DAV Veranstaltungen] Zugangsdaten'
    _template_name = 'dav_events/emails/password_set.txt'

    def __init__(self, user, password):
        self._user = user
        self._password = password

    def _get_recipients(self):
        r = '{fullname} <{email}>'.format(fullname=self._user.get_full_name(),
                                          email=self._user.email)
        return [r]

    def _get_body(self):
        template_name = self._template_name
        template = get_template(template_name)
        context = {
            'base_url': config.BASE_URL,
            'fullname': self._user.get_full_name(),
            'username': self._user.username,
            'password': self._password
        }
        return template.render(context)