# -*- coding: utf-8 -*-
import logging
from django.core.exceptions import ImproperlyConfigured
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')

    return [u'{name} <{addr}>'.format(name=u.get_full_name(), addr=u.email) for u in users]


class AbstractMail(object):
    _sender = config.EMAIL_SENDER
    _subject = 'Generic Mail'
    _template_name = None

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

    def _get_template(self):
        if not self._template_name:
            raise ImproperlyConfigured('%s._template_name ist not set.', self.__class__.__name__)
        return get_template(self._template_name)

    def _get_context_data(self, extra_context=None):
        context = {
            'base_url': config.EMAIL_BASE_URL,
        }
        if extra_context:
            context.update(extra_context)
        return context

    def _get_body(self):
        template = self._get_template()
        context = self._get_context_data()
        return template.render(context)

    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)
        logger.info(u'Send %s to %s', self.__class__.__name__, 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_context_data(self, extra_context=None):
        context = super(AbstractEventMail, self)._get_context_data(extra_context=extra_context)
        context.update(self._event.get_template_context())
        return 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 = u'{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 = u'{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 = u'{fullname} <{email}>'.format(fullname=self._user.get_full_name(),
                                           email=self._user.email)
        return [r]

    def _get_context_data(self, extra_context=None):
        context = super(PasswordSetEmail, self)._get_context_data(extra_context=extra_context)
        context.update({
            'fullname': self._user.get_full_name(),
            'username': self._user.username,
            'password': self._password
        })
        return context