from django.contrib.auth import get_user_model
from django.contrib.auth.models import Group
from django.core.mail import EmailMessage

from . import config


class AbstractMail(object):
    _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):
        subject = self._get_subject()
        body = self._get_body()
        recipients = self._get_recipients()

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


class AbstractEventMail(AbstractMail):
    _subject = 'DAV Events'

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


class NewEventMail(AbstractEventMail):
    def get_recipients(self):
        r = '{fullname} <{email}>'.format(fullname=self._event.owner.get_fullname(),
                                          email=self._event.owner.email)
        return [r]


class NewEventToAcceptMail(AbstractEventMail):
    def get_recipients(self):
        recipients = []

        sport = self._event.sport
        group_var_name = 'MANAGE_{K}_GROUP'.format(sport)
        group_name = getattr(config, group_var_name, None)
        if group_name:
            try:
                group = Group.objects.get(name=group_name)
                for user in group.user_set:
                    r = '{fullname} <{email}>'.format(fullname=user.get_fullname(),
                                                      email=user.email)
                    recipients.append(r)
            except Group.DoesNotExists:
                pass

        group_var_name = 'MANAGE_ALL_GROUP'
        group_name = getattr(config, group_var_name, None)
        if group_name:
            try:
                group = Group.objects.get(name=group_name)
                for user in group.user_set:
                    r = '{fullname} <{email}>'.format(fullname=user.get_fullname(),
                                                      email=user.email)
                    recipients.append(r)
            except Group.DoesNotExists:
                pass

        return recipients


class EventAcceptedMail(AbstractEventMail):
    def get_recipients(self):
        r = '{fullname} <{email}>'.format(fullname=self._event.owner.get_fullname(),
                                          email=self._event.owner.email)
        return [r]


class NewEventToPublishMail(AbstractEventMail):
    def get_recipients(self):
        recipients = []

        group_var_name = 'INCREMENTAL_PUBLISHER_GROUP'
        group_name = getattr(config, group_var_name, None)
        if group_name:
            try:
                group = Group.objects.get(name=group_name)
                for user in group.user_set:
                    r = '{fullname} <{email}>'.format(fullname=user.get_fullname(),
                                                      email=user.email)
                    recipients.append(r)
            except Group.DoesNotExists:
                pass

        return recipients