from django.conf import settings
from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
from django.contrib.contenttypes.models import ContentType
from django.db import models
from telegram import Bot
from telegram.ext import Dispatcher


class TelegramBot(models.Model):
    owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    active = models.BooleanField(default=True)
    title = models.CharField(max_length=32)
    bot_token = models.CharField(max_length=256)

    rpc_name = models.CharField(max_length=32, blank=True, null=True)
    periodic_interval = models.DurationField(blank=True, null=True)
    periodic_last_run = models.DateTimeField(blank=True, null=True)

    config_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    config_id = models.PositiveIntegerField()
    config = GenericForeignKey('config_type', 'config_id')

    def get_bot(self):
        return Bot(self.bot_token)

    def build_dispatcher(self, error_handler):
        bot = self.get_bot()
        bot.get_me()
        dispatcher = Dispatcher(bot, None, workers=0, use_context=True)
        dispatcher.add_error_handler(error_handler)
        self.config.build_dispatcher(dispatcher)
        return dispatcher

    def __str__(self):
        return f'#{self.pk} {self.title}'

    class Meta:
        unique_together = ('config_type', 'config_id')


class TelegramBotModuleConfig(models.Model):
    _bot = GenericRelation(TelegramBot, content_type_field='config_type', object_id_field='config_id')

    MODULE_NAME = '<Not set>'

    @property
    def bot(self):
        return self._bot.get()

    @property
    def content_type(self):
        return ContentType.objects.get_for_model(self.__class__)

    def build_dispatcher(self, dispatcher: Dispatcher):
        raise NotImplementedError()

    class Meta:
        abstract = True