import random

from django.db import models
from django_softdelete.models import SoftDeleteModel

from authentication.models import ExtendedUser
from core.settings import MAIL_DOMAIN
from files.models import AbstractFile
from inventory.models import Event
from tickets.models import IssueThread


class Email(SoftDeleteModel):
    id = models.AutoField(primary_key=True)
    timestamp = models.DateTimeField(auto_now_add=True)
    body = models.TextField()
    subject = models.CharField(max_length=255)
    sender = models.CharField(max_length=255)
    recipient = models.CharField(max_length=255)
    reference = models.CharField(max_length=255, null=True, unique=True)
    in_reply_to = models.CharField(max_length=255, null=True)
    raw = models.TextField()
    issue_thread = models.ForeignKey(IssueThread, models.SET_NULL, null=True, related_name='emails')
    event = models.ForeignKey(Event, models.SET_NULL, null=True)

    def save(self, *args, **kwargs):
        super().save(*args, **kwargs)
        if not self.reference:
            self.reference = f'<{random.randint(0, 1000000000):09}@{MAIL_DOMAIN}>'
            self.save()


class EventAddress(models.Model):
    id = models.AutoField(primary_key=True)
    event = models.ForeignKey(Event, models.SET_NULL, null=True)
    address = models.CharField(max_length=255)


class EmailAttachment(AbstractFile):
    email = models.ForeignKey(Email, models.CASCADE, related_name='attachments', null=True)
    name = models.CharField(max_length=255)


class UserNotificationChannel(models.Model):
    user = models.ForeignKey(ExtendedUser, models.CASCADE)
    channel_type = models.CharField(choices=[('telegram', 'telegram'), ('email', 'email')], max_length=255)
    channel_target = models.CharField(max_length=255)
    event_filter = models.CharField(max_length=255)
    active = models.BooleanField(default=True)
    created = models.DateTimeField(auto_now_add=True)

    def validate_constraints(self, exclude=None):  # TODO: email -> emailaddress, telegram -> chatid
        return True