from django.db import models
from django.contrib.auth.models import User

class App(models.Model):
    name = models.CharField(max_length=100)

    def __str__(self):
        return self.name

class Room(models.Model):
    name = models.CharField(max_length=100)
    app = models.ForeignKey(App, on_delete=models.CASCADE)

    def __str__(self):
        return self.name

class Message(models.Model):
    text = models.CharField(max_length=500)
    date = models.DateTimeField("date published")
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    room = models.ForeignKey(Room, on_delete=models.CASCADE)
    parent = models.ForeignKey('self', blank=True, null=True, on_delete=models.SET_NULL)

    def __str__(self):
        return self.text