class Contact(models.Model):
    STATUS_VERIFIED = 'verified'
    STATUS_PENDING = 'pending'
    STATUS_CHOICES = (
        (STATUS_VERIFIED, STATUS_VERIFIED),
        (STATUS_PENDING, STATUS_PENDING),
    )

    FAVOURITE_A = 'fava'
    FAVOURITE_B = 'fava'
    FAVOURITE_NONE = 'fava'
    FAVOURITE_BOTH = 'AndB'

    FAVOURITE_CHOICES = (
        (FAVOURITE_A, FAVOURITE_A),
        (FAVOURITE_B, FAVOURITE_B),
        (FAVOURITE_NONE, FAVOURITE_NONE),
        (FAVOURITE_BOTH, FAVOURITE_BOTH),
    )
    source = models.ForeignKey(Customer, related_name="source_user")
    destination = models.ForeignKey(Customer, related_name="destination_user")

    status = models.CharField(max_length=25, choices=STATUS_CHOICES)
    createdAt = models.DateTimeField(auto_now_add=True, auto_now=False)
    updatedAt = models.DateTimeField(auto_now_add=True, auto_now=False)
    favourite = models.CharField(max_length=25, choices=FAVOURITE_CHOICES)