import secrets

from django.conf import settings
from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils import timezone


class User(AbstractUser):
    """Plain Django user. Accounts are created with `manage.py createsuperuser`."""

    def __str__(self):
        return self.username


class ApiToken(models.Model):
    """Bearer token for the Flutter app (the web admin uses session auth)."""

    key = models.CharField(max_length=64, unique=True, editable=False)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="api_tokens"
    )
    name = models.CharField(
        max_length=100, blank=True, help_text="Which device this token is for."
    )
    created_at = models.DateTimeField(auto_now_add=True)
    last_used_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ["-created_at"]

    def __str__(self):
        return f"{self.user} — {self.name or 'unnamed device'}"

    def save(self, *args, **kwargs):
        if not self.key:
            self.key = secrets.token_urlsafe(32)
        return super().save(*args, **kwargs)

    def touch(self):
        self.last_used_at = timezone.now()
        self.save(update_fields=["last_used_at"])