from django.contrib.sessions.base_session import AbstractBaseSession
from django.db import models
from django.utils import timezone


class UserSession(AbstractBaseSession):
    """Database session with the user key in its own column (AD-6)."""

    username = models.CharField(max_length=256, blank=True, default="", db_index=True)
    created_at = models.DateTimeField(default=timezone.now)  # UTC

    @classmethod
    def get_session_store_class(cls):
        from .session_store import SessionStore

        return SessionStore


class ThrottleCounter(models.Model):
    """One row per (endpoint, subject); subject is `user:<key>` or `ip:<address>` (AD-7)."""

    endpoint = models.CharField(max_length=64)
    subject = models.CharField(max_length=256)
    count = models.PositiveIntegerField(default=0)
    window_started = models.DateTimeField(default=timezone.now)
    blocked_until = models.DateTimeField(null=True, blank=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(fields=["endpoint", "subject"], name="uniq_throttle_subject")
        ]