from django.conf import settings
from django.db import models


class AuditLog(models.Model):
    # Company is nullable only for truly global/system events. Tenant-scoped
    # business events should carry a company so HR administrators never need
    # global audit visibility.
    company = models.ForeignKey(
        "organization.Company",
        on_delete=models.PROTECT,
        null=True,
        blank=True,
        related_name="audit_logs",
    )
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET_NULL, null=True, blank=True, related_name="audit_events")
    action = models.CharField(max_length=30)
    module = models.CharField(max_length=100)
    object_id = models.CharField(max_length=100, blank=True)
    object_repr = models.CharField(max_length=255, blank=True)
    old_values = models.JSONField(default=dict, blank=True)
    new_values = models.JSONField(default=dict, blank=True)
    ip_address = models.GenericIPAddressField(null=True, blank=True)
    user_agent = models.TextField(blank=True)
    reason = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True, db_index=True)

    class Meta:
        ordering = ["-created_at"]
        indexes = [
            models.Index(fields=["company", "created_at"]),
            models.Index(fields=["module", "created_at"]),
            models.Index(fields=["user", "created_at"]),
        ]