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

from infrasynth.tenancy.mixins import GlobalOrTenantModel, TenantOwnedModel


class FeatureFlag(GlobalOrTenantModel):
    """An operational toggle. ``tenant IS NULL`` is the global default; a tenant row overrides it."""

    slug = models.SlugField(max_length=100)
    name = models.CharField(max_length=200)
    description = models.TextField(blank=True)
    is_active = models.BooleanField(default=False)
    rollout_percentage = models.PositiveSmallIntegerField(default=100, help_text="0-100. 100 = all users")
    environments = models.JSONField(default=list, help_text='["production", "staging"] or [] = all')
    category = models.CharField(max_length=50, blank=True, help_text="Grouping for UI")
    metadata = models.JSONField(default=dict)

    class Meta:
        db_table = "features_flag"
        constraints = [
            models.UniqueConstraint(fields=["tenant", "slug"], name="uniq_feature_flag_slug_per_tenant"),
            models.UniqueConstraint(
                fields=["slug"],
                condition=Q(tenant__isnull=True),
                name="uniq_global_feature_flag_slug",
            ),
        ]


class FeatureFlagOverride(TenantOwnedModel):
    flag = models.ForeignKey(FeatureFlag, on_delete=models.CASCADE, related_name="overrides")
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="+",
    )
    group = models.ForeignKey(
        "auth.Group",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="+",
    )
    is_enabled = models.BooleanField()

    class Meta:
        db_table = "features_override"
        constraints = [
            models.UniqueConstraint(fields=["flag", "user"], name="uniq_override_flag_user"),
            models.UniqueConstraint(fields=["flag", "group"], name="uniq_override_flag_group"),
        ]