from django.db import models
from django.db.models import functions
from django.core.validators import MinValueValidator, MaxValueValidator
from apps.core.history import TrackedModel
import pghistory


@pghistory.track()
class ParkReview(TrackedModel):

    # Import managers
    from ..managers import ParkReviewManager

    objects = ParkReviewManager()
    """
    A review of a park.
    """
    park = models.ForeignKey(
        "parks.Park", on_delete=models.CASCADE, related_name="reviews"
    )
    user = models.ForeignKey(
        "accounts.User", on_delete=models.CASCADE, related_name="park_reviews"
    )
    rating = models.PositiveSmallIntegerField(
        validators=[MinValueValidator(1), MaxValueValidator(10)]
    )
    title = models.CharField(max_length=200)
    content = models.TextField()
    visit_date = models.DateField()

    # Metadata
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    # Moderation
    is_published = models.BooleanField(default=True)
    moderation_notes = models.TextField(blank=True)
    moderated_by = models.ForeignKey(
        "accounts.User",
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name="moderated_park_reviews",
    )
    moderated_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ["-created_at"]
        unique_together = ["park", "user"]
        constraints = [
            # Business rule: Rating must be between 1 and 10 (database level
            # enforcement)
            models.CheckConstraint(
                name="park_review_rating_range",
                check=models.Q(rating__gte=1) & models.Q(rating__lte=10),
                violation_error_message="Rating must be between 1 and 10",
            ),
            # Business rule: Visit date cannot be in the future
            models.CheckConstraint(
                name="park_review_visit_date_not_future",
                check=models.Q(visit_date__lte=functions.Now()),
                violation_error_message="Visit date cannot be in the future",
            ),
            # Business rule: If moderated, must have moderator and timestamp
            models.CheckConstraint(
                name="park_review_moderation_consistency",
                check=models.Q(moderated_by__isnull=True, moderated_at__isnull=True)
                | models.Q(moderated_by__isnull=False, moderated_at__isnull=False),
                violation_error_message=(
                    "Moderated reviews must have both moderator and moderation "
                    "timestamp"
                ),
            ),
        ]

    def __str__(self):
        return f"Review of {self.park.name} by {self.user.username}"