from django.db import models
from django.contrib.auth.models import User


class StudentProfile(models.Model):
    user = models.OneToOneField(
        User,
        on_delete=models.CASCADE
    )

    xp = models.IntegerField(default=0)
    streak = models.IntegerField(default=0)
    last_activity_date = models.DateField(null=True, blank=True)
    daily_goal = models.IntegerField(default=60)

    target_band = models.FloatField(default=7.5)
    display_name = models.CharField(max_length=40, blank=True)
    country = models.CharField(max_length=80, blank=True)

    def __str__(self):
        return self.user.username


class PremiumEntitlement(models.Model):
    SOURCE_ADMIN = "admin"
    SOURCE_PAYMENT = "payment"
    SOURCE_PROMOTION = "promotion"
    SOURCE_CHOICES = [
        (SOURCE_ADMIN, "Admin grant"),
        (SOURCE_PAYMENT, "One-time payment"),
        (SOURCE_PROMOTION, "Promotion"),
    ]

    user = models.OneToOneField(
        User,
        on_delete=models.CASCADE,
        related_name="premium_entitlement",
    )
    source = models.CharField(max_length=20, choices=SOURCE_CHOICES, default=SOURCE_ADMIN)
    order_reference = models.CharField(max_length=120, blank=True)
    granted_at = models.DateTimeField(auto_now_add=True)
    revoked_at = models.DateTimeField(null=True, blank=True)
    notes = models.TextField(blank=True)

    @property
    def is_active(self):
        return self.revoked_at is None

    def __str__(self):
        state = "active" if self.is_active else "revoked"
        return f"{self.user} · Lifetime Premium ({state})"


class DailyMissionClaim(models.Model):
    """Records one XP reward per student, mission, and calendar day."""

    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="daily_mission_claims")
    mission_key = models.CharField(max_length=40)
    completed_on = models.DateField()
    xp_awarded = models.PositiveIntegerField()
    claimed_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=["user", "mission_key", "completed_on"],
                name="unique_daily_mission_claim",
            ),
        ]
        ordering = ["-completed_on", "-claimed_at"]

    def __str__(self):
        return f"{self.user} · {self.mission_key} · {self.completed_on}"