from django.db import models


class Atoll(models.Model):
    name = models.CharField(max_length=100, unique=True)
    # Maldivian administrative code, e.g. "F" for Faafu.
    code = models.CharField(max_length=8, blank=True)
    is_active = models.BooleanField(default=True)

    class Meta:
        ordering = ["name"]

    def __str__(self):
        return self.name


class Island(models.Model):
    atoll = models.ForeignKey(Atoll, on_delete=models.PROTECT, related_name="islands")
    name = models.CharField(max_length=100)
    is_active = models.BooleanField(default=True)

    class Meta:
        ordering = ["name"]
        constraints = [
            models.UniqueConstraint(
                fields=["atoll", "name"], name="unique_island_name_per_atoll"
            )
        ]

    def __str__(self):
        return f"{self.name}, {self.atoll.name}"