from django.db import models
from accounts.models import User

class RegistrationCode(models.Model):
    code = models.CharField(max_length=32, unique=True, verbose_name="注册码")
    manager = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        limit_choices_to={"role": "manager"},
        verbose_name="对应分管理"
    )
    description = models.CharField(max_length=100, blank=True, verbose_name="说明")
    usage_limit = models.IntegerField(default=1, verbose_name="最多使用次数")
    used_count = models.IntegerField(default=0, verbose_name="已使用次数")
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")

    class Meta:
        verbose_name = "注册码申请"
        verbose_name_plural = "注册码申请"

    def __str__(self):
        return f"{self.code} ({self.used_count}/{self.usage_limit})"

    def is_available(self):
        return self.used_count < self.usage_limit