from django.db import models
from django.conf import settings
from django.utils.translation import gettext_lazy as _


class UserCreditSummary(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        on_delete=models.DO_NOTHING,
        primary_key=True,
        related_name="credit_summary",
    )
    paid_credits = models.IntegerField(default=0)
    free_credits = models.IntegerField(default=0)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "billing_user_credits"

    def __str__(self):
        return f"UserCreditSummary(user_id={self.user_id}, paid_credits={self.paid_credits}, free_credits={self.free_credits})"


class UserCreditDetail(models.Model):
    class CreditType(models.TextChoices):
        PAID = "paid", _("Paid")
        FREE = "free", _("Free")

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.DO_NOTHING,
        related_name="credit_details",
    )
    credit_type = models.CharField(max_length=10, choices=CreditType.choices)
    initial_amount = models.IntegerField(
        blank=True,
        null=True,
        help_text="The initial amount of the credit, only used for free credits.",
    )
    amount = models.IntegerField(default=0)
    expires_at = models.DateTimeField(
        null=True,
        blank=True,
        help_text=(
            "The date and time when the credit expires."
            "Paid credits will never expire; "
            "Free credits always have an expiration date."
        ),
    )
    remark = models.CharField(
        max_length=255,
        null=True,
        blank=True,
        help_text="The remark of the credit.",
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "billing_user_credit_details"

    def __str__(self):
        return f"UserCreditDetail(user_id={self.user_id}, credit_type={self.credit_type}, amount={self.amount})"