from django.db import models

from apps.common.models import TimeStampedModel


class CreditAccount(TimeStampedModel):
    team = models.OneToOneField("accounts.Team", on_delete=models.CASCADE, related_name="credit_account")
    balance = models.DecimalField(max_digits=14, decimal_places=4, default=0)
    reserved_balance = models.DecimalField(max_digits=14, decimal_places=4, default=0)
    currency = models.CharField(max_length=16, default="CNY")

    def __str__(self) -> str:
        return f"{self.team} / {self.balance}"


class CreditLedger(TimeStampedModel):
    class Type(models.TextChoices):
        RECHARGE = "recharge", "Recharge"
        RESERVE = "reserve", "Reserve"
        RELEASE = "release", "Release"
        CHARGE = "charge", "Charge"
        ADJUSTMENT = "adjustment", "Adjustment"
        REFUND = "refund", "Refund"

    team = models.ForeignKey("accounts.Team", on_delete=models.CASCADE, related_name="credit_ledgers")
    user = models.ForeignKey("accounts.User", on_delete=models.SET_NULL, null=True, blank=True, related_name="credit_ledgers")
    project = models.ForeignKey(
        "projects.Project",
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name="credit_ledgers",
    )
    task = models.ForeignKey("ai.AITask", on_delete=models.SET_NULL, null=True, blank=True, related_name="credit_ledgers")
    ledger_type = models.CharField(max_length=32, choices=Type.choices)
    amount = models.DecimalField(max_digits=14, decimal_places=4)
    balance_after = models.DecimalField(max_digits=14, decimal_places=4)
    reason = models.CharField(max_length=255, blank=True)
    metadata = models.JSONField(default=dict, blank=True)

    class Meta:
        indexes = [
            models.Index(fields=["team", "ledger_type"]),
            models.Index(fields=["project", "task"]),
        ]


class CreditReservation(TimeStampedModel):
    class Status(models.TextChoices):
        ACTIVE = "active", "Active"
        RELEASED = "released", "Released"
        CHARGED = "charged", "Charged"
        CANCELLED = "cancelled", "Cancelled"

    team = models.ForeignKey("accounts.Team", on_delete=models.CASCADE, related_name="credit_reservations")
    user = models.ForeignKey("accounts.User", on_delete=models.SET_NULL, null=True, blank=True, related_name="credit_reservations")
    project = models.ForeignKey(
        "projects.Project",
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name="credit_reservations",
    )
    task = models.OneToOneField("ai.AITask", on_delete=models.CASCADE, related_name="credit_reservation")
    amount = models.DecimalField(max_digits=14, decimal_places=4)
    status = models.CharField(max_length=32, choices=Status.choices, default=Status.ACTIVE)
    expires_at = models.DateTimeField(null=True, blank=True)


class QuotaPolicy(TimeStampedModel):
    team = models.ForeignKey("accounts.Team", on_delete=models.CASCADE, related_name="quota_policies")
    user = models.ForeignKey("accounts.User", on_delete=models.CASCADE, null=True, blank=True, related_name="quota_policies")
    project = models.ForeignKey(
        "projects.Project",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="quota_policies",
    )
    monthly_limit = models.DecimalField(max_digits=14, decimal_places=4, null=True, blank=True)
    project_limit = models.DecimalField(max_digits=14, decimal_places=4, null=True, blank=True)
    per_task_limit = models.DecimalField(max_digits=14, decimal_places=4, null=True, blank=True)
    is_active = models.BooleanField(default=True)