from decimal import Decimal

from django.test import TestCase

from apps.accounts.models import Team, TeamMember, User
from apps.ai.models import AITask, ModelConfig, ModelProvider
from apps.billing.models import CreditAccount, CreditLedger, CreditReservation
from apps.billing.services.ledger import charge_reserved_credit, release_credit, reserve_credit


class CreditLedgerTests(TestCase):
    def setUp(self):
        self.user = User.objects.create_user(username="owner", password="pass")
        self.team = Team.objects.create(name="Billing Team", owner=self.user)
        TeamMember.objects.create(team=self.team, user=self.user, role=TeamMember.Role.OWNER)
        self.account = CreditAccount.objects.create(team=self.team, balance=Decimal("100.0000"))
        self.provider = ModelProvider.objects.create(name="volcengine", display_name="Volcano")
        self.model = ModelConfig.objects.create(
            provider=self.provider,
            name="doubao-seed-2-0-pro-260215",
            display_name="Doubao",
            capability=ModelConfig.Capability.TEXT,
        )
        self.task = AITask.objects.create(
            team=self.team,
            created_by=self.user,
            task_type=AITask.Type.SCRIPT_GENERATION,
            model_config=self.model,
            idempotency_key="billing-test-task",
            estimated_cost=Decimal("10.0000"),
        )

    def test_reserve_and_charge_credit(self):
        reservation = reserve_credit(team=self.team, user=self.user, task=self.task, amount=Decimal("10.0000"))
        self.account.refresh_from_db()

        self.assertEqual(reservation.status, CreditReservation.Status.ACTIVE)
        self.assertEqual(self.account.balance, Decimal("100.0000"))
        self.assertEqual(self.account.reserved_balance, Decimal("10.0000"))

        charge_reserved_credit(reservation=reservation, actual_amount=Decimal("8.0000"))
        self.account.refresh_from_db()
        reservation.refresh_from_db()

        self.assertEqual(reservation.status, CreditReservation.Status.CHARGED)
        self.assertEqual(self.account.balance, Decimal("92.0000"))
        self.assertEqual(self.account.reserved_balance, Decimal("0.0000"))
        self.assertEqual(CreditLedger.objects.filter(team=self.team).count(), 3)

    def test_release_reserved_credit(self):
        reservation = reserve_credit(team=self.team, user=self.user, task=self.task, amount=Decimal("10.0000"))
        release_credit(reservation=reservation, reason="model failed")
        self.account.refresh_from_db()
        reservation.refresh_from_db()

        self.assertEqual(reservation.status, CreditReservation.Status.RELEASED)
        self.assertEqual(self.account.balance, Decimal("100.0000"))
        self.assertEqual(self.account.reserved_balance, Decimal("0.0000"))
        self.assertEqual(CreditLedger.objects.filter(ledger_type=CreditLedger.Type.RELEASE).count(), 1)