from decimal import Decimal

from django.conf import settings
from django.test import TestCase
from rest_framework.test import APIClient

from apps.accounts.models import Team, TeamMember, User
from apps.billing.models import CreditAccount, CreditLedger


class AuthApiTests(TestCase):
    def test_register_creates_user_team_member_credit_account_and_token(self):
        client = APIClient()
        response = client.post(
            "/api/auth/register/",
            {
                "username": "new-owner",
                "password": "strong-password",
                "email": "owner@example.com",
                "team_name": "Launch Team",
            },
            format="json",
        )

        self.assertEqual(response.status_code, 201)
        self.assertIn("token", response.data)
        user = User.objects.get(username="new-owner")
        team = Team.objects.get(name="Launch Team")
        self.assertEqual(team.owner, user)
        self.assertTrue(TeamMember.objects.filter(team=team, user=user, role=TeamMember.Role.OWNER).exists())
        self.assertTrue(CreditAccount.objects.filter(team=team).exists())

    def test_register_trial_grant_is_recorded_in_ledger(self):
        """开户赠送额度必须进流水:余额=赠送额,且有一条 balance_after=赠送额的 genesis 流水,账目从第一条起可对账。"""
        client = APIClient()
        client.post(
            "/api/auth/register/",
            {"username": "ledger-owner", "password": "strong-password", "team_name": "Ledger Team"},
            format="json",
        )
        team = Team.objects.get(name="Ledger Team")
        trial = Decimal(str(settings.DEFAULT_TRIAL_CREDITS))
        account = CreditAccount.objects.get(team=team)
        self.assertEqual(account.balance, trial)
        genesis = CreditLedger.objects.filter(team=team, ledger_type=CreditLedger.Type.RECHARGE)
        self.assertEqual(genesis.count(), 1)
        self.assertEqual(genesis.first().amount, trial)
        self.assertEqual(genesis.first().balance_after, trial)  # 流水终点 == 账户余额,可对账


class InvitationFlowTests(TestCase):
    def _register(self, client, username, **extra):
        return client.post(
            "/api/auth/register/",
            {"username": username, "password": "strong-password", **extra},
            format="json",
        )

    def test_invite_join_same_team_no_duplicate_credits(self):
        from apps.accounts.models import Invitation

        owner_client = APIClient()
        r = self._register(owner_client, "inv-owner", team_name="Owner Team")
        self.assertEqual(r.status_code, 201)
        team = Team.objects.get(name="Owner Team")
        accounts_before = CreditAccount.objects.filter(team=team).count()
        ledgers_before = CreditLedger.objects.filter(team=team).count()

        # 超管生成邀请码
        owner_client.credentials(HTTP_AUTHORIZATION=f"Token {r.data['token']}")
        gen = owner_client.post(
            "/api/auth/team/invitations/",
            {"role": "member", "monthly_credit_limit": "500"},
            format="json",
        )
        self.assertEqual(gen.status_code, 201)
        code = gen.data["code"]
        self.assertTrue(code.startswith("TEAM-"))

        # 新用户凭码注册
        r2 = self._register(APIClient(), "inv-joiner", invite_code=code)
        self.assertEqual(r2.status_code, 201)
        joiner = User.objects.get(username="inv-joiner")

        # 进的是同一团队、角色对、active、额度对
        member = TeamMember.objects.get(team=team, user=joiner)
        self.assertEqual(member.role, TeamMember.Role.MEMBER)
        self.assertEqual(member.status, TeamMember.Status.ACTIVE)
        self.assertEqual(member.monthly_credit_limit, Decimal("500"))
        # 没开新团队
        self.assertFalse(Team.objects.filter(owner=joiner).exists())
        # 关键:不重复发额度 —— 团队 CreditAccount/ledger 数量不变
        self.assertEqual(CreditAccount.objects.filter(team=team).count(), accounts_before)
        self.assertEqual(CreditLedger.objects.filter(team=team).count(), ledgers_before)
        # 邀请标 used
        inv = Invitation.objects.get(code=code)
        self.assertEqual(inv.status, Invitation.Status.USED)
        self.assertEqual(inv.used_by, joiner)

    def test_register_with_unknown_invite_rejected(self):
        r = self._register(APIClient(), "bad-inv", invite_code="TEAM-ABCD-EFGH")
        self.assertEqual(r.status_code, 400)
        self.assertFalse(User.objects.filter(username="bad-inv").exists())

    def test_invite_generate_requires_manage_permission(self):
        owner_client = APIClient()
        ro = self._register(owner_client, "perm-owner", team_name="Perm Team")
        owner_client.credentials(HTTP_AUTHORIZATION=f"Token {ro.data['token']}")
        gen = owner_client.post("/api/auth/team/invitations/", {"role": "member"}, format="json")
        code = gen.data["code"]

        joiner_client = APIClient()
        rj = self._register(joiner_client, "perm-member", invite_code=code)
        # 普通成员尝试生成邀请码 → 403
        joiner_client.credentials(HTTP_AUTHORIZATION=f"Token {rj.data['token']}")
        gen2 = joiner_client.post("/api/auth/team/invitations/", {"role": "member"}, format="json")
        self.assertEqual(gen2.status_code, 403)