"""批次 C1 · 套餐/试用/配额系统测试。

覆盖：预置套餐、订阅开通与幂等、试用到期降级、配额拦截（商品数/单据量/AI 次数）、
功能开关（批次管理/总账/订货商城）、升级解除限制、租户隔离、API 全链路。
"""

import pytest
from datetime import date, timedelta
from decimal import Decimal
from django.utils import timezone
from model_bakery import baker
from rest_framework.test import APIClient
from rest_framework_simplejwt.tokens import RefreshToken

from apps.catalog.models import Product
from apps.inventory.models import Warehouse
from apps.partner.models import Customer
from apps.ai import usage as ai_usage
from apps.billing.models import Plan, Subscription, subscribe, upgrade, get_subscription, seed_plans
from apps.billing import quota as billing_quota
from apps.billing import tasks as billing_tasks


@pytest.fixture
def auth_client(db, user, tenant):
    c = APIClient()
    refresh = RefreshToken.for_user(user)
    c.credentials(
        HTTP_AUTHORIZATION=f"Bearer {refresh.access_token}",
        HTTP_X_TENANT_ID=tenant.code,
    )
    return c


@pytest.fixture
def plans(db):
    seed_plans()
    return {p.code: p for p in Plan.objects.all()}


@pytest.fixture
def warehouse(db, tenant):
    return baker.make(Warehouse, tenant=tenant, code="WH01", name="主仓")


@pytest.fixture
def customer(db, tenant):
    return baker.make(Customer, tenant=tenant, code="C001", name="张三便利店")


@pytest.fixture
def product(db, tenant):
    return baker.make(Product, tenant=tenant, code="P001", name="可乐",
                      sale_price=Decimal("10"))


# ---------- 套餐定义 ----------


def test_seed_plans_idempotent(db, plans):
    assert Plan.objects.count() == 3
    seed_plans()
    assert Plan.objects.count() == 3
    free = Plan.objects.get(code="free")
    assert free.price_monthly == 0
    assert free.limits["products"] == 100
    assert Plan.objects.get(code="basic").price_monthly == 998
    assert Plan.objects.get(code="pro").price_monthly == 4800


def test_plan_limits_pricing_consistency(db, plans):
    """价格页与配额同源：每个套餐的 limits 都含全部键（一处定义两处使用）。"""
    keys = {"users", "products", "bills_monthly", "ai_parse_order", "ai_ask",
            "batch_managed", "finance_ledger", "print_templates", "storefront"}
    for plan in Plan.objects.all():
        assert keys <= set(plan.limits.keys()), f"{plan.code} 缺键"


# ---------- 订阅 ----------


def test_subscribe_creates_trial(db, tenant, plans):
    sub = subscribe(tenant)
    assert sub.status == "trial"
    assert sub.plan.code == "free"
    assert sub.trial_ends_at > timezone.now()
    # 幂等
    again = subscribe(tenant)
    assert again.id == sub.id


def test_get_subscription_autocreates(db, tenant, plans):
    assert Subscription.objects.filter(tenant=tenant).count() == 0
    sub = get_subscription(tenant)
    assert sub is not None
    assert Subscription.objects.filter(tenant=tenant).count() == 1


def test_trial_expired_falls_back_to_free_limits(db, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="pro")
    sub.trial_ends_at = timezone.now() - timedelta(hours=1)
    sub.save()
    assert sub.is_trial_expired is True
    limits = sub.effective_limits()
    assert limits["products"] == 100          # 回落 free
    assert limits["storefront"] is False


def test_upgrade_sets_active_and_extends(db, tenant, plans):
    sub = subscribe(tenant)
    up = upgrade(tenant, "pro", months=2)
    assert up.plan.code == "pro"
    assert up.status == "active"
    assert up.trial_ends_at is None
    assert up.period_end > date.today() + timedelta(days=50)


def test_upgrade_unknown_plan_raises(db, tenant, plans):
    with pytest.raises(ValueError):
        upgrade(tenant, "nope")


# ---------- 配额 ----------


def test_products_quota_blocks(db, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="free")
    sub.status = "active"
    sub.save()
    # free 限 100 个商品
    for i in range(100):
        baker.make(Product, tenant=tenant, code=f"P{i:03d}", name=f"商品{i}")
    with pytest.raises(billing_quota.QuotaExceeded) as ei:
        billing_quota.check_and_count(tenant, "products", delta=1)
    assert ei.value.kind == "products"
    assert ei.value.limit == 100
    assert ei.value.as_dict()["upgrade_url"] == "/#/pricing"


def test_products_quota_allows_under_limit(db, tenant, plans):
    subscribe(tenant)
    baker.make(Product, tenant=tenant, code="P1", name="商品1")
    out = billing_quota.check_and_count(tenant, "products", delta=1)
    assert out["used"] == 1
    assert out["remaining"] == 99


def test_unlimited_when_limit_zero(db, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="pro")
    sub.status = "active"
    sub.save()
    out = billing_quota.check_and_count(tenant, "bills_monthly", delta=1)
    assert out["limit"] == 0
    assert out["remaining"] is None


def test_bills_monthly_counts_sales_and_purchase(db, tenant, plans, warehouse, customer, product):
    from apps.sales import services as sales_services

    subscribe(tenant)
    bill = sales_services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": 1, "unit_price": 10}],
    )
    out = billing_quota.check_and_count(tenant, "bills_monthly", delta=0)
    assert out["used"] >= 1


def test_feature_flag_blocks_when_disabled(db, tenant, plans):
    """free 版无 storefront（订货商城）→ 拦截。"""
    subscribe(tenant)
    with pytest.raises(billing_quota.QuotaExceeded) as ei:
        billing_quota.check_and_count(tenant, "storefront")
    assert "订货商城" in ei.value.as_dict()["detail"]


def test_feature_flag_allows_on_pro(db, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="pro")
    sub.status = "active"
    sub.save()
    out = billing_quota.check_and_count(tenant, "storefront")
    assert out["enabled"] is True


def test_ai_quota_delegates_to_ai_usage(db, tenant, plans, settings):
    """ai_* 走 apps.ai.usage 单一实现；billing 的 limits 是配额来源。"""
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="free")
    sub.status = "active"
    sub.save()
    assert billing_quota.quota_for(tenant, "ai_parse_order") == 10
    for _ in range(10):
        ai_usage.record_usage(tenant, ai_usage.KIND_PARSE_ORDER)
    with pytest.raises(billing_quota.QuotaExceeded):
        billing_quota.check_and_count(tenant, "ai_parse_order", delta=1)


def test_unknown_kind_raises_valueerror(db, tenant, plans):
    subscribe(tenant)
    with pytest.raises(ValueError):
        billing_quota.check_and_count(tenant, "nonexistent")


# ---------- 用量快照 + 到期处理 ----------


def test_usage_snapshot_structure(db, tenant, plans, product):
    subscribe(tenant)
    snap = billing_quota.usage_snapshot(tenant)
    assert snap["plan"]["code"] == "free"
    kinds = {i["kind"] for i in snap["items"]}
    assert {"users", "products", "bills_monthly",
            "ai_parse_order", "ai_ask"} <= kinds
    prod_item = next(i for i in snap["items"] if i["kind"] == "products")
    assert prod_item["used"] == 1
    assert prod_item["limit"] == 100
    assert prod_item["percent"] == 1.0
    assert "features" in snap


def test_expire_trials_downgrades_and_notifies(db, tenant, plans):
    from apps.notify.models import Notification

    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="pro")
    sub.trial_ends_at = timezone.now() - timedelta(minutes=1)
    sub.save()

    out = billing_tasks.expire_trials()
    assert out["expired_count"] == 1
    sub.refresh_from_db()
    assert sub.status == "expired"
    assert sub.plan.code == "free"
    assert Notification.objects.filter(
        tenant=tenant, extra_data__kind="trial_expired"
    ).count() == 1


def test_expire_trials_ignores_active_trial(db, tenant, plans):
    subscribe(tenant)   # 未到期
    out = billing_tasks.expire_trials()
    assert out["expired_count"] == 0


def test_paid_subscription_expiry(db, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="basic")
    sub.status = "active"
    sub.period_end = date.today() - timedelta(days=1)
    sub.save()
    out = billing_tasks.expire_trials()
    assert out["expired_count"] == 1
    sub.refresh_from_db()
    assert sub.status == "expired"


# ---------- API ----------


def test_plans_api(db, client):
    resp = client.get("/api/v1/billing/plans/")
    assert resp.status_code == 200, resp.content
    body = resp.json()
    assert len(body) == 3
    codes = [p["code"] for p in body]
    assert codes == ["free", "basic", "pro"]
    basic = next(p for p in body if p["code"] == "basic")
    assert basic["price_monthly"] == "998.00"
    assert basic["limits"]["products"] == 3000


def test_subscription_api(db, auth_client, tenant, plans):
    resp = auth_client.get("/api/v1/billing/subscription/")
    assert resp.status_code == 200, resp.content
    body = resp.json()
    assert body["plan"]["code"] == "free"
    assert body["status"] == "trial"


def test_subscribe_api(db, auth_client, tenant, plans):
    resp = auth_client.post("/api/v1/billing/subscribe/",
                            {"plan_code": "basic", "months": 1}, format="json")
    assert resp.status_code == 200, resp.content
    assert resp.json()["plan_code"] == "basic"
    sub = Subscription.objects.get(tenant=tenant)
    assert sub.status == "active"


def test_subscribe_api_bad_plan_400(db, auth_client, tenant, plans):
    resp = auth_client.post("/api/v1/billing/subscribe/",
                            {"plan_code": "nope"}, format="json")
    assert resp.status_code == 400


def test_quota_check_api_403_with_upgrade_hint(db, auth_client, tenant, plans):
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="free")
    sub.status = "active"
    sub.save()
    for i in range(100):
        baker.make(Product, tenant=tenant, code=f"Q{i:03d}", name=f"品{i}")
    resp = auth_client.get("/api/v1/billing/quota/?kind=products")
    assert resp.status_code == 403, resp.content
    body = resp.json()
    assert body["code"] == "quota_exceeded"
    assert body["limit"] == 100
    assert body["upgrade_url"] == "/#/pricing"


def test_create_product_blocked_by_quota(db, auth_client, tenant, plans):
    """真实拦截点：商品 ViewSet 的 acreate 被配额挡住。"""
    sub = subscribe(tenant)
    sub.plan = Plan.objects.get(code="free")
    sub.status = "active"
    sub.save()
    for i in range(100):
        baker.make(Product, tenant=tenant, code=f"R{i:03d}", name=f"货{i}")
    resp = auth_client.post("/api/v1/catalog/products/",
                            {"code": "NEW01", "name": "新商品"}, format="json")
    assert resp.status_code == 403, resp.content
    assert resp.json()["code"] == "quota_exceeded"


def test_create_product_ok_under_quota(db, auth_client, tenant, plans):
    subscribe(tenant)
    resp = auth_client.post("/api/v1/catalog/products/",
                            {"code": "OK01", "name": "正常商品"}, format="json")
    assert resp.status_code == 201, resp.content


def test_tenant_isolation_subscription(db, tenant, other_tenant, plans):
    sub = subscribe(tenant)
    other = subscribe(other_tenant)
    upgrade(tenant, "pro")
    sub.refresh_from_db()
    other.refresh_from_db()
    assert sub.plan.code == "pro"
    assert other.plan.code == "free"
    assert billing_quota.quota_for(tenant, "products") == 100000
    assert billing_quota.quota_for(other_tenant, "products") == 100


# ---------- 定时任务接线（C1 收尾） ----------


def test_billing_expiry_cron_registered(db, settings):
    """套餐到期检查必须挂进 dramatiq crontab（否则试用永不降级）。"""
    settings.TASK_BROKER = "stub"
    import config.dramatiq as dramatiq_setup

    assert hasattr(dramatiq_setup, "cron_daily_billing_expiry")
    from apps.billing.tasks import expire_trials_and_notify

    assert expire_trials_and_notify.actor_name == "expire_trials_and_notify"


def test_scheduler_tick_billing_expiry_runs(db, tenant, plans):
    """tick actor 可直接调用并返回降级结果。"""
    from datetime import timedelta

    from django.utils import timezone

    import config.dramatiq as dramatiq_setup

    sub = subscribe(tenant)
    sub.trial_ends_at = timezone.now() - timedelta(minutes=1)
    sub.save()
    out = dramatiq_setup.scheduler_tick_billing_expiry.fn()
    assert out["expired_count"] == 1