import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { NotificationType } from "@/generated/prisma/enums";
import {
  cleanupTestBusiness,
  createTestAppointment,
  createTestBusiness,
  createTestCustomer,
  createTestStaff,
  prisma,
} from "@/services/scheduling/__tests__/fixtures";
import type { TestBusiness } from "@/services/scheduling/__tests__/fixtures";
import { MockEmailProvider } from "../providers/mock-email-provider";
import { MockPushProvider } from "../providers/mock-push-provider";
import { notify } from "../notification.service";
import { subscribeToPush } from "../push-subscription.service";
import { processDueNotificationDeliveries } from "../reminder-worker";

/**
 * Exercises the background processor end to end against a real database,
 * with MockEmailProvider standing in for Brevo — no real network calls,
 * matching the Phase 7 brief's "no real API calls in automated tests".
 */
describe("processDueNotificationDeliveries (integration)", () => {
  let business: TestBusiness;
  let provider: MockEmailProvider;

  beforeEach(async () => {
    business = await createTestBusiness();
    provider = new MockEmailProvider();
  });

  afterEach(async () => {
    await cleanupTestBusiness(business);
  });

  async function createDueEmailNotification(customerId: string, idempotencyKey: string) {
    const { notification } = await notify(prisma, {
      businessId: business.businessId,
      type: NotificationType.LOYALTY_STAMP_ADDED,
      recipientCustomerId: customerId,
      bodyText: "You've earned a stamp.",
      idempotencyKey,
    });
    return notification;
  }

  it("sends a due PENDING EMAIL delivery and marks it SENT with the provider message id", async () => {
    const { customerId } = await createTestCustomer(business);
    const notification = await createDueEmailNotification(customerId, "test:worker:sent");

    const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
    expect(result.sent).toBe(1);
    expect(provider.sentEmails).toHaveLength(1);

    const delivery = await prisma.notificationDelivery.findFirstOrThrow({
      where: { notificationId: notification.id, channel: "EMAIL" },
    });
    expect(delivery.status).toBe("SENT");
    expect(delivery.providerMessageId).toBe("mock-message-id");
    expect(delivery.providerName).toBe("mock");
    expect(delivery.attemptCount).toBe(1);
  });

  it("does not send a delivery scheduled for the future", async () => {
    const { customerId } = await createTestCustomer(business);
    const { notification } = await notify(prisma, {
      businessId: business.businessId,
      type: NotificationType.BOOKING_REMINDER,
      recipientCustomerId: customerId,
      bodyText: "Reminder",
      idempotencyKey: "test:worker:future",
      scheduledFor: new Date(Date.now() + 60 * 60_000),
    });

    const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
    expect(result.claimed).toBe(0);
    expect(provider.sentEmails).toHaveLength(0);

    const delivery = await prisma.notificationDelivery.findFirstOrThrow({
      where: { notificationId: notification.id, channel: "EMAIL" },
    });
    expect(delivery.status).toBe("SCHEDULED");
  });

  it("retries a retryable failure with backoff, then eventually gives up after MAX_ATTEMPTS", async () => {
    const { customerId } = await createTestCustomer(business);
    const notification = await createDueEmailNotification(customerId, "test:worker:retry");
    provider.setDefaultResult({ status: "failed", retryable: true, reason: "Connection timed out" });

    // Attempt 1: retried with backoff — scheduledFor pushed into the future, so it won't be "due" again immediately.
    const first = await processDueNotificationDeliveries(prisma, { emailProvider: provider, now: new Date(), businessId: business.businessId });
    expect(first.retried).toBe(1);
    let delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });
    expect(delivery.status).toBe("PENDING");
    expect(delivery.attemptCount).toBe(1);
    expect(delivery.scheduledFor).not.toBeNull();

    // Simulate time passing past the backoff window on each subsequent attempt.
    for (let i = 0; i < 2; i++) {
      const future = new Date(delivery.scheduledFor!.getTime() + 1000);
      const run = await processDueNotificationDeliveries(prisma, { emailProvider: provider, now: future, businessId: business.businessId });
      expect(run.retried).toBe(1);
      delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });
    }
    expect(delivery.attemptCount).toBe(3);

    // 4th attempt (MAX_ATTEMPTS) exhausts the retry budget — permanent FAILED, not retried again.
    const finalRun = await processDueNotificationDeliveries(prisma, {
      emailProvider: provider,
      now: new Date(delivery.scheduledFor!.getTime() + 1000),
      businessId: business.businessId,
    });
    expect(finalRun.failed).toBe(1);
    expect(finalRun.retried).toBe(0);
    delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });
    expect(delivery.status).toBe("FAILED");
    expect(delivery.attemptCount).toBe(4);
  });

  it("never retries a permanent (non-retryable) failure, even on the first attempt", async () => {
    const { customerId } = await createTestCustomer(business);
    const notification = await createDueEmailNotification(customerId, "test:worker:permanent");
    provider.setDefaultResult({ status: "failed", retryable: false, reason: "Mailbox does not exist" });

    const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
    expect(result.failed).toBe(1);
    expect(result.retried).toBe(0);

    const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });
    expect(delivery.status).toBe("FAILED");
    expect(delivery.attemptCount).toBe(1);
    expect(delivery.failureReason).toBe("Mailbox does not exist");
  });

  it("fails a delivery cleanly when the recipient has no email address at all, without calling the provider", async () => {
    // NotificationService.notify() never creates an EMAIL delivery for a recipient with no
    // resolvable address in the first place (see resolveChannels) — so this scenario is only
    // reachable if the address changes between creation and processing (e.g. a customer record
    // edited afterward). Constructed directly here to exercise the worker's own defensive guard
    // in isolation, bypassing notify()'s channel resolution.
    const orphanCustomer = await prisma.customerProfile.create({
      data: { firstName: "No", lastName: "Email", email: "", phone: null, isGuest: true },
    });
    try {
      const notification = await prisma.notification.create({
        data: {
          businessId: business.businessId,
          recipientCustomerId: orphanCustomer.id,
          type: "LOYALTY_STAMP_ADDED",
          bodyText: "You've earned a stamp.",
          idempotencyKey: "test:worker:no-email",
          deliveries: { create: [{ channel: "EMAIL", status: "PENDING" }] },
        },
      });
      const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
      expect(result.failed).toBe(1);
      expect(provider.sentEmails).toHaveLength(0);
      const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });
      expect(delivery.status).toBe("FAILED");
    } finally {
      await prisma.notification.deleteMany({ where: { recipientCustomerId: orphanCustomer.id } });
      await prisma.customerProfile.delete({ where: { id: orphanCustomer.id } });
    }
  });

  it("does not double-send when a delivery has already been claimed (simulated concurrent worker)", async () => {
    const { customerId } = await createTestCustomer(business);
    const notification = await createDueEmailNotification(customerId, "test:worker:concurrent");
    const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "EMAIL" } });

    // Simulate another worker having already claimed this row a moment ago.
    await prisma.notificationDelivery.update({ where: { id: delivery.id }, data: { status: "PROCESSING" } });

    const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
    expect(result.claimed).toBe(0);
    expect(provider.sentEmails).toHaveLength(0);
  });

  it("raises OWNER_REPEATED_DELIVERY_FAILURE once several EMAIL deliveries fail for the same business in one run", async () => {
    const role = await prisma.role.create({
      data: { businessId: business.businessId, name: "Test Owner", permissions: { create: [{ permission: "VIEW_REPORTING" }] } },
    });
    const ownerUser = await prisma.user.create({
      data: {
        email: `${crypto.randomUUID()}@test.local`,
        staffProfile: { create: { businessId: business.businessId, roleId: role.id } },
      },
    });

    provider.setDefaultResult({ status: "failed", retryable: false, reason: "Rejected" });
    const customers = await Promise.all([createTestCustomer(business), createTestCustomer(business), createTestCustomer(business)]);
    for (const [i, c] of customers.entries()) {
      await createDueEmailNotification(c.customerId, `test:worker:repeated-failure-${i}`);
    }

    const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
    expect(result.failed).toBe(3);

    const ownerNotice = await prisma.notification.findFirst({
      where: { recipientUserId: ownerUser.id, type: "OWNER_REPEATED_DELIVERY_FAILURE" },
    });
    expect(ownerNotice).not.toBeNull();
  });

  describe("PUSH channel", () => {
    let pushProvider: MockPushProvider;

    beforeEach(() => {
      pushProvider = new MockPushProvider();
    });

    async function createDuePushNotification(customerId: string, userId: string, idempotencyKey: string) {
      const { notification } = await notify(prisma, {
        businessId: business.businessId,
        type: NotificationType.LOYALTY_STAMP_ADDED,
        recipientUserId: userId,
        recipientCustomerId: customerId,
        bodyText: "You've earned a stamp.",
        idempotencyKey,
      });
      return notification;
    }

    it("fans out to every active subscription and marks the delivery SENT if at least one succeeds", async () => {
      const { customerId, userId } = await createTestCustomer(business);
      await subscribeToPush(prisma, { businessId: business.businessId, userId, customerId, endpoint: "https://push.example.com/device-1", p256dhKey: "k1", authKey: "a1" });
      await subscribeToPush(prisma, { businessId: business.businessId, userId, customerId, endpoint: "https://push.example.com/device-2", p256dhKey: "k2", authKey: "a2" });

      const notification = await createDuePushNotification(customerId, userId, "test:worker:push-fanout");
      const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, pushProvider, businessId: business.businessId });

      expect(pushProvider.sentPushes).toHaveLength(2);
      const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "PUSH" } });
      expect(delivery.status).toBe("SENT");
      expect(result.sent).toBeGreaterThanOrEqual(1);
    });

    it("revokes a subscription the push service reports as gone (410), independent of the overall delivery outcome", async () => {
      const { customerId, userId } = await createTestCustomer(business);
      await subscribeToPush(prisma, { businessId: business.businessId, userId, customerId, endpoint: "https://push.example.com/stale-device", p256dhKey: "k1", authKey: "a1" });

      pushProvider.setDefaultResult({ status: "failed", retryable: false, subscriptionInvalid: true, reason: "Gone" });
      await createDuePushNotification(customerId, userId, "test:worker:push-revoke");
      await processDueNotificationDeliveries(prisma, { emailProvider: provider, pushProvider, businessId: business.businessId });

      const subscription = await prisma.pushSubscription.findUniqueOrThrow({ where: { endpoint: "https://push.example.com/stale-device" } });
      expect(subscription.revokedAt).not.toBeNull();
    });

    it("fails cleanly with no push provider configured, without touching subscriptions", async () => {
      const { customerId, userId } = await createTestCustomer(business);
      await subscribeToPush(prisma, { businessId: business.businessId, userId, customerId, endpoint: "https://push.example.com/no-provider", p256dhKey: "k", authKey: "a" });

      const notification = await createDuePushNotification(customerId, userId, "test:worker:push-no-provider");
      await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });

      const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notificationId: notification.id, channel: "PUSH" } });
      expect(delivery.status).toBe("PENDING"); // retryable — a future run with a configured provider can still succeed
      const subscription = await prisma.pushSubscription.findUniqueOrThrow({ where: { endpoint: "https://push.example.com/no-provider" } });
      expect(subscription.revokedAt).toBeNull();
    });
  });

  describe("stale reminder guard", () => {
    async function dueReminderFor(appointmentStartAt: Date, status: "CONFIRMED" | "CANCELLED") {
      const { staffId } = await createTestStaff(business);
      const { customerId } = await createTestCustomer(business);
      const { appointmentId } = await createTestAppointment(business, { customerId, staffId, startAt: appointmentStartAt });
      await prisma.appointment.update({ where: { id: appointmentId }, data: { status } });
      await notify(prisma, {
        businessId: business.businessId,
        type: NotificationType.BOOKING_REMINDER,
        recipientCustomerId: customerId,
        appointmentId,
        bodyText: "Reminder",
        idempotencyKey: `test:worker:stale:${appointmentId}`,
        scheduledFor: new Date(Date.now() - 60_000),
      });
      return appointmentId;
    }

    it("still sends a due reminder for an upcoming confirmed appointment", async () => {
      await dueReminderFor(new Date(Date.now() + 3 * 60 * 60_000), "CONFIRMED");

      const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
      expect(result.sent).toBe(1);
      expect(result.skippedStale).toBe(0);
    });

    it("drops — doesn't send, doesn't fail — a reminder whose appointment has already started", async () => {
      // e.g. the processor was down long enough that a 24h reminder came due after the appointment itself.
      const appointmentId = await dueReminderFor(new Date(Date.now() - 30 * 60_000), "CONFIRMED");

      const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
      expect(result.sent).toBe(0);
      expect(result.failed).toBe(0);
      expect(result.skippedStale).toBe(1);
      expect(provider.sentEmails).toHaveLength(0);

      const delivery = await prisma.notificationDelivery.findFirstOrThrow({ where: { notification: { appointmentId } } });
      expect(delivery.status).toBe("CANCELLED");
    });

    it("drops a reminder whose appointment is no longer confirmed", async () => {
      await dueReminderFor(new Date(Date.now() + 3 * 60 * 60_000), "CANCELLED");

      const result = await processDueNotificationDeliveries(prisma, { emailProvider: provider, businessId: business.businessId });
      expect(result.sent).toBe(0);
      expect(result.skippedStale).toBe(1);
      expect(provider.sentEmails).toHaveLength(0);
    });
  });
});