import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
import {
  getPermission,
  isOptedIn,
  notificationSupport,
  reminderFiredToNotification,
  sendTestDoneToNotification,
  setOptedIn,
  showNotification,
  type NotificationPermission,
} from "./notifications";

// ---------------------------------------------------------------------------
// Fake browser environment
// ---------------------------------------------------------------------------
// vitest's default node env has no `window`. We install a minimal shim
// before each test (and tear it down afterwards) so the helpers under
// test can run as if they were in a browser tab.

interface FakeStore {
  data: Map<string, string>;
}

function installWindow(opts: {
  permission?: NotificationPermission;
  notificationsEnabled?: boolean;
  ctorThrows?: boolean;
}) {
  const calls: Array<{ title: string; init: NotificationOptions | undefined }> = [];
  const store: FakeStore = { data: new Map() };

  class FakeNotification {
    static permission: NotificationPermission = opts.permission ?? "default";
    static async requestPermission(): Promise<NotificationPermission> {
      // Default test policy: granting on request unless the test
      // overrides Notification.permission directly.
      FakeNotification.permission = "granted";
      return "granted";
    }
    onclick: (() => void) | null = null;
    constructor(public title: string, public init?: NotificationOptions) {
      if (opts.ctorThrows) throw new Error("ctor failure");
      calls.push({ title, init });
    }
  }

  const fakeWindow = {
    Notification: opts.notificationsEnabled === false ? undefined : FakeNotification,
    localStorage: {
      getItem: (k: string) => store.data.get(k) ?? null,
      setItem: (k: string, v: string) => {
        store.data.set(k, v);
      },
      removeItem: (k: string) => {
        store.data.delete(k);
      },
    },
    location: { href: "/" },
    focus: vi.fn(),
  };

  // @ts-expect-error — augment globalThis at runtime
  globalThis.window = fakeWindow;
  return { calls, FakeNotification, store };
}

function tearDown() {
  // @ts-expect-error — clean up the shim
  delete globalThis.window;
}

beforeEach(() => {
  // Make sure no shim leaks across tests.
  tearDown();
});
afterEach(tearDown);

// ---------------------------------------------------------------------------
// notificationSupport / getPermission
// ---------------------------------------------------------------------------
describe("notificationSupport / getPermission", () => {
  it("reports unsupported when window is missing (SSR)", () => {
    expect(notificationSupport()).toBe("unsupported");
    expect(getPermission()).toBe("denied");
  });

  it("reports unsupported when the browser has no Notification API", () => {
    installWindow({ notificationsEnabled: false });
    expect(notificationSupport()).toBe("unsupported");
    expect(getPermission()).toBe("denied");
  });

  it("returns the live permission when supported", () => {
    installWindow({ permission: "granted" });
    expect(notificationSupport()).toBe("supported");
    expect(getPermission()).toBe("granted");
  });
});

// ---------------------------------------------------------------------------
// isOptedIn / setOptedIn — localStorage flag
// ---------------------------------------------------------------------------
describe("opt-in localStorage flag", () => {
  it("defaults to opted-out", () => {
    installWindow({ permission: "granted" });
    expect(isOptedIn()).toBe(false);
  });

  it("flips to opted-in after setOptedIn(true)", () => {
    installWindow({ permission: "granted" });
    setOptedIn(true);
    expect(isOptedIn()).toBe(true);
  });

  it("setOptedIn(false) removes the flag", () => {
    installWindow({ permission: "granted" });
    setOptedIn(true);
    setOptedIn(false);
    expect(isOptedIn()).toBe(false);
  });

  it("survives gracefully when window is missing", () => {
    expect(() => setOptedIn(true)).not.toThrow();
    expect(isOptedIn()).toBe(false);
  });
});

// ---------------------------------------------------------------------------
// showNotification — gating + dispatch
// ---------------------------------------------------------------------------
describe("showNotification gating", () => {
  it("returns 'unsupported' when there's no Notification API", () => {
    installWindow({ notificationsEnabled: false });
    setOptedIn(true);
    const r = showNotification({ title: "x" });
    expect(r.ok).toBe(false);
    if (!r.ok) expect(r.reason).toBe("unsupported");
  });

  it("returns 'opted-out' when the operator hasn't opted in", () => {
    installWindow({ permission: "granted" });
    const r = showNotification({ title: "x" });
    expect(r.ok).toBe(false);
    if (!r.ok) expect(r.reason).toBe("opted-out");
  });

  it("returns 'permission' when permission is default / not yet granted", () => {
    installWindow({ permission: "default" });
    setOptedIn(true);
    const r = showNotification({ title: "x" });
    expect(r.ok).toBe(false);
    if (!r.ok) expect(r.reason).toBe("permission");
  });

  it("returns 'permission' when blocked by the browser", () => {
    installWindow({ permission: "denied" });
    setOptedIn(true);
    const r = showNotification({ title: "x" });
    expect(r.ok).toBe(false);
    if (!r.ok) expect(r.reason).toBe("permission");
  });

  it("dispatches when supported + opted in + granted, and forwards body/tag/icon", () => {
    const { calls } = installWindow({ permission: "granted" });
    setOptedIn(true);
    const r = showNotification({
      title: "Reminder sent",
      body: "All groups received the message.",
      tag: "reminder:r-1",
    });
    expect(r.ok).toBe(true);
    expect(calls).toHaveLength(1);
    expect(calls[0]!.title).toBe("Reminder sent");
    expect(calls[0]!.init?.body).toBe("All groups received the message.");
    expect(calls[0]!.init?.tag).toBe("reminder:r-1");
    // Defaults to /icon-192.png + /icon-192.png for badge.
    expect(calls[0]!.init?.icon).toBe("/icon-192.png");
    expect(calls[0]!.init?.badge).toBe("/icon-192.png");
  });

  it("returns 'error' when the Notification ctor throws (rare)", () => {
    installWindow({ permission: "granted", ctorThrows: true });
    setOptedIn(true);
    const r = showNotification({ title: "x" });
    expect(r.ok).toBe(false);
    if (!r.ok) {
      expect(r.reason).toBe("error");
      expect(r.error).toMatch(/ctor failure/);
    }
  });
});

// ---------------------------------------------------------------------------
// Event mappers
// ---------------------------------------------------------------------------
describe("reminderFiredToNotification mapping", () => {
  it("renders 'success' as a positive 'sent' notification", () => {
    const args = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-1",
      runId: "run-1",
      status: "success",
    });
    expect(args).not.toBeNull();
    expect(args?.title).toBe("Reminder sent");
    expect(args?.body).toMatch(/All groups received/);
    expect(args?.tag).toBe("reminder:r-1");
    expect(args?.href).toBe("/reminders/r-1");
  });

  it("renders 'partial' with a hint to open Activity", () => {
    const args = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-2",
      runId: "run-2",
      status: "partial",
    });
    expect(args?.title).toBe("Reminder partly sent");
    expect(args?.body).toMatch(/Some groups received/);
    expect(args?.body).toMatch(/See activity/);
  });

  it("renders 'failed' with a clear failure headline", () => {
    const args = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-3",
      runId: "run-3",
      status: "failed",
    });
    expect(args?.title).toBe("Reminder failed");
  });

  it("returns null for 'skipped' (bookkeeping noise, not user-facing)", () => {
    const args = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-4",
      runId: "run-4",
      status: "skipped",
    });
    expect(args).toBeNull();
  });

  it("uses the same tag for repeat fires of the same reminder so they coalesce", () => {
    const a = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-1",
      runId: "run-A",
      status: "success",
    });
    const b = reminderFiredToNotification({
      type: "reminder.fired",
      reminderId: "r-1",
      runId: "run-B",
      status: "success",
    });
    expect(a?.tag).toBe(b?.tag);
  });
});

describe("sendTestDoneToNotification mapping", () => {
  it("renders ok=true as 'Test message sent' linked to the group", () => {
    const args = sendTestDoneToNotification({
      type: "send_test.done",
      groupId: "g-1",
      ok: true,
    });
    expect(args?.title).toBe("Test message sent");
    expect(args?.tag).toBe("send-test:g-1");
    expect(args?.href).toBe("/groups/g-1");
  });

  it("returns null on failure (toast already shows the error)", () => {
    const args = sendTestDoneToNotification({
      type: "send_test.done",
      groupId: "g-1",
      ok: false,
    });
    expect(args).toBeNull();
  });
});