import type { AddressInfo } from "node:net";
import type { MonitoringView } from "@batch-cooking/shared";
import { faker } from "@faker-js/faker";
import { expect } from "chai";
import { Server as SocketIoServer } from "socket.io";
import { type Socket as ClientSocket, io as ioClient } from "socket.io-client";
import { createServer } from "../src/app.js";
import { env } from "../src/config/env.js";
import { prisma } from "../src/db/prisma.js";
import { signAdminToken } from "../src/lib/admin-jwt.js";
import { MonitoringBroadcastService } from "../src/lib/monitoring-broadcast.service.js";
import { hashAdminPassword } from "../src/modules/admin/admin-auth.service.js";
import { resetDatabase } from "../test-support/reset-db.js";

const VALID_STATUSES = ["up", "degraded", "down", "unknown"];
const adminSecretConfigured = env.ADMIN_JWT_SECRET !== undefined;

async function seedAdmin(): Promise<{ adminUserId: number; tokenVersion: number }> {
  const admin = await prisma.adminUser.create({
    data: {
      email: faker.internet.email().toLowerCase(),
      name: faker.person.fullName(),
      passwordHash: await hashAdminPassword(faker.internet.password({ length: 16 })),
    },
  });
  return { adminUserId: admin.id, tokenVersion: admin.tokenVersion };
}

/**
 * Waits for `event` on `socket`, rejecting after `timeoutMs` (default
 * tuned for the auth-rejection tests, which never touch a real probe and
 * so resolve almost immediately — the probe-touching tests below pass a
 * larger value explicitly) — every real WebSocket round-trip in this file
 * goes through this instead of a bare `socket.once`, so a broken push
 * fails the test with a clear message instead of hanging until Mocha's
 * own default test timeout.
 */
function waitForEvent<T>(socket: ClientSocket, event: string, timeoutMs = 1500): Promise<T> {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(
      () => reject(new Error(`Timed out waiting for "${event}"`)),
      timeoutMs,
    );
    socket.once(event, (payload: T) => {
      clearTimeout(timer);
      resolve(payload);
    });
  });
}

describe("Admin monitoring — WebSocket push", () => {
  let baseUrl: string;
  let broadcast: MonitoringBroadcastService;
  const clientSockets: ClientSocket[] = [];

  // A real listening server, not just createApp()'s bare Express instance
  // (supertest's usual approach elsewhere in this suite) — socket.io needs
  // an actual http.Server to attach to, and a real client (socket.io-
  // client) needs a real port to connect to. Port 0 lets the OS pick a
  // free one, so this suite never collides with anything else listening.
  before(async () => {
    const httpServer = createServer().httpServer;
    const io = new SocketIoServer(httpServer, { cors: { origin: "*" } });
    broadcast = new MonitoringBroadcastService(io);
    await new Promise<void>((resolve) => httpServer.listen(0, resolve));
    const { port } = httpServer.address() as AddressInfo;
    baseUrl = `http://localhost:${port}`;
    broadcast.start();
  });

  after(async () => {
    broadcast.stop();
    await prisma.$disconnect();
  });

  beforeEach(async () => {
    await resetDatabase();
  });

  afterEach(() => {
    for (const socket of clientSockets.splice(0)) {
      socket.disconnect();
    }
  });

  /** Connects a client with the given cookie header (or none), tracked for automatic teardown in `afterEach`. */
  function connect(cookie?: string): ClientSocket {
    const socket = ioClient(baseUrl, {
      extraHeaders: cookie ? { Cookie: cookie } : undefined,
      // This suite creates several short-lived connections in a row —
      // socket.io-client's default reconnection would otherwise keep
      // retrying a deliberately-rejected connection in the background
      // after its own test has already moved on.
      reconnection: false,
      forceNew: true,
    });
    clientSockets.push(socket);
    return socket;
  }

  it("rejects a connection with no admin cookie at all", async () => {
    const socket = connect();
    const err = await waitForEvent<Error>(socket, "connect_error");
    expect(err.message).to.equal("Not authenticated");
  });

  it("rejects a connection carrying an end-user session cookie, not an admin one", async () => {
    const socket = connect("session=whatever-not-an-admin-token");
    const err = await waitForEvent<Error>(socket, "connect_error");
    expect(err.message).to.equal("Not authenticated");
  });

  it("accepts a valid admin session and pushes a monitoring:update covering all four targets", async function () {
    if (!adminSecretConfigured) {
      // biome-ignore lint/suspicious/noExplicitAny: mocha's `this.skip()` isn't typed here.
      (this as any).skip();
      return;
    }
    // Longer than Mocha's 2000ms default: the very first probe tick can
    // take close to PROBE_TIMEOUT_MS (2s) if e.g. the intent-service isn't
    // reachable from this test environment (a probe timing out is a valid,
    // expected outcome here — this test doesn't assert *which* status
    // comes back, only that the shape is right).
    this.timeout(8000);
    const { adminUserId, tokenVersion } = await seedAdmin();
    const token = signAdminToken({ adminUserId, tokenVersion });

    const socket = connect(`${env.ADMIN_COOKIE_NAME}=${token}`);
    const snapshot = await waitForEvent<MonitoringView>(socket, "monitoring:update", 6000);

    expect(typeof snapshot.generatedAt).to.equal("string");
    const keys = snapshot.services.map((service) => service.key);
    expect(keys).to.have.members(["postgres", "api", "intent-service", "tech-step-llm-worker"]);
    for (const service of snapshot.services) {
      expect(VALID_STATUSES).to.include(service.status);
    }
  });

  it("broadcasts the same update to every connected admin, not one probe per socket", async function () {
    if (!adminSecretConfigured) {
      // biome-ignore lint/suspicious/noExplicitAny: see above.
      (this as any).skip();
      return;
    }
    this.timeout(8000); // see the previous test's comment
    const { adminUserId, tokenVersion } = await seedAdmin();
    const token = signAdminToken({ adminUserId, tokenVersion });
    const cookie = `${env.ADMIN_COOKIE_NAME}=${token}`;

    const first = connect(cookie);
    const second = connect(cookie);
    const [firstSnapshot, secondSnapshot] = await Promise.all([
      waitForEvent<MonitoringView>(first, "monitoring:update", 6000),
      waitForEvent<MonitoringView>(second, "monitoring:update", 6000),
    ]);

    expect(firstSnapshot.generatedAt).to.equal(secondSnapshot.generatedAt);
  });
});