const assert = require("node:assert/strict");
const fs = require("node:fs");
const path = require("node:path");
const test = require("node:test");
const vm = require("node:vm");
const { webcrypto } = require("node:crypto");

const BACKGROUND_PATH = path.join(__dirname, "background.js");

function createHarness(options = {}) {
  let storageChangedListener;
  let alarmCreateCount = 0;
  let clock = options.now ?? Date.now();
  let fetchHandler = options.fetch;
  let cookieToken = "";
  const localData = options.localData || {};
  const fetchUrls = [];
  const settings = {
    apiBaseUrl: "http://localhost:8001",
    webBaseUrl: "http://localhost:5174",
    autoDiscoverServiceUrl: false,
    accessToken: "",
    tokenSyncEnabled: false,
    taskPollingEnabled: true,
    workerId: "test-worker",
    taskPollIntervalSeconds: 5,
    ...options.settings,
  };

  const chrome = {
    alarms: {
      clear: async () => {},
      create: async () => {
        alarmCreateCount += 1;
      },
      onAlarm: { addListener: () => {} },
    },
    cookies: { get: async () => cookieToken ? { value: cookieToken } : null },
    runtime: {
      onInstalled: { addListener: () => {} },
      onMessage: { addListener: () => {} },
      onStartup: { addListener: () => {} },
    },
    storage: {
      local: {
        get: async (defaults) => ({ ...defaults, ...localData }),
        set: async (updates) => Object.assign(localData, updates),
      },
      session: { get: async () => ({ actSessions: {} }), set: async () => {} },
      sync: {
        get: async () => ({ ...settings }),
        set: async (updates) => Object.assign(settings, updates),
      },
      onChanged: {
        addListener: (listener) => {
          storageChangedListener = listener;
        },
      },
    },
    tabs: { query: async () => [] },
  };

  const context = {
    chrome,
    console,
    fetch: async (url, init) => {
      fetchUrls.push(String(url));
      if (fetchHandler) return fetchHandler(url, init);
      return {
        ok: true,
        status: 200,
        json: async () => ({ enabled: true }),
      };
    },
    importScripts: () => {},
    setTimeout: () => 1,
    clearTimeout: () => {},
    URL,
    AbortController,
    TextEncoder,
    crypto: webcrypto,
    Date: class extends Date {
      constructor(...args) { super(...(args.length ? args : [clock])); }
      static now() { return clock; }
    },
    DEER_CLIPPER_DEFAULTS: settings,
    deerNormalizeBaseUrl: (value) => String(value || "").replace(/\/+$/, ""),
    deerMakeWorkerId: () => "test-worker",
    deerAuthHeaders: () => ({}),
    deerExtractAuthTokenFromPage: () => ({ token: "" }),
  };
  context.globalThis = context;
  vm.runInNewContext(fs.readFileSync(BACKGROUND_PATH, "utf8"), context, {
    filename: BACKGROUND_PATH,
  });

  return {
    emitStorageChange(changes) {
      storageChangedListener(changes, "sync");
    },
    getAlarmCreateCount: () => alarmCreateCount,
    getFetchUrls: () => [...fetchUrls],
    getSettings: () => context.getSettings(),
    setSettings: (updates) => Object.assign(settings, updates),
    getLocalData: () => ({ ...localData }),
    advanceTime: (ms) => { clock += ms; },
    getTime: () => clock,
    setFetch: (handler) => { fetchHandler = handler; },
    setCookie: (token) => { cookieToken = token; },
    status: (url, settings = {}, force = false) => context.browserContextStatus(url, settings, force),
    discoverServiceBases: (settings, force = false) =>
      context.discoverServiceBases(settings, force),
    resetAlarmCreateCount: () => {
      alarmCreateCount = 0;
    },
    getApiCandidates: (webBase, currentApiBase) =>
      vm.runInContext(`apiCandidatesForWebBase(${JSON.stringify(webBase)}, ${JSON.stringify(currentApiBase)})`, context),
  };
}

const settle = () => new Promise((resolve) => setImmediate(resolve));

test("self-written sync metadata does not restart browser task polling", async () => {
  const harness = createHarness();
  await settle();
  harness.resetAlarmCreateCount();

  harness.emitStorageChange({
    lastTokenSyncAt: { oldValue: "before", newValue: "after" },
  });
  await settle();

  assert.equal(harness.getAlarmCreateCount(), 0);
});

test("polling configuration changes restart browser task polling", async () => {
  const harness = createHarness();
  await settle();
  harness.resetAlarmCreateCount();

  harness.emitStorageChange({
    taskPollingEnabled: { oldValue: false, newValue: true },
  });
  await settle();

  assert.equal(harness.getAlarmCreateCount(), 1);
});

test("service discovery prefers the API paired with the open zncm tab", async () => {
  const harness = createHarness();

  assert.deepEqual(
    Array.from(harness.getApiCandidates("http://localhost:5174", "http://47.94.209.59:2026")),
    [
      "http://localhost:5174",
      "http://localhost:8001",
      "http://47.94.209.59:2026",
      "http://localhost:8001",
    ].filter((value, index, values) => values.indexOf(value) === index),
  );
});

test("automatic service discovery checks status once per ten minutes, not on every task poll", async () => {
  const harness = createHarness();
  const settings = await harness.getSettings();
  settings.autoDiscoverServiceUrl = true;

  await harness.discoverServiceBases(settings);
  assert.equal(harness.getFetchUrls().length, 1);

  await harness.discoverServiceBases(await harness.getSettings());
  assert.equal(harness.getFetchUrls().length, 1);

  await harness.discoverServiceBases(await harness.getSettings(), true);
  assert.equal(harness.getFetchUrls().length, 1);
  harness.advanceTime(30_000);
  await harness.discoverServiceBases(await harness.getSettings(), true);
  assert.equal(harness.getFetchUrls().length, 2);
});

test("unchanged service discovery refreshes its timestamp after TTL expiry", async () => {
  const harness = createHarness();
  await settle();
  harness.setSettings({ autoDiscoverServiceUrl: true });
  await harness.discoverServiceBases(await harness.getSettings());
  const firstSync = harness.getLocalData().lastServiceSyncAt;
  harness.advanceTime(10 * 60_000 + 1);
  await harness.discoverServiceBases(await harness.getSettings());
  assert.notEqual(harness.getLocalData().lastServiceSyncAt, firstSync);
  assert.equal(harness.getFetchUrls().length, 2);
  for (let i = 0; i < 20; i++) {
    harness.advanceTime(3_000);
    await harness.discoverServiceBases(await harness.getSettings());
  }
  assert.equal(harness.getFetchUrls().length, 2);
});

test("concurrent status callers share a request and successful results expire", async () => {
  const harness = createHarness();
  const url = "http://example.test";
  const results = await Promise.all(Array.from({ length: 30 }, () => harness.status(url)));
  assert.ok(results.every((result) => result.enabled));
  assert.equal(harness.getFetchUrls().length, 1);
  harness.advanceTime(59_000);
  await harness.status(`${url}/`);
  assert.equal(harness.getFetchUrls().length, 1);
  harness.advanceTime(1_001);
  await harness.status(url);
  assert.equal(harness.getFetchUrls().length, 2);
});

test("disabled status respects Retry-After even for manual calls and later recovers", async () => {
  const harness = createHarness({
    fetch: async () => ({
      ok: false,
      status: 403,
      headers: { get: () => "300" },
      json: async () => ({ detail: { code: "browser_status_disabled" } }),
    }),
  });
  const url = "http://example.test";
  const status = await harness.status(url);
  assert.equal(status.enabled, false);
  assert.equal(status.statusAccessDisabled, true);
  assert.equal(status.authenticationRequired, undefined);
  harness.advanceTime(299_999);
  await harness.status(url, {}, true);
  assert.equal(harness.getFetchUrls().length, 1);
  harness.setFetch(async () => ({ ok: true, status: 200, json: async () => ({ enabled: true }) }));
  harness.advanceTime(1);
  assert.equal((await harness.status(url)).enabled, true);
  assert.equal(harness.getFetchUrls().length, 2);
});

test("network and server failures back off for five minutes", async () => {
  for (const fetch of [
    async () => { throw new Error("offline"); },
    async () => ({ ok: false, status: 500, json: async () => ({ detail: "unavailable" }) }),
  ]) {
    const harness = createHarness({ fetch });
    for (let i = 0; i < 10; i++) assert.equal(await harness.status("http://example.test", {}, true), null);
    assert.equal(harness.getFetchUrls().length, 1);
    harness.advanceTime(300_000);
    assert.equal(await harness.status("http://example.test"), null);
    assert.equal(harness.getFetchUrls().length, 2);
  }
});

test("status cache separates service addresses, login tokens and cookies", async () => {
  const harness = createHarness();
  await harness.status("http://one.test", { accessToken: "account-a" });
  await harness.status("http://one.test", { accessToken: "account-b" });
  await harness.status("http://two.test", { accessToken: "account-b" });
  harness.setCookie("new-login");
  await harness.status("http://two.test", { accessToken: "account-b" });
  assert.equal(harness.getFetchUrls().length, 4);
  await harness.status("http://two.test", { accessToken: "account-b" });
  assert.equal(harness.getFetchUrls().length, 4);
});

test("discovery survives worker restarts but refreshes after account changes", async () => {
  const harness = createHarness();
  await settle();
  harness.setSettings({ autoDiscoverServiceUrl: true, accessToken: "account-a" });
  await harness.discoverServiceBases(await harness.getSettings());
  const localData = harness.getLocalData();
  assert.ok(!JSON.stringify(localData).includes("account-a"));
  const restarted = createHarness({
    localData,
    now: harness.getTime(),
    settings: { autoDiscoverServiceUrl: true, accessToken: "account-a" },
  });
  await restarted.discoverServiceBases(await restarted.getSettings());
  assert.equal(restarted.getFetchUrls().length, 0);
  restarted.setSettings({ accessToken: "account-b" });
  await restarted.discoverServiceBases(await restarted.getSettings());
  assert.equal(restarted.getFetchUrls().length, 1);
});