/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

"use strict";

var { XPCOMUtils } = ChromeUtils.importESModule(
  "resource://gre/modules/XPCOMUtils.sys.mjs"
);

ChromeUtils.defineESModuleGetters(this, {
  ObjectUtils: "resource://gre/modules/ObjectUtils.sys.mjs",
  PermissionTestUtils: "resource://testing-common/PermissionTestUtils.sys.mjs",
  PlacesTestUtils: "resource://testing-common/PlacesTestUtils.sys.mjs",
  PlacesUtils: "resource://gre/modules/PlacesUtils.sys.mjs",
  Preferences: "resource://gre/modules/Preferences.sys.mjs",
  PushCrypto: "resource://gre/modules/PushCrypto.sys.mjs",
  PushService: "resource://gre/modules/PushService.sys.mjs",
  PushServiceHttp2: "resource://gre/modules/PushService.sys.mjs",
  PushServiceWebSocket: "resource://gre/modules/PushService.sys.mjs",
  pushBroadcastService: "resource://gre/modules/PushBroadcastService.sys.mjs",
});

var {
  clearInterval,
  clearTimeout,
  setInterval,
  setIntervalWithTarget,
  setTimeout,
  setTimeoutWithTarget,
} = ChromeUtils.importESModule("resource://gre/modules/Timer.sys.mjs");

XPCOMUtils.defineLazyServiceGetter(
  this,
  "PushServiceComponent",
  "@mozilla.org/push/Service;1",
  "nsIPushService"
);

const servicePrefs = new Preferences("dom.push.");

const WEBSOCKET_CLOSE_GOING_AWAY = 1001;

const MS_IN_ONE_DAY = 24 * 60 * 60 * 1000;

var isParent =
  Services.appinfo.processType == Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;

// Stop and clean up after the PushService.
Services.obs.addObserver(function observe(subject, topic) {
  Services.obs.removeObserver(observe, topic);
  PushService.uninit();
  // Occasionally, `profile-change-teardown` and `xpcom-shutdown` will fire
  // before the PushService and AlarmService finish writing to IndexedDB. This
  // causes spurious errors and crashes, so we spin the event loop to let the
  // writes finish.
  let done = false;
  setTimeout(() => (done = true), 1000);
  let thread = Services.tm.mainThread;
  while (!done) {
    try {
      thread.processNextEvent(true);
    } catch (e) {
      console.error(e);
    }
  }
}, "profile-change-net-teardown");

/**
 * Gates a function so that it is called only after the wrapper is called a
 * given number of times.
 *
 * @param {Number} times The number of wrapper calls before |func| is called.
 * @param {Function} func The function to gate.
 * @returns {Function} The gated function wrapper.
 */
function after(times, func) {
  return function afterFunc() {
    if (--times <= 0) {
      func.apply(this, arguments);
    }
  };
}

/**
 * Defers one or more callbacks until the next turn of the event loop. Multiple
 * callbacks are executed in order.
 *
 * @param {Function[]} callbacks The callbacks to execute. One callback will be
 *  executed per tick.
 */
function waterfall(...callbacks) {
  callbacks
    .reduce(
      (promise, callback) =>
        promise.then(() => {
          callback();
        }),
      Promise.resolve()
    )
    .catch(console.error);
}

/**
 * Waits for an observer notification to fire.
 *
 * @param {String} topic The notification topic.
 * @returns {Promise} A promise that fulfills when the notification is fired.
 */
function promiseObserverNotification(topic, matchFunc) {
  return new Promise(resolve => {
    Services.obs.addObserver(function observe(subject, aTopic, data) {
      let matches = typeof matchFunc != "function" || matchFunc(subject, data);
      if (!matches) {
        return;
      }
      Services.obs.removeObserver(observe, aTopic);
      resolve({ subject, data });
    }, topic);
  });
}

/**
 * Wraps an object in a proxy that traps property gets and returns stubs. If
 * the stub is a function, the original value will be passed as the first
 * argument. If the original value is a function, the proxy returns a wrapper
 * that calls the stub; otherwise, the stub is called as a getter.
 *
 * @param {Object} target The object to wrap.
 * @param {Object} stubs An object containing stubbed values and functions.
 * @returns {Proxy} A proxy that returns stubs for property gets.
 */
function makeStub(target, stubs) {
  return new Proxy(target, {
    get(aTarget, property) {
      if (!stubs || typeof stubs != "object" || !(property in stubs)) {
        return aTarget[property];
      }
      let stub = stubs[property];
      if (typeof stub != "function") {
        return stub;
      }
      let original = aTarget[property];
      if (typeof original != "function") {
        return stub.call(this, original);
      }
      return function callStub(...params) {
        return stub.call(this, original, ...params);
      };
    },
  });
}

/**
 * Sets default PushService preferences. All pref names are prefixed with
 * `dom.push.`; any additional preferences will override the defaults.
 *
 * @param {Object} [prefs] Additional preferences to set.
 */
function setPrefs(prefs = {}) {
  let defaultPrefs = Object.assign(
    {
      loglevel: "all",
      serverURL: "wss://push.example.org",
      "connection.enabled": true,
      userAgentID: "",
      enabled: true,
      // Defaults taken from /modules/libpref/init/all.js.
      requestTimeout: 10000,
      retryBaseInterval: 5000,
      pingInterval: 30 * 60 * 1000,
      // Misc. defaults.
      "http2.maxRetries": 2,
      "http2.retryInterval": 500,
      "http2.reset_retry_count_after_ms": 60000,
      maxQuotaPerSubscription: 16,
      quotaUpdateDelay: 3000,
      "testing.notifyWorkers": false,
    },
    prefs
  );
  for (let pref in defaultPrefs) {
    servicePrefs.set(pref, defaultPrefs[pref]);
  }
}

function compareAscending(a, b) {
  if (a > b) {
    return 1;
  }
  return a < b ? -1 : 0;
}

/**
 * Creates a mock WebSocket object that implements a subset of the
 * nsIWebSocketChannel interface used by the PushService.
 *
 * The given protocol handlers are invoked for each Simple Push command sent
 * by the PushService. The ping handler is optional; all others will throw if
 * the PushService sends a command for which no handler is registered.
 *
 * All nsIWebSocketListener methods will be called asynchronously.
 * serverSendMsg() and serverClose() can be used to respond to client messages
 * and close the "server" end of the connection, respectively.
 *
 * @param {nsIURI} originalURI The original WebSocket URL.
 * @param {Function} options.onHello The "hello" handshake command handler.
 * @param {Function} options.onRegister The "register" command handler.
 * @param {Function} options.onUnregister The "unregister" command handler.
 * @param {Function} options.onACK The "ack" command handler.
 * @param {Function} [options.onPing] An optional ping handler.
 */
function MockWebSocket(originalURI, handlers = {}) {
  this._originalURI = originalURI;
  this._onHello = handlers.onHello;
  this._onRegister = handlers.onRegister;
  this._onUnregister = handlers.onUnregister;
  this._onACK = handlers.onACK;
  this._onPing = handlers.onPing;
  this._onBroadcastSubscribe = handlers.onBroadcastSubscribe;
}

MockWebSocket.prototype = {
  _originalURI: null,
  _onHello: null,
  _onRegister: null,
  _onUnregister: null,
  _onACK: null,
  _onPing: null,

  _listener: null,
  _context: null,

  QueryInterface: ChromeUtils.generateQI(["nsIWebSocketChannel"]),

  get originalURI() {
    return this._originalURI;
  },

  asyncOpen(uri, origin, originAttributes, windowId, listener, context) {
    this._listener = listener;
    this._context = context;
    waterfall(() => this._listener.onStart(this._context));
  },

  _handleMessage(msg) {
    let messageType, request;
    if (msg == "{}") {
      request = {};
      messageType = "ping";
    } else {
      request = JSON.parse(msg);
      messageType = request.messageType;
    }
    switch (messageType) {
      case "hello":
        if (typeof this._onHello != "function") {
          throw new Error("Unexpected handshake request");
        }
        this._onHello(request);
        break;

      case "register":
        if (typeof this._onRegister != "function") {
          throw new Error("Unexpected register request");
        }
        this._onRegister(request);
        break;

      case "unregister":
        if (typeof this._onUnregister != "function") {
          throw new Error("Unexpected unregister request");
        }
        this._onUnregister(request);
        break;

      case "ack":
        if (typeof this._onACK != "function") {
          throw new Error("Unexpected acknowledgement");
        }
        this._onACK(request);
        break;

      case "ping":
        if (typeof this._onPing == "function") {
          this._onPing(request);
        } else {
          // Echo ping packets.
          this.serverSendMsg("{}");
        }
        break;

      case "broadcast_subscribe":
        if (typeof this._onBroadcastSubscribe != "function") {
          throw new Error("Unexpected broadcast_subscribe");
        }
        this._onBroadcastSubscribe(request);
        break;

      default:
        throw new Error("Unexpected message: " + messageType);
    }
  },

  sendMsg(msg) {
    this._handleMessage(msg);
  },

  close() {
    waterfall(() => this._listener.onStop(this._context, Cr.NS_OK));
  },

  /**
   * Responds with the given message, calling onMessageAvailable() and
   * onAcknowledge() synchronously. Throws if the message is not a string.
   * Used by the tests to respond to client commands.
   *
   * @param {String} msg The message to send to the client.
   */
  serverSendMsg(msg) {
    if (typeof msg != "string") {
      throw new Error("Invalid response message");
    }
    waterfall(
      () => this._listener.onMessageAvailable(this._context, msg),
      () => this._listener.onAcknowledge(this._context, 0)
    );
  },

  /**
   * Closes the server end of the connection, calling onServerClose()
   * followed by onStop(). Used to test abrupt connection termination.
   *
   * @param {Number} [statusCode] The WebSocket connection close code.
   * @param {String} [reason] The connection close reason.
   */
  serverClose(statusCode, reason = "") {
    if (!isFinite(statusCode)) {
      statusCode = WEBSOCKET_CLOSE_GOING_AWAY;
    }
    waterfall(
      () => this._listener.onServerClose(this._context, statusCode, reason),
      () => this._listener.onStop(this._context, Cr.NS_BASE_STREAM_CLOSED)
    );
  },

  serverInterrupt(result = Cr.NS_ERROR_NET_RESET) {
    waterfall(() => this._listener.onStop(this._context, result));
  },
};

var setUpServiceInParent = async function (service, db) {
  if (!isParent) {
    return;
  }

  let userAgentID = "ce704e41-cb77-4206-b07b-5bf47114791b";
  setPrefs({
    userAgentID,
  });

  await db.put({
    channelID: "6e2814e1-5f84-489e-b542-855cc1311f09",
    pushEndpoint: "https://example.org/push/get",
    scope: "https://example.com/get/ok",
    originAttributes: "",
    version: 1,
    pushCount: 10,
    lastPush: 1438360548322,
    quota: 16,
  });
  await db.put({
    channelID: "3a414737-2fd0-44c0-af05-7efc172475fc",
    pushEndpoint: "https://example.org/push/unsub",
    scope: "https://example.com/unsub/ok",
    originAttributes: "",
    version: 2,
    pushCount: 10,
    lastPush: 1438360848322,
    quota: 4,
  });
  await db.put({
    channelID: "ca3054e8-b59b-4ea0-9c23-4a3c518f3161",
    pushEndpoint: "https://example.org/push/stale",
    scope: "https://example.com/unsub/fail",
    originAttributes: "",
    version: 3,
    pushCount: 10,
    lastPush: 1438362348322,
    quota: 1,
  });

  service.init({
    serverURI: "wss://push.example.org/",
    db: makeStub(db, {
      put(prev, record) {
        if (record.scope == "https://example.com/sub/fail") {
          return Promise.reject("synergies not aligned");
        }
        return prev.call(this, record);
      },
      delete(prev, channelID) {
        if (channelID == "ca3054e8-b59b-4ea0-9c23-4a3c518f3161") {
          return Promise.reject("splines not reticulated");
        }
        return prev.call(this, channelID);
      },
      getByIdentifiers(prev, identifiers) {
        if (identifiers.scope == "https://example.com/get/fail") {
          return Promise.reject("qualia unsynchronized");
        }
        return prev.call(this, identifiers);
      },
    }),
    makeWebSocket(uri) {
      return new MockWebSocket(uri, {
        onHello() {
          this.serverSendMsg(
            JSON.stringify({
              messageType: "hello",
              uaid: userAgentID,
              status: 200,
            })
          );
        },
        onRegister(request) {
          if (request.key) {
            let appServerKey = new Uint8Array(
              ChromeUtils.base64URLDecode(request.key, {
                padding: "require",
              })
            );
            equal(appServerKey.length, 65, "Wrong app server key length");
            equal(appServerKey[0], 4, "Wrong app server key format");
          }
          this.serverSendMsg(
            JSON.stringify({
              messageType: "register",
              uaid: userAgentID,
              channelID: request.channelID,
              status: 200,
              pushEndpoint: "https://example.org/push/" + request.channelID,
            })
          );
        },
        onUnregister(request) {
          this.serverSendMsg(
            JSON.stringify({
              messageType: "unregister",
              channelID: request.channelID,
              status: 200,
            })
          );
        },
      });
    },
  });
};

var tearDownServiceInParent = async function (db) {
  if (!isParent) {
    return;
  }

  let record = await db.getByIdentifiers({
    scope: "https://example.com/sub/ok",
    originAttributes: "",
  });
  ok(
    record.pushEndpoint.startsWith("https://example.org/push"),
    "Wrong push endpoint in subscription record"
  );

  record = await db.getByKeyID("3a414737-2fd0-44c0-af05-7efc172475fc");
  ok(!record, "Unsubscribed record should not exist");
};

function putTestRecord(db, keyID, scope, quota) {
  return db.put({
    channelID: keyID,
    pushEndpoint: "https://example.org/push/" + keyID,
    scope,
    pushCount: 0,
    lastPush: 0,
    version: null,
    originAttributes: "",
    quota,
    systemRecord: quota == Infinity,
  });
}

function getAllKeyIDs(db) {
  return db
    .getAllKeyIDs()
    .then(records =>
      records.map(record => record.keyID).sort(compareAscending)
    );
}
