/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * This module sends Origin Telemetry periodically:
 * https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/data/prio-ping.html
 */

"use strict";

var EXPORTED_SYMBOLS = ["TelemetryPrioPing", "Policy"];

const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);

XPCOMUtils.defineLazyModuleGetters(this, {
  TelemetryController: "resource://gre/modules/TelemetryController.jsm",
  Log: "resource://gre/modules/Log.jsm",
});

const { TelemetryUtils } = ChromeUtils.import(
  "resource://gre/modules/TelemetryUtils.jsm"
);
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");

const Utils = TelemetryUtils;

const LOGGER_NAME = "Toolkit.Telemetry";
const LOGGER_PREFIX = "TelemetryPrioPing";

// Triggered from native Origin Telemetry storage.
const PRIO_LIMIT_REACHED_TOPIC = "origin-telemetry-storage-limit-reached";

const PRIO_PING_VERSION = "1";

var Policy = {
  sendPing: (type, payload, options) =>
    TelemetryController.submitExternalPing(type, payload, options),
  getEncodedOriginSnapshot: async aClear =>
    Services.telemetry.getEncodedOriginSnapshot(aClear),
};

var TelemetryPrioPing = {
  Reason: Object.freeze({
    PERIODIC: "periodic", // Sent the ping containing Origin Telemetry from the past periodic interval (default 24h).
    MAX: "max", // Sent the ping containing at least the maximum number (default 10) of prioData elements, earlier than the periodic interval.
    SHUTDOWN: "shutdown", // Recorded data was sent on shutdown.
  }),

  PRIO_PING_TYPE: "prio",

  _logger: null,
  _testing: false,
  _timeoutId: null,

  startup() {
    if (!this._testing && !Services.telemetry.canRecordPrereleaseData) {
      this._log.trace("Extended collection disabled. Prio ping disabled.");
      return;
    }

    if (
      !this._testing &&
      !Services.prefs.getBoolPref(Utils.Preferences.PrioPingEnabled, true)
    ) {
      this._log.trace("Prio ping disabled by pref.");
      return;
    }
    this._log.trace("Starting up.");

    Services.obs.addObserver(this, PRIO_LIMIT_REACHED_TOPIC);
  },

  async shutdown() {
    this._log.trace("Shutting down.");
    // removeObserver may throw, which could interrupt shutdown.
    try {
      Services.obs.removeObserver(this, PRIO_LIMIT_REACHED_TOPIC);
    } catch (ex) {}

    await this._submitPing(this.Reason.SHUTDOWN);
  },

  observe(aSubject, aTopic, aData) {
    switch (aTopic) {
      case PRIO_LIMIT_REACHED_TOPIC:
        this._log.trace("prio limit reached");
        this._submitPing(this.Reason.MAX);
        break;
    }
  },

  periodicPing() {
    this._log.trace("periodic ping triggered");
    this._submitPing(this.Reason.PERIODIC);
  },

  /**
   * Submits an "prio" ping and restarts the timer for the next interval.
   *
   * @param {String} reason The reason we're sending the ping. One of TelemetryPrioPing.Reason.
   */
  async _submitPing(reason) {
    this._log.trace("_submitPing");

    let snapshot = await Policy.getEncodedOriginSnapshot(true /* clear */);

    if (!this._testing) {
      snapshot = snapshot.filter(
        ({ encoding }) => !encoding.startsWith("telemetry.test")
      );
    }

    if (snapshot.length === 0) {
      // Don't send a ping if we haven't anything to send
      this._log.trace("nothing to send");
      return;
    }

    let payload = {
      version: PRIO_PING_VERSION,
      reason,
      prioData: snapshot,
    };

    const options = {
      addClientId: false,
      addEnvironment: false,
      usePingSender: reason === this.Reason.SHUTDOWN,
    };

    Policy.sendPing(this.PRIO_PING_TYPE, payload, options);
  },

  /**
   * Test-only, restore to initial state.
   */
  testReset() {
    this._testing = true;
  },

  get _log() {
    if (!this._logger) {
      this._logger = Log.repository.getLoggerWithMessagePrefix(
        LOGGER_NAME,
        LOGGER_PREFIX + "::"
      );
    }

    return this._logger;
  },
};