/* 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/. */

"use strict";

this.EXPORTED_SYMBOLS = [
  "Translation",
  "TranslationProvider",
];

const {classes: Cc, interfaces: Ci, utils: Cu} = Components;

const TRANSLATION_PREF_SHOWUI = "browser.translation.ui.show";

Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/Promise.jsm");
Cu.import("resource://gre/modules/Metrics.jsm", this);
Cu.import("resource://gre/modules/Task.jsm", this);

const DAILY_COUNTER_FIELD = {type: Metrics.Storage.FIELD_DAILY_COUNTER};
const DAILY_LAST_TEXT_FIELD = {type: Metrics.Storage.FIELD_DAILY_LAST_TEXT};
const DAILY_LAST_NUMERIC_FIELD = {type: Metrics.Storage.FIELD_DAILY_LAST_NUMERIC};


this.Translation = {
  STATE_OFFER: 0,
  STATE_TRANSLATING: 1,
  STATE_TRANSLATED: 2,
  STATE_ERROR: 3,

  supportedSourceLanguages: ["en", "zh", "ja", "es", "de", "fr", "ru", "ar", "ko", "pt"],
  supportedTargetLanguages: ["en", "pl", "tr", "vi"],

  _defaultTargetLanguage: "",
  get defaultTargetLanguage() {
    if (!this._defaultTargetLanguage) {
      this._defaultTargetLanguage = Cc["@mozilla.org/chrome/chrome-registry;1"]
                                      .getService(Ci.nsIXULChromeRegistry)
                                      .getSelectedLocale("global")
                                      .split("-")[0];
    }
    return this._defaultTargetLanguage;
  },

  documentStateReceived: function(aBrowser, aData) {
    if (aData.state == this.STATE_OFFER) {
      if (this.supportedSourceLanguages.indexOf(aData.detectedLanguage) == -1 ||
          aData.detectedLanguage == this.defaultTargetLanguage)
        return;

      TranslationHealthReport.recordTranslationOpportunity(aData.detectedLanguage);
    }

    if (!Services.prefs.getBoolPref(TRANSLATION_PREF_SHOWUI))
      return;

    if (!aBrowser.translationUI)
      aBrowser.translationUI = new TranslationUI(aBrowser);
    let trUI = aBrowser.translationUI;

    // Set all values before showing a new translation infobar.
    trUI._state = aData.state;
    trUI.detectedLanguage = aData.detectedLanguage;
    trUI.translatedFrom = aData.translatedFrom;
    trUI.translatedTo = aData.translatedTo;
    trUI.originalShown = aData.originalShown;

    trUI.showURLBarIcon();

    if (trUI.shouldShowInfoBar(aBrowser.currentURI))
      trUI.showTranslationInfoBar();
  }
};

/* TranslationUI objects keep the information related to translation for
 * a specific browser.  This object is passed to the translation
 * infobar so that it can initialize itself.  The properties exposed to
 * the infobar are:
 * - detectedLanguage, code of the language detected on the web page.
 * - state, the state in which the infobar should be displayed
 * - translatedFrom, if already translated, source language code.
 * - translatedTo, if already translated, target language code.
 * - translate, method starting the translation of the current page.
 * - showOriginalContent, method showing the original page content.
 * - showTranslatedContent, method showing the translation for an
 *   already translated page whose original content is shown.
 * - originalShown, boolean indicating if the original or translated
 *   version of the page is shown.
 */
function TranslationUI(aBrowser) {
  this.browser = aBrowser;
  aBrowser.messageManager.addMessageListener("Translation:Finished", this);
}

TranslationUI.prototype = {
  translate: function(aFrom, aTo) {
    if (aFrom == aTo ||
        (this.state == Translation.STATE_TRANSLATED &&
         this.translatedFrom == aFrom && this.translatedTo == aTo)) {
      // Nothing to do.
      return;
    }

    this.state = Translation.STATE_TRANSLATING;
    this.translatedFrom = aFrom;
    this.translatedTo = aTo;

    this.browser.messageManager.sendAsyncMessage(
      "Translation:TranslateDocument",
      { from: aFrom, to: aTo }
    );
  },

  showURLBarIcon: function() {
    let chromeWin = this.browser.ownerGlobal;
    let PopupNotifications = chromeWin.PopupNotifications;
    let removeId = this.originalShown ? "translated" : "translate";
    let notification =
      PopupNotifications.getNotification(removeId, this.browser);
    if (notification)
      PopupNotifications.remove(notification);

    let callback = aTopic => {
      if (aTopic != "showing")
        return false;
      let notification = this.notificationBox.getNotificationWithValue("translation");
      if (notification)
        notification.close();
      else
        this.showTranslationInfoBar();
      return true;
    };

    let addId = this.originalShown ? "translate" : "translated";
    PopupNotifications.show(this.browser, addId, null,
                            addId + "-notification-icon", null, null,
                            {dismissed: true, eventCallback: callback});
  },

  _state: 0,
  get state() this._state,
  set state(val) {
    let notif = this.notificationBox.getNotificationWithValue("translation");
    if (notif)
      notif.state = val;
    this._state = val;
  },

  originalShown: true,
  showOriginalContent: function() {
    this.originalShown = true;
    this.showURLBarIcon();
    this.browser.messageManager.sendAsyncMessage("Translation:ShowOriginal");
  },

  showTranslatedContent: function() {
    this.originalShown = false;
    this.showURLBarIcon();
    this.browser.messageManager.sendAsyncMessage("Translation:ShowTranslation");
  },

  get notificationBox() this.browser.ownerGlobal.gBrowser.getNotificationBox(this.browser),

  showTranslationInfoBar: function() {
    let notificationBox = this.notificationBox;
    let notif = notificationBox.appendNotification("", "translation", null,
                                                   notificationBox.PRIORITY_INFO_HIGH);
    notif.init(this);
    return notif;
  },

  shouldShowInfoBar: function(aURI) {
    // Check if we should never show the infobar for this language.
    let neverForLangs =
      Services.prefs.getCharPref("browser.translation.neverForLanguages");
    if (neverForLangs.split(",").indexOf(this.detectedLanguage) != -1)
      return false;

    // or if we should never show the infobar for this domain.
    let perms = Services.perms;
    return perms.testExactPermission(aURI, "translate") != perms.DENY_ACTION;
  },

  showTranslationUI: function(aDetectedLanguage) {
    this.detectedLanguage = aDetectedLanguage;

    // Reset all values before showing a new translation infobar.
    this.state = 0;
    this.translatedFrom = "";
    this.translatedTo = "";
    this.originalShown = true;

    this.showURLBarIcon();

    if (!this.shouldShowInfoBar(this.browser.currentURI))
      return null;

    return this.showTranslationInfoBar();
  },

  receiveMessage: function(msg) {
    switch (msg.name) {
      case "Translation:Finished":
        if (msg.data.success) {
          this.originalShown = false;
          this.state = Translation.STATE_TRANSLATED;
          this.showURLBarIcon();

          // Record the number of characters translated.
          TranslationHealthReport.recordTranslation(msg.data.from, msg.data.to,
                                                    msg.data.characterCount);
        } else {
          this.state = Translation.STATE_ERROR;
        }
        break;
    }
  }
};

/**
 * Helper methods for recording translation data in FHR.
 */
let TranslationHealthReport = {
  /**
   * Record a translation opportunity in the health report.
   * @param language
   *        The language of the page.
   */
  recordTranslationOpportunity: function (language) {
    this._withProvider(provider => provider.recordTranslationOpportunity(language));
   },

   /**
   * Record a translation in the health report.
   * @param langFrom
   *        The language of the page.
   * @param langTo
   *        The language translated to
   * @param numCharacters
   *        The number of characters that were translated
   */
  recordTranslation: function (langFrom, langTo, numCharacters) {
    this._withProvider(provider => provider.recordTranslation(langFrom, langTo, numCharacters));
  },

  /**
   * Record a change of the detected language in the health report. This should
   * only be called when actually executing a translation not every time the
   * user changes in the language in the UI.
   *
   * @param beforeFirstTranslation
   *        A boolean indicating if we are recording a change of detected
   *        language before translating the page for the first time. If we
   *        have already translated the page from the detected language and
   *        the user has manually adjusted the detected language false should
   *        be passed.
   */
  recordLanguageChange: function (beforeFirstTranslation) {
    this._withProvider(provider => provider.recordLanguageChange(beforeFirstTranslation));
  },

  /**
   * Retrieve the translation provider and pass it to the given function.
   *
   * @param callback
   *        The function that will be passed the translation provider.
   */
  _withProvider: function (callback) {
    try {
      let reporter = Cc["@mozilla.org/datareporting/service;1"]
                        .getService().wrappedJSObject.healthReporter;

      if (reporter) {
        reporter.onInit().then(function () {
          callback(reporter.getProvider("org.mozilla.translation"));
        }, Cu.reportError);
      } else {
        callback(null);
      }
    } catch (ex) {
      Cu.reportError(ex);
    }
  }
};

/**
 * Holds usage data about the Translation feature.
 *
 * This is a special telemetry measurement that is transmitted in the FHR
 * payload. Data will only be recorded/transmitted when both telemetry and
 * FHR are enabled. Additionally, if telemetry was previously enabled but
 * is currently disabled, old recorded data will not be transmitted.
 */
function TranslationMeasurement1() {
  Metrics.Measurement.call(this);

  this._serializers[this.SERIALIZE_JSON].singular =
    this._wrapJSONSerializer(this._serializers[this.SERIALIZE_JSON].singular);

  this._serializers[this.SERIALIZE_JSON].daily =
    this._wrapJSONSerializer(this._serializers[this.SERIALIZE_JSON].daily);
}

TranslationMeasurement1.prototype = Object.freeze({
  __proto__: Metrics.Measurement.prototype,

  name: "translation",
  version: 1,

  fields: {
    translationOpportunityCount: DAILY_COUNTER_FIELD,
    pageTranslatedCount: DAILY_COUNTER_FIELD,
    charactersTranslatedCount: DAILY_COUNTER_FIELD,
    translationOpportunityCountsByLanguage: DAILY_LAST_TEXT_FIELD,
    pageTranslatedCountsByLanguage: DAILY_LAST_TEXT_FIELD,
    detectedLanguageChangedBefore: DAILY_COUNTER_FIELD,
    detectedLanguageChangedAfter: DAILY_COUNTER_FIELD,
    detectLanguageEnabled: DAILY_LAST_NUMERIC_FIELD,
    showTranslationUI: DAILY_LAST_NUMERIC_FIELD,
  },

  shouldIncludeField: function (field) {
    if (!Services.prefs.getBoolPref("toolkit.telemetry.enabled")) {
      // This measurement should only be included when telemetry is
      // enabled, so we will not include any fields.
      return false;
    }

    return field in this._fields;
  },

  _getDailyLastTextFieldAsJSON: function(name, date) {
    let id = this.fieldID(name);

    return this.storage.getDailyLastTextFromFieldID(id, date).then((data) => {
      if (data.hasDay(date)) {
        data = JSON.parse(data.getDay(date));
      } else {
        data = {};
      }

      return data;
    });
  },

  _wrapJSONSerializer: function (serializer) {
    let _parseInPlace = function(o, k) {
      if (k in o) {
        o[k] = JSON.parse(o[k]);
      }
    };

    return function (data) {
      let result = serializer(data);

      // Special case the serialization of these fields so that
      // they are sent as objects, not stringified objects.
      _parseInPlace(result, "translationOpportunityCountsByLanguage");
      _parseInPlace(result, "pageTranslatedCountsByLanguage");

      return result;
    }
  }
});

this.TranslationProvider = function () {
  Metrics.Provider.call(this);
}

TranslationProvider.prototype = Object.freeze({
  __proto__: Metrics.Provider.prototype,

  name: "org.mozilla.translation",

  measurementTypes: [
    TranslationMeasurement1,
  ],

  recordTranslationOpportunity: function (language, date=new Date()) {
    let m = this.getMeasurement(TranslationMeasurement1.prototype.name,
                                TranslationMeasurement1.prototype.version);

    return this._enqueueTelemetryStorageTask(function* recordTask() {
      yield m.incrementDailyCounter("translationOpportunityCount", date);

      let langCounts = yield m._getDailyLastTextFieldAsJSON(
        "translationOpportunityCountsByLanguage", date);

      langCounts[language] = (langCounts[language] || 0) + 1;
      langCounts = JSON.stringify(langCounts);

      yield m.setDailyLastText("translationOpportunityCountsByLanguage",
                               langCounts, date);

    }.bind(this));
  },

  recordTranslation: function (langFrom, langTo, numCharacters, date=new Date()) {
    let m = this.getMeasurement(TranslationMeasurement1.prototype.name,
                                TranslationMeasurement1.prototype.version);

    return this._enqueueTelemetryStorageTask(function* recordTask() {
      yield m.incrementDailyCounter("pageTranslatedCount", date);
      yield m.incrementDailyCounter("charactersTranslatedCount", date,
                                    numCharacters);

      let langCounts = yield m._getDailyLastTextFieldAsJSON(
        "pageTranslatedCountsByLanguage", date);

      let counts = langCounts[langFrom] || {};
      counts["total"] = (counts["total"] || 0) + 1;
      counts[langTo] = (counts[langTo] || 0) + 1;
      langCounts[langFrom] = counts;
      langCounts = JSON.stringify(langCounts);

      yield m.setDailyLastText("pageTranslatedCountsByLanguage",
                               langCounts, date);
    }.bind(this));
  },

  recordLanguageChange: function (beforeFirstTranslation) {
    let m = this.getMeasurement(TranslationMeasurement1.prototype.name,
                                TranslationMeasurement1.prototype.version);

    return this._enqueueTelemetryStorageTask(function* recordTask() {
      if (beforeFirstTranslation) {
          yield m.incrementDailyCounter("detectedLanguageChangedBefore");
        } else {
          yield m.incrementDailyCounter("detectedLanguageChangedAfter");
        }
    }.bind(this));
  },

  collectDailyData: function () {
    let m = this.getMeasurement(TranslationMeasurement1.prototype.name,
                                TranslationMeasurement1.prototype.version);

    return this._enqueueTelemetryStorageTask(function* recordTask() {
      let detectLanguageEnabled = Services.prefs.getBoolPref("browser.translation.detectLanguage");
      yield m.setDailyLastNumeric("detectLanguageEnabled", detectLanguageEnabled ? 1 : 0);

      let showTranslationUI = Services.prefs.getBoolPref("browser.translation.ui.show");
      yield m.setDailyLastNumeric("showTranslationUI", showTranslationUI ? 1 : 0);
    }.bind(this));
  },

  _enqueueTelemetryStorageTask: function (task) {
    if (!Services.prefs.getBoolPref("toolkit.telemetry.enabled")) {
      // This measurement should only be included when telemetry is
      // enabled, so don't record any data.
      return Promise.resolve(null);
    }

    return this.enqueueStorageOperation(() => {
      return Task.spawn(task);
    });
  }
});