// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.


var pref = chrome.privacy.websites.referrersEnabled;

function $(id) {
  return document.getElementById(id);
}

/**
 * Returns whether the |levelOfControl| means that the extension can change the
 * preference value.
 *
 * @param levelOfControl{string}
 */
function settingIsControllable(levelOfControl) {
  return (levelOfControl == 'controllable_by_this_extension' ||
          levelOfControl == 'controlled_by_this_extension');
}

/**
 * Updates the UI to reflect the state of the preference.
 *
 * @param settings{object} A settings object, as returned from |get()| or the
 * |onchange| event.
 */
function updateUI(settings) {
  var disableUI = !settingIsControllable(settings.levelOfControl);
  document.getElementById('regularValue').disabled = disableUI;
  document.getElementById('useSeparateIncognitoSettings').disabled = disableUI;
  if (settings.hasOwnProperty('incognitoSpecific')) {
    var hasIncognitoValue = settings.incognitoSpecific;
    document.getElementById('useSeparateIncognitoSettings').checked =
        hasIncognitoValue;
    document.getElementById('incognitoValue').disabled =
        disableUI || !hasIncognitoValue;
    document.getElementById('incognitoValue').checked = settings.value;
  } else {
    document.getElementById('regularValue').checked = settings.value;
  }
}

/**
 * Wrapper for |updateUI| which is used as callback for the |get()| method and
 * which logs the result.
 * If there was an error getting the preference, does nothing.
 *
 * @param settings{object} A settings object, as returned from |get()|.
 */
function updateUIFromGet(settings) {
  if (settings) {
    console.log('pref.get result:' + JSON.stringify(settings));
    updateUI(settings);
  }
}

/**
 * Wrapper for |updateUI| which is used as handler for the |onchange| event
 * and which logs the result.
 *
 * @param settings{object} A settings object, as returned from the |onchange|
 * event.
 */
function updateUIFromOnChange(settings) {
  console.log('pref.onChange event:' + JSON.stringify(settings));
  updateUI(settings);
}

/*
 * Initializes the UI.
 */
function init() {
  chrome.extension.isAllowedIncognitoAccess(function(allowed) {
    if (allowed) {
      pref.get({'incognito': true}, updateUIFromGet);
      $('incognito').style.display = 'block';
      $('incognito-forbidden').style.display = 'none';
    }
  });
  pref.get({}, updateUIFromGet);
  pref.onChange.addListener(updateUIFromOnChange);

  $('regularValue').addEventListener('click', function () {
    setPrefValue(this.checked, false);
  });
  $('useSeparateIncognitoSettings').addEventListener('click', function () {
     setUseSeparateIncognitoSettings(this.checked);
  });
  $('incognitoValue').addEventListener('click', function () {
    setPrefValue(this.checked, true);
  });
}

/**
 * Called from the UI to change the preference value.
 *
 * @param enabled{boolean} The new preference value.
 * @param incognito{boolean} Whether the value is specific to incognito mode.
 */
function setPrefValue(enabled, incognito) {
  var scope = incognito ? 'incognito_session_only' : 'regular';
  pref.set({'value': enabled, 'scope': scope});
}

/**
 * Called from the UI to change whether to use separate settings for
 * incognito mode.
 *
 * @param value{boolean} whether to use separate settings for
 * incognito mode.
 */
function setUseSeparateIncognitoSettings(value) {
  if (!value) {
    pref.clear({'incognito': true});
  } else {
    // Explicitly set the value for incognito mode.
    pref.get({'incognito': true}, function(settings) {
      pref.set({'incognito': true, 'value': settings.value});
    });
  }
  document.getElementById('incognitoValue').disabled = !value;
}

// Call `init` to kick things off.
document.addEventListener('DOMContentLoaded', init);