/* 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/. */

Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
Components.utils.import("resource://gre/modules/AddonManager.jsm");

// =================================================
// Console constructor
function Console() {
  this._console = Components.classes["@mozilla.org/consoleservice;1"]
                            .getService(Ci.nsIConsoleService);
}

// =================================================
// Console implementation
Console.prototype = {
  log: function cs_log(aMsg) {
    this._console.logStringMessage(aMsg);
  },

  open: function cs_open() {
    var wMediator = Components.classes["@mozilla.org/appshell/window-mediator;1"]
                              .getService(Ci.nsIWindowMediator);
    var console = wMediator.getMostRecentWindow("global:console");
    if (!console) {
      var wWatch = Components.classes["@mozilla.org/embedcomp/window-watcher;1"]
                             .getService(Ci.nsIWindowWatcher);
      wWatch.openWindow(null, "chrome://global/content/console.xul", "_blank",
                        "chrome,dialog=no,all", null);
    } else {
      // console was already open
      console.focus();
    }
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIConsole])
};


// =================================================
// EventItem constructor
function EventItem(aType, aData) {
  this._type = aType;
  this._data = aData;
}

// =================================================
// EventItem implementation
EventItem.prototype = {
  _cancel: false,

  get type() {
    return this._type;
  },

  get data() {
    return this._data;
  },

  preventDefault: function ei_pd() {
    this._cancel = true;
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIEventItem])
};


// =================================================
// Events constructor
function Events(notifier) {
  this._listeners = [];
  this._notifier = notifier;
}

// =================================================
// Events implementation
Events.prototype = {
  addListener: function evts_al(aEvent, aListener) {
    function hasFilter(element) {
      return element.event == aEvent && element.listener == aListener;
    }

    if (this._listeners.some(hasFilter))
      return;

    this._listeners.push({
      event: aEvent,
      listener: aListener
    });

    if (this._notifier) {
      this._notifier(aEvent, aListener);
    }
  },

  removeListener: function evts_rl(aEvent, aListener) {
    function hasFilter(element) {
      return (element.event != aEvent) || (element.listener != aListener);
    }

    this._listeners = this._listeners.filter(hasFilter);
  },

  dispatch: function evts_dispatch(aEvent, aEventItem) {
    var eventItem = new EventItem(aEvent, aEventItem);

    this._listeners.forEach(function(key) {
      if (key.event == aEvent) {
        key.listener.handleEvent ?
          key.listener.handleEvent(eventItem) :
          key.listener(eventItem);
      }
    });

    return !eventItem._cancel;
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIEvents])
};

// =================================================
// PreferenceObserver (internal class)
//
// PreferenceObserver is a global singleton which watches the browser's
// preferences and sends you events when things change.

function PreferenceObserver() {
  this._observersDict = {};
}

PreferenceObserver.prototype = {
  /**
   * Add a preference observer.
   *
   * @param aPrefs the nsIPrefBranch onto which we'll install our listener.
   * @param aDomain the domain our listener will watch (a string).
   * @param aEvent the event to listen to (you probably want "change").
   * @param aListener the function to call back when the event fires.  This
   *                  function will receive an EventData argument.
   */
  addListener: function po_al(aPrefs, aDomain, aEvent, aListener) {
    var root = aPrefs.root;
    if (!this._observersDict[root]) {
      this._observersDict[root] = {};
    }
    var observer = this._observersDict[root][aDomain];

    if (!observer) {
      observer = {
        events: new Events(),
        observe: function po_observer_obs(aSubject, aTopic, aData) {
          this.events.dispatch("change", aData);
        },
        QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
                                               Ci.nsISupportsWeakReference])
      };
      observer.prefBranch = aPrefs;
      observer.prefBranch.addObserver(aDomain, observer, /* ownsWeak = */ true);

      // Notice that the prefBranch keeps a weak reference to the observer;
      // it's this._observersDict which keeps the observer alive.
      this._observersDict[root][aDomain] = observer;
    }
    observer.events.addListener(aEvent, aListener);
  },

  /**
   * Remove a preference observer.
   *
   * This function's parameters are identical to addListener's.
   */
  removeListener: function po_rl(aPrefs, aDomain, aEvent, aListener) {
    var root = aPrefs.root;
    if (!this._observersDict[root] ||
        !this._observersDict[root][aDomain]) {
      return;
    }
    var observer = this._observersDict[root][aDomain];
    observer.events.removeListener(aEvent, aListener);

    if (observer.events._listeners.length == 0) {
      // nsIPrefBranch objects are not singletons -- we can have two
      // nsIPrefBranch'es for the same branch.  There's no guarantee that
      // aPrefs is the same object as observer.prefBranch, so we have to call
      // removeObserver on observer.prefBranch.
      observer.prefBranch.removeObserver(aDomain, observer);
      delete this._observersDict[root][aDomain];
      if (Object.keys(this._observersDict[root]).length == 0) {
        delete this._observersDict[root];
      }
    }
  }
};

// =================================================
// PreferenceBranch constructor
function PreferenceBranch(aBranch) {
  if (!aBranch)
    aBranch = "";

  this._root = aBranch;
  this._prefs = Components.classes["@mozilla.org/preferences-service;1"]
                          .getService(Ci.nsIPrefService)
                          .QueryInterface(Ci.nsIPrefBranch);

  if (aBranch)
    this._prefs = this._prefs.getBranch(aBranch);

  let prefs = this._prefs;
  this._events = {
    addListener: function pb_al(aEvent, aListener) {
      gPreferenceObserver.addListener(prefs, "", aEvent, aListener);
    },
    removeListener: function pb_rl(aEvent, aListener) {
      gPreferenceObserver.removeListener(prefs, "", aEvent, aListener);
    },
    QueryInterface: XPCOMUtils.generateQI([Ci.extIEvents])
  };
}

// =================================================
// PreferenceBranch implementation
PreferenceBranch.prototype = {
  get root() {
    return this._root;
  },

  get all() {
    return this.find({});
  },

  get events() {
    return this._events;
  },

  // XXX: Disabled until we can figure out the wrapped object issues
  // name: "name" or /name/
  // path: "foo.bar." or "" or /fo+\.bar/
  // type: Boolean, Number, String (getPrefType)
  // locked: true, false (prefIsLocked)
  // modified: true, false (prefHasUserValue)
  find: function prefs_find(aOptions) {
    var retVal = [];
    var items = this._prefs.getChildList("");

    for (var i = 0; i < items.length; i++) {
      retVal.push(new Preference(items[i], this));
    }

    return retVal;
  },

  has: function prefs_has(aName) {
    return (this._prefs.getPrefType(aName) != Ci.nsIPrefBranch.PREF_INVALID);
  },

  get: function prefs_get(aName) {
    return this.has(aName) ? new Preference(aName, this) : null;
  },

  getValue: function prefs_gv(aName, aValue) {
    var type = this._prefs.getPrefType(aName);

    switch (type) {
      case Ci.nsIPrefBranch.PREF_STRING:
        aValue = this._prefs.getComplexValue(aName, Ci.nsISupportsString).data;
        break;
      case Ci.nsIPrefBranch.PREF_BOOL:
        aValue = this._prefs.getBoolPref(aName);
        break;
      case Ci.nsIPrefBranch.PREF_INT:
        aValue = this._prefs.getIntPref(aName);
        break;
    }

    return aValue;
  },

  setValue: function prefs_sv(aName, aValue) {
    var type = aValue != null ? aValue.constructor.name : "";

    switch (type) {
      case "String":
        var str = Components.classes["@mozilla.org/supports-string;1"]
                            .createInstance(Ci.nsISupportsString);
        str.data = aValue;
        this._prefs.setComplexValue(aName, Ci.nsISupportsString, str);
        break;
      case "Boolean":
        this._prefs.setBoolPref(aName, aValue);
        break;
      case "Number":
        this._prefs.setIntPref(aName, aValue);
        break;
      default:
        throw ("Unknown preference value specified.");
    }
  },

  reset: function prefs_reset() {
    this._prefs.resetBranch("");
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIPreferenceBranch])
};


// =================================================
// Preference constructor
function Preference(aName, aBranch) {
  this._name = aName;
  this._branch = aBranch;

  var self = this;
  this._events = {
    addListener: function pref_al(aEvent, aListener) {
      gPreferenceObserver.addListener(self._branch._prefs, self._name, aEvent, aListener);
    },
    removeListener: function pref_rl(aEvent, aListener) {
      gPreferenceObserver.removeListener(self._branch._prefs, self._name, aEvent, aListener);
    },
    QueryInterface: XPCOMUtils.generateQI([Ci.extIEvents])
  };
}

// =================================================
// Preference implementation
Preference.prototype = {
  get name() {
    return this._name;
  },

  get type() {
    var value = "";
    var type = this.branch._prefs.getPrefType(this._name);

    switch (type) {
      case Ci.nsIPrefBranch.PREF_STRING:
        value = "String";
        break;
      case Ci.nsIPrefBranch.PREF_BOOL:
        value = "Boolean";
        break;
      case Ci.nsIPrefBranch.PREF_INT:
        value = "Number";
        break;
    }

    return value;
  },

  get value() {
    return this.branch.getValue(this._name, null);
  },

  set value(aValue) {
    return this.branch.setValue(this._name, aValue);
  },

  get locked() {
    return this.branch._prefs.prefIsLocked(this.name);
  },

  set locked(aValue) {
    this.branch._prefs[aValue ? "lockPref" : "unlockPref"](this.name);
  },

  get modified() {
    return this.branch._prefs.prefHasUserValue(this.name);
  },

  get branch() {
    return this._branch;
  },

  get events() {
    return this._events;
  },

  reset: function pref_reset() {
    this.branch._prefs.clearUserPref(this.name);
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIPreference])
};


// =================================================
// SessionStorage constructor
function SessionStorage() {
  this._storage = {};
  this._events = new Events();
}

// =================================================
// SessionStorage implementation
SessionStorage.prototype = {
  get events() {
    return this._events;
  },

  has: function ss_has(aName) {
    return this._storage.hasOwnProperty(aName);
  },

  set: function ss_set(aName, aValue) {
    this._storage[aName] = aValue;
    this._events.dispatch("change", aName);
  },

  get: function ss_get(aName, aDefaultValue) {
    return this.has(aName) ? this._storage[aName] : aDefaultValue;
  },

  QueryInterface : XPCOMUtils.generateQI([Ci.extISessionStorage])
};

// =================================================
// ExtensionObserver constructor (internal class)
//
// ExtensionObserver is a global singleton which watches the browser's
// extensions and sends you events when things change.

function ExtensionObserver() {
  this._eventsDict = {};

  AddonManager.addAddonListener(this);
  AddonManager.addInstallListener(this);
}

// =================================================
// ExtensionObserver implementation (internal class)
ExtensionObserver.prototype = {
  onDisabling: function eo_onDisabling(addon, needsRestart) {
    this._dispatchEvent(addon.id, "disable");
  },

  onEnabling: function eo_onEnabling(addon, needsRestart) {
    this._dispatchEvent(addon.id, "enable");
  },

  onUninstalling: function eo_onUninstalling(addon, needsRestart) {
    this._dispatchEvent(addon.id, "uninstall");
  },

  onOperationCancelled: function eo_onOperationCancelled(addon) {
    this._dispatchEvent(addon.id, "cancel");
  },

  onInstallEnded: function eo_onInstallEnded(install, addon) {
    this._dispatchEvent(addon.id, "upgrade");
  },

  addListener: function eo_al(aId, aEvent, aListener) {
    var events = this._eventsDict[aId];
    if (!events) {
      events = new Events();
      this._eventsDict[aId] = events;
    }
    events.addListener(aEvent, aListener);
  },

  removeListener: function eo_rl(aId, aEvent, aListener) {
    var events = this._eventsDict[aId];
    if (!events) {
      return;
    }
    events.removeListener(aEvent, aListener);
    if (events._listeners.length == 0) {
      delete this._eventsDict[aId];
    }
  },

  _dispatchEvent: function eo_dispatchEvent(aId, aEvent) {
    var events = this._eventsDict[aId];
    if (events) {
      events.dispatch(aEvent, aId);
    }
  }
};

// =================================================
// Extension constructor
function Extension(aItem) {
  this._item = aItem;
  this._firstRun = false;
  this._prefs = new PreferenceBranch("extensions." + this.id + ".");
  this._storage = new SessionStorage();

  let id = this.id;
  this._events = {
    addListener: function ext_events_al(aEvent, aListener) {
      gExtensionObserver.addListener(id, aEvent, aListener);
    },
    removeListener: function ext_events_rl(aEvent, aListener) {
      gExtensionObserver.addListener(id, aEvent, aListener);
    },
    QueryInterface: XPCOMUtils.generateQI([Ci.extIEvents])
  };

  var installPref = "install-event-fired";
  if (!this._prefs.has(installPref)) {
    this._prefs.setValue(installPref, true);
    this._firstRun = true;
  }
}

// =================================================
// Extension implementation
Extension.prototype = {
  get id() {
    return this._item.id;
  },

  get name() {
    return this._item.name;
  },

  get enabled() {
    return this._item.isActive;
  },

  get version() {
    return this._item.version;
  },

  get firstRun() {
    return this._firstRun;
  },

  get storage() {
    return this._storage;
  },

  get prefs() {
    return this._prefs;
  },

  get events() {
    return this._events;
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIExtension])
};


// =================================================
// Extensions constructor
function Extensions(addons) {
  this._cache = {};

  addons.forEach(function (addon) {
    this._cache[addon.id] = new Extension(addon);
  }, this);
}

// =================================================
// Extensions implementation
Extensions.prototype = {
  get all() {
    return this.find({});
  },

  // XXX: Disabled until we can figure out the wrapped object issues
  // id: "some@id" or /id/
  // name: "name" or /name/
  // version: "1.0.1"
  // minVersion: "1.0"
  // maxVersion: "2.0"
  find: function exts_find(aOptions) {
    return Object.keys(this._cache).map(id => this._cache[id]);
  },

  has: function exts_has(aId) {
    return aId in this._cache;
  },

  get: function exts_get(aId) {
    return this.has(aId) ? this._cache[aId] : null;
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIExtensions])
};

// =================================================
// Application globals

var gExtensionObserver = new ExtensionObserver();
var gPreferenceObserver = new PreferenceObserver();

// =================================================
// extApplication constructor
function extApplication() {
}

// =================================================
// extApplication implementation
extApplication.prototype = {
  initToolkitHelpers: function extApp_initToolkitHelpers() {
    XPCOMUtils.defineLazyServiceGetter(this, "_info",
                                       "@mozilla.org/xre/app-info;1",
                                       "nsIXULAppInfo");

    this._obs = Cc["@mozilla.org/observer-service;1"].
                getService(Ci.nsIObserverService);
    this._obs.addObserver(this, "xpcom-shutdown", /* ownsWeak = */ true);
    this._registered = {"unload": true};
  },

  classInfo: XPCOMUtils.generateCI({interfaces: [Ci.extIApplication,
                                                 Ci.nsIObserver],
                                    flags: Ci.nsIClassInfo.SINGLETON}),

  // extIApplication
  get id() {
    return this._info.ID;
  },

  get name() {
    return this._info.name;
  },

  get version() {
    return this._info.version;
  },

  // for nsIObserver
  observe: function app_observe(aSubject, aTopic, aData) {
    if (aTopic == "app-startup") {
      this.events.dispatch("load", "application");
    }
    else if (aTopic == "final-ui-startup") {
      this.events.dispatch("ready", "application");
    }
    else if (aTopic == "quit-application-requested") {
      // we can stop the quit by checking the return value
      if (this.events.dispatch("quit", "application") == false)
        aSubject.data = true;
    }
    else if (aTopic == "xpcom-shutdown") {
      this.events.dispatch("unload", "application");
      gExtensionObserver = null;
      gPreferenceObserver = null;
    }
  },

  get console() {
    let console = new Console();
    this.__defineGetter__("console", () => console);
    return this.console;
  },

  get storage() {
    let storage = new SessionStorage();
    this.__defineGetter__("storage", () => storage);
    return this.storage;
  },

  get prefs() {
    let prefs = new PreferenceBranch("");
    this.__defineGetter__("prefs", () => prefs);
    return this.prefs;
  },

  getExtensions: function(callback) {
    AddonManager.getAddonsByTypes(["extension"], function (addons) {
      callback.callback(new Extensions(addons));
    });
  },

  get events() {

    // This ensures that FUEL only registers for notifications as needed
    // by callers. Note that the unload (xpcom-shutdown) event is listened
    // for by default, as it's needed for cleanup purposes.
    var self = this;
    function registerCheck(aEvent) {
      var rmap = { "load": "app-startup",
                   "ready": "final-ui-startup",
                   "quit": "quit-application-requested"};
      if (!(aEvent in rmap) || aEvent in self._registered)
        return;

      self._obs.addObserver(self, rmap[aEvent], /* ownsWeak = */ true);
      self._registered[aEvent] = true;
    }

    let events = new Events(registerCheck);
    this.__defineGetter__("events", () => events);
    return this.events;
  },

  // helper method for correct quitting/restarting
  _quitWithFlags: function app__quitWithFlags(aFlags) {
    let cancelQuit = Components.classes["@mozilla.org/supports-PRBool;1"]
                               .createInstance(Components.interfaces.nsISupportsPRBool);
    let quitType = aFlags & Components.interfaces.nsIAppStartup.eRestart ? "restart" : null;
    this._obs.notifyObservers(cancelQuit, "quit-application-requested", quitType);
    if (cancelQuit.data)
      return false; // somebody canceled our quit request

    let appStartup = Components.classes['@mozilla.org/toolkit/app-startup;1']
                               .getService(Components.interfaces.nsIAppStartup);
    appStartup.quit(aFlags);
    return true;
  },

  quit: function app_quit() {
    return this._quitWithFlags(Components.interfaces.nsIAppStartup.eAttemptQuit);
  },

  restart: function app_restart() {
    return this._quitWithFlags(Components.interfaces.nsIAppStartup.eAttemptQuit |
                               Components.interfaces.nsIAppStartup.eRestart);
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.extIApplication, Ci.nsISupportsWeakReference])
};
