/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* 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 process script is for small observers that we want to register
 * once per content process, usually in order to forward content-based
 * observer service notifications to the chrome process through
 * message passing. Using a process script avoids having them in
 * content.js and thereby registering N observers for N open tabs,
 * which is bad for perf.
 */

"use strict";

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

Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "ContentWebRTC",
  "resource:///modules/ContentWebRTC.jsm");

var gEMEUIObserver = function(subject, topic, data) {
  let win = subject.top;
  let mm = getMessageManagerForWindow(win);
  if (mm) {
    mm.sendAsyncMessage("EMEVideo:ContentMediaKeysRequest", data);
  }
};

var gDecoderDoctorObserver = function(subject, topic, data) {
  let win = subject.top;
  let mm = getMessageManagerForWindow(win);
  if (mm) {
    mm.sendAsyncMessage("DecoderDoctor:Notification", data);
  }
};

function getMessageManagerForWindow(aContentWindow) {
  let ir = aContentWindow.QueryInterface(Ci.nsIInterfaceRequestor)
                         .getInterface(Ci.nsIDocShell)
                         .sameTypeRootTreeItem
                         .QueryInterface(Ci.nsIInterfaceRequestor);
  try {
    // If e10s is disabled, this throws NS_NOINTERFACE for closed tabs.
    return ir.getInterface(Ci.nsIContentFrameMessageManager);
  } catch (e) {
    if (e.result == Cr.NS_NOINTERFACE) {
      return null;
    }
    throw e;
  }
}

Services.obs.addObserver(gEMEUIObserver, "mediakeys-request");
Services.obs.addObserver(gDecoderDoctorObserver, "decoder-doctor-notification");


// ContentWebRTC observer registration.
const kWebRTCObserverTopics = ["getUserMedia:request",
                               "recording-device-stopped",
                               "PeerConnection:request",
                               "recording-device-events",
                               "recording-window-ended"];

function webRTCObserve(aSubject, aTopic, aData) {
  ContentWebRTC.observe(aSubject, aTopic, aData);
}

for (let topic of kWebRTCObserverTopics) {
  Services.obs.addObserver(webRTCObserve, topic);
}

if (Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_CONTENT)
  Services.obs.addObserver(processShutdown, "content-child-shutdown");

function processShutdown() {
  for (let topic of kWebRTCObserverTopics) {
    Services.obs.removeObserver(webRTCObserve, topic);
  }
  Services.obs.removeObserver(processShutdown, "content-child-shutdown");
}
