/* -*- Mode: javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
/* 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";

const { Cc, Ci, Cu, Cr } = require("chrome");
const promise = Cu.import("resource://gre/modules/Promise.jsm", {}).Promise;
const EventEmitter = require("devtools/toolkit/event-emitter");
const { CanvasFront } = require("devtools/server/actors/canvas");
const { DevToolsUtils } = Cu.import("resource://gre/modules/devtools/DevToolsUtils.jsm", {});

function CanvasDebuggerPanel(iframeWindow, toolbox) {
  this.panelWin = iframeWindow;
  this._toolbox = toolbox;
  this._destroyer = null;

  EventEmitter.decorate(this);
};

exports.CanvasDebuggerPanel = CanvasDebuggerPanel;

CanvasDebuggerPanel.prototype = {
  /**
   * Open is effectively an asynchronous constructor.
   *
   * @return object
   *         A promise that is resolved when the Canvas Debugger completes opening.
   */
  open: function() {
    let targetPromise;

    // Local debugging needs to make the target remote.
    if (!this.target.isRemote) {
      targetPromise = this.target.makeRemote();
    } else {
      targetPromise = promise.resolve(this.target);
    }

    return targetPromise
      .then(() => {
        this.panelWin.gToolbox = this._toolbox;
        this.panelWin.gTarget = this.target;
        this.panelWin.gFront = new CanvasFront(this.target.client, this.target.form);
        return this.panelWin.startupCanvasDebugger();
      })
      .then(() => {
        this.isReady = true;
        this.emit("ready");
        return this;
      })
      .then(null, function onError(aReason) {
        DevToolsUtils.reportException("CanvasDebuggerPanel.prototype.open", aReason);
      });
  },

  // DevToolPanel API

  get target() this._toolbox.target,

  destroy: function() {
    // Make sure this panel is not already destroyed.
    if (this._destroyer) {
      return this._destroyer;
    }

    return this._destroyer = this.panelWin.shutdownCanvasDebugger().then(() => {
      this.emit("destroyed");
    });
  }
};