/*
 * Copyright 2016 Google Inc. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var EventEmitter = require('eventemitter3');
var IFrameMessageSender = require('./iframe-message-sender');
var Message = require('../message');
var Util = require('../util');

// Save the executing script. This will be used to calculate the embed URL.
var CURRENT_SCRIPT_SRC = Util.getCurrentScript().src;
var FAKE_FULLSCREEN_CLASS = 'vrview-fake-fullscreen';

/**
 * Entry point for the VR View JS API.
 *
 * Emits the following events:
 *    ready: When the player is loaded.
 *    modechange: When the viewing mode changes (normal, fullscreen, VR).
 *    click (id): When a hotspot is clicked.
 */
function Player(selector, contentInfo) {
  // Create a VR View iframe depending on the parameters.
  var iframe = this.createIframe_(contentInfo);
  this.iframe = iframe;

  var parentEl = document.querySelector(selector);
  parentEl.appendChild(iframe);

  // Make a sender as well, for relying commands to the child IFrame.
  this.sender = new IFrameMessageSender(iframe);

  // Listen to messages from the IFrame.
  window.addEventListener('message', this.onMessage_.bind(this), false);

  // Expose a public .isPaused attribute.
  this.isPaused = false;

  // Expose a public .isMuted attribute.
  this.isMuted = false;
  if (typeof contentInfo.muted !== 'undefined') {
    this.isMuted = contentInfo.muted;
  }

  // Other public attributes
  this.currentTime = 0;
  this.duration = 0;
  this.volume = contentInfo.volume != undefined ? contentInfo.volume : 1;

  if (Util.isIOS()) {
    this.injectFullscreenStylesheet_();
  }
}
Player.prototype = new EventEmitter();

/**
 * @param pitch {Number} The latitude of center, specified in degrees, between
 * -90 and 90, with 0 at the horizon.
 * @param yaw {Number} The longitude of center, specified in degrees, between
 * -180 and 180, with 0 at the image center.
 * @param radius {Number} The radius of the hotspot, specified in meters.
 * @param distance {Number} The distance of the hotspot from camera, specified
 * in meters.
 * @param hotspotId {String} The ID of the hotspot.
 */
Player.prototype.addHotspot = function(hotspotId, params) {
  // TODO: Add validation to params.
  var data = {
    pitch: params.pitch,
    yaw: params.yaw,
    radius: params.radius,
    distance: params.distance,
    id: hotspotId
  };
  this.sender.send({type: Message.ADD_HOTSPOT, data: data});
};

Player.prototype.play = function() {
  this.sender.send({type: Message.PLAY});
};

Player.prototype.pause = function() {
  this.sender.send({type: Message.PAUSE});
};

/**
 * Equivalent of HTML5 setSrc().
 * @param {String} contentInfo
 */
Player.prototype.setContent = function(contentInfo) {
  this.absolutifyPaths_(contentInfo);
  var data = {
    contentInfo: contentInfo
  };
  this.sender.send({type: Message.SET_CONTENT, data: data});
};

/**
 * Sets the software volume of the video. 0 is mute, 1 is max.
 */
Player.prototype.setVolume = function(volumeLevel) {
  var data = {
    volumeLevel: volumeLevel
  };
  this.sender.send({type: Message.SET_VOLUME, data: data});
};

Player.prototype.getVolume = function() {
  return this.volume;
};

/**
 * Sets the mute state of the video element. true is muted, false is unmuted.
 */
Player.prototype.mute = function(muteState) {
  var data = {
    muteState: muteState
  };
  this.sender.send({type: Message.MUTED, data: data});
};

/**
 * Set the current time of the media being played
 * @param {Number} time
 */
Player.prototype.setCurrentTime = function(time) {
  var data = {
    currentTime: time
  };
  this.sender.send({type: Message.SET_CURRENT_TIME, data: data});
};

Player.prototype.getCurrentTime = function() {
  return this.currentTime;
};

Player.prototype.getDuration = function() {
  return this.duration;
};
Player.prototype.setFullscreen = function() {
  this.sender.send({type: Message.SET_FULLSCREEN});
};

/**
 * Helper for creating an iframe.
 *
 * @return {IFrameElement} The iframe.
 */
Player.prototype.createIframe_ = function(contentInfo) {
  this.absolutifyPaths_(contentInfo);

  var iframe = document.createElement('iframe');
  iframe.setAttribute('allowfullscreen', true);
  iframe.setAttribute('scrolling', 'no');
  iframe.style.border = 0;

  // Handle iframe size if width and height are specified.
  if (contentInfo.hasOwnProperty('width')) {
    iframe.setAttribute('width', contentInfo.width);
    delete contentInfo.width;
  }
  if (contentInfo.hasOwnProperty('height')) {
    iframe.setAttribute('height', contentInfo.height);
    delete contentInfo.height;
  }

  var url = this.getEmbedUrl_() + Util.createGetParams(contentInfo);
  iframe.src = url;

  return iframe;
};

Player.prototype.onMessage_ = function(event) {
  var message = event.data;
  if (!message || !message.type) {
    console.warn('Received message with no type.');
    return;
  }
  var type = message.type.toLowerCase();
  var data = message.data;
  switch (type) {
    case 'ready':
      if (data !== undefined && data.duration !== undefined) {
        this.duration = data.duration;
      }
    case 'modechange':
    case 'error':
    case 'click':
    case 'ended':
    case 'getposition':
      this.emit(type, data);
      break;
    case 'volumechange':
      this.volume = data;
      this.emit('volumechange', data);
      break;
    case 'muted':
      this.isMuted = data;
      this.emit('mute', data);
      break;
    case 'timeupdate':
      this.currentTime = data;
      this.emit('timeupdate', {
        currentTime: this.currentTime,
        duration: this.duration
      });
      break;
    case 'play':
    case 'paused':
      this.isPaused = data;
      if (this.isPaused) {
        this.emit('pause', data);
      } else {
        this.emit('play', data);
      }
      break;
    case 'enter-fullscreen':
    case 'enter-vr':
      this.setFakeFullscreen_(true);
      break;
    case 'exit-fullscreen':
      this.setFakeFullscreen_(false);
      break;
    default:
      console.warn('Got unknown message of type %s from %s', message.type, message.origin);
  }
};

/**
 * Note: iOS doesn't support the fullscreen API.
 * In standalone <iframe> mode, VR View emulates fullscreen by redirecting to
 * another page.
 * In JS API mode, we stretch the iframe to cover the extent of the page using
 * CSS. To do this cleanly, we also inject a stylesheet.
 */
Player.prototype.setFakeFullscreen_ = function(isFullscreen) {
  if (isFullscreen) {
    this.iframe.classList.add(FAKE_FULLSCREEN_CLASS);
  } else {
    this.iframe.classList.remove(FAKE_FULLSCREEN_CLASS);
  }
};

Player.prototype.injectFullscreenStylesheet_ = function() {
  var styleString = [
    'iframe.' + FAKE_FULLSCREEN_CLASS,
    '{',
      'position: fixed !important;',
      'display: block !important;',
      'z-index: 9999999999 !important;',
      'top: 0 !important;',
      'left: 0 !important;',
      'width: 100% !important;',
      'height: 100% !important;',
      'margin: 0 !important;',
    '}',
  ].join('\n');
  var style = document.createElement('style');
  style.innerHTML = styleString;
  document.body.appendChild(style);
};

Player.prototype.getEmbedUrl_ = function() {
  // Assume that the script is in $ROOT/build/something.js, and that the iframe
  // HTML is in $ROOT/index.html.
  //
  // E.g: /vrview/2.0/build/vrview.min.js => /vrview/2.0/index.html.
  var path = CURRENT_SCRIPT_SRC;
  var split = path.split('/');
  var rootSplit = split.slice(0, split.length - 2);
  var rootPath = rootSplit.join('/');
  return rootPath + '/index.html';
};

Player.prototype.getDirName_ = function() {
  var path = window.location.pathname;
  path = path.substring(0, path.lastIndexOf('/'));
  return location.protocol + '//' + location.host + path;
};

/**
 * Make all of the URLs inside contentInfo absolute instead of relative.
 */
Player.prototype.absolutifyPaths_ = function(contentInfo) {
  var dirName = this.getDirName_();
  var urlParams = ['image', 'preview', 'video'];

  for (var i = 0; i < urlParams.length; i++) {
    var name = urlParams[i];
    var path = contentInfo[name];
    if (path && Util.isPathAbsolute(path)) {
      var absolute = Util.relativeToAbsolutePath(dirName, path);
      contentInfo[name] = absolute;
      //console.log('Converted to absolute: %s', absolute);
    }
  }
};
/**
 * Get position YAW, PITCH
 */
Player.prototype.getPosition = function() {
    this.sender.send({type: Message.GET_POSITION, data: {}});
};

module.exports = Player;