/**
* @output wp-includes/js/wp-custom-header.js
*/

/* global YT */
(function( window, settings ) {

var NativeHandler, YouTubeHandler;

/** @namespace wp */
window.wp = window.wp || {};

// Fail gracefully in unsupported browsers.
if ( ! ( 'addEventListener' in window ) ) {
return;
}

/**
* Trigger an event.
*
* @param {Element} target HTML element to dispatch the event on.
* @param {string} name Event name.
*/
function trigger( target, name ) {
var evt;

if ( 'function' === typeof window.Event ) {
evt = new Event( name );
} else {
evt = document.createEvent( 'Event' );
evt.initEvent( name, true, true );
}

target.dispatchEvent( evt );
}

/**
* Create a custom header instance.
*
* @memberOf wp
*
* @class
*/
function CustomHeader() {
this.handlers = {
nativeVideo: new NativeHandler(),
youtube: new YouTubeHandler()
};
}

CustomHeader.prototype = {
/**
* Initialize the custom header.
*
* If the environment supports video, loops through registered handlers
* until one is found that can handle the video.
*/
initialize: function() {
if ( this.supportsVideo() ) {
for ( var id in this.handlers ) {
var handler = this.handlers[ id ];

if ( 'test' in handler && handler.test( settings ) ) {
this.activeHandler = handler.initialize.call( handler, settings );

// Dispatch custom event when the video is loaded.
trigger( document, 'wp-custom-header-video-loaded' );
break;
}
}
}
},

/**
* Determines if the current environment supports video.
*
* Themes and plugins can override this method to change the criteria.
*
* @return {boolean}
*/
supportsVideo: function() {
// Don't load video on small screens. @todo Consider bandwidth and other factors.
if ( window.innerWidth < settings.minWidth || window.innerHeight < settings.minHeight ) {
return false;
}

return true;
},

/**
* Base handler for custom handlers to extend.
*
* @type {BaseHandler}
*/
BaseVideoHandler: BaseHandler
};

/**
* Create a video handler instance.
*
* @memberOf wp
*
* @class
*/
function BaseHandler() {}

BaseHandler.prototype = {
/**
* Initialize the video handler.
*
* @param {Object} settings Video settings.
*/
initialize: function( settings ) {
var handler = this,
button = document.createElement( 'button' );

this.settings = settings;
this.container = document.getElementById( 'wp-custom-header' );
this.button = button;

button.setAttribute( 'type', 'button' );
button.setAttribute( 'id', 'wp-custom-header-video-button' );
button.setAttribute( 'class', 'wp-custom-header-video-button wp-custom-header-video-play' );
button.innerHTML = settings.l10n.play;

// Toggle video playback when the button is clicked.
button.addEventListener( 'click', function() {
if ( handler.isPaused() ) {
handler.play();
} else {
handler.pause();
}
});

// Update the button class and text when the video state changes.
this.container.addEventListener( 'play', function() {
button.className = 'wp-custom-header-video-button wp-custom-header-video-play';
button.innerHTML = settings.l10n.pause;
if ( 'a11y' in window.wp ) {
window.wp.a11y.speak( settings.l10n.playSpeak);
}
});

this.container.addEventListener( 'pause', function() {
button.className = 'wp-custom-header-video-button wp-custom-header-video-pause';
button.innerHTML = settings.l10n.play;
if ( 'a11y' in window.wp ) {
window.wp.a11y.speak( settings.l10n.pauseSpeak);
}
});

this.ready();
},

/**
* Ready method called after a handler is initialized.
*
* @abstract
*/
ready: function() {},

/**
* Whether the video is paused.
*
* @abstract
* @return {boolean}
*/
isPaused: function() {},

/**
* Pause the video.
*
* @abstract
*/
pause: function() {},

/**
* Play the video.
*
* @abstract
*/
play: function() {},

/**
* Append a video node to the header container.
*
* @param {Element} node HTML element.
*/
setVideo: function( node ) {
var editShortcutNode,
editShortcut = this.container.getElementsByClassName( 'customize-partial-edit-shortcut' );

if ( editShortcut.length ) {
editShortcutNode = this.container.removeChild( editShortcut[0] );
}

this.container.innerHTML = '';
this.container.appendChild( node );

if ( editShortcutNode ) {
this.container.appendChild( editShortcutNode );
}
},

/**
* Show the video controls.
*
* Appends a play/pause button to header container.
*/
showControls: function() {
if ( ! this.container.contains( this.button ) ) {
this.container.appendChild( this.button );
}
},

/**
* Whether the handler can process a video.
*
* @abstract
* @param {Object} settings Video settings.
* @return {boolean}
*/
test: function() {
return false;
},

/**
* Trigger an event on the header container.
*
* @param {string} name Event name.
*/
trigger: function( name ) {
trigger( this.container, name );
}
};

/**
* Create a custom handler.
*
* @memberOf wp
*
* @param {Object} protoProps Properties to apply to the prototype.
* @return CustomHandler The subclass.
*/
BaseHandler.extend = function( protoProps ) {
var prop;

function CustomHandler() {
var result = BaseHandler.apply( this, arguments );
return result;
}

CustomHandler.prototype = Object.create( BaseHandler.prototype );
CustomHandler.prototype.constructor = CustomHandler;

for ( prop in protoProps ) {
CustomHandler.prototype[ prop ] = protoProps[ prop ];
}

return CustomHandler;
};

/**
* Native video handler.
*
* @memberOf wp
*
* @class
*/
NativeHandler = BaseHandler.extend(/** @lends wp.NativeHandler.prototype */{
/**
* Whether the native handler supports a video.
*
* @param {Object} settings Video settings.
* @return {boolean}
*/
test: function( settings ) {
var video = document.createElement( 'video' );
return video.canPlayType( settings.mimeType );
},

/**
* Set up a native video element.
*/
ready: function() {
var handler = this,
video = document.createElement( 'video' );

video.id = 'wp-custom-header-video';
video.autoplay = true;
video.loop = true;
video.muted = true;
video.playsInline = true;
video.width = this.settings.width;
video.height = this.settings.height;

video.addEventListener( 'play', function() {
handler.trigger( 'play' );
});

video.addEventListener( 'pause', function() {
handler.trigger( 'pause' );
});

video.addEventListener( 'canplay', function() {
handler.showControls();
});

this.video = video;
handler.setVideo( video );
video.src = this.settings.videoUrl;
},

/**
* Whether the video is paused.
*
* @return {boolean}
*/
isPaused: function() {
return this.video.paused;
},

/**
* Pause the video.
*/
pause: function() {
this.video.pause();
},

/**
* Play the video.
*/
play: function() {
this.video.play();
}
});

/**
* YouTube video handler.
*
* @memberOf wp
*
* @class wp.YouTubeHandler
*/
YouTubeHandler = BaseHandler.extend(/** @lends wp.YouTubeHandler.prototype */{
/**
* Whether the handler supports a video.
*
* @param {Object} settings Video settings.
* @return {boolean}
*/
test: function( settings ) {
return 'video/x-youtube' === settings.mimeType;
},

/**
* Set up a YouTube iframe.
*
* Loads the YouTube IFrame API if the 'YT' global doesn't exist.
*/
ready: function() {
var handler = this;

if ( 'YT' in window ) {
YT.ready( handler.loadVideo.bind( handler ) );
} else {
var tag = document.createElement( 'script' );
tag.src = 'https://www.youtube.com/iframe_api';
tag.onload = function () {
YT.ready( handler.loadVideo.bind( handler ) );
};

document.getElementsByTagName( 'head' )[0].appendChild( tag );
}
},

/**
* Load a YouTube video.
*/
loadVideo: function() {
var handler = this,
video = document.createElement( 'div' ),
// @link http://stackoverflow.com/a/27728417
VIDEO_ID_REGEX = /^.*(?:(?:youtu\.be\/|v\/|vi\/|u\/\w\/|embed\/)|(?:(?:watch)?\?v(?:i)?=|\&v(?:i)?=))([^#\&\?]*).*/;

video.id = 'wp-custom-header-video';
handler.setVideo( video );

handler.player = new YT.Player( video, {
height: this.settings.height,
width: this.settings.width,
videoId: this.settings.videoUrl.match( VIDEO_ID_REGEX )[1],
events: {
onReady: function( e ) {
e.target.mute();
handler.showControls();
},
onStateChange: function( e ) {
if ( YT.PlayerState.PLAYING === e.data ) {
handler.trigger( 'play' );
} else if ( YT.PlayerState.PAUSED === e.data ) {
handler.trigger( 'pause' );
} else if ( YT.PlayerState.ENDED === e.data ) {
e.target.playVideo();
}
}
},
playerVars: {
autoplay: 1,
controls: 0,
disablekb: 1,
fs: 0,
iv_load_policy: 3,
loop: 1,
modestbranding: 1,
playsinline: 1,
rel: 0,
showinfo: 0
}
});
},

/**
* Whether the video is paused.
*
* @return {boolean}
*/
isPaused: function() {
return YT.PlayerState.PAUSED === this.player.getPlayerState();
},

/**
* Pause the video.
*/
pause: function() {
this.player.pauseVideo();
},

/**
* Play the video.
*/
play: function() {
this.player.playVideo();
}
});

// Initialize the custom header when the DOM is ready.
window.wp.customHeader = new CustomHeader();
document.addEventListener( 'DOMContentLoaded', window.wp.customHeader.initialize.bind( window.wp.customHeader ), false );

// Selective refresh support in the Customizer.
if ( 'customize' in window.wp ) {
window.wp.customize.selectiveRefresh.bind( 'render-partials-response', function( response ) {
if ( 'custom_header_settings' in response ) {
settings = response.custom_header_settings;
}
});

window.wp.customize.selectiveRefresh.bind( 'partial-content-rendered', function( placement ) {
if ( 'custom_header' === placement.partial.id ) {
window.wp.customHeader.initialize();
}
});
}

})( window, window._wpCustomHeaderSettings || {} );