/* Add to Homescreen v3.2.2 ~ (c) 2015 Matteo Spinelli ~ @license: http://cubiq.org/license */
(function (window, document) {
// Check for addEventListener browser support (prevent errors in IE<9)
var _eventListener = 'addEventListener' in window;

// Check if document is loaded, needed by autostart
var _DOMReady = false;
if ( document.readyState === 'complete' ) {
	_DOMReady = true;
} else if ( _eventListener ) {
	window.addEventListener('load', loaded, false);
}

function loaded () {
	window.removeEventListener('load', loaded, false);
	_DOMReady = true;
}

// regex used to detect if app has been added to the homescreen
var _reSmartURL = /\/ath(\/)?$/;
var _reQueryString = /([\?&]ath=[^&]*$|&ath=[^&]*(&))/;

// singleton
var _instance;
function ath (options) {
	_instance = _instance || new ath.Class(options);

	return _instance;
}

// message in all supported languages
ath.intl = {
	en_us: {
		ios: 'To add this web app to the home screen: tap %icon and then <strong>Add to Home Screen</strong>.',
		android: 'To add this web app to the home screen open the browser option menu and tap on <strong>Add to homescreen</strong>. <small>The menu can be accessed by pressing the menu hardware button if your device has one, or by tapping the top right menu icon %icon.</small>'
	},
	zh_cn: {
		ios: '如要把应用程序加至主屏幕,请点击%icon, 然后<strong>添加到主屏幕</strong>',
		android: 'To add this web app to the home screen open the browser option menu and tap on <strong>Add to homescreen</strong>. <small>The menu can be accessed by pressing the menu hardware button if your device has one, or by tapping the top right menu icon %icon.</small>'
	},
	zh_tw: {
		ios: '如要把應用程式加至主屏幕, 請點擊%icon, 然後<strong>加至主屏幕</strong>.',
		android: 'To add this web app to the home screen open the browser option menu and tap on <strong>Add to homescreen</strong>. <small>The menu can be accessed by pressing the menu hardware button if your device has one, or by tapping the top right menu icon %icon.</small>'
	}
};

// Add 2 characters language support (Android mostly)
for ( var lang in ath.intl ) {
	ath.intl[lang.substr(0, 2)] = ath.intl[lang];
}

// default options
ath.defaults = {
	appID: 'org.cubiq.addtohome',		// local storage name (no need to change)
	fontSize: 15,				// base font size, used to properly resize the popup based on viewport scale factor
	debug: false,				// override browser checks
	logging: false,				// log reasons for showing or not showing to js console; defaults to true when debug is true
	modal: false,				// prevent further actions until the message is closed
	mandatory: false,			// you can't proceed if you don't add the app to the homescreen
	autostart: true,			// show the message automatically
	skipFirstVisit: false,		// show only to returning visitors (ie: skip the first time you visit)
	startDelay: 1,				// display the message after that many seconds from page load
	lifespan: 15,				// life of the message in seconds
	displayPace: 1440,			// minutes before the message is shown again (0: display every time, default 24 hours)
	maxDisplayCount: 0,			// absolute maximum number of times the message will be shown to the user (0: no limit)
	icon: true,					// add touch icon to the message
	message: '',				// the message can be customized
	validLocation: [],			// list of pages where the message will be shown (array of regexes)
	onInit: null,				// executed on instance creation
	onShow: null,				// executed when the message is shown
	onRemove: null,				// executed when the message is removed
	onAdd: null,				// when the application is launched the first time from the homescreen (guesstimate)
	onPrivate: null,			// executed if user is in private mode
	privateModeOverride: false,	// show the message even in private mode (very rude)
	detectHomescreen: false		// try to detect if the site has been added to the homescreen (false | true | 'hash' | 'queryString' | 'smartURL')
};

// browser info and capability
var _ua = window.navigator.userAgent;

var _nav = window.navigator;
_extend(ath, {
	hasToken: document.location.hash == '#ath' || _reSmartURL.test(document.location.href) || _reQueryString.test(document.location.search),
	isRetina: window.devicePixelRatio && window.devicePixelRatio > 1,
	isIDevice: (/iphone|ipod|ipad/i).test(_ua),
	isMobileChrome: _ua.indexOf('Android') > -1 && (/Chrome\/[.0-9]*/).test(_ua) && _ua.indexOf("Version") == -1,
	isMobileIE: _ua.indexOf('Windows Phone') > -1,
	language: _nav.language && _nav.language.toLowerCase().replace('-', '_') || ''
});

// falls back to en_us if language is unsupported
ath.language = ath.language && ath.language in ath.intl ? ath.language : 'en_us';

ath.isMobileSafari = ath.isIDevice && _ua.indexOf('Safari') > -1 && _ua.indexOf('CriOS') < 0;
ath.OS = ath.isIDevice ? 'ios' : ath.isMobileChrome ? 'android' : ath.isMobileIE ? 'windows' : 'unsupported';

ath.OSVersion = _ua.match(/(OS|Android) (\d+[_\.]\d+)/);
ath.OSVersion = ath.OSVersion && ath.OSVersion[2] ? +ath.OSVersion[2].replace('_', '.') : 0;

ath.isStandalone = 'standalone' in window.navigator && window.navigator.standalone;
ath.isTablet = (ath.isMobileSafari && _ua.indexOf('iPad') > -1) || (ath.isMobileChrome && _ua.indexOf('Mobile') < 0);

ath.isCompatible = (ath.isMobileSafari && ath.OSVersion >= 6) || ath.isMobileChrome;	// TODO: add winphone

var _defaultSession = {
	lastDisplayTime: 0,			// last time we displayed the message
	returningVisitor: false,	// is this the first time you visit
	displayCount: 0,			// number of times the message has been shown
	optedout: false,			// has the user opted out
	added: false				// has been actually added to the homescreen
};

ath.removeSession = function (appID) {
	try {
		if (!localStorage) {
			throw new Error('localStorage is not defined');
		}

		localStorage.removeItem(appID || ath.defaults.appID);
	} catch (e) {
		// we are most likely in private mode
	}
};

ath.doLog = function (logStr) {
	if ( this.options.logging ) {
		console.log(logStr);
	}
};

ath.Class = function (options) {
	// class methods
	this.doLog = ath.doLog;

	// merge default options with user config
	this.options = _extend({}, ath.defaults);
	_extend(this.options, options);
	// override defaults that are dependent on each other
	if ( options && options.debug && (typeof options.logging === "undefined") ) {
		this.options.logging = true;
	}

	// IE<9 so exit (I hate you, really)
	if ( !_eventListener ) {
		return;
	}

	// normalize some options
	this.options.mandatory = this.options.mandatory && ( 'standalone' in window.navigator || this.options.debug );
	this.options.modal = this.options.modal || this.options.mandatory;
	if ( this.options.mandatory ) {
		this.options.startDelay = -0.5;		// make the popup hasty
	}
	this.options.detectHomescreen = this.options.detectHomescreen === true ? 'hash' : this.options.detectHomescreen;

	// setup the debug environment
	if ( this.options.debug ) {
		ath.isCompatible = true;
		ath.OS = typeof this.options.debug == 'string' ? this.options.debug : ath.OS == 'unsupported' ? 'android' : ath.OS;
		ath.OSVersion = ath.OS == 'ios' ? '8' : '4';
	}

	// the element the message will be appended to
	this.container = document.documentElement;

	// load session
	this.session = this.getItem(this.options.appID);
	this.session = this.session ? JSON.parse(this.session) : undefined;

	// user most likely came from a direct link containing our token, we don't need it and we remove it
	if ( ath.hasToken && ( !ath.isCompatible || !this.session ) ) {
		ath.hasToken = false;
		_removeToken();
	}

	//----------------- the device is not supported
	if ( !ath.isCompatible ) {
 		this.doLog("Add to homescreen: not displaying callout because device not supported");
		return;
	}

	this.session = this.session || _defaultSession;

	// check if we can use the local storage
	try {
		if (!localStorage) {
			throw new Error('localStorage is not defined');
		}

		localStorage.setItem(this.options.appID, JSON.stringify(this.session));
		ath.hasLocalStorage = true;
	} catch (e) {
		// we are most likely in private mode
		ath.hasLocalStorage = false;

		if ( this.options.onPrivate ) {
			this.options.onPrivate.call(this);
		}
	}

	// check if this is a valid location
	var isValidLocation = !this.options.validLocation.length;
	for ( var i = this.options.validLocation.length; i--; ) {
		if ( this.options.validLocation[i].test(document.location.href) ) {
			isValidLocation = true;
			break;
		}
	}

	// check compatibility with old versions of add to homescreen. Opt-out if an old session is found
	if ( this.getItem('addToHome') ) {
		this.optOut();
	}

	// critical errors:
	if ( this.session.optedout ) {
		this.doLog("Add to homescreen: not displaying callout because user opted out");
		return;
	}
	if ( this.session.added ) {
		this.doLog("Add to homescreen: not displaying callout because already added to the homescreen");
		return;
	}
	if ( !isValidLocation ) {
		this.doLog("Add to homescreen: not displaying callout because not a valid location");
		return;
	}

	// check if the app is in stand alone mode
	if ( ath.isStandalone ) {
		// execute the onAdd event if we haven't already
		if ( !this.session.added ) {
			this.session.added = true;
			this.updateSession();

			if ( this.options.onAdd && ath.hasLocalStorage ) {	// double check on localstorage to avoid multiple calls to the custom event
				this.options.onAdd.call(this);
			}
		}

		this.doLog("Add to homescreen: not displaying callout because in standalone mode");
		return;
	}

	// (try to) check if the page has been added to the homescreen
	if ( this.options.detectHomescreen ) {
		// the URL has the token, we are likely coming from the homescreen
		if ( ath.hasToken ) {
			_removeToken();		// we don't actually need the token anymore, we remove it to prevent redistribution

			// this is called the first time the user opens the app from the homescreen
			if ( !this.session.added ) {
				this.session.added = true;
				this.updateSession();

				if ( this.options.onAdd && ath.hasLocalStorage ) {	// double check on localstorage to avoid multiple calls to the custom event
					this.options.onAdd.call(this);
				}
			}

			this.doLog("Add to homescreen: not displaying callout because URL has token, so we are likely coming from homescreen");
			return;
		}

		// URL doesn't have the token, so add it
		if ( this.options.detectHomescreen == 'hash' ) {
			history.replaceState('', window.document.title, document.location.href + '#ath');
		} else if ( this.options.detectHomescreen == 'smartURL' ) {
			history.replaceState('', window.document.title, document.location.href.replace(/(\/)?$/, '/ath$1'));
		} else {
			history.replaceState('', window.document.title, document.location.href + (document.location.search ? '&' : '?' ) + 'ath=');
		}
	}

	// check if this is a returning visitor
	if ( !this.session.returningVisitor ) {
		this.session.returningVisitor = true;
		this.updateSession();

		// we do not show the message if this is your first visit
		if ( this.options.skipFirstVisit ) {
			this.doLog("Add to homescreen: not displaying callout because skipping first visit");
			return;
		}
	}

	// we do no show the message in private mode
	if ( !this.options.privateModeOverride && !ath.hasLocalStorage ) {
		this.doLog("Add to homescreen: not displaying callout because browser is in private mode");
		return;
	}

	// all checks passed, ready to display
	this.ready = true;

	if ( this.options.onInit ) {
		this.options.onInit.call(this);
	}

	if ( this.options.autostart ) {
		this.doLog("Add to homescreen: autostart displaying callout");
		this.show();
	}
};

ath.Class.prototype = {
	// event type to method conversion
	events: {
		load: '_delayedShow',
		error: '_delayedShow',
		orientationchange: 'resize',
		resize: 'resize',
		scroll: 'resize',
		click: 'remove',
		touchmove: '_preventDefault',
		transitionend: '_removeElements',
		webkitTransitionEnd: '_removeElements',
		MSTransitionEnd: '_removeElements'
	},

	handleEvent: function (e) {
		var type = this.events[e.type];
		if ( type ) {
			this[type](e);
		}
	},

	show: function (force) {
		// in autostart mode wait for the document to be ready
		if ( this.options.autostart && !_DOMReady ) {
			setTimeout(this.show.bind(this), 50);
			// we are not displaying callout because DOM not ready, but don't log that because
			// it would log too frequently
			return;
		}

		// message already on screen
		if ( this.shown ) {
			this.doLog("Add to homescreen: not displaying callout because already shown on screen");
			return;
		}

		var now = Date.now();
		var lastDisplayTime = this.session.lastDisplayTime;

		if ( force !== true ) {
			// this is needed if autostart is disabled and you programmatically call the show() method
			if ( !this.ready ) {
				this.doLog("Add to homescreen: not displaying callout because not ready");
				return;
			}

			//------------------ we obey the display pace (prevent the message to popup too often)
			if ( now - lastDisplayTime < this.options.displayPace * 60000 ) {
				this.doLog("Add to homescreen: not displaying callout because displayed recently");
				return;
			}

			// obey the maximum number of display count
			if ( this.options.maxDisplayCount && this.session.displayCount >= this.options.maxDisplayCount ) {
				this.doLog("Add to homescreen: not displaying callout because displayed too many times already");
				return;
			}
		}

		this.shown = true;

		// increment the display count
		this.session.lastDisplayTime = now;
		this.session.displayCount++;
		this.updateSession();

		// try to get the highest resolution application icon
		if ( !this.applicationIcon ) {
			if ( ath.OS == 'ios' ) {
				this.applicationIcon = document.querySelector('head link[rel^=apple-touch-icon][sizes="152x152"],head link[rel^=apple-touch-icon][sizes="144x144"],head link[rel^=apple-touch-icon][sizes="120x120"],head link[rel^=apple-touch-icon][sizes="114x114"],head link[rel^=apple-touch-icon]');
			} else {
				this.applicationIcon = document.querySelector('head link[rel^="shortcut icon"][sizes="196x196"],head link[rel^=apple-touch-icon]');
			}
		}

		var message = '';

		if ( typeof this.options.message == 'object' && ath.language in this.options.message ) {		// use custom language message
			message = this.options.message[ath.language][ath.OS];
		} else if ( typeof this.options.message == 'object' && ath.OS in this.options.message ) {		// use custom os message
			message = this.options.message[ath.OS];
		} else if ( this.options.message in ath.intl ) {				// you can force the locale
			message = ath.intl[this.options.message][ath.OS];
		} else if ( this.options.message !== '' ) {						// use a custom message
			message = this.options.message;
		} else if ( ath.OS in ath.intl[ath.language] ) {				// otherwise we use our message
			message = ath.intl[ath.language][ath.OS];
		}

		// add the action icon
		message = '<p>' + message.replace(/%icon(?:\[([^\]]+)\])?/gi, function(matches, group1) {
			return '<span class="ath-action-icon">' + (!!group1 ? group1 : 'icon') + '</span>';
		}); + '</p>';

		// create the message container
		this.viewport = document.createElement('div');
		this.viewport.className = 'ath-viewport';
		if ( this.options.modal ) {
			this.viewport.className += ' ath-modal';
		}
		if ( this.options.mandatory ) {
			this.viewport.className += ' ath-mandatory';
		}
		this.viewport.style.position = 'absolute';

		// create the actual message element
		this.element = document.createElement('div');
		this.element.className = 'ath-container ath-' + ath.OS + ' ath-' + ath.OS + (ath.OSVersion + '').substr(0,1) + ' ath-' + (ath.isTablet ? 'tablet' : 'phone');
		this.element.style.cssText = '-webkit-transition-property:-webkit-transform,opacity;-webkit-transition-duration:0s;-webkit-transition-timing-function:ease-out;transition-property:transform,opacity;transition-duration:0s;transition-timing-function:ease-out;';
		this.element.style.webkitTransform = 'translate3d(0,-' + window.innerHeight + 'px,0)';
		this.element.style.transform = 'translate3d(0,-' + window.innerHeight + 'px,0)';

		// add the application icon
		if ( this.options.icon && this.applicationIcon ) {
			this.element.className += ' ath-icon';
			this.img = document.createElement('img');
			this.img.className = 'ath-application-icon';
			this.img.addEventListener('load', this, false);
			this.img.addEventListener('error', this, false);

			this.img.src = this.applicationIcon.href;
			this.element.appendChild(this.img);
		}

		this.element.innerHTML += message;

		// we are not ready to show, place the message out of sight
		this.viewport.style.left = '-99999em';

		// attach all elements to the DOM
		this.viewport.appendChild(this.element);
		this.container.appendChild(this.viewport);

		// if we don't have to wait for an image to load, show the message right away
		if ( this.img ) {
			this.doLog("Add to homescreen: not displaying callout because waiting for img to load");
		} else {
			this._delayedShow();
		}
	},

	_delayedShow: function (e) {
		setTimeout(this._show.bind(this), this.options.startDelay * 1000 + 500);
	},

	_show: function () {
		var that = this;

		// update the viewport size and orientation
		this.updateViewport();

		// reposition/resize the message on orientation change
		window.addEventListener('resize', this, false);
		window.addEventListener('scroll', this, false);
		window.addEventListener('orientationchange', this, false);

		if ( this.options.modal ) {
			// lock any other interaction
			document.addEventListener('touchmove', this, true);
		}

		// Enable closing after 1 second
		if ( !this.options.mandatory ) {
			setTimeout(function () {
				that.element.addEventListener('click', that, true);
			}, 1000);
		}

		// kick the animation
		setTimeout(function () {
			that.element.style.webkitTransitionDuration = '1.2s';
			that.element.style.transitionDuration = '1.2s';
			that.element.style.webkitTransform = 'translate3d(0,0,0)';
			that.element.style.transform = 'translate3d(0,0,0)';
		}, 0);

		// set the destroy timer
		if ( this.options.lifespan ) {
			this.removeTimer = setTimeout(this.remove.bind(this), this.options.lifespan * 1000);
		}

		// fire the custom onShow event
		if ( this.options.onShow ) {
			this.options.onShow.call(this);
		}
	},

	remove: function () {
		clearTimeout(this.removeTimer);

		// clear up the event listeners
		if ( this.img ) {
			this.img.removeEventListener('load', this, false);
			this.img.removeEventListener('error', this, false);
		}

		window.removeEventListener('resize', this, false);
		window.removeEventListener('scroll', this, false);
		window.removeEventListener('orientationchange', this, false);
		document.removeEventListener('touchmove', this, true);
		this.element.removeEventListener('click', this, true);

		// remove the message element on transition end
		this.element.addEventListener('transitionend', this, false);
		this.element.addEventListener('webkitTransitionEnd', this, false);
		this.element.addEventListener('MSTransitionEnd', this, false);

		// start the fade out animation
		this.element.style.webkitTransitionDuration = '0.3s';
		this.element.style.opacity = '0';
	},

	_removeElements: function () {
		this.element.removeEventListener('transitionend', this, false);
		this.element.removeEventListener('webkitTransitionEnd', this, false);
		this.element.removeEventListener('MSTransitionEnd', this, false);

		// remove the message from the DOM
		this.container.removeChild(this.viewport);

		this.shown = false;

		// fire the custom onRemove event
		if ( this.options.onRemove ) {
			this.options.onRemove.call(this);
		}
	},

	updateViewport: function () {
		if ( !this.shown ) {
			return;
		}

		this.viewport.style.width = window.innerWidth + 'px';
		this.viewport.style.height = window.innerHeight + 'px';
		this.viewport.style.left = window.scrollX + 'px';
		this.viewport.style.top = window.scrollY + 'px';

		var clientWidth = document.documentElement.clientWidth;

		this.orientation = clientWidth > document.documentElement.clientHeight ? 'landscape' : 'portrait';

		var screenWidth = ath.OS == 'ios' ? this.orientation == 'portrait' ? screen.width : screen.height : screen.width;
		this.scale = screen.width > clientWidth ? 1 : screenWidth / window.innerWidth;

		this.element.style.fontSize = this.options.fontSize / this.scale + 'px';
	},

	resize: function () {
		clearTimeout(this.resizeTimer);
		this.resizeTimer = setTimeout(this.updateViewport.bind(this), 100);
	},

	updateSession: function () {
		if ( ath.hasLocalStorage === false ) {
			return;
		}

        if (localStorage) {
            localStorage.setItem(this.options.appID, JSON.stringify(this.session));
        }
	},

	clearSession: function () {
		this.session = _defaultSession;
		this.updateSession();
	},

	getItem: function(item) {
		try {
			if (!localStorage) {
				throw new Error('localStorage is not defined');
			}

			return localStorage.getItem(item);
		} catch(e) {
			// Preventing exception for some browsers when fetching localStorage key
			ath.hasLocalStorage = false;
		}
	},

	optOut: function () {
		this.session.optedout = true;
		this.updateSession();
	},

	optIn: function () {
		this.session.optedout = false;
		this.updateSession();
	},

	clearDisplayCount: function () {
		this.session.displayCount = 0;
		this.updateSession();
	},

	_preventDefault: function (e) {
		e.preventDefault();
		e.stopPropagation();
	}
};

// utility
function _extend (target, obj) {
	for ( var i in obj ) {
		target[i] = obj[i];
	}

	return target;
}

function _removeToken () {
	if ( document.location.hash == '#ath' ) {
		history.replaceState('', window.document.title, document.location.href.split('#')[0]);
	}

	if ( _reSmartURL.test(document.location.href) ) {
		history.replaceState('', window.document.title, document.location.href.replace(_reSmartURL, '$1'));
	}

	if ( _reQueryString.test(document.location.search) ) {
		history.replaceState('', window.document.title, document.location.href.replace(_reQueryString, '$2'));
	}
}

// expose to the world
window.addToHomescreen = ath;

})(window, document);
