;( function( window ) {
	
	'use strict';

	function extend( a, b ) {
		for( var key in b ) { 
			if( b.hasOwnProperty( key ) ) {
				a[key] = b[key];
			}
		}
		return a;
	}

	// taken from https://github.com/inuyaksa/jquery.nicescroll/blob/master/jquery.nicescroll.js
	function hasParent( e, id ) {
		if (!e) return false;
		var el = e.target||e.srcElement||e||false;
		while (el && el.id != id) {
			el = el.parentNode||false;
		}
		return (el!==false);
	}

	// returns the depth of the element "e" relative to element with id=id
	// for this calculation only parents with classname = waypoint are considered
	function getLevelDepth( e, id, waypoint, cnt ) {
		cnt = cnt || 0;
		if ( e.id.indexOf( id ) >= 0 ) return cnt;
		if( classie.has( e, waypoint ) ) {
			++cnt;
		}
		return e.parentNode && getLevelDepth( e.parentNode, id, waypoint, cnt );
	}

	// http://coveroverflow.com/a/11381730/989439
	function mobilecheck() {
		var check = false;
		(function(a){if(/(android|ipad|playbook|silk|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino/i.test(a)||/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(a.substr(0,4)))check = true})(navigator.userAgent||navigator.vendor||window.opera);
		return check;
	}

	// returns the closest element to 'e' that has class "classname"
	function closest( e, classname ) {
		if( classie.has( e, classname ) ) {
			return e;
		}
		return e.parentNode && closest( e.parentNode, classname );
	}

	function mlPushMenu( el, trigger, options ) {	
		this.el = el;
		this.trigger = trigger;
		this.options = extend( this.defaults, options );
		// support 3d transforms
		this.support = Modernizr.csstransforms3d;
		if( this.support ) {
			this._init();
		}
	}

	mlPushMenu.prototype = {
		defaults : {
			// overlap: there will be a gap between open levels
			// cover: the open levels will be on top of any previous open level
			type : 'overlap', // overlap || cover
			// space between each overlaped level
			levelSpacing : 40,
			// classname for the element (if any) that when clicked closes the current level
			backClass : 'sj-back'
		},
		_init : function() {
			// if menu is open or not
			this.open = false;
			// level depth
			this.level = 0;
			// the moving wrapper
			this.wrapper = document.getElementById( 'sj-pusher' );
			// the sj-level elements
			this.levels = Array.prototype.slice.call( this.el.querySelectorAll( 'div.sj-level' ) );
			// save the depth of each of these sj-level elements
			var self = this;
			this.levels.forEach( function( el, i ) { el.setAttribute( 'data-level', getLevelDepth( el, self.el.id, 'sj-level' ) ); } );
			// the menu items
			this.menuItems = Array.prototype.slice.call( this.el.querySelectorAll( 'li' ) );
			// if type == "cover" these will serve as hooks to move back to the previous level
			this.levelBack = Array.prototype.slice.call( this.el.querySelectorAll( '.' + this.options.backClass ) );
			// event type (if mobile use touch events)
			this.eventtype = mobilecheck() ? 'touchstart' : 'click';
			// add the class sj-overlap or sj-cover to the main element depending on options.type
			classie.add( this.el, 'sj-' + this.options.type );
			
			// initialize / bind the necessary events
			this._initEvents();
		},
		_initEvents : function() {
			
			var self = this;

			// the menu should close if clicking somewhere on the body
			var bodyClickFn = function( el ) {
				self._resetMenu();
				el.removeEventListener( self.eventtype, bodyClickFn );
			};

			// open (or close) the menu
			this.trigger.addEventListener( this.eventtype, function( ev ) {
				ev.stopPropagation();
				ev.preventDefault();
				if( self.open ) {
					self._resetMenu();
				}
				else {
					self._openMenu();
					// the menu should close if clicking somewhere on the body (excluding clicks on the menu)
					document.addEventListener( self.eventtype, function( ev ) {
						if( self.open && !hasParent( ev.target, self.el.id ) ) {
							bodyClickFn( this );
						}
					} );
				}
			} );

			// opening a sub level menu
			this.menuItems.forEach( function( el, i ) {
				// check if it has a sub level
				var subLevel = el.querySelector( 'div.sj-level' );
				if( subLevel ) {
					el.querySelector( 'a' ).addEventListener( self.eventtype, function( ev ) {
						ev.preventDefault();
						var level = closest( el, 'sj-level' ).getAttribute( 'data-level' );
						if( self.level <= level ) {
							ev.stopPropagation();
							classie.add( closest( el, 'sj-level' ), 'sj-level-overlay' );
							self._openMenu( subLevel );
						}
					} );
				}
			} );

			// closing the sub levels :
			// by clicking on the visible part of the level element
			this.levels.forEach( function( el, i ) {
				el.addEventListener( self.eventtype, function( ev ) {
					ev.stopPropagation();
					var level = el.getAttribute( 'data-level' );
					if( self.level > level ) {
						self.level = level;
						self._closeMenu();
					}
				} );
			} );

			// by clicking on a specific element
			this.levelBack.forEach( function( el, i ) {
				el.addEventListener( self.eventtype, function( ev ) {
					ev.preventDefault();
					var level = closest( el, 'sj-level' ).getAttribute( 'data-level' );
					if( self.level <= level ) {
						ev.stopPropagation();
						self.level = closest( el, 'sj-level' ).getAttribute( 'data-level' ) - 1;
						self.level === 0 ? self._resetMenu() : self._closeMenu();
					}
				} );
			} );	
		},
		_openMenu : function( subLevel ) {
			// increment level depth
			++this.level;
			
			// move the main wrapper
			var levelFactor = ( this.level - 1 ) * this.options.levelSpacing,
				translateVal = this.options.type === 'overlap' ? this.el.offsetWidth + levelFactor : this.el.offsetWidth;
			
			this._setTransform( 'translate3d(' + translateVal + 'px,0,0)' );

			if( subLevel ) {
				// reset transform for sublevel
				this._setTransform( '', subLevel );
				// need to reset the translate value for the level menus that have the same level depth and are not open
				for( var i = 0, len = this.levels.length; i < len; ++i ) {
					var levelEl = this.levels[i];
					if( levelEl != subLevel && !classie.has( levelEl, 'sj-level-open' ) ) {
						this._setTransform( 'translate3d(-100%,0,0) translate3d(' + -1*levelFactor + 'px,0,0)', levelEl );
					}
				}				
			}
			// add class sj-pushed to main wrapper if opening the first time
			if( this.level === 1 ) {
				classie.add( this.wrapper, 'sj-pushed' );
				this.open = true;
			}
			// add class sj-level-open to the opening level element
			classie.add( subLevel || this.levels[0], 'sj-level-open' );
		},
		// close the menu
		_resetMenu : function() {
			this._setTransform('translate3d(0,0,0)');
			this.level = 0;
			// remove class sj-pushed from main wrapper
			classie.remove( this.wrapper, 'sj-pushed' );
			this._toggleLevels();
			this.open = false;
		},
		// close sub menus
		_closeMenu : function() {
			var translateVal = this.options.type === 'overlap' ? this.el.offsetWidth + ( this.level - 1 ) * this.options.levelSpacing : this.el.offsetWidth;
			this._setTransform( 'translate3d(' + translateVal + 'px,0,0)' );
			this._toggleLevels();
		},
		// translate the el
		_setTransform : function( val, el ) {
			el = el || this.wrapper;
			el.style.WebkitTransform = val;
			el.style.MozTransform = val;
			el.style.transform = val;
		},
		// removes classes sj-level-open from closing levels
		_toggleLevels : function() {
			for( var i = 0, len = this.levels.length; i < len; ++i ) {
				var levelEl = this.levels[i];
				if( levelEl.getAttribute( 'data-level' ) >= this.level + 1 ) {
					classie.remove( levelEl, 'sj-level-open' );
					classie.remove( levelEl, 'sj-level-overlay' );
				}
				else if( Number( levelEl.getAttribute( 'data-level' ) ) == this.level ) {
					classie.remove( levelEl, 'sj-level-overlay' );
				}
			}
		}
	}

	// add to global namespace
	window.mlPushMenu = mlPushMenu;

} )( window );