var presentation = ["<word>prokaryotes<\/word>","<word>single, double-stranded DNA molecule<\/word>","<word>nucleoid<\/word>","<word>plasmids<\/word>","<word>eukaryotes<\/word>","<word>double-stranded, linear DNA molecules<\/word>","<word>46 chromosomes<\/word>","<word>diploid<\/word>","<word>designated 2n<\/word>","<word>gametes<\/word>","<word>designated n<\/word>","<word>haploid<\/word>","<word>locus<\/word>","<word>Genes, the functional units of chromosomes<\/word>","<word>sex chromosomes, X and Y<\/word>","<word>exception to the rule<\/word>","<phrase>A cell's complete complement of DNA is called its genome. In <strong data-readahead=\"prokaryotes\" class=\"presentation_word\">prokaryotes<\/strong>, the genome is composed of a <strong data-readahead=\"single, double-stranded DNA molecule\" class=\"presentation_word\">single, double-stranded DNA molecule<\/strong> in the form of a loop or circle. A <strong data-readahead=\"nucleoid\" class=\"presentation_word\">nucleoid<\/strong> is a region in the cell that contains this genetic material. Some <strong data-readahead=\"prokaryotes\">prokaryotes<\/strong> also have smaller loops of DNA called <strong data-readahead=\"plasmids\" class=\"presentation_word\">plasmids<\/strong> that are not essential for normal growth.\nIn <strong data-readahead=\"eukaryotes\" class=\"presentation_word\">eukaryotes<\/strong>, the genome comprises several <strong data-readahead=\"double-stranded, linear DNA molecules\" class=\"presentation_word\">double-stranded, linear DNA molecules<\/strong> bound with proteins to form complexes called chromosomes. Each species of eukaryote has a characteristic number of chromosomes in the nuclei of its cells. Human body cells (somatic cells) have <strong data-readahead=\"46 chromosomes\" class=\"presentation_word\">46 chromosomes<\/strong>. A somatic cell contains two matched sets of chromosomes, a configuration known as <strong data-readahead=\"diploid\" class=\"presentation_word\">diploid<\/strong>. The letter n is used to represent a single set of chromosomes; therefore a <strong data-readahead=\"diploid\">diploid<\/strong> organism is <strong data-readahead=\"designated 2n\" class=\"presentation_word\">designated 2n<\/strong>. Human cells that contain one set of 23 chromosomes are called <strong data-readahead=\"gametes\" class=\"presentation_word\">gametes<\/strong> or sex cells. These cells, eggs and sperms, are <strong data-readahead=\"designated n\" class=\"presentation_word\">designated n<\/strong> or <strong data-readahead=\"haploid\" class=\"presentation_word\">haploid<\/strong>.\nThe matched pairs of chromosomes in a <strong data-readahead=\"diploid\">diploid<\/strong> organism are called homologous chromosomes. Homologous chromosomes are the same length and have specific nucleotide segments called genes in exactly the same location, or <strong data-readahead=\"locus\" class=\"presentation_word\">locus<\/strong>. <strong data-readahead=\"Genes, the functional units of chromosomes\" class=\"presentation_word\">Genes, the functional units of chromosomes<\/strong>, determine specific characteristics by coding for specific proteins. Traits are the different forms of a characteristic. For example, the shape of earlobes is a characteristic with traits of free or attached.\nEach copy of the homologous pair of chromosomes originates from a different parent; therefore, the copies of each of the genes themselves may not be identical. The variation of individuals within a species is caused by the specific combination of the genes inherited from both parents. For example, there are three possible gene sequences on the human chromosome that codes for blood type: sequence A, sequence B, and sequence O. Because all <strong data-readahead=\"diploid\">diploid<\/strong> human cells have two copies of the chromosome that determines blood type, the blood type (the trait) is determined by which two versions of the marker gene are inherited. It is possible to have two copies of the same gene sequence, one on each homologous chromosome (for example, AA, BB, or OO), or two different sequences, such as AB.\nMinor variations in traits such as those for blood type, eye color, and height contribute to the natural variation found within a species. The <strong data-readahead=\"sex chromosomes, X and Y\" class=\"presentation_word\">sex chromosomes, X and Y<\/strong>, are the single <strong data-readahead=\"exception to the rule\" class=\"presentation_word\">exception to the rule<\/strong> of homologous chromosomes; other than a small amount of homology that is necessary to reliably produce <strong data-readahead=\"gametes\">gametes<\/strong>, the genes found on the X and Y chromosomes are not the same.<\/phrase>"];
	var currentPosition = 0;
	var totalPositions = 0;
	var timePerWord = 1500;
	var timePerPhraseWord = 120
	var readAheadPlayerTimer;
	var autoPlay = true;
	var setMinimized = false;

	var wordSpeedOptions = {'Slower':2000,'Moderate':1200,'Fast':800};
	var phraseSpeedOptions = {'Slower':280,'Moderate':200,'Fast':80};
	var defaultWordSpeedOption = 'Moderate';
	var defaultPhraseSpeedOption = 'Moderate';
	var logToLTI = false;

	$(window).load(function(){
		totalPositions = presentation.length;
		if (totalPositions > 0){
			$('body').prepend('<div id="read_ahead_player_back"></div>');
			$('body').prepend('<div id="read_ahead_player"></div>');
			$('#read_ahead_player').prepend('<div id="read_ahead_player_field" class="read_ahead_word_section"></div>');
			initializeReadAheadControls();
			initializeReadAheadSlider();
			initializeReadAheadSpeedOptions();
			currentReadAheadControls();
			resumeReadAheadPlayback();
		}
	});

	$(document).keyup(function(e){
		switch(e.which) {
			case 37: 
				pauseReadAheadPresentation();
				priorReadAheadPresentationItem();
				break;
			case 39:
				pauseReadAheadPresentation();
				nextReadAheadPresentationItem();
				break;
			default:
				break;
		}

	});

	function initializeReadAheadControls(){
		var s = '';
		s += '<a href="javascript:void(0)" onclick="read_ahead_switch_min_max(true);" id="read_ahead_player_max_min" class="player-icons" aria-label="minimize/maximize player">';
		s += '<span class="fa-stack fa-lg " aria-hidden><i class="fa fa-circle fa-stack-2x"></i><i class="fa fa-minus fa-stack-1x fa-inverse"></i></span>';
		s += '</a>';
		s += '<div id="read_ahead_controls">';
		s += '<a href="javascript:void(0)" onclick="priorReadAheadPresentationItem()" id="read_ahead_player_previous_word" class="player-icons" aria-label="previous keyword">';
		s += '<span class="fa-stack fa-lg " aria-hidden><i class="fa fa-circle fa-stack-2x"></i><i class="fa fa-backward fa-stack-1x fa-inverse"></i></span>';
		s += '</a>';
		s += '<a href="javascript:void(0)" onclick="pauseReadAheadPresentation()" id="read_ahead_player_pause_play" class="player-icons" aria-label="play/pause">';
		s += '<span class="fa-stack fa-lg " aria-hidden><i class="fa fa-circle fa-stack-2x"></i><i class="fa fa-pause fa-stack-1x fa-inverse"></i></span>';
		s += '</a>';
		s += '<a href="javascript:void(0)" onclick="nextReadAheadPresentationItem()" id="read_ahead_player_next_word" class="player-icons" aria-label="next keyword">';
		s += '<span class="fa-stack fa-lg " aria-hidden><i class="fa fa-circle fa-stack-2x"></i><i class="fa fa-forward fa-stack-1x fa-inverse"></i></span>';
		s += '</a>';
		s += '</div>';
		$('#read_ahead_player').append(s);
	}

	function initializeReadAheadSlider(){
		var s = '';
		s += '<div class="read_ahead_slider" id="readAheadSlider">';
		s += '<div class="read_ahead_slider_bar" id="readAheadSliderBar"></div>';
		s += '</div>';
		$('#read_ahead_controls').prepend(s);
		updateReadAheadSliderPosition();
	}

	function initializeReadAheadSpeedOptions(){
		var s = '<div id="read_ahead_player_options">';
		s += '<div class="slider_control" id="slider_control_word_speed">';
		s += ' Word Speed<br/>';
		s += '<div class="slider_bar">';
		optionCount = 0;
		for (index in wordSpeedOptions) { optionCount++; }
		optionWidth = 100 / optionCount;
		for (index in wordSpeedOptions) {
			var option = wordSpeedOptions[index];
			if (index == defaultWordSpeedOption) {
				s += '<a href="javascript:void(0)" id="slider_control_word_speed_'+option+'" onclick="updateReadAheadWordSpeed('+option+',this)" style="width:'+optionWidth+'%;" title="'+index+'" data-speed="'+option+'" class="current_speed" aria-label="'+index+'"></a>';
				updateReadAheadWordSpeed(option);
			} else {
				s += '<a href="javascript:void(0)" id="slider_control_word_speed_'+option+'" onclick="updateReadAheadWordSpeed('+option+',this)" style="width:'+optionWidth+'%;" title="'+index+'" data-speed="'+option+'" aria-label="'+index+'"></a>';
			}
		}
		s += '</div>';
		s += '</div>';
		s += '<div class="slider_control" id="slider_control_phrase_speed">';
		s += ' Phrase Speed<br/>';
		s += '<div class="slider_bar">';
		optionCount = 0;
		for (index in phraseSpeedOptions) { optionCount++; }
		optionWidth = 100 / optionCount;
		for (index in phraseSpeedOptions) {
			var option = phraseSpeedOptions[index];
			if (index == defaultWordSpeedOption) {
				s += '<a href="javascript:void(0)" id="slider_control_phrase_speed_'+option+'" onclick="updateReadAheadPhraseSpeed('+option+',this)" style="width:'+optionWidth+'%;" title="'+index+'" data-speed="'+option+'" class="current_speed" aria-label="'+index+'"></a>';
				updateReadAheadPhraseSpeed(option);
			} else {
				s += '<a href="javascript:void(0)" id="slider_control_phrase_speed_'+option+'" onclick="updateReadAheadPhraseSpeed('+option+',this)" style="width:'+optionWidth+'%;" title="'+index+'" data-speed="'+option+'" aria-label="'+index+'"></a>';
			}
		}
		s += '</div>';
		s += '</div>';
		s += '</div>';
		$('#read_ahead_controls').append(s);
	}

	function updateReadAheadWordSpeed(microseconds,sender) {
		microseconds = microseconds != undefined && microseconds > 0 ? microseconds : 0;
		if (microseconds > 0) { timePerWord = microseconds; }
		if (sender!=undefined) { 
			$('#slider_control_word_speed').find('a').removeClass('current_speed');
			$(sender).addClass('current_speed');
		}
		logReadAheadPlayerAction('updateReadAheadWordSpeed','Presentation',microseconds);
	}

	function updateReadAheadPhraseSpeed(microseconds,sender) {
		microseconds = microseconds != undefined && microseconds > 0 ? microseconds : 0;
		if (microseconds > 0 ) { timePerPhraseWord = microseconds; }
		if (sender!=undefined) { 
			$('#slider_control_phrase_speed').find('a').removeClass('current_speed');
			$(sender).addClass('current_speed');
		}
		logReadAheadPlayerAction('updateReadAheadPhraseSpeed','Presentation',microseconds);
	}

	function updateReadAheadSliderPosition(){
		var currentSliderBarWidth = 100 - (100 / totalPositions * (currentPosition + 1));
		$('#readAheadSliderBar').css('width',currentSliderBarWidth+'%');
	}

	function currentReadAheadControls(){
		$('#read_ahead_player_pause_play').show();
		if (currentPosition < totalPositions - 1)	{
			$('#read_ahead_player_next_word').removeClass('disabled');
		} else {
			$('#read_ahead_player_next_word').addClass('disabled');
		}
		if (currentPosition > 0) {
			$('#read_ahead_player_previous_word').removeClass('disabled');
		} else {
			$('#read_ahead_player_previous_word').addClass('disabled');
		}
	}

	function restartReadAheadPresentation(){
		currentPosition = 0;
		logReadAheadPlayerAction('restartReadAheadPresentation','Presentation','');
		resumeReadAheadPlayback();
	}

	function resumeReadAheadPlayback(){
		$('.fa-repeat').removeClass('fa-repeat').addClass('fa-play');
		$('#read_ahead_player_pause_play').each(function(){
			$(this).find('.fa-play').removeClass('fa-play').addClass('fa-pause');
			$(this).off('click');
			$(this).attr('onclick','pauseReadAheadPresentation()');
		});
		logReadAheadPlayerAction('resumeReadAheadPlayback','Presentation','');
		playReadAheadPresentation();
	}

	function pauseReadAheadPresentation(){
		$('#read_ahead_player_pause_play').each(function(){
			$(this).find('.fa-pause').removeClass('fa-pause').addClass('fa-play');
			$(this).off('click');
			$(this).attr('onclick','resumeReadAheadPlayback()');
		});
		logReadAheadPlayerAction('pauseReadAheadPresentation','Presentation','');
		read_ahead_pause();
	}

	function endReadAheadPresentation(){
		$('.fa-play').removeClass('fa-play').addClass('fa-repeat');
		$('.fa-pause').removeClass('fa-pause').addClass('fa-repeat');
		$('#read_ahead_player_pause_play').each(function(){
			$(this).off('click');
			$(this).attr('onclick','restartReadAheadPresentation()');
		});
		logReadAheadPlayerAction('endReadAheadPresentation','Presentation','');
		logLTIEndPresentation();
	}

	function playReadAheadPresentation(){
		autoPlay=true;
		currentPosition--;
		logReadAheadPlayerAction('playReadAheadPresentation','Presentation','');
		nextReadAheadPresentationItem(); 
	}

	function startReadAheadStepper(timeDisplayWord){
		clearInterval(readAheadPlayerTimer);
		readAheadPlayerTimer = setTimeout(function() { read_ahead_step(); },timeDisplayWord);
	}

	function stopReadAheadStepper(){
		clearInterval(readAheadPlayerTimer);
	}

	function read_ahead_step(){
		if (autoPlay) {
			nextReadAheadPresentationItem();
		}
	}

	function read_ahead_pause(){
		autoPlay=false;
		stopReadAheadStepper();
	}

	function showReadAheadPresentationItem(index){
		currentPosition = index;
		currentPresentationItem = presentation[currentPosition] != undefined ? presentation[currentPosition].trim() : "";
		if (currentPresentationItem != "") {
			currentItemWordCount = presentation[currentPosition].replace("\n","").split(" ").length;
			if (currentPresentationItem.startsWith("<word>")){
				startReadAheadStepper(currentItemWordCount*timePerWord);
				$('#read_ahead_player_field').html('<div class="read_ahead_word" style="display:block;">'+currentPresentationItem+'</div>');
				logReadAheadPlayerAction('showReadAheadPresentationItem','Word',currentPresentationItem);
		
			} else {
				startReadAheadStepper(currentItemWordCount*timePerPhraseWord);
				$('#read_ahead_player_field').html('<div class="read_ahead_text_box" style="display:block;"><div class="read_ahead_text">'+currentPresentationItem.replace("\n","<br />")+'</div></div>');
				logReadAheadPlayerAction('showReadAheadPresentationItem','Phrase','');
		
			}
		} else {
			if (currentPosition < totalPositions) {
				nextReadAheadPresentationItem();
			} else {
				endReadAheadPresentation();
				read_ahead_minimize();
			}
		}
		currentReadAheadControls();
		updateReadAheadSliderPosition();
		saveReadAheadPosition();
	}

	function priorReadAheadPresentationItem(){
		stopReadAheadStepper();
		logReadAheadPlayerAction('priorReadAheadPresentationItem','Controls','');
		showReadAheadPresentationItem(currentPosition-1);
	}


	function nextReadAheadPresentationItem(){
		stopReadAheadStepper();
		logReadAheadPlayerAction('nextReadAheadPresentationItem','Controls','');
		showReadAheadPresentationItem(currentPosition+1);
	}

	function read_ahead_playAgain(){
		currentWordIndex = 0;
		logReadAheadPlayerAction('read_ahead_playAgain','Controls','');
		playReadAheadPresentation();
	}


	function read_ahead_minimize(){
		setMinimized = true;
		logReadAheadPlayerAction('read_ahead_minimize','Controls','');
		read_ahead_switch_min_max();
	}

	function read_ahead_maximize(){
		setMinimized = false;
		logReadAheadPlayerAction('read_ahead_maximize','Controls','');
		read_ahead_switch_min_max();
	}

	function read_ahead_switch_min_max(forceSwitch){
		forceSwitch = forceSwitch != undefined ? forceSwitch : false;
		if (forceSwitch) { setMinimized = !setMinimized; }

		if (setMinimized) {
			$('#read_ahead_player_back').fadeOut();
			$('#read_ahead_player').addClass('minimize');
			$('.player-icons .fa-stack').removeClass('fa-lg').addClass('fa-sm');
			$('.player-icons .fa-minus').removeClass('fa-minus').addClass('fa-expand');
			logReadAheadPlayerAction('read_ahead_switch_min_max','Min','');
			//$('#read_ahead_player_max_min').each(function(){
			//	$(this).off('click');
			//	$(this).attr('onclick','read_ahead_maximize()');
			//});
		} else {
			$('#read_ahead_player_back').fadeIn();
			$('#read_ahead_player').removeClass('minimize');
			$('.player-icons .fa-stack').removeClass('fa-sm').addClass('fa-lg');
			$('.player-icons .fa-expand').removeClass('fa-expand').addClass('fa-minus');
			logReadAheadPlayerAction('read_ahead_switch_min_max','Max','');
			//$('#read_ahead_player_max_min').each(function(){
			//	$(this).off('click');
			//	$(this).attr('onclick','read_ahead_minimize()');
			//});
		}

	}

	function saveReadAheadPosition(){
		$.ajax({
			type:'POST',
			url:'/ajax/save_user_presentation_position.php',
			data: { 'id':2183,
					'position': currentPosition
				}
		})
		.done(function(results){
		})
		.fail(function( jqXHR, textStatus ) {
			alert( "Request failed: " + textStatus );
		});

	}

	function logLTIEndPresentation(action) {
		if (!logToLTI) {
			return;
		}

		$.ajax({
			type:'POST',
			url:'/lti/presentationEnded.php',
			data: { 'documentId':2183,
					'userId':0,
				}
		})
	}

	function logReadAheadPlayerAction(action,area,details){
		var d = new Date();
		var t = d.getTime();
		action = action != undefined ? action.trim() : 'UNKNOWN';
		area = area != undefined ? area.trim() : '';
		details = details != undefined ? details : '';

		// If we are about to show a new word, increase the number of keywords
		// reinforced so we can log that for the Dashboard page.
		if (area == 'Word') {
			window.keywordCount++;
		}

		$.ajax({
			type:'POST',
			url:'/logging/logPlayerAction.php',
			data: { 'documentId':2183,
					'userId':0,
					'playerAction':action,
					'playerArea':area,
					'details':details,
					'timestamp': t
				}
		})
		.done(function(results){
		})
		.fail(function( jqXHR, textStatus ) {
			alert( "Request failed: " + textStatus );
		});

	}