sintonia/public/js/playlist/playlist.js

var estimatedSchedulePosixTime = -1;

var localRemoteTimeOffset;

var previousSongs = new Array();
var currentSong = new Array();
var nextSongs = new Array();

var currentElem;

var serverUpdateInterval = 5000;
var uiUpdateInterval = 200;

var songEndFunc;

var showStartPosixTime = 0;
var showEndPosixTime = 0;
var showLengthMs = 1;

/* boolean flag to let us know if we should prepare to execute a function
 * that flips the playlist to the next song. This flags purpose is to
 * make sure the function is only executed once*/
var nextSongPrepare = true;

/* Another script can register its function here
 * when it wishes to know when a song ends. */
function registerSongEndListener(func){
	songEndFunc = func;
}

function notifySongEndListener(){
    if (typeof songEndFunc == "function")
        songEndFunc();
}

/* Takes an input parameter of milliseconds and converts these into
 * the format HH:MM:SS */
function convertToHHMMSS(timeInMS){
	var time = parseInt(timeInMS);
	
	var hours = parseInt(time / 3600000);
	time -= 3600000*hours;
		
	var minutes = parseInt(time / 60000);
	time -= 60000*minutes;
	
	var seconds = parseInt(time / 1000);
	
	hours = "" + hours;
	minutes = "" + minutes;
	seconds = "" + seconds;
	
	if (hours.length == 1)
		hours = "0" + hours;
	if (minutes.length == 1)
		minutes = "0" + minutes;
	if (seconds.length == 1)
		seconds = "0" + seconds;
	return "" + hours + ":" + minutes + ":" + seconds;
}

function convertDateToPosixTime(s){
	var year = s.substring(0, 4);
	var month = s.substring(5, 7);
	var day = s.substring(8, 10);
	var hour = s.substring(11, 13);
	var minute = s.substring(14, 16);
	var sec = s.substring(17, 19);
	var msec = 0;
	if (s.length >= 20){
		msec = s.substring(20);
	}

	return Date.UTC(year, month, day, hour, minute, sec, msec);
}

function getTrackInfo(song){
	var str = "";
	
	if (song.track_title != null)
		str += song.track_title;
	if (song.artist_name != null)
		str += " - " + song.artist_name;
	if (song.album_title != null)
		str += " - " + song.album_title;
		
	return str;
}

function secondsTimer(){
	var date = new Date();
	estimatedSchedulePosixTime = date.getTime() - localRemoteTimeOffset;
	updateProgressBarValue();
}

function updateGlobalValues(obj){
    showStartPosixTime = obj.showStartPosixTime;
    showEndPosixTime = obj.showEndPosixTime;
    showLengthMs = showEndPosixTime - showStartPosixTime;
}

function newSongStart(){
    nextSongPrepare = true;
	currentSong[0] = nextSongs.shift();
    updateGlobalValues(currentSong[0]);
    updatePlaybar();
    
    notifySongEndListener();
}

/* Called every "uiUpdateInterval" mseconds. */
function updateProgressBarValue(){
	if (estimatedSchedulePosixTime != -1){
        if (showStartPosixTime != 0){
            var showPercentDone = (estimatedSchedulePosixTime - showStartPosixTime)/showLengthMs*100;
            if (showPercentDone < 0 || showPercentDone > 100){
                showPercentDone = 0;
            }
            $('#showprogressbar').progressBar(showPercentDone);
        }

        var songPercentDone = 0;
		if (currentSong.length > 0){
			songPercentDone = (estimatedSchedulePosixTime - currentSong[0].songStartPosixTime)/currentSong[0].songLengthMs*100;
			if (songPercentDone < 0 || songPercentDone > 100){
				songPercentDone = 0;
                currentSong = new Array();
			}
		}
        $('#progressbar').progressBar(songPercentDone);

        //calculate how much time left to next song if there is any
        if (nextSongs.length > 0 && nextSongPrepare){
            if (nextSongs[0].songStartPosixTime - estimatedSchedulePosixTime < serverUpdateInterval){
                nextSongPrepare = false;
                setTimeout(newSongStart, nextSongs[0].songStartPosixTime - estimatedSchedulePosixTime);
            }
        }
        
		updatePlaybar();
	}
	setTimeout(secondsTimer, uiUpdateInterval);
}

function updatePlaybar(){
	/* Column 0 update */
	
	/* Column 1 update */
    $('#playlist').empty();
	for (var i=0; i<currentSong.length; i++){
		//alert (currentSong[i].playlistname);
		//$('#show').text(currentSong[i].show);
		$('#playlist').text(currentSong[i].name);
		//$('#host').text(currentSong[i].creator);
	}
	
	/* Column 2 update */
    $('#previous').empty();
    $('#current').empty();
    $('#next').empty();
	for (var i=0; i<previousSongs.length; i++){
		$('#previous').text(getTrackInfo(previousSongs[i]));
	}
	for (var i=0; i<currentSong.length; i++){
		$('#current').text(getTrackInfo(currentSong[i]));
	}
	for (var i=0; i<nextSongs.length; i++){
		$('#next').text(getTrackInfo(nextSongs[i]));
	}
	
	/* Column 3 update */
    $('#start').empty();
    $('#end').empty();
    $('#songposition').empty();
    $('#songlength').empty();
    $('#showposition').empty();
    $('#showlength').empty();
	for (var i=0; i<currentSong.length; i++){
		$('#start').text(currentSong[i].starts.substring(currentSong[i].starts.indexOf(" ")+1));
		$('#end').text(currentSong[i].ends.substring(currentSong[i].starts.indexOf(" ")+1));

        /* Get rid of the millisecond accuracy so that the second counters for both
         * show and song change at the same time. */
        var songStartRoughly = parseInt(currentSong[i].songStartPosixTime/1000)*1000;
        
		$('#songposition').text(convertToHHMMSS(estimatedSchedulePosixTime - songStartRoughly));
		$('#songlength').text(currentSong[i].clip_length);
	}
    if (estimatedSchedulePosixTime < showEndPosixTime){
        $('#showposition').text(convertToHHMMSS(estimatedSchedulePosixTime - showStartPosixTime));
        $('#showlength').text(convertToHHMMSS(showEndPosixTime - showStartPosixTime));
    }
}

function calcAdditionalData(currentItem, bUpdateGlobalValues){
	for (var i=0; i<currentItem.length; i++){
		currentItem[i].songStartPosixTime = convertDateToPosixTime(currentItem[i].starts);
		currentItem[i].songEndPosixTime = convertDateToPosixTime(currentItem[i].ends);
		currentItem[i].songLengthMs = currentItem[i].songEndPosixTime - currentItem[i].songStartPosixTime;

        currentItem[i].showStartPosixTime = convertDateToPosixTime(currentItem[i].starts.substring(0, currentItem[i].starts.indexOf(" ")) + " " + currentItem[i].start_time);
        currentItem[i].showEndPosixTime = convertDateToPosixTime(currentItem[i].starts.substring(0, currentItem[i].starts.indexOf(" ")) + " " + currentItem[i].end_time);

        //check if there is a rollover past midnight
        if (currentItem[i].start_time > currentItem[i].end_time){
            //start_time is greater than end_time, so we rolled through midnight.
            currentItem[i].showEndPosixTime += (1000*3600*24); //add 24 hours
        }

        currentItem[i].showLengthMs = currentItem[i].showEndPosixTime - currentItem[i].showStartPosixTime;
            
        if (bUpdateGlobalValues){
            updateGlobalValues(currentItem[i]);
        }
	}
}

function parseItems(obj){
	var schedulePosixTime = convertDateToPosixTime(obj.schedulerTime);
	
	previousSongs = obj.previous;
	currentSong = obj.current;
	nextSongs = obj.next;

	calcAdditionalData(previousSongs, false);
	calcAdditionalData(currentSong, true);
	calcAdditionalData(nextSongs, false);

	if (estimatedSchedulePosixTime == -1){
		var date = new Date();
		localRemoteTimeOffset = date.getTime() - schedulePosixTime;
		estimatedSchedulePosixTime = schedulePosixTime;
	}
}

function getScheduleFromServer(){
	$.ajax({ url: "/Schedule/get-current-playlist/format/json", dataType:"json", success:function(data){
			parseItems(data.entries);
		  }});
	setTimeout(getScheduleFromServer, serverUpdateInterval);
}

function init(elemID) {
	var currentElem = $("#" + elemID).attr("style", "z-index: 1; width: 100%; left: 0px; right: 0px; bottom: 0px; color: black; min-height: 100px; background-color: #FEF1B5;");
	
	$('#progressbar').progressBar(0, {showText : false});
	$('#showprogressbar').progressBar(0, {showText : false, barImage:'/js/progressbar/images/progressbg_red.gif'});

    //begin producer "thread"
	getScheduleFromServer();

    //begin consumer "thread"
	updateProgressBarValue();
	
}