var downloadedFilesCounter = 0;

var numOfChunksToDownload;

var downloadQueue = [];

var currentDownloadName;

var status = "idle";

var theWindow = null;

var firstTimeOpenWindow = 1;

var chunksBaseUrl, quality, chunksURLQuery;

function updataStatus(){

    downloadedFilesCounter++;

    let completedPercentage = (downloadedFilesCounter / (numOfChunksToDownload+1) ) ;

    let fullWidth = $("#progressBar"+downloadQueue[0].playlistid).width();

    let percentageDivWidth = $("#progressBarPercent"+downloadQueue[0].playlistid).width();

    let updatedWidth = parseInt(completedPercentage*fullWidth);

    if ( updatedWidth > percentageDivWidth)

        $("#progressBarPercent"+downloadQueue[0].playlistid).css("width", updatedWidth);

    if ( downloadedFilesCounter == (numOfChunksToDownload+1)  )

        $("#progressBarPercent"+downloadQueue[0].playlistid).css({"background-color": "#e91e63", "width":"100%"}).text("ההורדה הושלמה!");

    else

        $("#progressBarPercent"+downloadQueue[0].playlistid).text("בהורדה: " + parseInt(completedPercentage*100) + "%");

}

var tmrCheckPlaylistLoad;

var currentOpenCollectionId = $("#ovc_collections_list").find("li.active").find("a").attr("c-value");

addDownloadButtons(currentOpenCollectionId);

// add click event for all download buttons

$(document).on("click", ".downloadButton", function(){

    var url = "https://opal.openu.ac.il/mod/ouilvideocollection/actions.php";

    var context = $(this).attr('context');

    var playlistId = $(this).attr('playlistid');

    downloadQueue.push( { context: context, playlistid: playlistId } );

    // add progress bar

    let videoTop = $("#playlist"+playlistId).find(".ovc_playlist_border");

    let progressBarDiv = $("<div id='progressBar"+playlistId+"'></div>").css({"background-color": "#01579B"});

    let progressBarPercentDiv = $("<div id='progressBarPercent"+playlistId+"'>ממתין להתחלת הורדה... <a href='javascript:void(0);' class='cancelDownload' context="+context+" playlistid="+playlistId+" style='color:lightgreen;font-size: 120%;margin-right:10px;'><b>בטל</b></a></div>").css({"color": "white"});

    progressBarDiv.append(progressBarPercentDiv);

    videoTop.prepend(progressBarDiv);

    $(".downloadButton[playlistid="+playlistId+"]").hide();

    getVideosOnQueue();

});

// add click event for all cancel download buttons

$(document).on("click", ".cancelDownload", function(){

    var playlistId = $(this).attr('playlistid');

    downloadQueue = downloadQueue.filter(video => video.playlistid !== playlistId );

    $("#progressBar"+playlistId).remove();

    $(".downloadButton[playlistid="+playlistId+"]").show();

});

// automatically add download buttons when a new collection is loaded

function onPlaylistLoad(){

    $(".collection_link").each(function(){

        $(this).on("click", function(){

            var cValue = $(this).attr("c-value");

            tmrCheckPlaylistLoad = setInterval(function(){handleCollectionChange(cValue)}, 300);

        });  

    }); 

}

onPlaylistLoad();

function handleCollectionChange (cValue) {

    if( $('#collection'+cValue).is(':visible') ){ 

        addDownloadButtons(cValue);

        clearInterval(tmrCheckPlaylistLoad);

    }

}

// adds download buttons to an open collection( a collection that has been loaded )

function addDownloadButtons(collectionId) {

    // add buttons only if not been added before

    if ( $( "#collection"+collectionId ).find("button").length == 0 ) {

        var collectionDiv = $("#collection"+collectionId);

        var currentContext = collectionDiv.attr("cid");

        var videoCount = 0;

        collectionDiv.children().each(function(i) {

            let videoDescription = $(this).find("span.instructor_row");

            let currentPlaylistId = $(this).attr("id").substring(8);

            let buttonElement = $("<button></button>").text("הורד סרטון").attr('class','downloadButton').attr('context',currentContext).attr('playlistid',currentPlaylistId);

            buttonElement.css({"margin-right":"10px","background":"rgb(202, 60, 60)","color":"white","borderRadius":"4px","textShadow":"0 1px 1px rgba(0, 0, 0, 0.2)"});

            videoDescription.append(buttonElement);

        }); 

    }

}

function getPlaylistFile(context, playlistid){

    var courseIdStart = $('.coursename_header').children()[0].href.indexOf("id=");

    var courseIdNum = $('.coursename_header').children()[0].href.substring(courseIdStart+3);

    jQuery.ajax({

        type: "POST",

        url: "https://opal.openu.ac.il/mod/ouilvideocollection/actions.php",

        data: {action: "getplaylist", context: context, playlistid: playlistid, course: courseIdNum},

        success: function(data) {

          let anotherURL = "https://opal.openu.ac.il/local/ouil_video/player.php?mediaid=" + data.media.cipher;

          currentDownloadName = data.title;

					$.get(anotherURL, function(data) {

						let mediaStart = data.indexOf("media: ");

						let mediaEnd = data.indexOf("\"", mediaStart+11);

						let myMedia = data.substring(mediaStart+8, mediaEnd);

						let url = myMedia;

						$.get(url, function(data) {

                            let playlistStart = data.indexOf("file=")+5;

                            let playlistEnd = data.indexOf("\"", playlistStart+8);

                            var playlistURL = data.substring(playlistStart+1, playlistEnd).replace("&", "&");

                            let url = playlistURL;

							$.get(url, function(data) {

								let baseURL = playlistURL.substring(0, playlistURL.indexOf("playlist."))

								let quality_list = data.match(/BANDWIDTH=\d+/g).map(function(n){return parseInt(n.replace("BANDWIDTH=", ""))}).sort(function(a,b){ return a-b; });

								let highestQuality = quality_list[quality_list.length-1];

								let URLQuery = playlistURL.substring(playlistURL.indexOf("?"));

								chunksBaseUrl = baseURL;

								quality = highestQuality;

								chunksURLQuery = URLQuery;

								let url = chunksBaseUrl+"chunklist_b"+quality+".m3u8"+chunksURLQuery;

								$.get(url, function(data) {

									data = data.split("\n");

									let lastChunkLine = data[data.length-3];

									let lastChunkStart = lastChunkLine.indexOf("_", lastChunkLine.indexOf(quality));

									let lastChunkEnd = lastChunkLine.indexOf(".ts");

									let lastChunkNum = lastChunkLine.substring(lastChunkStart+1, lastChunkEnd);

									numOfChunksToDownload = parseInt(lastChunkNum);

									startVideoDownload();

								});

							});

						}, "text");   

					});     

        }

    });    

}

function getVideosOnQueue(){

    if ( downloadQueue.length > 0 && status === "idle"  ){

        status = "downloading";        

        $("#progressBar"+downloadQueue[0].playlistid).css({"background-color": "#ddd"});

        $("#progressBarPercent"+downloadQueue[0].playlistid).css({"background-color": "#4CAF50", "display": "inline-block", "font-weight": "bold"}).html("בהורדה: 0%");

        getPlaylistFile(downloadQueue[0].context, downloadQueue[0].playlistid);

    }

}

function startVideoDownload(){

    if ( theWindow === null ){

        theWindow = window.open('https://opal.openu.ac.il/'+new Date().getTime(), "", 'toolbar=no,status=no,width=250,height=100');

        if (theWindow == null || typeof(theWindow)=='undefined') {  

            alert('יש לאפשר פתיחת חלון נוסף (popup). ליד שורת הכתובת בדפדפן מופיע סימן קטן של אפשרות לאפשר popup,\n יש ללחוץ עליו ולבחור ב "Always allow pop-ups from. לאחר מכאן לרענן את הדף ולהפעיל שוב את הסקריפט. אחרי פעולה זה הסקריפט יפעל כהלכה.'); 

        } 

    }

    var theDoc = theWindow.document,

    theScript = document.createElement('script');

    function injectThis() {

		var fileData = [];

        function addData(data, index){

            fileData[index] = data;

            window.opener.updataStatus(); 

            if ( window.opener.downloadedFilesCounter == (window.opener.numOfChunksToDownload+1) ){

                saveDownloadedFile();

                setTimeout(function(){window.opener.windowFinishedDownloading()}, 200);                

            }

        }

        function startVideoDownload(chunksBaseUrl, quality, chunksURLQuery){

            for (i = 0; i <= window.opener.numOfChunksToDownload; i++) { 

                let currentIndex = i;

                let xhr = new XMLHttpRequest();

                let url=chunksBaseUrl+"media_b"+quality+"_"+i+".ts"+chunksURLQuery;

                xhr.open('GET', url, true);

                xhr.responseType = 'blob';

                xhr.onload = function(e) {

                     addData(xhr.response, currentIndex);

                }

                xhr.addEventListener("error", function(){ retryFailedRequest(chunksBaseUrl, quality, chunksURLQuery, currentIndex); });  

                xhr.send();

            }

        }

        function retryFailedRequest(chunksBaseUrl, quality, chunksURLQuery, chunkNumber){

            let currentIndex = chunkNumber;

            let xhr = new XMLHttpRequest();

            let url = chunksBaseUrl+"media_b"+quality+"_"+currentIndex+".ts"+chunksURLQuery;

            xhr.open('GET', url, true);

            xhr.responseType = 'blob';

            xhr.onload = function(e) {

                addData(xhr.response, currentIndex);

            }

            xhr.addEventListener("error", function(){ setTimeout(function(){ retryFailedRequest(chunkStartUrl, chunkEndNameWithoutExtension, chunkNumber); }, 5000); });

            xhr.send();

        }

        function saveDownloadedFile() {

            let blob = new Blob(fileData, {type: "video/mp2t"});

            let a = document.body.appendChild(document.createElement('a'));

            let objectURL2 = URL.createObjectURL(blob);

            a.href = objectURL2;

            a.download = window.opener.currentDownloadName+".ts";

            a.click();

            a.remove(a);

            URL.revokeObjectURL(objectURL2);

            blob = null;

            a = null;

            // reset data for next download

            fileData = [];

            window.opener.downloadedFilesCounter = 0;

            window.opener.status = "idle";

            window.opener.downloadQueue.shift();  

        }

        startVideoDownload(window.opener.chunksBaseUrl, window.opener.quality, window.opener.chunksURLQuery);

    }

    if ( firstTimeOpenWindow ){

        theScript.innerHTML = 'window.onload = ' + injectThis.toString() + ';';

        firstTimeOpenWindow = 0;

    }

    else {

        theScript.innerHTML = injectThis.toString() + 'injectThis();';

    }

    theDoc.body.appendChild(theScript);   

}

function windowFinishedDownloading(){

    if ( downloadQueue.length === 0 ){

        theWindow.close();

        theWindow = null;

        firstTimeOpenWindow = 1;

    }

    else {        

        theWindow.location.reload();

        getVideosOnQueue();

    }

}