/*
* slideCastController.js
* © by pschne2s, nkopp2s, 2012
*
* Basically encapsulates the Media Player Object, handling the function of the HTML5-Player
*/

/****************************OBJECT DEFINITION***********************************/

CanvasRenderingContext2D.prototype.clear = CanvasRenderingContext2D.prototype.clear ||
function(preserveTransform) {
    if (preserveTransform) {
        this.save();
        this.setTransform(1, 0, 0, 1, 0, 0);
    }

    this.clearRect(0, 0, this.canvas.width, this.canvas.height);

    if (preserveTransform) {
        this.restore();
    }
};

var mediaPlayer = (function() {
    //Members
    var _cueIdx = 0;
    var _cues = [];
    var _target;
    var _track;
    var _readyToPlay = false;
    var _currImgSrc;

    function setupCues() {
        if (_readyToPlay) {
            if (_track === undefined) {
                // var trackElements = document.getElementById("audioTrack");
                var trackElements = $(_target).children("track")[0];
                _track = trackElements.track;
            }
            _cues = _track.cues;

            $("#maxcues").text(_cues.length - 1);
            for (var j = 0; j < _cues.length; ++j) {
                var cue = _cues[j];
                cue.onenter = getOnEnter(j);
            }

            _track.oncuechange = function() {
                //updateURL(mediaPlayerInfo.cueIdx);
            };

            checkFragments();
        } else {
            setTimeout(setupCues, 1);
        }
    };

    function getOnEnter(idx) {
        return function() {
            setCueIdx(idx);
            updateURL(idx);
            var json = JSON.parse(this.text);

            _currImgSrc = json.src;
            drawIt();
        }
    };

    function drawIt() {
        var ctx = $("#slide")[0].getContext('2d');
        ctx.clear();

        var tmpImg = new Image();
        tmpImg.onload = function() {
            ctx.drawImage(tmpImg, 0, 0,592,256);
        }

        tmpImg.src = _currImgSrc;

    }

    function checkFragments() {
        var fragments = purl(window.document.URL);
        var slide = fragments.fparam("slide");
        if (slide !== undefined) {
            gotoCue(slide);
        }
        var action = fragments.fparam("action");
        if (action == "play") {
            _target.play();
        }
    };

    function setCueIdx(idx) {
        //alert("Cue idx set to: " + idx);
        _cueIdx = idx;
        $("#cueidx").text(idx);
    };

    function gotoCue(index) {
        if (index >= 0 && index < _cues.length) {
            _cueIdx = index;
            var audioElement = $("#audiocast").get(0);
            //mediaPlayerInfo.cues[mediaPlayerInfo.cueIdx].onenter();
            audioElement.currentTime = _cues[index].startTime;
        }
    };

    var updateURL = (function() {
        // set Base-URL (without query/hash-String)
        var url = location.protocol + "//" + location.host + location.pathname;
        var html5 = window.history.replaceState !== undefined ? true : false;

        return function(slideIdx) {
            if (html5)
                window.history.replaceState(null, document.title + " | Slide #" + slideIdx, url + "#slide=" + slideIdx);
            else
                location.href = url + "#slide=" + slideIdx;
            // No nice browser history
        };
    })();

    return {
        init : function() {
            setupCues();
        },
        setTarget : function(obj) {
            _target = obj;
        },
        setTrack : function(obj) {
            _track = obj;
        },
        setReadyToPlay : function() {
            _readyToPlay = true;
        },
        gotoNextCue : function() {
            gotoCue(_cueIdx + 1);
        },
        gotoPrevCue : function() {
            gotoCue(_cueIdx - 1);
        }
    };
})();

$(document).ready(function() {
    // "Unobstrusive" Function-Bindings
    $("#btnPrevCue").bind("click", mediaPlayer.gotoPrevCue);
    $("#btnNextCue").bind("click", mediaPlayer.gotoNextCue);

    mediaPlayer.setTarget($("#audiocast")[0]);
    mediaPlayer.init();
});

window.setReadyToPlay = mediaPlayer.setReadyToPlay;
// does not work using other ways atm