(function () {
    // The constrcutor can be empty or passed in the lrc string
    var Lyricer = function (options) {
        this.divID = "lyricer"; // the default html container id
        this.currentcss = "lyricer-current-line"; // this css for the line current playing
        this.lineidPrefix = "lyricer-line"; // the id prefix for each line
        this.showLines = 8; //lines showing before and after;
        this.clickable = true;
        this.clickEventName = "lyricerclick";
        if( options ) {
            for( var prop in options ) {
                if ( typeof this[prop] != "undefined" && options.hasOwnProperty(prop)) {
                    this[prop] =  options[prop];
                }
            }
        }
    };

    Lyricer.prototype.setLrc = function(rawLrc) {
        this.tags = {};
        this.lrc = [];
        this.rangeLrc = [];

        var tagRegex = /\[([a-z]+):(.*)\].*/;
        var lrcAllRegex = /(\[[0-9.:\[\]]*\])+(.*)/;
        var timeRegex = /\[([0-9]+):([0-9.]+)\]/;
        var timeRegexGim = /\[([0-9]+):([0-9.]+)\]/g;
        var rawLrcArray = rawLrc.split(/[\r\n]/);
        for (var i = 0; i < rawLrcArray.length; i++) {
            // handle tags first
            var tag = tagRegex.exec(rawLrcArray[i]);
            if ( tag && tag[0] ) {
                this.tags[tag[1]] = tag[2];
                continue;
            }
            // handle lrc
            var lrc = lrcAllRegex.exec(rawLrcArray[i]);
            if ( lrc && lrc[0] ) {
                var times = lrc[1].replace(/\]\[/g,"],[").split(",");
                for (var j = 0; j < times.length; j++) {
                    var time = timeRegex.exec(times[j]);
                    if ( time && time[0] ) {
                        this.lrc.push( { "starttime": parseInt(time[1],10) * 60 + parseFloat(time[2]), "line": lrc[2].replace(timeRegexGim,'') } );
                    };
                };
            };
        };

        //sort lrc array
        this.lrc.sort(function (a,b) {
            return a.starttime - b.starttime;
        });

        // crate the range lrc array
        // dummy lines
        for (var i = 0; i < this.showLines; i++) {
            this.rangeLrc.push( { "starttime": -1, "endtime": 0, "line": "&nbsp;" } );
        };
        // real data
        var starttime = 0;
        var line = "";
        for (var i = 0; i < this.lrc.length; i++) {
            endtime =  parseFloat(this.lrc[i].starttime);
            this.rangeLrc.push( { "starttime": starttime, "endtime": endtime, "line": line } );
            starttime = endtime;
            line = this.lrc[i].line;
        };
        this.rangeLrc.push( { "starttime": starttime, "endtime": 999.99, "line": line } );
        // dummy lines
        for (var i = 0; i < this.showLines; i++) {
            this.rangeLrc.push( { "starttime": -1, "endtime": 0, "line": "&nbsp;" } );
        };
        this.totalLines = this.rangeLrc.length;

        // set html and move to start
        setHtml(this);
        this.move(0);
    };

    var setHtml = function(self) {
        self.currentLine = 0;

        var container = document.getElementById(self.divID);
        container.innerHTML = "";
        var ul = document.createElement("ul");
        container.appendChild(ul);
        for (var i = 0; i < self.totalLines; i++) {
            var li = document.createElement("li");
            li.innerHTML = self.rangeLrc[i].line;
            if (!li.innerHTML) {li.innerHTML="&nbsp;"};
            li.setAttribute("id", self.lineidPrefix + i);
            if (self.clickable) {
                li.onclick = lineClicked(self, i);
                li.style.cursor = 'pointer';
            }
            ul.appendChild(li);
        };

        // hide the later ones
        for (var i = self.showLines; i < self.totalLines; i++) {
            document.getElementById(self.lineidPrefix + i).style.display = "none";
        };
    };

    var lineClicked = function(self, id) {
        return function(){
            var detail = {"time": self.rangeLrc[id].starttime};
            var e = new CustomEvent(self.clickEventName, {
                'detail': detail,
                "bubbles": true
            });
            var elem = document.getElementById(self.lineidPrefix + id);
            elem.dispatchEvent(e);
        };
    };


    Lyricer.prototype.move = function(time) {
        for (var i = 0; i < this.totalLines; i++) {
            if (time >= this.rangeLrc[i].starttime && time < this.rangeLrc[i].endtime) {
                this.currentLine = i;
                moveToLine(this,this.currentLine);
                return;
            };
        };
    };

    var moveToLine = function (self, line) {
        var startShow = line - self.showLines;
        var endShow = line + self.showLines;
        for (var i = 0; i < self.totalLines; i++) {
            var li = document.getElementById(self.lineidPrefix + i);
            if ( i >= startShow && i <= endShow ) {
                li.style.display = "block";
            } else{
                li.style.display = "none";
            };
            if (i==line) {
                li.className = self.currentcss;
            } else {
                li.className = "";
            };
        };
    };

    window.Lyricer = Lyricer; //exposed to global

})();