// polyfill indexOf for IE8
if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function(elt /*, from*/) {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++) {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

HTMLWidgets.widget({

  name: "dygraphs",

  type: "output",

  factory: function(el, width, height) {
    
    // reference to dygraph
    var dygraph = null;
    
    // reference to widget global groups
    var groups = this.groups;
 
    // add qt style if we are running under Qt
    if (window.navigator.userAgent.indexOf(" Qt/") > 0)
      el.className += " qt";
    
    return {
      
      renderValue: function(x) {
        
        // reference to this for closures
        var thiz = this;
        
        // get dygraph attrs and populate file field
        var attrs = x.attrs;
        attrs.file = x.data;
        
        // convert non-arrays to arrays
        for (var index = 0; index < attrs.file.length; index++) {
          if (!$.isArray(attrs.file[index]))
            attrs.file[index] = [].concat(attrs.file[index]);
        }
            
        // resolve "auto" legend behavior
        if (x.attrs.legend == "auto") {
          if (x.data.length <= 2)
            x.attrs.legend = "onmouseover";
          else
            x.attrs.legend = "always";
        }
        
        if (x.format == "date") {
          
          // set appropriated function in case of fixed tz
          if ((attrs.axes.x.axisLabelFormatter === undefined) && x.fixedtz)
            attrs.axes.x.axisLabelFormatter = this.xAxisLabelFormatterFixedTZ(x.tzone);
            
          if ((attrs.axes.x.valueFormatter === undefined) && x.fixedtz)
            attrs.axes.x.valueFormatter = this.xValueFormatterFixedTZ(x.scale, x.tzone);
      
          if ((attrs.axes.x.ticker === undefined) && x.fixedtz)
            attrs.axes.x.ticker = this.customDateTickerFixedTZ(x.tzone);
        
          // provide an automatic x value formatter if none is already specified
          if ((attrs.axes.x.valueFormatter === undefined) && (x.fixedtz != true))
            attrs.axes.x.valueFormatter = this.xValueFormatter(x.scale);
          
          // convert time to js time
          attrs.file[0] = attrs.file[0].map(function(value) {
            return thiz.normalizeDateValue(x.scale, value, x.fixedtz);
          });
          if (attrs.dateWindow != null) {
            attrs.dateWindow = attrs.dateWindow.map(function(value) {
              var date = thiz.normalizeDateValue(x.scale, value, x.fixedtz);
              return date.getTime();
            });
          }
        }
        
        
        // transpose array
        attrs.file = HTMLWidgets.transposeArray2D(attrs.file);
        
        // add drawCallback for group
        if (x.group != null)
          this.addGroupDrawCallback(x);  
          
        // add shading and event callback if necessary
        this.addShadingCallback(x);
        this.addEventCallback(x);
        this.addZoomCallback(x);
        
        // disable y-axis touch events on mobile phones
        if (attrs.mobileDisableYTouch !== false && this.isMobilePhone()) {
          // create default interaction model if necessary
          if (!attrs.interactionModel)
            attrs.interactionModel = Dygraph.Interaction.defaultModel;
          // disable y touch direction
          attrs.interactionModel.touchstart = function(event, dygraph, context) {
            Dygraph.defaultInteractionModel.touchstart(event, dygraph, context);
            context.touchDirections = { x: true, y: false };
          };
        }
    
        // create plugins
        if (x.plugins) {
          attrs.plugins = [];
          for (var plugin in x.plugins) {
            if (x.plugins.hasOwnProperty(plugin)) {
              
              // get plugin options
              var options = x.plugins[plugin];
              
              // create plugin and add to dygraph
              var p = new Dygraph.Plugins[plugin](options);
              attrs.plugins.push(p);
            }
          }
        }
    
        // if there is no existing dygraph perform initialization
        if (!dygraph) {
          
          // subscribe to custom shown event (fired by ioslides to trigger
          // shiny reactivity but we can use it as well). this is necessary
          // because if a dygraph starts out as display:none it has height
          // and width == 0 and this doesn't change when it becomes visible
          $(el).closest('slide').on('shown', function() {
            if (dygraph)
              dygraph.resize();  
          });
          
          // do the same for reveal.js
          $(el).closest('section.slide').on('shown', function() {
            if (dygraph)
              dygraph.resize();  
          });
          
          // redraw on R Markdown {.tabset} tab visibility changed
          var tab = $(el).closest('div.tab-pane');
          if (tab !== null) {
            var tabID = tab.attr('id');
            var tabAnchor = $('a[data-toggle="tab"][href="#' + tabID + '"]');
            if (tabAnchor !== null) {
              tabAnchor.on('shown.bs.tab', function() {
                if (dygraph)
                  dygraph.resize();  
              });
            }
          }
          // add default font for viewer mode
          if (this.queryVar("viewer_pane") === "1")
            document.body.style.fontFamily = "Arial, sans-serif";
    
          // inject css if necessary
          if (x.css != null) {
            var style = document.createElement('style');
            style.type = 'text/css';
            if (style.styleSheet) 
              style.styleSheet.cssText = x.css;
            else 
              style.appendChild(document.createTextNode(x.css));
            document.getElementsByTagName("head")[0].appendChild(style);
          }
          
        } else {
          
            // retain the userDateWindow if requested
            if (dygraph.userDateWindow != null
                && attrs.retainDateWindow == true) {
              attrs.dateWindow = dygraph.xAxisRange();
            }
                
            // remove it from groups if it's there
            if (x.group != null && groups[x.group] != null) {
              var index = groups[x.group].indexOf(dygraph);
              if (index != -1)
                groups[x.group].splice(index, 1);
            }
            
            // destroy the existing dygraph 
            dygraph.destroy();
            dygraph = null;
        }
        
        // create the dygraph and add it to it's group (if any)
        dygraph = new Dygraph(el, attrs.file, attrs);
        dygraph.userDateWindow = attrs.dateWindow;
        if (x.group != null)
          groups[x.group].push(dygraph);
        
        // add shiny input for date window
        if (HTMLWidgets.shinyMode)
          this.addDateWindowShinyInput(el.id, x);
        
        // set annotations
        if (x.annotations != null) {
          dygraph.ready(function() {
            if (x.format == "date") {
              x.annotations.map(function(annotation) {
                var date = thiz.normalizeDateValue(x.scale, annotation.x, x.fixedtz);
                annotation.x = date.getTime();
              });
            }
            dygraph.setAnnotations(x.annotations);
          }); 
        }
          
      },
      
      customDateTickerFixedTZ : function(tz){
        return function(t,e,a,i,r) {   
          var a=Dygraph.pickDateTickGranularity(t,e,a,i);
          if(a >= 0){
            
            var n=i("axisLabelFormatter"),
            o=i("labelsUTC"),
            s=o?Dygraph.DateAccessorsUTC:Dygraph.DateAccessorsLocal;
            l=Dygraph.TICK_PLACEMENT[a].datefield;
            h=Dygraph.TICK_PLACEMENT[a].step;
            p=Dygraph.TICK_PLACEMENT[a].spacing;
            
            var y = [];
            var d = moment(t);
            d.tz(tz); 
            d.millisecond(0);
          
            if(l > Dygraph.DATEFIELD_M){
              var x;
              if (l === Dygraph.DATEFIELD_SS) {  // seconds 
                x = d.second();         
                d.second(x - x % h);     
              } else if(l === Dygraph.DATEFIELD_MM){
                d.second(0)
                x = d.minute();
                d.minute(x - x % h);
              } else if(l === Dygraph.DATEFIELD_HH){
                d.second(0);
                d.minute(0);
                x = d.hour();
                d.hour(x - x % h);
              } else if(l === Dygraph.DATEFIELD_D){
                d.second(0);
                d.minute(0);
                d.hour(0);
                if (h == 7) {  // one week
                    d.startOf('week');
                }
              }
              
              v = d.valueOf();
              _=moment(v).tz(tz);
            
              // For spacings coarser than two-hourly, we want to ignore daylight
              // savings transitions to get consistent ticks. For finer-grained ticks,
              // it's essential to show the DST transition in all its messiness.
              var start_offset_min = moment(v).tz(tz).zone();
              var check_dst = (p >= Dygraph.TICK_PLACEMENT[Dygraph.TWO_HOURLY].spacing);
              
    	        if(a<=Dygraph.HOURLY){
    		        for(t>v&&(v+=p,_=moment(v).tz(tz));e>=v;){
    			        y.push({v:v,label:n(_,a,i,r)});
    			        v+=p;
    			        _=moment(v).tz(tz);
    		        }
    	        }else{
                for(t>v&&(v+=p,_=moment(v).tz(tz));e>=v;){  
                
                  // This ensures that we stay on the same hourly "rhythm" across
                  // daylight savings transitions. Without this, the ticks could get off
                  // by an hour. See tests/daylight-savings.html or issue 147.
                  if (check_dst && _.zone() != start_offset_min) {
                    var delta_min = _.zone() - start_offset_min;
                    v += delta_min * 60 * 1000;
                    _= moment(v).tz(tz);
                    start_offset_min = _.zone();
    
                    // Check whether we've backed into the previous timezone again.
                    // This can happen during a "spring forward" transition. In this case,
                    // it's best to skip this tick altogether (we may be shooting for a
                    // non-existent time like the 2AM that's skipped) and go to the next
                    // one.
                    if (moment(v + p).tz(tz).zone() != start_offset_min) {
                      v += p;
                      _= moment(v).tz(tz);
                      start_offset_min = _.zone();
                    }
                  }
                
                  (a>=Dygraph.DAILY||_.get('hour')%h===0)&&y.push({v:v,label:n(_,a,i,r)});
    			        v+=p;
    			        _=moment(v).tz(tz);
    		        }
    	        }
    	      }else{
              var start_year = moment(t).tz(tz).year();
              var end_year   = moment(e).tz(tz).year();
              var start_month = moment(t).tz(tz).month();
              
              if(l === Dygraph.DATEFIELD_M){
                var step_month = h;
                for (var ii = start_year; ii <= end_year; ii++) {
                  for (var j = 0; j < 12;) {
                    var dt = moment(new Date(ii, j, 1)).tz(tz); 
                    // fix some tz bug
                    dt.year(ii);
                    dt.month(j);
                    dt.date(1);
                    dt.hour(0);
                    v = dt.valueOf();
                    y.push({v:v,label:n(moment(v).tz(tz),a,i,r)});
                    j+=step_month;
                  }
                }
              }else{
                var step_year = h;
                for (var ii = start_year; ii <= end_year;) {
                  var dt = moment(new Date(ii, 1, 1)).tz(tz); 
                  // fix some tz bug
                  dt.year(ii);
                  dt.month(j);
                  dt.date(1);
                  dt.hour(0);
                  v = dt.valueOf();
                  y.push({v:v,label:n(moment(v).tz(tz),a,i,r)});
                  ii+=step_year;
                }
              }
    	      }
    	      return y;
    	    }else{
           return []; 
    	    }
        };
      },
    
      xAxisLabelFormatterFixedTZ : function(tz){
      
        return function dateAxisFormatter(date, granularity){
          var mmnt = moment(date).tz(tz);
          if (granularity >= Dygraph.DECADAL){
            return mmnt.format('YYYY');
          }else{
            if(granularity >= Dygraph.MONTHLY){
              return mmnt.format('MMM YYYY');
            }else{
              var frac = mmnt.hour() * 3600 + mmnt.minute() * 60 + mmnt.second() + mmnt.millisecond();
                if (frac === 0 || granularity >= Dygraph.DAILY) {
                  return mmnt.format('DD MMM');
                } else {
                 if (mmnt.second()) {
                   return mmnt.format('HH:mm:ss');
                 } else {
                   return mmnt.format('HH:mm');
                 }
                }
             } 
                            
           }         
       }
      },
             
      xValueFormatterFixedTZ: function(scale, tz) {
                       
        return function(millis) {
          var mmnt = moment(millis).tz(tz);
            if (scale == "yearly")
              return mmnt.format('YYYY') + ' (' + mmnt.zoneAbbr() + ')';
            else if (scale == "monthly" || scale == "quarterly")
              return mmnt.format('MMM, YYYY')+ ' (' + mmnt.zoneAbbr() + ')';
            else if (scale == "daily" || scale == "weekly")
              return mmnt.format('MMM, DD, YYYY')+ ' (' + mmnt.zoneAbbr() + ')';
            else
              return mmnt.format('dddd, MMMM DD, YYYY HH:mm:ss')+ ' (' + mmnt.zoneAbbr() + ')';
        }
      },
      
      xValueFormatter: function(scale) {
        
        var monthNames = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", 
                          "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
                          
        return function(millis) {
          var date = new Date(millis);
            if (scale == "yearly")
              return date.getFullYear();
            else if (scale == "monthly" || scale == "quarterly")
              return monthNames[date.getMonth()] + ', ' + date.getFullYear(); 
            else if (scale == "daily" || scale == "weekly")
              return monthNames[date.getMonth()] + ', ' + 
                               date.getDate() + ', ' + 
                               date.getFullYear();
            else
              return date.toLocaleString();
        }
      },
      
      addZoomCallback: function(x) {
        
        // alias this
        var thiz = this;
        
        // get attrs
        var attrs = x.attrs;
        
        // check for an existing zoomCallback
        var prevZoomCallback = attrs["zoomCallback"];
        
        attrs.zoomCallback = function(minDate, maxDate, yRanges) {
          
          // call existing
          if (prevZoomCallback)
            prevZoomCallback(minDate, maxDate, yRanges);
            
          // record user date window (or lack thereof)
          if (dygraph.xAxisExtremes()[0] != minDate ||
              dygraph.xAxisExtremes()[1] != maxDate) {
             dygraph.userDateWindow = [minDate, maxDate];
          } else {
             dygraph.userDateWindow = null;
          }
          
          // record in group if necessary
          if (x.group != null && groups[x.group] != null) {
            var group = groups[x.group];
            for(var i = 0; i<group.length; i++)
              group[i].userDateWindow = dygraph.userDateWindow;
          }
        };
      },
      
      addGroupDrawCallback: function(x) {
        
        // get attrs
        var attrs = x.attrs;
        
        // check for an existing drawCallback
        var prevDrawCallback = attrs["drawCallback"];
        
        groups[x.group] = groups[x.group] || [];
        var group = groups[x.group];
        var blockRedraw = false;
        attrs.drawCallback = function(me, initial) {
          
          // call existing
          if (prevDrawCallback)
            prevDrawCallback(me, initial);
          
          // sync peers in group
          if (blockRedraw || initial) return;
          blockRedraw = true;
          var range = dygraph.xAxisRange();
          for (var j = 0; j < group.length; j++) {
            if (group[j] == me) continue;
            // update group range only if it's different (prevents
            // infinite recursion in updateOptions)
            var peerRange = group[j].xAxisRange();
            if (peerRange[0] != range[0] || peerRange[1] != range[1]) {
              group[j].updateOptions({
                dateWindow: range
              });
            }
          }
          blockRedraw = false;
        };
      },
      
      addShadingCallback: function(x) {
        
        // bail if no shadings
        if (x.shadings.length == 0)
          return;
        
        // alias this
        var thiz = this;
        
        // get attrs
        var attrs = x.attrs;
        
        // check for an existing underlayCallback
        var prevUnderlayCallback = attrs["underlayCallback"];
        
        // install callback
        attrs.underlayCallback = function(canvas, area, g) {
          
          // call existing
          if (prevUnderlayCallback)
            prevUnderlayCallback(canvas, area, g);
            
          for (var i = 0; i < x.shadings.length; i++) {
            var shading = x.shadings[i];
            canvas.save();
            canvas.fillStyle = shading.color;
            if (shading.axis == "x") {
              var x1 = shading.from;
              var x2 = shading.to;
              if (x.format == "date") {
                x1 = thiz.normalizeDateValue(x.scale, x1, x.fixedtz).getTime();
                x2 = thiz.normalizeDateValue(x.scale, x2, x.fixedtz).getTime();
              }
              var left = g.toDomXCoord(x1);
              var right = g.toDomXCoord(x2);
              
              canvas.fillRect(left, area.y, right - left, area.h);
            } else if (shading.axis == "y") {
              var bottom = g.toDomYCoord(shading.from);
              var top = g.toDomYCoord(shading.to);
    
              canvas.fillRect(area.x, bottom, area.w, top - bottom);
            }
            canvas.restore();
          }
        };
      },
      
      addEventCallback: function(x) {
        
        // bail if no evets
        if (x.events.length == 0)
          return;
        
        // alias this
        var thiz = this;
        
        // get attrs
        var attrs = x.attrs;
        
        // check for an existing underlayCallback
        var prevUnderlayCallback = attrs["underlayCallback"];
        
        // install callback
        attrs.underlayCallback = function(canvas, area, g) {
          
          // call existing
          if (prevUnderlayCallback)
            prevUnderlayCallback(canvas, area, g);
            
          for (var i = 0; i < x.events.length; i++) {
            
            // get event and x-coordinate
            var event = x.events[i];
            
            // draw line
            canvas.save();
            canvas.strokeStyle = event.color;
            if (event.axis == "x") {
              var xPos;
              if (jQuery.isNumeric(event.pos)) {
                xPos = g.toDomXCoord(event.pos);
              } else {
                xPos = thiz.normalizeDateValue(x.scale, event.pos, x.fixedtz).getTime();
                xPos = g.toDomXCoord(xPos);
              }
              
              // draw line
              thiz.dashedLine(canvas, 
                              xPos, 
                              area.y, 
                              xPos, 
                              area.y + area.h,
                              event.strokePattern);
            } else if (event.axis == "y") {
              yPos = g.toDomYCoord(event.pos);
              
              thiz.dashedLine(canvas, 
                              area.x, 
                              yPos, 
                              area.x + area.w, 
                              yPos,
                              event.strokePattern);
            }
            canvas.restore();
            
            // draw label
            if (event.label != null) {
              canvas.save();
              thiz.setFontSize(canvas, 12);
              var size = canvas.measureText(event.label);
              if (event.axis == "x") {
                var tx = xPos - 4;
                var ty;
                if (event.labelLoc == "top")
                  ty = area.y + size.width + 10;
                else
                  ty = area.y + area.h - 10;
                canvas.translate(tx, ty);
                canvas.rotate(3 * Math.PI / 2);
                canvas.translate(-tx,-ty);
              } else if (event.axis == "y") {
                var ty = yPos - 4;
                var tx;
                if (event.labelLoc == "right")
                  tx = area.x + area.w - size.width - 10;
                else
                  tx = area.x + 10;
              }
              canvas.fillStyle = event.color;
              canvas.fillText(event.label, tx, ty);
              canvas.restore();
            }
          }
        };
      },
      
      addDateWindowShinyInput: function(id, x) {
          
        // check for an existing drawCallback
        var prevDrawCallback = x.attrs["drawCallback"];
        
        // install the callback
        x.attrs.drawCallback = function(me, initial) {
          
          // call existing
          if (prevDrawCallback)
            prevDrawCallback(me, initial);
            
          // fire input change
          var range = dygraph.xAxisRange();
          var dateWindow = [new Date(range[0]), new Date(range[1])];
          Shiny.onInputChange(id + "_date_window", dateWindow); 
        };
      },
      
      // Add dashed line support to canvas rendering context
      // See: http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas
      dashedLine: function(canvas, x, y, x2, y2, dashArray) {
        canvas.beginPath();
        if (!dashArray) dashArray=[10,5];
        if (dashLength==0) dashLength = 0.001; // Hack for Safari
        var dashCount = dashArray.length;
        canvas.moveTo(x, y);
        var dx = (x2-x), dy = (y2-y);
        var slope = dx ? dy/dx : 1e15;
        var distRemaining = Math.sqrt( dx*dx + dy*dy );
        var dashIndex=0, draw=true;
        while (distRemaining>=0.1){
          var dashLength = dashArray[dashIndex++%dashCount];
          if (dashLength > distRemaining) dashLength = distRemaining;
          var xStep = Math.sqrt( dashLength*dashLength / (1 + slope*slope) );
          if (dx<0) xStep = -xStep;
          x += xStep
          y += slope*xStep;
          canvas[draw ? 'lineTo' : 'moveTo'](x,y);
          distRemaining -= dashLength;
          draw = !draw;
        }
        canvas.stroke();
      },
      
      setFontSize: function(canvas, size) {
        var cFont = canvas.font;
        var parts = cFont.split(' ');
        if (parts.length === 2)
          canvas.font = size + 'px ' + parts[1];
        else if (parts.length === 3)
          canvas.font = parts[0] + ' ' + size + 'px ' + parts[2];
      },
      
      // Returns the value of a GET variable
      queryVar: function(name) {
        return decodeURI(window.location.search.replace(
          new RegExp("^(?:.*[&\\?]" +
                     encodeURI(name).replace(/[\.\+\*]/g, "\\$&") +
                     "(?:\\=([^&]*))?)?.*$", "i"),
          "$1"));
      },
      
      // We deal exclusively in UTC dates within R, however dygraphs deals 
      // exclusively in the local time zone. Therefore, in order to plot date
      // labels that make sense to the user when we are dealing with days,
      // months or years we need to convert the UTC date value to a local time
      // value that "looks like" the equivilant UTC value. To do this we add the
      // timezone offset to the UTC date.
      // Don't use in case of fixedtz
      normalizeDateValue: function(scale, value, fixedtz) {
        var date = new Date(value); 
        if (scale != "minute" && scale != "hourly" && scale != "seconds" && !fixedtz) {
          var localAsUTC = date.getTime() + (date.getTimezoneOffset() * 60000);
          date = new Date(localAsUTC);
        }
        return date;
      },
      
      // safely detect rendering on a mobile phone
      isMobilePhone: function() {
        try
        {
          return ! window.matchMedia("only screen and (min-width: 768px)").matches;
        }
        catch(e) {
          return false;
        }
      },
        
      
      resize: function(width, height) {
        if (dygraph)
          dygraph.resize();
      },
      
      // export dygraph so other code can get a hold of it
      dygraph: dygraph
    
    };
  },
  
  // track groups globally
  groups: {}
  
});