
nv.models.multiBarHorizontal = function() {
  "use strict";
  //============================================================
  // Public Variables with Default Settings
  //------------------------------------------------------------

  var margin = {top: 0, right: 0, bottom: 0, left: 0}
    , width = 960
    , height = 500
    , id = Math.floor(Math.random() * 10000) //Create semi-unique ID in case user doesn't select one
    , x = d3.scale.ordinal()
    , y = d3.scale.linear()
    , getX = function(d) { return d.x }
    , getY = function(d) { return d.y }
    , forceY = [0] // 0 is forced by default.. this makes sense for the majority of bar graphs... user can always do chart.forceY([]) to remove
    , color = nv.utils.defaultColor()
    , barColor = null // adding the ability to set the color for each rather than the whole group
    , disabled // used in conjunction with barColor to communicate from multiBarHorizontalChart what series are disabled
    , stacked = false
    , showValues = false
    , showBarLabels = false
    , valuePadding = 60
    , valueFormat = d3.format(',.2f')
    , delay = 1200
    , xDomain
    , yDomain
    , xRange
    , yRange
    , dispatch = d3.dispatch('chartClick', 'elementClick', 'elementDblClick', 'elementMouseover', 'elementMouseout')
    ;

  //============================================================


  //============================================================
  // Private Variables
  //------------------------------------------------------------

  var x0, y0 //used to store previous scales
      ;

  //============================================================


  function chart(selection) {
    selection.each(function(data) {
      var availableWidth = width - margin.left - margin.right,
          availableHeight = height - margin.top - margin.bottom,
          container = d3.select(this);


      if (stacked)
        data = d3.layout.stack()
                 .offset('zero')
                 .values(function(d){ return d.values })
                 .y(getY)
                 (data);


      //add series index to each data point for reference
      data.forEach(function(series, i) {
        series.values.forEach(function(point) {
          point.series = i;
        });
      });


      //------------------------------------------------------------
      // HACK for negative value stacking
      if (stacked)
        data[0].values.map(function(d,i) {
          var posBase = 0, negBase = 0;
          data.map(function(d) {
            var f = d.values[i]
            f.size = Math.abs(f.y);
            if (f.y<0)  {
              f.y1 = negBase - f.size;
              negBase = negBase - f.size;
            } else
            {
              f.y1 = posBase;
              posBase = posBase + f.size;
            }
          });
        });


      //------------------------------------------------------------
      // Setup Scales

      // remap and flatten the data for use in calculating the scales' domains
      var seriesData = (xDomain && yDomain) ? [] : // if we know xDomain and yDomain, no need to calculate
            data.map(function(d) {
              return d.values.map(function(d,i) {
                return { x: getX(d,i), y: getY(d,i), y0: d.y0, y1: d.y1 }
              })
            });

      x   .domain(xDomain || d3.merge(seriesData).map(function(d) { return d.x }))
          .rangeBands(xRange || [0, availableHeight], .1);

      //y   .domain(yDomain || d3.extent(d3.merge(seriesData).map(function(d) { return d.y + (stacked ? d.y0 : 0) }).concat(forceY)))
      y   .domain(yDomain || d3.extent(d3.merge(seriesData).map(function(d) { return stacked ? (d.y > 0 ? d.y1 + d.y : d.y1 ) : d.y }).concat(forceY)))

      if (showValues && !stacked)
        y.range(yRange || [(y.domain()[0] < 0 ? valuePadding : 0), availableWidth - (y.domain()[1] > 0 ? valuePadding : 0) ]);
      else
        y.range(yRange || [0, availableWidth]);

      x0 = x0 || x;
      y0 = y0 || d3.scale.linear().domain(y.domain()).range([y(0),y(0)]);

      //------------------------------------------------------------


      //------------------------------------------------------------
      // Setup containers and skeleton of chart

      var wrap = d3.select(this).selectAll('g.nv-wrap.nv-multibarHorizontal').data([data]);
      var wrapEnter = wrap.enter().append('g').attr('class', 'nvd3 nv-wrap nv-multibarHorizontal');
      var defsEnter = wrapEnter.append('defs');
      var gEnter = wrapEnter.append('g');
      var g = wrap.select('g');

      gEnter.append('g').attr('class', 'nv-groups');

      wrap.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');

      //------------------------------------------------------------


      var groups = wrap.select('.nv-groups').selectAll('.nv-group')
          .data(function(d) { return d }, function(d,i) { return i });
      groups.enter().append('g')
          .style('stroke-opacity', 1e-6)
          .style('fill-opacity', 1e-6);
      groups.exit().transition()
          .style('stroke-opacity', 1e-6)
          .style('fill-opacity', 1e-6)
          .remove();
      groups
          .attr('class', function(d,i) { return 'nv-group nv-series-' + i })
          .classed('hover', function(d) { return d.hover })
          .style('fill', function(d,i){ return color(d, i) })
          .style('stroke', function(d,i){ return color(d, i) });
      groups.transition()
          .style('stroke-opacity', 1)
          .style('fill-opacity', .75);


      var bars = groups.selectAll('g.nv-bar')
          .data(function(d) { return d.values });

      bars.exit().remove();


      var barsEnter = bars.enter().append('g')
          .attr('transform', function(d,i,j) {
              return 'translate(' + y0(stacked ? d.y0 : 0) + ',' + (stacked ? 0 : (j * x.rangeBand() / data.length ) + x(getX(d,i))) + ')'
          });

      barsEnter.append('rect')
          .attr('width', 0)
          .attr('height', x.rangeBand() / (stacked ? 1 : data.length) )

      bars
          .on('mouseover', function(d,i) { //TODO: figure out why j works above, but not here
            d3.select(this).classed('hover', true);
            dispatch.elementMouseover({
              value: getY(d,i),
              point: d,
              series: data[d.series],
              pos: [ y(getY(d,i) + (stacked ? d.y0 : 0)), x(getX(d,i)) + (x.rangeBand() * (stacked ? data.length / 2 : d.series + .5) / data.length) ],
              pointIndex: i,
              seriesIndex: d.series,
              e: d3.event
            });
          })
          .on('mouseout', function(d,i) {
            d3.select(this).classed('hover', false);
            dispatch.elementMouseout({
              value: getY(d,i),
              point: d,
              series: data[d.series],
              pointIndex: i,
              seriesIndex: d.series,
              e: d3.event
            });
          })
          .on('click', function(d,i) {
            dispatch.elementClick({
              value: getY(d,i),
              point: d,
              series: data[d.series],
              pos: [x(getX(d,i)) + (x.rangeBand() * (stacked ? data.length / 2 : d.series + .5) / data.length), y(getY(d,i) + (stacked ? d.y0 : 0))],  // TODO: Figure out why the value appears to be shifted
              pointIndex: i,
              seriesIndex: d.series,
              e: d3.event
            });
            d3.event.stopPropagation();
          })
          .on('dblclick', function(d,i) {
            dispatch.elementDblClick({
              value: getY(d,i),
              point: d,
              series: data[d.series],
              pos: [x(getX(d,i)) + (x.rangeBand() * (stacked ? data.length / 2 : d.series + .5) / data.length), y(getY(d,i) + (stacked ? d.y0 : 0))],  // TODO: Figure out why the value appears to be shifted
              pointIndex: i,
              seriesIndex: d.series,
              e: d3.event
            });
            d3.event.stopPropagation();
          });


      barsEnter.append('text');

      if (showValues && !stacked) {
        bars.select('text')
            .attr('text-anchor', function(d,i) { return getY(d,i) < 0 ? 'end' : 'start' })
            .attr('y', x.rangeBand() / (data.length * 2))
            .attr('dy', '.32em')
            .text(function(d,i) { return valueFormat(getY(d,i)) })
        bars.transition()
          .select('text')
            .attr('x', function(d,i) { return getY(d,i) < 0 ? -4 : y(getY(d,i)) - y(0) + 4 })
      } else {
        bars.selectAll('text').text('');
      }

      if (showBarLabels && !stacked) {
        barsEnter.append('text').classed('nv-bar-label',true);
        bars.select('text.nv-bar-label')
            .attr('text-anchor', function(d,i) { return getY(d,i) < 0 ? 'start' : 'end' })
            .attr('y', x.rangeBand() / (data.length * 2))
            .attr('dy', '.32em')
            .text(function(d,i) { return getX(d,i) });
        bars.transition()
          .select('text.nv-bar-label')
            .attr('x', function(d,i) { return getY(d,i) < 0 ? y(0) - y(getY(d,i)) + 4 : -4 });
      }
      else {
        bars.selectAll('text.nv-bar-label').text('');
      }

      bars
          .attr('class', function(d,i) { return getY(d,i) < 0 ? 'nv-bar negative' : 'nv-bar positive'})

      if (barColor) {
        if (!disabled) disabled = data.map(function() { return true });
        bars
          .style('fill', function(d,i,j) { return d3.rgb(barColor(d,i)).darker(  disabled.map(function(d,i) { return i }).filter(function(d,i){ return !disabled[i]  })[j]   ).toString(); })
          .style('stroke', function(d,i,j) { return d3.rgb(barColor(d,i)).darker(  disabled.map(function(d,i) { return i }).filter(function(d,i){ return !disabled[i]  })[j]   ).toString(); });
      }

      if (stacked)
        bars.transition()
            .attr('transform', function(d,i) {
              return 'translate(' + y(d.y1) + ',' + x(getX(d,i)) + ')'
            })
          .select('rect')
            .attr('width', function(d,i) {
              return Math.abs(y(getY(d,i) + d.y0) - y(d.y0))
            })
            .attr('height', x.rangeBand() );
      else
        bars.transition()
            .attr('transform', function(d,i) {
              //TODO: stacked must be all positive or all negative, not both?
              return 'translate(' +
              (getY(d,i) < 0 ? y(getY(d,i)) : y(0))
              + ',' +
              (d.series * x.rangeBand() / data.length
              +
              x(getX(d,i)) )
              + ')'
            })
          .select('rect')
            .attr('height', x.rangeBand() / data.length )
            .attr('width', function(d,i) {
              return Math.max(Math.abs(y(getY(d,i)) - y(0)),1)
            });


      //store old scales for use in transitions on update
      x0 = x.copy();
      y0 = y.copy();

    });

    return chart;
  }


  //============================================================
  // Expose Public Variables
  //------------------------------------------------------------

  chart.dispatch = dispatch;

  chart.options = nv.utils.optionsFunc.bind(chart);

  chart.x = function(_) {
    if (!arguments.length) return getX;
    getX = _;
    return chart;
  };

  chart.y = function(_) {
    if (!arguments.length) return getY;
    getY = _;
    return chart;
  };

  chart.margin = function(_) {
    if (!arguments.length) return margin;
    margin.top    = typeof _.top    != 'undefined' ? _.top    : margin.top;
    margin.right  = typeof _.right  != 'undefined' ? _.right  : margin.right;
    margin.bottom = typeof _.bottom != 'undefined' ? _.bottom : margin.bottom;
    margin.left   = typeof _.left   != 'undefined' ? _.left   : margin.left;
    return chart;
  };

  chart.width = function(_) {
    if (!arguments.length) return width;
    width = _;
    return chart;
  };

  chart.height = function(_) {
    if (!arguments.length) return height;
    height = _;
    return chart;
  };

  chart.xScale = function(_) {
    if (!arguments.length) return x;
    x = _;
    return chart;
  };

  chart.yScale = function(_) {
    if (!arguments.length) return y;
    y = _;
    return chart;
  };

  chart.xDomain = function(_) {
    if (!arguments.length) return xDomain;
    xDomain = _;
    return chart;
  };

  chart.yDomain = function(_) {
    if (!arguments.length) return yDomain;
    yDomain = _;
    return chart;
  };

  chart.xRange = function(_) {
    if (!arguments.length) return xRange;
    xRange = _;
    return chart;
  };

  chart.yRange = function(_) {
    if (!arguments.length) return yRange;
    yRange = _;
    return chart;
  };

  chart.forceY = function(_) {
    if (!arguments.length) return forceY;
    forceY = _;
    return chart;
  };

  chart.stacked = function(_) {
    if (!arguments.length) return stacked;
    stacked = _;
    return chart;
  };

  chart.color = function(_) {
    if (!arguments.length) return color;
    color = nv.utils.getColor(_);
    return chart;
  };

  chart.barColor = function(_) {
    if (!arguments.length) return barColor;
    barColor = nv.utils.getColor(_);
    return chart;
  };

  chart.disabled = function(_) {
    if (!arguments.length) return disabled;
    disabled = _;
    return chart;
  };

  chart.id = function(_) {
    if (!arguments.length) return id;
    id = _;
    return chart;
  };

  chart.delay = function(_) {
    if (!arguments.length) return delay;
    delay = _;
    return chart;
  };

  chart.showValues = function(_) {
    if (!arguments.length) return showValues;
    showValues = _;
    return chart;
  };

  chart.showBarLabels = function(_) {
    if (!arguments.length) return showBarLabels;
    showBarLabels = _;
    return chart;
  };


  chart.valueFormat= function(_) {
    if (!arguments.length) return valueFormat;
    valueFormat = _;
    return chart;
  };

  chart.valuePadding = function(_) {
    if (!arguments.length) return valuePadding;
    valuePadding = _;
    return chart;
  };

  //============================================================


  return chart;
}