
nv.models.multiBarChart = function() {
    "use strict";

    //============================================================
    // Public Variables with Default Settings
    //------------------------------------------------------------

    var multibar = nv.models.multiBar()
        , xAxis = nv.models.axis()
        , yAxis = nv.models.axis()
        , legend = nv.models.legend()
        , controls = nv.models.legend()
        , tooltip = nv.models.tooltip()
        ;

    var margin = {top: 30, right: 20, bottom: 50, left: 60}
        , width = null
        , height = null
        , color = nv.utils.defaultColor()
        , showControls = true
        , controlLabels = {}
        , showLegend = true
        , showXAxis = true
        , showYAxis = true
        , rightAlignYAxis = false
        , reduceXTicks = true // if false a tick will show for every data point
        , staggerLabels = false
        , rotateLabels = 0
        , x //can be accessed via chart.xScale()
        , y //can be accessed via chart.yScale()
        , state = nv.utils.state()
        , defaultState = null
        , noData = null
        , dispatch = d3.dispatch('stateChange', 'changeState', 'renderEnd')
        , controlWidth = function() { return showControls ? 180 : 0 }
        , duration = 250
        ;

    state.stacked = false // DEPRECATED Maintained for backward compatibility

    multibar.stacked(false);
    xAxis
        .orient('bottom')
        .tickPadding(7)
        .showMaxMin(false)
        .tickFormat(function(d) { return d })
    ;
    yAxis
        .orient((rightAlignYAxis) ? 'right' : 'left')
        .tickFormat(d3.format(',.1f'))
    ;

    tooltip
        .duration(0)
        .valueFormatter(function(d, i) {
            return yAxis.tickFormat()(d, i);
        })
        .headerFormatter(function(d, i) {
            return xAxis.tickFormat()(d, i);
        });

    controls.updateState(false);

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

    var renderWatch = nv.utils.renderWatch(dispatch);
    var stacked = false;

    var stateGetter = function(data) {
        return function(){
            return {
                active: data.map(function(d) { return !d.disabled }),
                stacked: stacked
            };
        }
    };

    var stateSetter = function(data) {
        return function(state) {
            if (state.stacked !== undefined)
                stacked = state.stacked;
            if (state.active !== undefined)
                data.forEach(function(series,i) {
                    series.disabled = !state.active[i];
                });
        }
    };

    function chart(selection) {
        renderWatch.reset();
        renderWatch.models(multibar);
        if (showXAxis) renderWatch.models(xAxis);
        if (showYAxis) renderWatch.models(yAxis);

        selection.each(function(data) {
            var container = d3.select(this),
                that = this;
            nv.utils.initSVG(container);
            var availableWidth = nv.utils.availableWidth(width, container, margin),
                availableHeight = nv.utils.availableHeight(height, container, margin);

            chart.update = function() {
                if (duration === 0)
                    container.call(chart);
                else
                    container.transition()
                        .duration(duration)
                        .call(chart);
            };
            chart.container = this;

            state
                .setter(stateSetter(data), chart.update)
                .getter(stateGetter(data))
                .update();

            // DEPRECATED set state.disableddisabled
            state.disabled = data.map(function(d) { return !!d.disabled });

            if (!defaultState) {
                var key;
                defaultState = {};
                for (key in state) {
                    if (state[key] instanceof Array)
                        defaultState[key] = state[key].slice(0);
                    else
                        defaultState[key] = state[key];
                }
            }

            // Display noData message if there's nothing to show.
            if (!data || !data.length || !data.filter(function(d) { return d.values.length }).length) {
                nv.utils.noData(chart, container)
                return chart;
            } else {
                container.selectAll('.nv-noData').remove();
            }

            // Setup Scales
            x = multibar.xScale();
            y = multibar.yScale();

            // Setup containers and skeleton of chart
            var wrap = container.selectAll('g.nv-wrap.nv-multiBarWithLegend').data([data]);
            var gEnter = wrap.enter().append('g').attr('class', 'nvd3 nv-wrap nv-multiBarWithLegend').append('g');
            var g = wrap.select('g');

            gEnter.append('g').attr('class', 'nv-x nv-axis');
            gEnter.append('g').attr('class', 'nv-y nv-axis');
            gEnter.append('g').attr('class', 'nv-barsWrap');
            gEnter.append('g').attr('class', 'nv-legendWrap');
            gEnter.append('g').attr('class', 'nv-controlsWrap');

            // Legend
            if (showLegend) {
                legend.width(availableWidth - controlWidth());

                g.select('.nv-legendWrap')
                    .datum(data)
                    .call(legend);

                if ( margin.top != legend.height()) {
                    margin.top = legend.height();
                    availableHeight = nv.utils.availableHeight(height, container, margin);
                }

                g.select('.nv-legendWrap')
                    .attr('transform', 'translate(' + controlWidth() + ',' + (-margin.top) +')');
            }

            // Controls
            if (showControls) {
                var controlsData = [
                    { key: controlLabels.grouped || 'Grouped', disabled: multibar.stacked() },
                    { key: controlLabels.stacked || 'Stacked', disabled: !multibar.stacked() }
                ];

                controls.width(controlWidth()).color(['#444', '#444', '#444']);
                g.select('.nv-controlsWrap')
                    .datum(controlsData)
                    .attr('transform', 'translate(0,' + (-margin.top) +')')
                    .call(controls);
            }

            wrap.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');
            if (rightAlignYAxis) {
                g.select(".nv-y.nv-axis")
                    .attr("transform", "translate(" + availableWidth + ",0)");
            }

            // Main Chart Component(s)
            multibar
                .disabled(data.map(function(series) { return series.disabled }))
                .width(availableWidth)
                .height(availableHeight)
                .color(data.map(function(d,i) {
                    return d.color || color(d, i);
                }).filter(function(d,i) { return !data[i].disabled }));


            var barsWrap = g.select('.nv-barsWrap')
                .datum(data.filter(function(d) { return !d.disabled }));

            barsWrap.call(multibar);

            // Setup Axes
            if (showXAxis) {
                xAxis
                    .scale(x)
                    ._ticks( nv.utils.calcTicksX(availableWidth/100, data) )
                    .tickSize(-availableHeight, 0);

                g.select('.nv-x.nv-axis')
                    .attr('transform', 'translate(0,' + y.range()[0] + ')');
                g.select('.nv-x.nv-axis')
                    .call(xAxis);

                var xTicks = g.select('.nv-x.nv-axis > g').selectAll('g');

                xTicks
                    .selectAll('line, text')
                    .style('opacity', 1)

                if (staggerLabels) {
                    var getTranslate = function(x,y) {
                        return "translate(" + x + "," + y + ")";
                    };

                    var staggerUp = 5, staggerDown = 17;  //pixels to stagger by
                    // Issue #140
                    xTicks
                        .selectAll("text")
                        .attr('transform', function(d,i,j) {
                            return  getTranslate(0, (j % 2 == 0 ? staggerUp : staggerDown));
                        });

                    var totalInBetweenTicks = d3.selectAll(".nv-x.nv-axis .nv-wrap g g text")[0].length;
                    g.selectAll(".nv-x.nv-axis .nv-axisMaxMin text")
                        .attr("transform", function(d,i) {
                            return getTranslate(0, (i === 0 || totalInBetweenTicks % 2 !== 0) ? staggerDown : staggerUp);
                        });
                }

                if (reduceXTicks)
                    xTicks
                        .filter(function(d,i) {
                            return i % Math.ceil(data[0].values.length / (availableWidth / 100)) !== 0;
                        })
                        .selectAll('text, line')
                        .style('opacity', 0);

                if(rotateLabels)
                    xTicks
                        .selectAll('.tick text')
                        .attr('transform', 'rotate(' + rotateLabels + ' 0,0)')
                        .style('text-anchor', rotateLabels > 0 ? 'start' : 'end');

                g.select('.nv-x.nv-axis').selectAll('g.nv-axisMaxMin text')
                    .style('opacity', 1);
            }

            if (showYAxis) {
                yAxis
                    .scale(y)
                    ._ticks( nv.utils.calcTicksY(availableHeight/36, data) )
                    .tickSize( -availableWidth, 0);

                g.select('.nv-y.nv-axis')
                    .call(yAxis);
            }

            //============================================================
            // Event Handling/Dispatching (in chart's scope)
            //------------------------------------------------------------

            legend.dispatch.on('stateChange', function(newState) {
                for (var key in newState)
                    state[key] = newState[key];
                dispatch.stateChange(state);
                chart.update();
            });

            controls.dispatch.on('legendClick', function(d,i) {
                if (!d.disabled) return;
                controlsData = controlsData.map(function(s) {
                    s.disabled = true;
                    return s;
                });
                d.disabled = false;

                switch (d.key) {
                    case 'Grouped':
                    case controlLabels.grouped:
                        multibar.stacked(false);
                        break;
                    case 'Stacked':
                    case controlLabels.stacked:
                        multibar.stacked(true);
                        break;
                }

                state.stacked = multibar.stacked();
                dispatch.stateChange(state);
                chart.update();
            });

            // Update chart from a state object passed to event handler
            dispatch.on('changeState', function(e) {
                if (typeof e.disabled !== 'undefined') {
                    data.forEach(function(series,i) {
                        series.disabled = e.disabled[i];
                    });
                    state.disabled = e.disabled;
                }
                if (typeof e.stacked !== 'undefined') {
                    multibar.stacked(e.stacked);
                    state.stacked = e.stacked;
                    stacked = e.stacked;
                }
                chart.update();
            });
        });

        renderWatch.renderEnd('multibarchart immediate');
        return chart;
    }

    //============================================================
    // Event Handling/Dispatching (out of chart's scope)
    //------------------------------------------------------------

    multibar.dispatch.on('elementMouseover.tooltip', function(evt) {
        evt.value = chart.x()(evt.data);
        evt['series'] = {
            key: evt.data.key,
            value: chart.y()(evt.data),
            color: evt.color
        };
        tooltip.data(evt).hidden(false);
    });

    multibar.dispatch.on('elementMouseout.tooltip', function(evt) {
        tooltip.hidden(true);
    });

    multibar.dispatch.on('elementMousemove.tooltip', function(evt) {
        tooltip.position({top: d3.event.pageY, left: d3.event.pageX})();
    });

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

    // expose chart's sub-components
    chart.dispatch = dispatch;
    chart.multibar = multibar;
    chart.legend = legend;
    chart.controls = controls;
    chart.xAxis = xAxis;
    chart.yAxis = yAxis;
    chart.state = state;
    chart.tooltip = tooltip;

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

    chart._options = Object.create({}, {
        // simple options, just get/set the necessary values
        width:      {get: function(){return width;}, set: function(_){width=_;}},
        height:     {get: function(){return height;}, set: function(_){height=_;}},
        showLegend: {get: function(){return showLegend;}, set: function(_){showLegend=_;}},
        showControls: {get: function(){return showControls;}, set: function(_){showControls=_;}},
        controlLabels: {get: function(){return controlLabels;}, set: function(_){controlLabels=_;}},
        showXAxis:      {get: function(){return showXAxis;}, set: function(_){showXAxis=_;}},
        showYAxis:    {get: function(){return showYAxis;}, set: function(_){showYAxis=_;}},
        defaultState:    {get: function(){return defaultState;}, set: function(_){defaultState=_;}},
        noData:    {get: function(){return noData;}, set: function(_){noData=_;}},
        reduceXTicks:    {get: function(){return reduceXTicks;}, set: function(_){reduceXTicks=_;}},
        rotateLabels:    {get: function(){return rotateLabels;}, set: function(_){rotateLabels=_;}},
        staggerLabels:    {get: function(){return staggerLabels;}, set: function(_){staggerLabels=_;}},

        // deprecated options
        tooltips:    {get: function(){return tooltip.enabled();}, set: function(_){
            // deprecated after 1.7.1
            nv.deprecated('tooltips', 'use chart.tooltip.enabled() instead');
            tooltip.enabled(!!_);
        }},
        tooltipContent:    {get: function(){return tooltip.contentGenerator();}, set: function(_){
            // deprecated after 1.7.1
            nv.deprecated('tooltipContent', 'use chart.tooltip.contentGenerator() instead');
            tooltip.contentGenerator(_);
        }},

        // options that require extra logic in the setter
        margin: {get: function(){return margin;}, set: function(_){
            margin.top    = _.top    !== undefined ? _.top    : margin.top;
            margin.right  = _.right  !== undefined ? _.right  : margin.right;
            margin.bottom = _.bottom !== undefined ? _.bottom : margin.bottom;
            margin.left   = _.left   !== undefined ? _.left   : margin.left;
        }},
        duration: {get: function(){return duration;}, set: function(_){
            duration = _;
            multibar.duration(duration);
            xAxis.duration(duration);
            yAxis.duration(duration);
            renderWatch.reset(duration);
        }},
        color:  {get: function(){return color;}, set: function(_){
            color = nv.utils.getColor(_);
            legend.color(color);
        }},
        rightAlignYAxis: {get: function(){return rightAlignYAxis;}, set: function(_){
            rightAlignYAxis = _;
            yAxis.orient( rightAlignYAxis ? 'right' : 'left');
        }},
        barColor:  {get: function(){return multibar.barColor;}, set: function(_){
            multibar.barColor(_);
            legend.color(function(d,i) {return d3.rgb('#ccc').darker(i * 1.5).toString();})
        }}
    });

    nv.utils.inheritOptions(chart, multibar);
    nv.utils.initOptions(chart);

    return chart;
};
