var bubbleCF = dc.bubbleChart('#bubble-cf'),
    heatCF = dc.heatMap('#heatmap-cf'),
    heatClone = dc.heatMap('#heatmap-clone'),
    bubbleClone = dc.bubbleChart('#bubble-clone');

d3.csv('iris.csv', function(error, iris) {
    var fields = {
        sl: 'sepal_length',
        sw: 'sepal_width',
        pl: 'petal_length',
        pw: 'petal_width'
    };
    var species = ['setosa', 'versicolor', 'virginica'];

    iris.forEach(function(d) {
        Object.keys(fields).forEach(function(ab) {
            d[fields[ab]] = +d[fields[ab]];
        });
    });
    // autogenerate a key function for an extent
    function key_function(extent) {
        var div = extent[1]-extent[0] < 5 ? 2 : 1;
        return function(k) {
            return Math.floor(k*div)/div;
        };
    }
    var extents = {};
    var keyfuncs = {};
    Object.keys(fields).forEach(function(ab) {
        extents[ab] = d3.extent(iris, function(d) { return d[fields[ab]]; });
        keyfuncs[ab] = key_function(extents[ab]);
    });
    var cf = crossfilter(iris);
    function duo_key(ab1, ab2) {
        return function(d) {
            return [keyfuncs[ab1](d[fields[ab1]]), keyfuncs[ab2](d[fields[ab2]])];
        };
    }
    function key_part(i) {
        return function(kv) {
            return kv.key[i];
        };
    }
    function reduce_species(group) {
        group.reduce(
            function(p, v) {
                p[v.species]++;
                p.total++;
                return p;
            }, function(p, v) {
                p[v.species]--;
                p.total--;
                return p;
            }, function() {
                var init = {total: 0};
                species.forEach(function(s) { init[s] = 0; });
                return init;
            }
        );
    }
    function max_species(d) {
        var max = 0, i = -1;
        species.forEach(function(s, j) {
            if(d.value[s] > max) {
                max = d.value[s];
                i = j;
            }
        });
        return i >= 0 ? species[i] : null;
    }
    function initialize_bubble(bubbleChart, dim, group) {
        bubbleChart
      	    .width(400)
            .height(400)
            .x(d3.scale.linear()).xAxisPadding(0.5)
            .y(d3.scale.linear()).yAxisPadding(0.5)
            .elasticX(true)
            .elasticY(true)
            .label(d3.functor(''))
            .keyAccessor(key_part(0))
            .valueAccessor(key_part(1))
            .radiusValueAccessor(function(kv) { return kv.value.total; })
            .colors(d3.scale.ordinal()
                    .domain(species.concat('none'))
                    .range(['#e41a1c','#377eb8','#4daf4a', '#bbb']))
            .colorAccessor(function(d) {
                return max_species(d) || 'none';
            });
    }
    function initialize_heatmap(heatMap) {
        heatMap
            .width(400)
            .height(400)
            .xBorderRadius(15).yBorderRadius(15)
            .keyAccessor(key_part(0))
            .valueAccessor(key_part(1))
            .colors(d3.scale.ordinal()
                    .domain(species.concat('none'))
                    .range(['#e41a1c','#377eb8','#4daf4a', '#bbb']))
            .colorAccessor(function(d) {
                return max_species(d) || 'none';
            });
    }

    var sepalDim = cf.dimension(duo_key('sl', 'sw')), sepalGroup = sepalDim.group(),
        petalDim = cf.dimension(duo_key('pl', 'pw')), petalGroup = petalDim.group();

    reduce_species(sepalGroup);
    reduce_species(petalGroup);
    initialize_bubble(bubbleCF.dimension(sepalDim).group(sepalGroup));
    initialize_heatmap(heatCF.dimension(petalDim).group(petalGroup));

    // return brand-new objects and keys every time
    function clone_group(group) {
        function clone_kvs(all) {
            return all.map(function(kv) {
                return {
                    key: kv.key.slice(0),
                    value: Object.assign({}, kv.value)
                    };
            });
        }
        return {
            all: function() {
                return clone_kvs(group.all());
            },
            top: function(N) {
                return clone_kvs(group.top(N));
            }
        };
    }

    var lengthDim = cf.dimension(duo_key('sl', 'pl')), lengthGroup = lengthDim.group(),
        widthDim = cf.dimension(duo_key('sw', 'pw')), widthGroup = widthDim.group();

    reduce_species(widthGroup);
    reduce_species(lengthGroup);
    initialize_heatmap(heatClone.dimension(widthDim).group(clone_group(widthGroup)));
    initialize_bubble(bubbleClone.dimension(lengthDim).group(clone_group(lengthGroup)));

    dc.renderAll();
});