// Utils
/////////////////////////

//Modified from http://scott.sauyet.com/Javascript/Talk/Compose/2013-05-22/#slide-28
var pipelineStart = (function(){
    var chain = function(fn){
        var f1 = function(g){
            var func = function(){
                return g.call(this, fn.apply(this, arguments));};
            chain(func);
            return func;
        };
        var f2 = function(g){
            return function(){ return g.call(this, fn.apply(this, arguments));}; };
        fn.then = f1;
        fn.pipelineEnd = f2;
    };
    return function(f){
        var fn = function(){ return f.apply(this, arguments); };
        chain(fn);
        return fn;
    };
}());

function deepExtend(destination, source) {
    for (var property in source) {
        if (source[property] && source[property].constructor &&
            source[property].constructor === Object) {
            destination[property] = destination[property] || {};
            arguments.callee(destination[property], source[property]);
        } else {
            destination[property] = source[property];
        }
    }
    return destination;
}


// Visualization pipes
/////////////////////////

// Initialize the chart configuration and template
function init(config){
    var defaultConfig = {
        container: null,
        data: null,
        width: 800,
        height: 200,
        margin: {top: 60, right: 60, bottom: 20, left: 20}
    };
    config = deepExtend(defaultConfig, config);
    config.cache = {
        root: null,
        data: null,
        chartW: config.width - config.margin.left - config.margin.right,
        chartH: config.height - config.margin.top - config.margin.bottom
    };
    var template = '<div class="chart"><svg>' +
        '<g class="chart-panel">' +
            '<g class="background"><rect class="bg-rect"></rect></g>' +
            '<g class="axis-x"></g>' +
            '<g class="axis-y"></g>' +
            '<g class="geometry"></g>' +
            '<g class="hover"></g>' +
        '</g>' +
        '</svg></div>';
    config.cache.root = d3.select(config.container)
        .html(template)
        .select('svg')
        .attr({
            height: config.height,
            width: config.width
        });
    config.cache.root.select('.chart-panel')
        .attr({transform: 'translate('+[config.margin.left, config.margin.top]+')'})
    return config;
}

// Prepare the data
function prepareData(config){
    config.cache.data = config.data;
    return config;
}

// Build the scales
function prepareCatNumScales(config){
    config.cache.scaleX = d3.scale.ordinal()
        .domain(config.cache.data[0].x)
        .rangeBands([0, config.cache.chartW]);
    config.cache.scaleY = d3.scale.linear()
        .domain([0, d3.max(d3.merge(config.cache.data.map(function(d){ return d.y; })))])
        .range([0, config.cache.chartH]);
    config.cache.dataPixelSpace = config.cache.data.map(function(d, i){
        return d.x.map(function(dB, iB){ return {x: config.cache.scaleX(dB), y: config.cache.scaleY(d.y[iB])}; });
    });
    return config;
}

function prepareNumNumScales(config){
    config.cache.scaleX = d3.scale.linear()
        .domain([0, d3.max(d3.merge(config.cache.data.map(function(d){ return d.x; })))])
        .range([0, config.cache.chartW]);
    config.cache.scaleY = d3.scale.linear()
        .domain([0, d3.max(d3.merge(config.cache.data.map(function(d){ return d.y; })))])
        .range([0, config.cache.chartH]);
    config.cache.dataPixelSpace = config.cache.data.map(function(d, i){
        return d.x.map(function(dB, iB){ return {x: config.cache.scaleX(dB), y: config.cache.scaleY(d.y[iB])}; });
    });
    return config;
}

function prepareNumCatScales(config){
    config.cache.scaleX = d3.scale.linear()
        .domain(d3.extent(config.cache.data.y))
        .range([0, config.cache.chartW]);
    config.cache.scaleY = d3.scale.ordinal()
        .domain(config.cache.data.x)
        .rangeBands([0, config.cache.chartH]);
    config.cache.dataPixelSpace = config.cache.data.x.map(function(d, i){
        return {x: config.cache.scaleX(config.cache.data.y[i]), y: config.cache.scaleY(d)};
    });
    return config;
}

// Render the axes
function renderAxis(config){
    config = renderBackground(config);
    config = renderStripes(config);
    var scaleY = config.cache.scaleY.copy();
    scaleY.range(scaleY.range().reverse());
    var axisX = d3.svg.axis()
        .scale(config.cache.scaleX);
    config.cache.root.select('g.axis-x')
        .attr({transform: 'translate('+[0, config.cache.chartH + 1]+')'})
        .call(axisX)
        .selectAll('path.domain').style({fill: 'none'});
    var axisY = d3.svg.axis()
        .scale(scaleY)
        .orient('left');
    config.cache.root.select('g.axis-y')
        .attr({transform: 'translate('+[-1, 0]+')'})
        .call(axisY)
        .selectAll('path.domain').style({fill: 'none'});
    return cleanupAxis(config);
}

function renderBackground(config){
    config.cache.root.select('.background .bg-rect')
        .attr({
            height: config.cache.chartH,
            width: config.cache.chartW
        });
    return config;
}

function renderStripes(config){
    if(!config.cache.scaleX.rangeBand) return config;
    var stripeSpan = 2;
    var barGroupW = config.cache.scaleX.rangeBand() * stripeSpan;
    var attr = {
        width: barGroupW,
        height: config.cache.chartH,
        x: function(d, i, pI){ return i * barGroupW; },
        y: 0
    };
    var markSelection = config.cache.root.select('.background').selectAll('rect.stripe')
        .data(config.cache.dataPixelSpace[0].filter(function(d, i){ return !!(i%stripeSpan); }));
    markSelection.enter().append('rect').attr({'class': 'stripe'});
    markSelection.attr(attr)
        .each(function(d, i, pI){ d3.select(this).classed('stripe' + (i%stripeSpan), true); });
    markSelection.exit().remove();
    return config;
}

function cleanupAxis(config){
    var ticksX = config.cache.root.select('g.axis-x').selectAll('.tick');
    var ticksMaxW = d3.max(ticksX[0].map(function(d){ return d.getBBox().width; }));
    var divisor = Math.ceil(ticksMaxW / (config.cache.chartW / ticksX[0].length));
    ticksX.filter(function(d, i){ return i%divisor !== 0; })
        .style({display: 'none'});
    var ticksY = config.cache.root.select('g.axis-y').selectAll('.tick');
    var ticksMaxH = d3.max(ticksY[0].map(function(d){ return d.getBBox().height; }));
    divisor = Math.ceil(ticksMaxH / (config.cache.chartH / ticksY[0].length));
    ticksY.filter(function(d, i){ return i%divisor !== 0; })
        .style({display: 'none'});
    ticksY.filter(function(d, i){ return i%divisor === 0; }).selectAll('line').classed('grid', true).attr({x1: config.cache.chartW})
    return config;
}

// Render the geometries
function renderBarGeometry(config){
    var barCountInGroup = config.cache.dataPixelSpace.length;
    var barGroupW = config.cache.scaleX.rangeBand();
    var barMargin = barGroupW/10;
    var barW = (barGroupW - barMargin*2) / barCountInGroup;
    var attr = {
        width: barW - 1,
        height: function(d){ return d.y; },
        x: function(d, i, pI){ return i * barGroupW + pI * (barW) + barMargin; },
        y: function(d, i){ return config.cache.chartH - d.y;  }
    };
    var markGroupSelection = config.cache.root.select('g.geometry')
        .selectAll('g.mark-group')
        .data(config.cache.dataPixelSpace);
    markGroupSelection.enter().append('g').attr({'class': 'mark-group'});
    markGroupSelection.exit().remove();

    var markSelection = markGroupSelection.selectAll('rect.mark')
        .data(function(d){ return d; });
    markSelection.enter().append('rect').attr({'class': 'mark'});
    markSelection.attr(attr)
        .each(function(d, i, pI){ d3.select(this).classed('color' + pI, true); });
    markSelection.exit().remove();
    return config;
}

function renderDotGeometry(config){
    var attr = {
        r: 3,
        cx: function(d, i, pI){ return d.x;  },
        cy: function(d, i){ return config.cache.chartH - d.y;  }
    };
    var markGroupSelection = config.cache.root.select('g.geometry')
        .selectAll('g.mark-group')
        .data(config.cache.dataPixelSpace);
    markGroupSelection.enter().append('g').attr({'class': 'mark-group'});
    markGroupSelection.exit().remove();

    var markSelection = markGroupSelection.selectAll('circle.mark')
        .data(function(d){ return d; });
    markSelection.enter().append('circle').attr({'class': 'mark', transform: (config.cache.scaleX.rangeBand) ? 'translate('+[config.cache.scaleX.rangeBand()/2, 0]+')' : null});
    markSelection.attr(attr)
        .each(function(d, i, pI){ d3.select(this).classed('color' + pI, true); });
    markSelection.exit().remove();
    return config;
}

function renderLineGeometry(config){
    var attr = {
        r: 4,
        cx: function(d, i){ var dotSpacing = config.cache.scaleX.rangeBand(); return i*dotSpacing + dotSpacing/2;  },
        cy: function(d, i){ return config.cache.chartH - d.y;  }
    };
    var line = d3.svg.line()
        .x(function(d){ return d.x })
        .y(function(d){ return config.cache.chartH - d.y });
    var lineSelection = config.cache.root.select('g.geometry')
        .selectAll('path')
        .data(config.cache.dataPixelSpace);
    lineSelection.enter().append('path')
        .attr({transform: 'translate('+[config.cache.scaleX.rangeBand()/2, 0]+')'})
        .style({'pointer-events': 'none', fill: 'none'});
    lineSelection.attr({
            d: line
        })
        .each(function(d, i){ d3.select(this).classed('color' + i, true); });
    lineSelection.exit().remove();
    return config;
}

// Add interactors
function tooltip(config){
    var tickSize = 10;
    var padding = 2;
    var tooltipSelection = config.cache.root.select('.hover').selectAll('g.tooltip')
        .data([0]);
    var tooltipEnter = tooltipSelection.enter().append('g').attr({'class': 'tooltip'})
    .style({opacity: 0, 'pointer-events': 'none'});
    tooltipEnter.append('path');
    tooltipEnter.append('text').attr({dx: tickSize + padding, dy: 5});
    config.cache.root.selectAll('.mark')
        .on('mousemove', function(d, i, pI){
            var color = window.getComputedStyle(this).fill;
            var mousePos = d3.mouse(config.cache.root.select('.chart-panel').node());
            tooltipSelection
                .attr({transform: 'translate('+mousePos+')'})
                .style({opacity: 1});
            var textSelection = tooltipSelection.select('text')
                .text(function(dB){
                    var dataXLength = config.cache.data[0].x.length;
                    var groupRank = +(i>dataXLength);
                    return config.cache.data[groupRank].x[i%dataXLength] +' '+ config.cache.data[groupRank].y[i%dataXLength];
                });
            var bbox = textSelection.node().getBBox();
            var backGroundW = bbox.width + padding*2 + tickSize;
            var backGroundH = bbox.height + padding*2;
            tooltipSelection.select('path')
                .attr({
                    d: 'M' + [[tickSize, -backGroundH/2],
                        [tickSize, -backGroundH/4], [0, 0], [tickSize, backGroundH/4],
                        [tickSize, backGroundH/2],
                        [backGroundW, backGroundH/2],
                        [backGroundW, -backGroundH/2]].join('L') + 'Z'
                })
                .style({fill: color, stroke: 'white'});
            d3.select(this).classed('hovered', true);
        })
        .on('mouseout', function(){
            tooltipSelection.style({opacity: 0});
            d3.select(this).classed('hovered', false);
        });
    return config;
}


// Compose the visualization pipeline
/////////////////////////

var barChart = pipelineStart(init)
    .then(prepareData)
    .then(prepareCatNumScales)
    .then(renderAxis)
    .then(renderBarGeometry)
    .pipelineEnd(tooltip);

var groupedBarChart = pipelineStart(init)
    .then(prepareData)
    .then(prepareCatNumScales)
    .then(renderAxis)
    .then(renderBarGeometry)
    .pipelineEnd(tooltip);

var lineChart = pipelineStart(init)
    .then(prepareData)
    .then(prepareCatNumScales)
    .then(renderAxis)
    .then(renderLineGeometry)
    .then(renderDotGeometry)
    .pipelineEnd(tooltip);

var scatterplot = pipelineStart(init)
    .then(prepareData)
    .then(prepareNumNumScales)
    .then(renderAxis)
    .then(renderDotGeometry)
    .pipelineEnd(tooltip);


// Usage
/////////////////////////

var dataCount = 20;
var generateCatNumData = function(){
    return {
        x: d3.range(dataCount).map(function (d, i) { return 'p'+i; }),
        y: d3.range(dataCount).map(function (d, i) { return ~~(Math.random()*100); })
    }
};
var generatedCatNumData = generateCatNumData();
var generateCatNumData2 = function(){
    return {
        x: generatedCatNumData.x,
        y: d3.range(dataCount).map(function (d, i) { return ~~(Math.random()*100); })
    }
};
var generateNumNumData = function(){
    return {
        x: d3.range(dataCount).map(function (d, i) { return ~~(Math.random()*100); }),
        y: d3.range(dataCount).map(function (d, i) { return ~~(Math.random()*100); })
    }
};
lineChart({
    container: d3.select('#container').append('div').attr({class: 'chart1'}).node(),
    data: [generatedCatNumData, generateCatNumData2(), generateCatNumData2(), generateCatNumData2()]
});
barChart({
    container: d3.select('#container').append('div').attr({class: 'chart2'}).node(),
    data: [generateCatNumData()]
});
groupedBarChart({
    container: d3.select('#container').append('div').attr({class: 'chart3'}).node(),
    data: [generatedCatNumData, generateCatNumData2(), generateCatNumData2()]
});
scatterplot({
    container: d3.select('#container').append('div').attr({class: 'chart5'}).node(),
    data: [generateNumNumData(), generateNumNumData(), generateNumNumData(), generateNumNumData()],
    height: 300,
    width: 300
});