// Dimensions of chart.
let margin = { top: 30, right: 10, bottom: 30, left: 45 },
    // width = parseInt(d3.select('#chart').style('width'), 10) - margin.left - margin.right,
    width = 600 - margin.left - margin.right,
    height = width*.8 - margin.top - margin.bottom;
    
let svg = d3.select("#chart").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
    
    
// Scales: x and y
let x = d3.scaleLinear()
    .domain([1909, 2017])
	.range([0, width]);
let y = d3.scaleLinear()
    .domain([0, 100])
	.range([height, 0]);
    

// Geometries
let area = d3.area()
    .x(d => x(d.year))
    .y1(d => y(d.amt));
let line = d3.line()
    .x(d => x(d.year))
    .y(d => y(d.amt));
    

let xAxis, yAxis, xAxisEl, yAxisEL;

let meats, beef, chicken;

    
// Load data
const meatData = Promise.all([
    d3.csv("data/beef-vs-chicken-difference.csv", d3.autoType)
]);
meatData.then(function(data) {
    
    meats = data[0];
    console.log(meats);
    
    svg.datum(meats);
    
    // Initialize chart now that data is loaded.
    initChart();
});



function initChart() {
    
    // x-axis
    xAxis = d3.axisBottom(x)
        .ticks(4)
        .tickFormat(d => d)
	    .tickSize(-height-8)
	    .tickPadding(5);
    xAxisEl = svg.append("g")
	    .attr("class", "x axis bottom")
	    .attr("transform", "translate(0,"+(height+8)+")");
    xAxisEl.call(xAxis);

    // y-axis
    yAxis = d3.axisLeft(y)
        // .ticks(7)
        .ticks(5)
	    .tickSize(-width-8)
	    .tickPadding(5);
    yAxisEl = svg.append("g")
	    .attr("class", "y axis left")
        .attr("transform", "translate("+(-8)+",0)");
    yAxisEl.append("text")
	    .attr("class", "axistitle")
	    .attr("x", 0).attr("y", 0)
        .attr("dx", "-2.25em")
        .attr("dy", "-1.5em")
        .style("text-anchor", "start")
        .text("Pounds per capita");
    yAxisEl.call(yAxis);
    
    // Area clipping paths
    svg.append("clipPath")
        .attr("id", "clip-above")
      .append("path")
        .attr("d", d3.area()
            .x(d => x(d.Year))
            .y0(0)
            .y1(d => y(d.Chicken)));
    svg.append("clipPath")
        .attr("id", "clip-below")
        .append("path")
        .attr("d", d3.area()
            .x(d => x(d.Year))
            .y0(height)
            .y1(d => y(d.Chicken)));

    // Area differences
    svg.append("path")
        .attr("class", "area above")
        .attr("clip-path", "url(#clip-above)")
        .attr("fill", "#fdad94")
        .attr("d", d3.area()
            .x(d => x(d.Year)).y0(height).y1(d => y(d.Beef)));
    svg.append("path")
        .attr("class", "area below")
        .attr("fill", "#f9e59f")
        .attr("clip-path", "url(#clip-below)")
        .attr("d", d3.area()
            .x(d => x(d.Year)).y0(0).y1(d => y(d.Beef)));

    // Lines
    svg.append("path")
        .attr("class", "line chicken")
        .attr("fill", "none")
        .attr("stroke", "#bf980d")
        .attr("stroke-width", "2px")
        .attr("d", d3.line()
            .x(d => x(d.Year))
            .y(d => y(d.Chicken)));
    svg.append("path")
        .attr("class", "line beef")
        .attr("fill", "none")
        .attr("stroke", "#fb470e")
        .attr("stroke-width", "2px")
        .attr("d", d3.line()
            .x(d => x(d.Year))
            .y(d => y(d.Beef)));
    
    
    setAnnotation();
}




function setAnnotation() {
    svg.append("text")
        .attr("class", "mainlab")
        .attr("fill", "#fb470e")
        .attr("x", x(1962))
        .attr("y", y(40))
        .text("BEEF");
    
    svg.append("text")
        .attr("text-anchor", "end")
        .attr("class", "mainlab")
        .attr("fill", "#bf980d")
        .attr("x", x(2017))
        .attr("y", y(65))
        .text("CHICKEN");
}