const Diagram = {
    build: (eventIndex, data, metaMatrix, chordMatrix) => {
        const svg = d3.select("svg"),
            width = +svg.attr("width"),
            height = +svg.attr("height"),
            outerArcThickness = 5,
            outerRadius = Math.min(width, height) * 0.5 - 100,
            innerRadius = outerRadius - outerArcThickness;

        const chord = d3.chord()
            .padAngle(0.05);

        const arc = d3.arc()
            .innerRadius(innerRadius)
            .outerRadius(outerRadius);

        const ribbon = d3.ribbon()
            .radius(innerRadius);

        // const color = d3.scaleOrdinal(d3.schemeCategory20);
        // const color = d3.scaleOrdinal(d3.schemeCategory10);
        // const color = d3.scaleOrdinal(d3.interpolateCool);
        // const color = d3.scaleSequential(d3.interpolateRainbow);

        const color = d3.scaleLinear().domain([0,10]).range(["red", "blue"]).interpolate(d3.interpolateRgb)

        // const colors = ["#f1eef6","#d4b9da","#c994c7","#df65b0","#e7298a","#ce1256","#91003f"];
        // const colors = ["#ffffcc","#c7e9b4","#7fcdbb","#41b6c4","#1d91c0","#225ea8","#0c2c84"];
        // const colors = ["#7fcdbb","#41b6c4","#1d91c0","#225ea8","#253494","#081d58"];
        // const colors = ["#1B9E77", "#D95F02", "#7570B3", "#E7298A", "#66A61E", "#E6AB02", "#A6761D", "#666666"];
        // const color = i => colors[i % colors.length];

        const g = svg.append("g")
            .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
            .datum(chord(chordMatrix));

        const group = g.append("g")
            .attr("class", "groups")
          .selectAll("g")
            .data(function(chords) { return chords.groups; })
          .enter().append("g");

        group.append("path")
            .style("fill", function(d) { return color(d.index); })
            .style("stroke", function(d) { return d3.rgb(color(d.index)).darker(); })
            .attr("d", arc);

            g.append("g")
                .attr("class", "ribbons")
              .selectAll("path")
                .data(function(chords) { return chords; })
              .enter().append("path")
                .attr("d", ribbon)
                .style("fill", function(d) { return color(d.target.index); })
                .style("stroke", function(d) { return d3.rgb(color(d.target.index)).darker(); })
                .attr("class", "ribbon")
                // .append("title")
                // .text(function(d) {
                //     const meta1 = metaMatrix[d.target.index][d.source.index];
                //     const meta2 = metaMatrix[d.source.index][d.target.index];
                //
                //     const g = meta1.game;
                //
                //     const t1 = lookup.teams[g.t1];
                //     const t2 = lookup.teams[g.t2];
                //
                //     const e1 = g.s1e ? `(+${g.s1e} in extended time)` : '';
                //     const e2 = g.s2e ? `(+${g.s2e} in extended time)` : '';
                //
                //     const p1 = g.s1p ? `(+${g.s1p} in penalties)` : '';
                //     const p2 = g.s2p ? `(+${g.s2p} in penalties)` : '';
                //
                //     return `${t1}: ${g.s1} ${e1} ${p1}\n${t2}: ${g.s2} ${e2} ${p2}`;
                // });

        group.append("text")
          .each(function(d) { d.angle = (d.startAngle + d.endAngle) / 2; })
          .attr("dy", ".35em")
          .attr("transform", function(d) {
            return "rotate(" + (d.angle * 180 / Math.PI - 90) + ")"
                + "translate(" + (innerRadius + 26) + ")"
                + (d.angle > Math.PI ? "rotate(180)" : "");
          })
          .style("text-anchor", function(d) { return d.angle > Math.PI ? "end" : null; })
          .text(function(d) {
              // SORT BY GOALS SCORED
              // SORT BY ALPHABETICAL
              // SORT BY COUNTRY SIZE
              // SORT BY COUNTRY POPULATION
              // COLOR BY CONTINENT
              // STRANGE EXTENDED TIME CHILE-BRAZIL - FIX BY HAND? IS BECAUE se1 IS SCORE __GOING INTO__ EXTENDED TIME
            //   console.info(metaMatrix[d.index])
                const t = data.tourneys[eventIndex].teams[d.index];
                const c = data.countries[data.teams[t]];
              return data.countries[data.teams[t]].n;
          });
    },
};

// const main = (data) => {
//     const lookup = buildLookup(endpoints, data);
//     const chordMatrix = buildChordMatrix(lookup.games, lookup.reducedTeams)
//     const metaMatrix = buildMetaMatrix(lookup.games, lookup.reducedTeams)
// };