// SARS-CoV-2-Viz
// Animated COVID case count visualization
// Copyright 2022 Edward L. Platt <ed@elplatt.com>

function createChoropleth(us, msPerFrame) {

    const counties = topojson.feature(us, us.objects.counties);
    const states = topojson.feature(us, us.objects.states)
    const statemesh = topojson.mesh(
	us, us.objects.states, (a, b) => a !== b)
    const statemap = new Map(states.features.map(d => [d.id, d]));

    let chart = Choropleth({
	id: d => d.FIPS,
	value: d => d.sevenDayMeanPer100KCap,
	domain: d => {
	    let domain = [0, Math.max(1, d["10001"].dayMax)];
	    return domain;
	},
	title: (f, d) => `${f.properties.name}, ${statemap.get(f.id.slice(0, 2)).properties.name}\n${d?.sevenDayMean}`,
	features: counties,
	borders: statemesh,
	width: 975,
	height: 610,
	duration: msPerFrame
    });

    return chart;
}