election.js

const https = require('https');

let url = "https://www.wsj.com/election-results-2020-data/president.json";

var careAbout = [ "PA", "AZ", "NV", "NC", "GA" ];
var res = null;
var pollRateSeconds = 60;

function getUpdate() {
    https.get(url,(res) => {
        let body = "";

        res.on("data", (chunk) => {
            body += chunk;
        });

        res.on("end", () => {
            try {
                let json = JSON.parse(body);
                checkForChanges(json);
                setTimeout(getUpdate, pollRateSeconds * 1000);
            } catch (error) {
                console.error(error.message);
            };
        });

    }).on("error", (error) => {
        console.error(error.message);
    });
}

function checkForChanges(json) {
    if (res && res.created == json.meta.created)
        return;

    var changed = false;
    var first = res == null;
    careAbout.forEach(function (state) {
        var sData = json.data[state];
        if (res == null || res[state] == null) {
            console.log(state, "NEW");
        } else if (sData.tv != res[state].tv) {
            console.log(state, "UPDATE", " - ", timestamp());
            changed = true;
        } else {
            return;
        }

        if (first) {
            printState(sData, null);

            // Init first time through (messy because we are caching as a hash instead of an array)
            res = res || {};
            res[state] = {}
            res[state].tv = sData.tv;
            res[state].votes = {};
            sData.cand.forEach(function (candData) { res[state].votes[candData.name] = candData.votes });
        } else {
            printState(sData, res[state]);
            res[state].tv = sData.tv;            
        }
    });

    res.created = json.meta.created;

    if (first || changed)
        console.log();
}

function printState(newData, oldData) {
    if (oldData != null) {
        var delta = newData.tv - oldData.tv
        console.log("  Total Votes:", comma(newData.tv), (delta > 0 ? "+" : "") + comma(delta));
    } else {
        console.log("  Total Votes:", comma(newData.tv));
    }

    var newFirst, newSecond;
    var oldFirst, oldSecond;

    newData.cand.forEach(function (candData) {
        if (oldData != null) {
            var diff = candData.votes - oldData.votes[candData.name];
            console.log("  " + candData.name + ":", comma(candData.votes), (diff > 0 ? "(+" : "(") + comma(diff) + ")");
            if (newFirst == null) {
                newFirst = candData.votes;
                oldFirst = oldData.votes[candData.name];
            } else if (newSecond == null) {
                newSecond = candData.votes;
                oldSecond = oldData.votes[candData.name];
            }
            oldData.votes[candData.name] = candData.votes;
        } else {
            console.log("  " + candData.name + ":", comma(candData.votes));
            if (newFirst == null) {
                newFirst = candData.votes;
            } else if (newSecond == null) {
                newSecond = candData.votes;
            }
        }
    })

    if (oldData != null) {
        var diff = newFirst - newSecond - oldFirst + oldSecond;
        console.log("  Lead By:", comma(newFirst - newSecond), (diff > 0 ? "(+" : "(") + comma(diff) + ")");
    } else {
        console.log("  Lead By:", comma(newFirst - newSecond));
    }
}

function comma(x) {
    x = x.toString();
    var pattern = /(-?\d+)(\d{3})/;
    while (pattern.test(x))
        x = x.replace(pattern, "$1,$2");
    return x;
}

function timestamp() {
    let date = new Date();
    let day = intTwoChars(date.getDate());
    let month = intTwoChars(date.getMonth() + 1);
    let hours = intTwoChars(date.getHours());
    let minutes = intTwoChars(date.getMinutes());
    let seconds = intTwoChars(date.getSeconds());
    return `${month}/${day} ${hours}:${minutes}:${seconds}`;    
}

function intTwoChars(i) {
    return (`0${i}`).slice(-2);
}

getUpdate();