Real Estate Priced in BTC UserScript

userscript.js

// ==UserScript==
// @name         Real Estate Priced in BTC
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Display all home prices in BTC.
// @author       Phteven
// @match        http*://www.zillow.com/*
// @match        http*://www.redfin.com/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// ==/UserScript==

async function getBTC() {
  const url = "https://mempool.space/api/v1/prices";
  const btc = await fetch(url).then(function (response) {
    return response.json();
  }).then(function (data) {
    return data.USD;
  }).catch(function (err) {
    console.log('Fetch Error :-S', err);
  })
  return btc;
}

function getAllPrices() {
  // Combined query selector for all possible price elements
  return document.querySelectorAll(
    'div.stat-block .statsValue,' + // Redfin
    '.price-text,' + // Zillow
    '[data-testid="primary-zestimate"],' + // Zestimate
    '[data-test="property-card-price"],' + // Zillow Cards
    '.bp-Homecard__Price--value' // Redfin Homepage Cards
  );
}

// setBTC takes an element with a USD price, and btcPrice,
// and updates the element's innerHTML to show the BTC equivalent
// of the USD price
function setBTC(elem, btcPrice) {
  if (!elem.textContent.includes('$')) {
    return;
  }
  let usdPrice = Number(elem.textContent.replace(/[^0-9.-]+/g, ""));
  let BTC = (usdPrice / btcPrice).toFixed(8) + ' ₿';
  const inner = '<span title="' + elem.textContent + ' @ $' + btcPrice + '/BTC">' + BTC + '</span>';
  elem.innerHTML = inner;
}

(async function() {
  'use strict';

  var btcPrice = await getBTC();
  var runIt = function() {
    var prices = getAllPrices();
    for (let i = 0; i < prices.length; i++) {
      const priceObj = prices[i];
      setBTC(priceObj, btcPrice);
    }
  };
  window.onload = runIt;
  setInterval(runIt, 1000);
  setInterval(async function() { btcPrice = await getBTC(); }, 60000);
})();