kraken-change-reader.tapermonkey.js

// ==UserScript==
// @name         Kraken speech
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://trade.kraken.com/*
// @grant        none
// ==/UserScript==

(() => {
    function speak(message) {
        const msg = new SpeechSynthesisUtterance(message);
        const voices = speechSynthesis.getVoices();
        msg.voice = voices.find(v => v.name === 'Google UK English Male') ||
            voices.find(v => v.lang.startsWith('en'));
        speechSynthesis.speak(msg);
    }

    function strip(number) {
        return (parseFloat(number).toPrecision(12));
    }

    let lastValue = null;
    setInterval(() => {
        const raw = parseFloat(
            document.querySelector('#price-ticker').innerText
        );

        if (lastValue === null) {
            return lastValue = raw;
        } else if (lastValue !== raw) {
            const diff = strip(lastValue - raw);
            let negative = diff < 0;

            const absDiff = Math.abs(diff);
            const eur = Number(parseInt(absDiff));
            const cent = Number(parseInt((absDiff % 1) * 100));
            const mid = (eur && cent && ' and ') || '';

            if (eur || cent) {
                const start = `Price ${negative ? 'went up to' : 'dropped'} `;
                const end = `around ${eur ? `${eur} Euro ` : ''} ${mid} ${cent ? `${cent} Cent` : ''}`;
                const str = start + end;

                console.log({absDiff, eur, cent, str});
                speak(str);
            }
        }

        lastValue = raw;
    }, 1000);
})();