Silly FEHeroes Minigame script

// ==UserScript==
// @name         FEH QHB Auto
// @version      0.2
// @description  FEH auto-battle, but for a browser minigame
// @match        https://events.fire-emblem-heroes.com/color/play
// @grant        none
// ==/UserScript==

const $ = document.querySelector.bind(document); // keep `this` as `document`
const $$ = document.querySelectorAll.bind(document); // keep `this` as `document`
const matchupMap = new Map([ // enemy -> Hero with WTA
    [`green`, `Roy`],
    [`red`, `Lucina`],
    [`blue`, `Ike`],
    [`white`, `Lyn`],
]);
const coordinateMap = new Map([ // Hero -> touch coordinates for Hero's button
    [`Roy`, [160, 701]],
    [`Lucina`, [251, 701]],
    [`Ike`, [368, 701]],
    [`Lyn`, [546, 701]],
]);

// generate fake touch events
function sendTouchEvent (x, y, element, eventType) {
    const touch = new Touch({
        identifier: Date.now(),
        target: element,
        clientX: x,
        clientY: y,
    });
    const touchEvent = new TouchEvent(eventType, {
        changedTouches: [touch],
    });
    element.dispatchEvent(touchEvent);
}

// skip sound options, difficulty select, tweet and play
function checkForModal() {
    if ($(`.btn-sound-off`)) {
        console.log(`Turning off sound...`);
        sendTouchEvent(0, 0, $(`.btn-sound-off`), `touchend`);
    } else if ($(`.btn-battle-lunatic`)) {
        console.log(`Selecting lunatic difficulty...`);
        sendTouchEvent(0, 0, $(`.btn-battle-lunatic`), `touchend`);
        console.log(`Clicking "Tweet and Play" button...`);
        sendTouchEvent(0, 0, [...$$(`.modal-container-connect > .btn-general-link`)][3], `touchend`);
    } else if($(".modal-container-result") && $(".modal-container-result").parentNode.parentNode.style.display==="") { // game over popup is visible
        if ($(`.btn-result-tweet`)) {
            console.log(`Clicking "Tweet and Try Again" button...`);
            sendTouchEvent(0, 0, $(`.btn-result-tweet`), 'touchend');
        }
        if ($(`.btn-result-retry`)) {
            console.log(`Clicking "Try Again" button...`);
            sendTouchEvent(0, 0, $(`.btn-result-retry`), 'touchend');
        }
    }
}

// return Hero with WTA against enemy
function getHero(color, flying) {
    return flying ? `Lyn` : matchupMap.get(color); // Lyn gives two combo points against all flying enemies
}

// determine which Hero icon to press given enemy properties
function processNewEnemy(color, flying) {
    const hero = getHero(color, flying);
    console.log(`Selected ${hero} against ${flying ? `flying ` : ``}${color} enemy.`);
    setTimeout(function() {
        sendTouchEvent(...coordinateMap.get(hero), $(`canvas`), `touchstart`);
    }, 300); // slight delay to ensure button is pressed when pressable
}

// wrap Console.log() to intercept data logged by the game
const oldLog = window.console.log;
window.console.log = function(...args) {
    if (typeof args[0] === `number` && args[1].color) {
        processNewEnemy(args[1].color, args[1].flying);
    }
    oldLog(...args);
};


setTimeout(function() { // refresh every 10 minutes just in case the game breaks
    console.log(`Reloading page...`);
    location.reload();
}, 600000);
setInterval(checkForModal, 1000); // check every second