Kindroid Character Counter

A character counter for message length when messaging Kins via browser
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// ==UserScript==
// @name         Kindroid Character Counter
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  A character counter for message length when messaging Kins via browser
// @match        https://kindroid.ai/chat*
// @grant        none
// @author       Valco (Discord @alphawuff)
// @license      GNU GPLv3
// ==/UserScript==

(function () {
    'use strict';

    const MAX_CHARS = 4000;
    const ACCENT = "#8271f2";

    function findElements() {
        const input = document.querySelector("textarea");
        const button = document.querySelector(".chakra-button.css-s31pb8");
        return { input, button };
    }

    function createCounter(input, button) {
        if (document.querySelector(".kindroid-counter")) return;

        const counterWrapper = document.createElement('div');
        counterWrapper.className = "kindroid-counter";
        counterWrapper.style.position = 'fixed';
        counterWrapper.style.zIndex = '9999';
        counterWrapper.style.pointerEvents = 'none';

        const size = 42;
        const strokeWidth = 4;
        const radius = (size / 2) - strokeWidth - 1;
        const circumference = 2 * Math.PI * radius;

        const svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
        svg.setAttribute("width", size);
        svg.setAttribute("height", size);

        const bgCircle = document.createElementNS("http://www.w3.org/2000/svg", "circle");
        bgCircle.setAttribute("cx", size / 2);
        bgCircle.setAttribute("cy", size / 2);
        bgCircle.setAttribute("r", radius);
        bgCircle.setAttribute("stroke", "rgba(255,255,255,0.15)");
        bgCircle.setAttribute("stroke-width", strokeWidth);
        bgCircle.setAttribute("fill", "none");

        const progressCircle = document.createElementNS("http://www.w3.org/2000/svg", "circle");
        progressCircle.setAttribute("cx", size / 2);
        progressCircle.setAttribute("cy", size / 2);
        progressCircle.setAttribute("r", radius);
        progressCircle.setAttribute("stroke", ACCENT);
        progressCircle.setAttribute("stroke-width", strokeWidth);
        progressCircle.setAttribute("fill", "none");
        progressCircle.setAttribute("stroke-dasharray", circumference);
        progressCircle.setAttribute("stroke-dashoffset", circumference);
        progressCircle.style.transition = "all 0.2s ease";
        progressCircle.style.filter = `drop-shadow(0 0 4px ${ACCENT})`;
        progressCircle.setAttribute("transform", `rotate(-90 ${size / 2} ${size / 2})`);

        const text = document.createElementNS("http://www.w3.org/2000/svg", "text");
        text.setAttribute("x", "50%");
        text.setAttribute("y", "54%");
        text.setAttribute("dominant-baseline", "middle");
        text.setAttribute("text-anchor", "middle");
        text.setAttribute("fill", "white");

        text.style.fontFamily = "system-ui, sans-serif";
        text.style.fontWeight = "700";
        text.style.fontSize = "14px";
        text.style.paintOrder = "stroke";


        text.style.textShadow = "0 0 4px rgba(0,0,0,0.8), 0 0 2px rgba(0,0,0,0.6)";

        text.textContent = "0";

        svg.appendChild(bgCircle);
        svg.appendChild(progressCircle);
        svg.appendChild(text);
        counterWrapper.appendChild(svg);
        document.body.appendChild(counterWrapper);

        function positionCounter() {
            if (!button) return;

            const rect = button.getBoundingClientRect();

            counterWrapper.style.left = `${rect.right + 10}px`;
            counterWrapper.style.top = `${rect.top + rect.height / 2 - size / 2}px`;
        }

        function update() {
            const length = input.value.length;
            const progress = Math.min(length / MAX_CHARS, 1);

            progressCircle.setAttribute(
                "stroke-dashoffset",
                circumference * (1 - progress)
            );

            text.textContent = length;

            const digits = length.toString().length;

            let fontSize = 14;

            if (digits >= 4) fontSize = 10;
            else if (digits === 3) fontSize = 12;

            text.style.fontSize = fontSize + "px";

            if (length >= MAX_CHARS) {
                progressCircle.setAttribute("stroke", "#ff4d4f");
            } else if (length > 3000) {
                progressCircle.setAttribute("stroke", "#facc15");
            } else {
                progressCircle.setAttribute("stroke", ACCENT);
            }
        }

        input.addEventListener("input", update);

        window.addEventListener("resize", positionCounter);
        window.addEventListener("scroll", positionCounter);

        const observer = new MutationObserver(() => {
            const { button: newButton } = findElements();
            if (newButton) button = newButton;
            positionCounter();
        });

        observer.observe(document.body, { childList: true, subtree: true });

        positionCounter();
        update();
    }

    function init() {
        const observer = new MutationObserver(() => {
            const { input, button } = findElements();

            if (input && button) {
                createCounter(input, button);
            }
        });

        observer.observe(document.body, { childList: true, subtree: true });
    }

    init();
})();