Dynamic DeepSeek RTL/LTR Direction

Dynamically set text direction for Deepseek chat elements based on content
换行
// ==UserScript==
// @name          Dynamic DeepSeek RTL/LTR Direction
// @namespace     http://tampermonkey.net/
// @version       V4.2
// @description   Dynamically set text direction for Deepseek chat elements based on content
// @author        Reda Elsayed
// @match         https://chat.deepseek.com/
// @match         https://chat.deepseek.com/*
// @match         https://chat.deepseek.com/*/chat/*/*
// @icon          https://www.deepseek.com/path/to/icon.png
// @grant         none
// ==/UserScript==

(function () {
  "use strict";

  // --- Selectors (update these if DeepSeek changes its class names again) ---

  // Assistant markdown response container
  // Old: "ds-markdown ds-markdown--block"
  const ASSISTANT_MSG_SELECTOR = ".ds-markdown.ds-assistant-message-main-content";

  // User message bubble
  const USER_MSG_SELECTOR = ".fbb737a4";

  // Code blocks (always force LTR)
  const CODE_BLOCK_SELECTOR = ".md-code-block";

  // Textarea (the input box)
  // Old: "c92459f0"  |  New: "d96f2d2a"
  const TEXTAREA_SELECTOR = "textarea.d96f2d2a, textarea.c92459f0";

  // -------------------------------------------------------------------------

  function isRTL(text) {
    const rtlPattern = /[\u0591-\u07FF\uFB1D-\uFDFD\uFE70-\uFEFC]/;
    return rtlPattern.test(text);
  }

  function applyDirection(element, text) {
    if (!text || text.length === 0) return;
    const dir = isRTL(text) ? "rtl" : "ltr";
    if (element.style.direction !== dir) {
      element.style.direction = dir;
      element.style.textAlign = dir === "rtl" ? "right" : "left";
    }
  }

  function updateDirection() {
    // Assistant messages
    document.querySelectorAll(ASSISTANT_MSG_SELECTOR).forEach((el) => {
      applyDirection(el, el.textContent.trim());
    });

    // User messages
    document.querySelectorAll(USER_MSG_SELECTOR).forEach((el) => {
      applyDirection(el, el.textContent.trim());
    });

    // Code blocks — always LTR regardless of content
    document.querySelectorAll(CODE_BLOCK_SELECTOR).forEach((el) => {
      el.style.direction = "ltr";
      el.style.textAlign = "left";
    });
  }

  // Attach input-direction listener to a textarea element (idempotent)
  const boundTextareas = new WeakSet();
  function bindTextarea(textarea) {
    if (boundTextareas.has(textarea)) return;
    boundTextareas.add(textarea);
    textarea.addEventListener("input", () => {
      const text = textarea.value.trim();
      const dir = isRTL(text) ? "rtl" : "ltr";
      textarea.style.direction = dir;
      textarea.style.textAlign = dir === "rtl" ? "right" : "left";
    });
  }

  function bindAllTextareas() {
    document.querySelectorAll(TEXTAREA_SELECTOR).forEach(bindTextarea);
  }

  function observeChanges() {
    const observer = new MutationObserver(() => {
      updateDirection();
      bindAllTextareas(); // re-bind in case new textareas were injected
    });
    observer.observe(document.body, { childList: true, subtree: true });
  }

  // Initialize
  updateDirection();
  bindAllTextareas();
  observeChanges();
})();