// ==UserScript==
// @name         调整网页字体和行间距倍数
// @author       ChatGPT
// @version      6.2
// @description  脚本菜单可用于调整网页的字体和行间距倍数
// @match        *://*/*
// @grant        GM_registerMenuCommand
// @grant        GM_setValue
// @grant        GM_getValue
// @run-at       document-start
// @namespace https://greasyfork.org/users/452911
// @downloadURL none
// ==/UserScript==

(function () {
  "use strict";

  var storageKey = window.location.hostname;
  var fontMultiplier = GM_getValue(storageKey + "_font_multiplier", 1);
  var lineHeightMultiplier = GM_getValue(
    storageKey + "_line_height_multiplier",
    1
  );

  function enlargeFontSize() {
    const rootFontSize = parseFloat(
      getComputedStyle(document.documentElement).fontSize
    );
    const newRootFontSize = rootFontSize * fontMultiplier;
    document.documentElement.style.fontSize = `${newRootFontSize}px`;
    const rootLineHeight = parseFloat(
      getComputedStyle(document.documentElement).lineHeight
    );
    const newRootLineHeight = rootLineHeight * lineHeightMultiplier;
    document.documentElement.style.lineHeight = `${newRootLineHeight}px`;
    const elementsToScale = document.querySelectorAll("*");
    elementsToScale.forEach((element) => {
      const fontSize = parseFloat(getComputedStyle(element).fontSize);
      element.style.fontSize = `${(fontSize / rootFontSize) * newRootFontSize}px`;
      const lineHeight = parseFloat(getComputedStyle(element).lineHeight);
      element.style.lineHeight = `${
        (lineHeight / rootLineHeight) * newRootLineHeight
      }px`;
    });
  }

  enlargeFontSize();

  GM_registerMenuCommand("调整字体大小", function () {
    var newFontMultiplier = prompt(
      "请输入字体大小倍数",
      fontMultiplier.toString()
    );
    if (newFontMultiplier !== null) {
      fontMultiplier = parseFloat(newFontMultiplier);
      GM_setValue(storageKey + "_font_multiplier", fontMultiplier);
      enlargeFontSize();
    }
  });

  GM_registerMenuCommand("调整行间距", function () {
    var newLineHeightMultiplier = prompt(
      "请输入行间距倍数",
      lineHeightMultiplier.toString()
    );
    if (newLineHeightMultiplier !== null) {
      lineHeightMultiplier = parseFloat(newLineHeightMultiplier);
      GM_setValue(
        storageKey + "_line_height_multiplier",
        lineHeightMultiplier
      );
      enlargeFontSize();
    }
  });
})();