(function () {
  "use strict";

  const THEME_KEY = "doxa_theme";
  let systemMediaQuery = null;
  let systemMediaListener = null;

  function applyTheme(theme) {
    try {
      if (systemMediaQuery && systemMediaListener) {
        try {
          if (systemMediaQuery.removeEventListener)
            systemMediaQuery.removeEventListener("change", systemMediaListener);
          else systemMediaQuery.removeListener(systemMediaListener);
        } catch (e) {}
        systemMediaQuery = null;
        systemMediaListener = null;
      }

      if (theme === "dark") {
        document.body.classList.add("dark");
      } else if (theme === "light") {
        document.body.classList.remove("dark");
      } else {
        try {
          const mql = window.matchMedia("(prefers-color-scheme: dark)");
          if (mql.matches) document.body.classList.add("dark");
          else document.body.classList.remove("dark");
          systemMediaQuery = mql;
          systemMediaListener = function (e) {
            if (e.matches) document.body.classList.add("dark");
            else document.body.classList.remove("dark");
            updateThemeButton();
          };
          if (mql.addEventListener)
            mql.addEventListener("change", systemMediaListener);
          else mql.addListener(systemMediaListener);
        } catch (e) {
          document.body.classList.remove("dark");
        }
      }
    } catch (e) {}
    updateThemeButton();
  }

  function updateThemeButton() {
      const btn = document.getElementById("themeToggle");
      if (!btn) return;
      const theme = getStoredTheme() || "system";
      let icon = "🌓";
      if (theme === "dark") {
        icon = "🌙";
      } else if (theme === "light") {
        icon = "☀️";
      }
      btn.textContent = icon;
  }

  function getStoredTheme() {
    try {
      return localStorage.getItem(THEME_KEY);
    } catch (e) { return null; }
  }
  function setStoredTheme(value) {
    try {
      localStorage.setItem(THEME_KEY, value);
    } catch (e) {}
  }

  function toggleTheme() {
    const stored = getStoredTheme() || "system";
    const order = ["light", "dark", "system"];
    let idx = order.indexOf(stored);
    if (idx === -1) idx = 2;
    const next = order[(idx + 1) % order.length];
    setStoredTheme(next);
    applyTheme(next);
  }

  document.addEventListener("DOMContentLoaded", () => {
    const themeBtn = document.getElementById("themeToggle");
    if (themeBtn) themeBtn.addEventListener("click", toggleTheme);
    applyTheme(getStoredTheme() || "system");
  });
})();