// Persist theme preference with zero flash on load
const STORAGE_KEY = "theme";
type Theme = "light" | "dark";

export function initTheme(): void {
  const saved = localStorage.getItem(STORAGE_KEY) as Theme | null;
  const prefersDark = window.matchMedia("(prefers-color-scheme: dark)").matches;
  applyTheme(saved ?? (prefersDark ? "dark" : "light"));
}

export function applyTheme(theme: Theme): void {
  document.documentElement.setAttribute("data-bs-theme", theme);
  localStorage.setItem(STORAGE_KEY, theme);
  syncHighlightTheme(theme);
}

function syncHighlightTheme(theme: Theme): void {
  const light = document.getElementById("hljs-light") as HTMLLinkElement;
  const dark = document.getElementById("hljs-dark") as HTMLLinkElement;
  light.disabled = theme === "dark";
  dark.disabled = theme === "light";
}