import Head from "next/head";
import { useEffect, useState } from "react";
import { Maybe } from "@trpc/server";
// This method is stringified and executed only on client. So,
// - Pass all the params explicitly to this method. Don't use closure
function applyThemeAndAddListener(theme: string) {
const mediaQueryList = window.matchMedia("(prefers-color-scheme: dark)");
const applyTheme = function (theme: string, darkMatch: boolean) {
if (!theme) {
if (darkMatch) {
document.documentElement.classList.add("dark");
} else {
document.documentElement.classList.remove("dark");
}
} else {
document.documentElement.classList.add(theme);
}
};
mediaQueryList.onchange = function (e) {
applyTheme(theme, e.matches);
};
applyTheme(theme, mediaQueryList.matches);
}
// makes sure the ui doesn't flash
export default function useTheme(theme?: Maybe<string>) {
const [isReady, setIsReady] = useState(false);
useEffect(() => {
// TODO: isReady doesn't seem required now. This is also impacting PSI Score for pages which are using isReady.
setIsReady(true);
}, []);
function Theme() {
const code = applyThemeAndAddListener.toString();
const themeStr = theme ? `"${theme}"` : null;
return (
<Head>
<script dangerouslySetInnerHTML={{ __html: `(${code})(${themeStr})` }}></script>
</Head>
);
}
return {
isReady,
Theme,
};
}