import React from "react";
import { useRouter } from "next/router";
import { decompressFromEncodedURIComponent } from "lz-string";
import base64url from "base64url";

type UseCodeReturn = {
  code: string | null;
  css: string | null;
  isReady: boolean;
  hasQuery: boolean;
  disableScroll: boolean;
  useTailwind: boolean;
  isLoading: boolean;
};

export const useCode = (): UseCodeReturn => {
  const { query, isReady } = useRouter();
  const {
    code: encoded,
    hash,
    disableScroll,
    tailwind,
    css: cssCompressed,
  } = query ?? {};

  const [isLoading, setIsLoading] = React.useState<boolean>(true);
  const [compressed, setCompressed] = React.useState<string | undefined>();

  React.useEffect(() => {
    if (!isReady) return;
    if (compressed) return;

    if (encoded) {
      setCompressed(encoded as string);
      setIsLoading(false);
      return;
    }

    if (hash) {
      fetch(
        `https://${process.env.NEXT_PUBLIC_PREVIEWS_BUCKET_NAME}.fra1.cdn.digitaloceanspaces.com/preview-strings/${hash}`,
      )
        .then((body) =>
          body.text().then((data) => {
            setCompressed(data);
            setIsLoading(false);
          }),
        )
        .catch((e) => {
          setIsLoading(false);
        });
    }
  }, [isReady, compressed, encoded, hash]);

  const code = React.useMemo(() => {
    if (!isReady) return "";
    if (!compressed) return "";
    const decompressed = decompressFromEncodedURIComponent(
      compressed as string,
    );
    const fixed = decompressed?.replace(/React\$1/g, "React");

    const shouldChangeEntrypoint =
      fixed.match(/render\(<App \/>\);?/) &&
      fixed.match(/createRoot\(container\);?/);

    let content = fixed;

    if (shouldChangeEntrypoint) {
      content = fixed.replace(/render\(<App \/>\);?/, "");
      content = content.replace(
        /createRoot\(container\);?/,
        "{ render: (children) => render(<RefineCore.ExternalNavigationProvider>{children}</RefineCore.ExternalNavigationProvider>) };",
      );
    }

    return content;
  }, [compressed, isReady]);

  const css = React.useMemo(() => {
    if (!isReady) return "";
    if (!cssCompressed) return "";
    try {
      return base64url.decode(cssCompressed as string);
    } catch (err) {
      console.log("CSS Decode Error", { err });
      return "";
    }
  }, [cssCompressed, isReady]);

  return {
    code,
    css,
    isReady,
    hasQuery: !!encoded || !!hash,
    disableScroll: !!disableScroll,
    useTailwind: !!tailwind,
    isLoading,
  };
};