import * as NodeFS from "node:fs";

import type { MobileThemeAppearance, MobileThemeVariables } from "./mobileTheme";

export function readDefaultMobileThemeVariables(
  appearance: MobileThemeAppearance,
): MobileThemeVariables {
  const stylesheet = NodeFS.readFileSync(new URL("../../global.css", import.meta.url), "utf8");
  const variant = new RegExp(`@variant ${appearance} \\{([\\s\\S]*?)\\n    \\}`, "u").exec(
    stylesheet,
  )?.[1];
  if (variant === undefined) throw new Error(`Missing default ${appearance} theme in global.css.`);

  return Object.fromEntries(
    Array.from(variant.matchAll(/(--color-[a-z0-9-]+):\s*([^;]+);/gu), ([, name, value]) => [
      name,
      value.trim(),
    ]),
  ) as MobileThemeVariables;
}