import postcss from "postcss";
import { transform } from "lightningcss";

const LEGACY_CHROME = 100 << 16;

/**
 * Keep Vite's PostCSS pipeline (required by Tailwind 4), then compile the
 * resulting CSS to Chrome 100-compatible syntax for both dev and production.
 */
export default function lightningCssLegacyChrome() {
  return {
    postcssPlugin: "postcss-lightningcss-legacy-chrome",
    OnceExit(root, { result }) {
      const filename = root.source?.input.file ?? result.opts.from ?? "style.css";
      const output = transform({
        filename,
        code: Buffer.from(root.toString()),
        targets: { chrome: LEGACY_CHROME },
        minify: false,
      });
      const compiled = postcss.parse(output.code.toString(), { from: filename });

      root.removeAll();
      root.append(compiled.nodes);

      for (const warning of output.warnings) {
        result.warn(warning.message, { plugin: "lightningcss" });
      }
    },
  };
}

lightningCssLegacyChrome.postcss = true;