import lucide from "@iconify-json/lucide/icons.json";
import { readFileSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { createRequire } from "node:module";

/** Inline the real shipped icon shapes: preview frames never need an icon CDN. */
export function previewIconCss(markup: string) {
  const names = new Set([...markup.matchAll(/icon-\[lucide--([\w-]+)\]/g)].map((m) => m[1]!));
  // Controllers introduce these icons after interaction.
  for (const name of ["check", "x", "chevron-down", "chevron-up", "loader-circle"]) names.add(name);
  const icons = lucide.icons as Record<string, { body: string }>;
  return [...names]
    .map((name) => {
      const aliases = lucide.aliases as Record<string, { parent: string }>;
      let key = name;
      const visited = new Set<string>();
      while (!icons[key] && aliases[key] && !visited.has(key)) {
        visited.add(key);
        key = aliases[key]!.parent;
      }
      const icon = icons[key];
      if (!icon) throw Error(`Unknown preview icon: lucide--${name}`);
      const svg = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">${icon.body}</svg>`;
      const url = `url("data:image/svg+xml,${encodeURIComponent(svg)}")`;
      return `[class~="icon-[lucide--${name}]"]{display:inline-block;width:1em;height:1em;flex-shrink:0;background-color:currentColor;mask:${url} center/contain no-repeat;-webkit-mask:${url} center/contain no-repeat}`;
    })
    .join("\n");
}

const runtimeCache = new Map<string, Promise<string>>();
export async function previewProviderRuntime(name: "chart" | "drawflow") {
  if (!runtimeCache.has(name))
    runtimeCache.set(
      name,
      (async () => {
        const result = await Bun.build({
          entrypoints: [fileURLToPath(import.meta.resolve(`@wrnexus/ui/${name}-runtime`))],
          target: "browser",
          format: "iife",
          minify: true,
        });
        if (!result.success) throw Error(result.logs.join("\n"));
        return result.outputs[0]!.text();
      })().catch((error) => {
        runtimeCache.delete(name);
        throw error;
      }),
    );
  return runtimeCache.get(name)!;
}
export function previewDrawflowCss() {
  const require = createRequire(import.meta.resolve("@wrnexus/ui/drawflow-runtime"));
  return (
    readFileSync(require.resolve("drawflow/dist/drawflow.min.css"), "utf8") +
    readFileSync(fileURLToPath(import.meta.resolve("@wrnexus/ui/drawflow.css")), "utf8")
  );
}