import { readdir, readFile } from "node:fs/promises";
import { stdout } from "node:process";
import { fileURLToPath, URL } from "node:url";
import path from "node:path";

const assetsDirectory = fileURLToPath(new URL("../dist/assets/", import.meta.url));
const assetNames = await readdir(assetsDirectory);
const stylesheetName = assetNames.find((name) => /^index-.*\.css$/.test(name));

if (!stylesheetName) {
  throw new Error("Production CSS verification failed: index stylesheet was not emitted.");
}

const stylesheet = await readFile(path.join(assetsDirectory, stylesheetName), "utf8");
const selector = ".agent-panel-shell.acrylic-panel";
const selectorOffset = stylesheet.indexOf(selector);
const ruleStart = stylesheet.indexOf("{", selectorOffset);
const ruleEnd = stylesheet.indexOf("}", ruleStart);

if (selectorOffset < 0 || ruleStart < 0 || ruleEnd < 0) {
  throw new Error(`Production CSS verification failed: ${selector} rule is missing.`);
}

const declarations = stylesheet
  .slice(ruleStart + 1, ruleEnd)
  .split(";")
  .map((declaration) => declaration.trim());

if (!declarations.some((declaration) => declaration.startsWith("backdrop-filter:"))) {
  throw new Error(
    "Production CSS verification failed: the standard backdrop-filter declaration was removed."
  );
}

stdout.write(`Verified standard backdrop-filter in ${stylesheetName}.\n`);