import { existsSync } from "node:fs";
import { join } from "node:path";
import { spawnSync } from "node:child_process";

export function resolvePrimeRoot() {
  const npmRoot = spawnSync("npm", ["root", "--global"], { encoding: "utf8" });
  const candidates = [
    process.env.PRIME_AGENT_ROOT,
    npmRoot.status === 0 ? join(npmRoot.stdout.trim(), "prime-agent") : undefined,
    "/opt/homebrew/lib/node_modules/prime-agent",
    "/usr/local/lib/node_modules/prime-agent",
    "/usr/lib/node_modules/prime-agent",
  ];
  const root = candidates.find((candidate) =>
    candidate && existsSync(join(candidate, "dist/index.d.ts"))
  );
  if (!root) {
    throw new Error("Prime Agent was not found; set PRIME_AGENT_ROOT to its package directory");
  }
  return root;
}