import { execFileSync } from "node:child_process";

export type GpuVendor = "nvidia" | "amd" | "intel";

// ponytail: card-generation nuance (e.g. Nouveau for pre-Turing NVIDIA cards) isn't
// handled — add if an unsupported-card report comes in.
const DRIVER_PACKAGES: Record<GpuVendor, string[]> = {
  nvidia: ["nvidia-open-dkms", "nvidia-utils", "egl-wayland"],
  amd: ["mesa", "vulkan-radeon", "libva-mesa-driver"],
  intel: ["mesa", "vulkan-intel", "intel-media-driver"],
};

const VENDOR_PATTERNS: [RegExp, GpuVendor][] = [
  [/nvidia/i, "nvidia"],
  [/\b(amd|ati)\b/i, "amd"],
  [/intel/i, "intel"],
];

export function detectGpuVendors(): GpuVendor[] {
  let output: string;
  try {
    output = execFileSync("lspci", [], { encoding: "utf8" });
  } catch {
    return [];
  }

  const controllerLines = output
    .split("\n")
    .filter((line) => /VGA compatible controller|3D controller/i.test(line));

  const found = new Set<GpuVendor>();
  for (const line of controllerLines) {
    for (const [pattern, vendor] of VENDOR_PATTERNS) {
      if (pattern.test(line)) found.add(vendor);
    }
  }
  return [...found];
}

export function driverPackagesFor(vendors: GpuVendor[]): string[] {
  return vendors.flatMap((vendor) => DRIVER_PACKAGES[vendor]);
}