import { fileURLToPath } from "node:url";
import { resolve, sep } from "node:path";
import { getAgentDir } from "@mariozechner/pi-coding-agent";

export type ExtensionInstallScope = "global" | "project";

function normalizeDir(path: string): string {
  const normalized = resolve(path);
  return normalized.endsWith(sep) ? normalized : normalized + sep;
}

function isWithin(path: string, parent: string): boolean {
  const normalizedPath = normalizeDir(path);
  const normalizedParent = normalizeDir(parent);
  return normalizedPath.startsWith(normalizedParent);
}

export function detectExtensionInstallScope(cwd: string): ExtensionInstallScope {
  const extensionFile = fileURLToPath(import.meta.url);
  const agentDir = getAgentDir();
  const projectPiDir = resolve(cwd, ".pi");

  if (isWithin(extensionFile, projectPiDir)) return "project";
  if (isWithin(extensionFile, agentDir)) return "global";
  return "global";
}