import { isAbsolute, relative, resolve } from "node:path";

const MAX_ACCESSED_PATHS = 500;
const accessedPaths = new Set<string>();

function normalizeRelativePath(path: string): string {
  return path.replace(/\\/g, "/").replace(/^\.\//, "");
}

function isInsideCwd(cwd: string, absolutePath: string): boolean {
  const relativePath = relative(resolve(cwd), absolutePath);
  return relativePath === "" || (!relativePath.startsWith("..") && !isAbsolute(relativePath));
}

export function recordAccess(cwd: string, absolutePath: string): void {
  const resolvedCwd = resolve(cwd);
  const resolvedPath = isAbsolute(absolutePath) ? resolve(absolutePath) : resolve(resolvedCwd, absolutePath);
  if (!isInsideCwd(resolvedCwd, resolvedPath)) return;

  const relativePath = normalizeRelativePath(relative(resolvedCwd, resolvedPath));
  if (!relativePath) return;

  if (accessedPaths.has(relativePath)) accessedPaths.delete(relativePath);
  accessedPaths.add(relativePath);

  while (accessedPaths.size > MAX_ACCESSED_PATHS) {
    const oldest = accessedPaths.values().next().value as string | undefined;
    if (!oldest) break;
    accessedPaths.delete(oldest);
  }
}

export function getAccessedPaths(): string[] {
  return Array.from(accessedPaths);
}

export function resetTracker(): void {
  accessedPaths.clear();
}