import { readFileSync, writeFileSync, existsSync, mkdirSync, renameSync } from 'node:fs';
import { dirname, join } from 'node:path';

const DATA_DIR = join(process.cwd(), 'data');

if (!existsSync(DATA_DIR)) mkdirSync(DATA_DIR, { recursive: true });

export function dataPath(name: string): string {
  return join(DATA_DIR, name);
}

export function readJson<T>(name: string, fallback: T): T {
  const p = dataPath(name);
  if (!existsSync(p)) return fallback;
  try {
    return JSON.parse(readFileSync(p, 'utf8')) as T;
  } catch {
    return fallback;
  }
}

export function writeJson<T>(name: string, value: T): void {
  const p = dataPath(name);
  const dir = dirname(p);
  if (!existsSync(dir)) mkdirSync(dir, { recursive: true });
  const tmp = `${p}.tmp`;
  writeFileSync(tmp, JSON.stringify(value, null, 2), 'utf8');
  renameSync(tmp, p);
}