import 'dart:convert';
import 'dart:math';
import 'dart:typed_data';
import 'package:crypto/crypto.dart';

class HashUtils {
  static final _random = Random.secure();

  static String generateHash() {
    final bytes = List<int>.generate(32, (_) => _random.nextInt(256));
    return sha256.convert(bytes).toString();
  }

  static String hashFromBytes(Uint8List bytes) {
    return sha256.convert(bytes).toString();
  }

  static String hashFromString(String input) {
    return sha256.convert(utf8.encode(input)).toString();
  }

  static bool isValidHash(String hash) {
    if (hash.length != 64) return false;
    return RegExp(r'^[a-f0-9]{64}$').hasMatch(hash);
  }

  static List<String> extractHashes(String text) {
    final regex = RegExp(r'[a-f0-9]{64}');
    return regex.allMatches(text).map((m) => m.group(0)!).toList();
  }

  static String truncateHash(String hash, {int length = 8}) {
    if (hash.length <= length) return hash;
    return '${hash.substring(0, length)}...';
  }
}