import 'dart:async';
import 'dart:io';
import 'package:http/http.dart' as http;

import 'net_guard.dart';

typedef BodyEncoder = Future<http.Response> Function();

class HttpRetry {
  /// ريتراي لـ network/transient errors فقط.
  static Future<http.Response> sendWithRetry(
    BodyEncoder send, {
    int maxRetries = 3,
    Duration baseDelay = const Duration(milliseconds: 400),
    Duration timeout = const Duration(seconds: 12),
  }) async {
    // ✅ Pre-flight check for internet connection
    if (!await NetGuard().hasInternet()) {
      // Immediately throw a specific exception if there's no internet.
      // This avoids pointless retries.
      throw const SocketException("No internet connection");
    }
    int attempt = 0;
    while (true) {
      attempt++;
      try {
        final res = await send().timeout(timeout);
        return res;
      } on TimeoutException catch (_) {
        if (attempt >= maxRetries) rethrow;
      } on SocketException catch (_) {
        if (attempt >= maxRetries) rethrow;
      } on HandshakeException catch (_) {
        if (attempt >= maxRetries) rethrow;
      } on http.ClientException catch (e) {
        // مثال: Connection reset by peer
        final msg = e.message.toLowerCase();
        final transient = msg.contains('connection reset') ||
            msg.contains('broken pipe') ||
            msg.contains('timed out');
        if (!transient || attempt >= maxRetries) rethrow;
      }
      // backoff: 0.4s, 0.8s, 1.6s
      final delay = baseDelay * (1 << (attempt - 1));
      await Future.delayed(delay);
    }
  }
}