import 'dart:convert';
import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;

/// Service for sending OTP emails via SMTP API
class EmailJSService {
  // Gmail SMTP Configuration
  static const String _senderEmail = 'erdiseptawahyupratamaggwp@gmail.com';
  static const String _appPassword = 'bcwgpewcqxcyhszp';
  static const String _apiUrl = 'https://freeemailapi.vercel.app/sendEmail/';

  // Store OTP codes temporarily
  static final Map<String, _OTPData> _otpStore = {};
  static String? lastGeneratedOTP;

  /// Generate a random 5-digit OTP
  static String generateOTP() {
    final random = Random();
    return (10000 + random.nextInt(90000)).toString();
  }

  /// Send OTP to email
  static Future<bool> sendOTP(String email) async {
    try {
      final otp = generateOTP();
      final expiresAt = DateTime.now().add(const Duration(minutes: 5));

      _otpStore[email] = _OTPData(otp: otp, expiresAt: expiresAt);
      lastGeneratedOTP = otp;

      debugPrint('📤 Sending OTP to $email...');

      final response = await http.post(
        Uri.parse(_apiUrl),
        headers: {'Content-Type': 'application/json'},
        body: jsonEncode({
          'fromEmail': _senderEmail,
          'passkey': _appPassword,
          'toEmail': email,
          'title': 'Amori Assistant',
          'subject': 'Kode Verifikasi OTP',
          'body':
              'Kode verifikasi Anda adalah: $otp\n\n'
              'Kode ini berlaku selama 5 menit.\n'
              'Jika Anda tidak meminta kode ini, abaikan email ini.',
        }),
      );

      final data = jsonDecode(response.body);
      final message = data['message']?.toString() ?? '';

      debugPrint('📥 Email API Response: $message');

      if (message == 'emailSendSuccess') {
        debugPrint('✅ OTP sent successfully to $email');
        return true;
      } else {
        debugPrint('❌ Failed to send OTP: $message');
        return false;
      }
    } catch (e) {
      debugPrint('❌ Error sending OTP: $e');
      return false;
    }
  }

  /// Verify OTP code
  static bool verifyOTP(String email, String code) {
    final otpData = _otpStore[email];

    if (otpData == null) {
      debugPrint('❌ No OTP found for $email');
      return false;
    }

    if (DateTime.now().isAfter(otpData.expiresAt)) {
      debugPrint('❌ OTP expired for $email');
      _otpStore.remove(email);
      return false;
    }

    if (otpData.otp != code) {
      debugPrint(
        '❌ Invalid OTP for $email (expected: ${otpData.otp}, got: $code)',
      );
      return false;
    }

    debugPrint('✅ OTP verified for $email');
    _otpStore.remove(email);
    return true;
  }

  /// Check if OTP exists and is valid (not expired)
  static bool hasValidOTP(String email) {
    final otpData = _otpStore[email];
    if (otpData == null) return false;
    return DateTime.now().isBefore(otpData.expiresAt);
  }

  /// Clear OTP for email
  static void clearOTP(String email) {
    _otpStore.remove(email);
  }

  /// Get last generated OTP (for dev mode display)
  static String? getLastOTP() => lastGeneratedOTP;
}

class _OTPData {
  final String otp;
  final DateTime expiresAt;

  _OTPData({required this.otp, required this.expiresAt});
}