import 'dart:convert';
import 'dart:io';

import 'package:waylume_server/core/utils.dart';
import 'package:waylume_server/wireguard/utils.dart';
import 'package:waylume_server/wireguard/traffic_control.dart';

class WireGuardPeer {
  final String privateKey;
  final String publicKey;
  final String ip;

  WireGuardPeer({
    required this.privateKey,
    required this.publicKey,
    required this.ip,
  });

  Map<String, dynamic> toJson() => {
    'privateKey': privateKey,
    'publicKey': publicKey,
    'ip': ip,
  };

  factory WireGuardPeer.fromJson(Map<String, dynamic> json) => WireGuardPeer(
    privateKey: json['privateKey'],
    publicKey: json['publicKey'],
    ip: json['ip'],
  );

  String generateClientConfig({
    required String serverPublicKey,
    required String serverEndpoint,
    String dns = '1.1.1.1, 8.8.8.8', // Cloudflare and Google DNS
    String allowedIPs = '0.0.0.0/0',
  }) {
    return '''
[Interface]
PrivateKey = $privateKey
Address = $ip/32
DNS = $dns

[Peer]
PublicKey = $serverPublicKey
Endpoint = $serverEndpoint
AllowedIPs = $allowedIPs
PersistentKeepalive = 25
''';
  }
}

Future<String> generateClientConfigForPeer(WireGuardPeer peer) async {
  String serverEndpoint = '${await getWanIp()}:51820';
  String serverPublicKey = await getServerPublicKey();

  return peer.generateClientConfig(
    serverPublicKey: serverPublicKey,
    serverEndpoint: serverEndpoint,
  );
}

/// Creates a new WireGuard peer and returns the peer info
Future<WireGuardPeer> createPeer() async {
  // Generate private key
  final privateKeyResult = await Process.run('wg', ['genkey']);
  final privateKey = privateKeyResult.stdout.toString().trim();

  // Generate public key from private key
  final pubProcess = await Process.start('wg', ['pubkey']);
  pubProcess.stdin.writeln(privateKey);
  await pubProcess.stdin.close();
  final publicKey = await pubProcess.stdout.transform(utf8.decoder).join();

  // Get next available IP
  final ip = await _getNextIP();

  // Add peer to WireGuard
  await Process.run('wg', ['set', 'wg0', 'peer', publicKey.trim(), 'allowed-ips', '$ip/32']);

  return WireGuardPeer(
    privateKey: privateKey,
    publicKey: publicKey.trim(),
    ip: ip,
  );
}

Future<bool> deletePeer(String publicKey) async {
  // Remove peer from WireGuard
  final result = await Process.run('wg', ['set', 'wg0', 'peer', publicKey, 'remove']);
  if (result.exitCode != 0) {
    print('Error removing peer: ${result.stderr}');
    return false;
  }
  return true;
}

Future<void> setSpeedLimit(String publicKey, int speedKbps) async {
  print('Setting speed limit for peer $publicKey to ${speedKbps}kbps');
  final peerIP = await _getPeerIP(publicKey);
  print('Found peer IP: $peerIP for publicKey: $publicKey');
  if (peerIP == null) throw Exception('Peer not found');
  
  await TrafficControlService.setSpeedLimit(peerIP, speedKbps);
}

Future<void> setDataCap(String publicKey, int dataCapMB) async {
  final peerIP = await _getPeerIP(publicKey);
  if (peerIP == null) throw Exception('Peer not found');
  
  await TrafficControlService.setDataCap(peerIP, dataCapMB);
}

Future<String?> _getPeerIP(String publicKey) async {
  final result = await Process.run('wg', ['show', 'wg0', 'allowed-ips']);
  if (result.exitCode != 0) return null;

  final lines = result.stdout.toString().split('\n');
  for (final line in lines) {
    if (line.contains(publicKey)) {
      final match = RegExp(r'(\d+\.\d+\.\d+\.\d+)').firstMatch(line);
      return match?.group(1);
    }
  }
  return null;
}

Future<String> _getNextIP() async {
  final result = await Process.run('wg', ['show', 'wg0', 'allowed-ips']);
  final usedIPs = RegExp(r'10\.(\d+)\.(\d+)\.(\d+)')
      .allMatches(result.stdout.toString())
      .map((m) => '${m.group(1)}.${m.group(2)}.${m.group(3)}')
      .toSet();

  // Start from 10.0.0.2 (skip .1 for server)
  for (int a = 0; a <= 255; a++) {
    for (int b = 0; b <= 255; b++) {
      for (int c = (a == 0 && b == 0 ? 2 : 1); c <= 254; c++) {
        final ip = '10.$a.$b.$c';
        if (!usedIPs.contains('$a.$b.$c')) return ip;
      }
    }
  }
  throw Exception('No available IPs');
}