import "dart:io";
import "package:flutter/services.dart";

/// Detected beacon from native scanner
class DetectedBeacon {
  final String uuid;
  final int rssi;
  final int samples;

  const DetectedBeacon({
    required this.uuid,
    required this.rssi,
    required this.samples,
  });

  factory DetectedBeacon.fromMap(Map<dynamic, dynamic> map) {
    return DetectedBeacon(
      uuid: (map["uuid"] as String?) ?? "",
      rssi: (map["rssi"] as int?) ?? -100,
      samples: (map["samples"] as int?) ?? 0,
    );
  }

  @override
  String toString() => "DetectedBeacon(uuid: $uuid, rssi: $rssi, samples: $samples)";
}

/// Native beacon scanner via MethodChannel
/// Only works on Android. iOS falls back to Flutter plugin.
class BeaconChannel {
  static const _channel = MethodChannel("com.payfrit.app/beacon");

  /// Check if running on Android (native scanner only works there)
  static bool get isSupported => Platform.isAndroid;

  /// Check if Bluetooth permissions are granted
  static Future<bool> hasPermissions() async {
    if (!isSupported) return false;

    try {
      final result = await _channel.invokeMethod<bool>("hasPermissions");
      return result ?? false;
    } on PlatformException catch (e) {
      print("[BeaconChannel] hasPermissions error: $e");
      return false;
    }
  }

  /// Check if Bluetooth is enabled
  static Future<bool> isBluetoothEnabled() async {
    if (!isSupported) return false;

    try {
      final result = await _channel.invokeMethod<bool>("isBluetoothEnabled");
      return result ?? false;
    } on PlatformException catch (e) {
      print("[BeaconChannel] isBluetoothEnabled error: $e");
      return false;
    }
  }

  /// Start scanning for beacons
  /// Returns list of detected beacons sorted by RSSI (strongest first)
  static Future<List<DetectedBeacon>> startScan({List<String>? regions}) async {
    if (!isSupported) {
      print("[BeaconChannel] Not supported on this platform");
      return [];
    }

    try {
      print("[BeaconChannel] Starting native beacon scan...");

      final result = await _channel.invokeMethod<List<dynamic>>(
        "startScan",
        {"regions": regions ?? []},
      );

      if (result == null) {
        print("[BeaconChannel] Scan returned null");
        return [];
      }

      final beacons = result
          .map((e) => DetectedBeacon.fromMap(e as Map<dynamic, dynamic>))
          .toList();

      print("[BeaconChannel] Scan complete: found ${beacons.length} beacons");
      for (final b in beacons) {
        print("[BeaconChannel]   $b");
      }

      return beacons;
    } on PlatformException catch (e) {
      print("[BeaconChannel] Scan error: ${e.message}");
      return [];
    }
  }

  /// Stop an ongoing scan
  static Future<void> stopScan() async {
    if (!isSupported) return;

    try {
      await _channel.invokeMethod("stopScan");
    } on PlatformException catch (e) {
      print("[BeaconChannel] stopScan error: $e");
    }
  }
}