import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:dchs_flutter_beacon/dchs_flutter_beacon.dart';

class BeaconPermissions {
  static Future<bool> requestPermissions() async {
    try {
      // Request location permission (required for Bluetooth scanning)
      final locationStatus = await Permission.locationWhenInUse.request();
      debugPrint('[BeaconPermissions] Location: $locationStatus');

      bool bluetoothGranted = true;

      if (Platform.isIOS) {
        // iOS uses a single Bluetooth permission
        final bluetoothStatus = await Permission.bluetooth.request();
        debugPrint('[BeaconPermissions] Bluetooth (iOS): $bluetoothStatus');
        bluetoothGranted = bluetoothStatus.isGranted;
      } else {
        // Android 12+ requires separate scan/connect permissions
        final bluetoothScan = await Permission.bluetoothScan.request();
        final bluetoothConnect = await Permission.bluetoothConnect.request();
        debugPrint('[BeaconPermissions] BluetoothScan: $bluetoothScan, BluetoothConnect: $bluetoothConnect');
        bluetoothGranted = bluetoothScan.isGranted && bluetoothConnect.isGranted;
      }

      final allGranted = locationStatus.isGranted && bluetoothGranted;

      if (allGranted) {
        debugPrint('[BeaconPermissions] ✅ All permissions granted');
      } else {
        debugPrint('[BeaconPermissions] ❌ Permissions denied');
      }

      return allGranted;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error requesting permissions: $e');
      return false;
    }
  }

  /// Check if Bluetooth is enabled - returns current state without prompting
  static Future<bool> isBluetoothEnabled() async {
    try {
      final bluetoothState = await flutterBeacon.bluetoothState;
      return bluetoothState == BluetoothState.stateOn;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error checking Bluetooth state: $e');
      return false;
    }
  }

  /// Request to enable Bluetooth via system prompt (Android only)
  static Future<bool> requestEnableBluetooth() async {
    try {
      debugPrint('[BeaconPermissions] 📶 Requesting Bluetooth enable...');
      // This opens a system dialog on Android asking user to turn on Bluetooth
      final result = await flutterBeacon.requestAuthorization;
      debugPrint('[BeaconPermissions] Request authorization result: $result');
      return result;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error requesting Bluetooth enable: $e');
      return false;
    }
  }

  /// Open Bluetooth settings
  static Future<bool> openBluetoothSettings() async {
    try {
      debugPrint('[BeaconPermissions] Opening Bluetooth settings...');
      final opened = await flutterBeacon.openBluetoothSettings;
      debugPrint('[BeaconPermissions] Open Bluetooth settings result: $opened');
      return opened;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error opening Bluetooth settings: $e');
      return false;
    }
  }

  /// Check if Bluetooth is enabled, and try to enable it if not
  static Future<bool> ensureBluetoothEnabled() async {
    try {
      // Check current Bluetooth state
      final bluetoothState = await flutterBeacon.bluetoothState;
      debugPrint('[BeaconPermissions] 📶 Bluetooth state: $bluetoothState');

      if (bluetoothState == BluetoothState.stateOn) {
        debugPrint('[BeaconPermissions] ✅ Bluetooth is ON');
        return true;
      }

      // Request to enable Bluetooth via system prompt
      debugPrint('[BeaconPermissions] ⚠️ Bluetooth is OFF, requesting enable...');
      await requestEnableBluetooth();

      // Poll for Bluetooth state change (wait up to 10 seconds)
      for (int i = 0; i < 20; i++) {
        await Future.delayed(const Duration(milliseconds: 500));
        final newState = await flutterBeacon.bluetoothState;
        debugPrint('[BeaconPermissions] 📶 Polling Bluetooth state ($i): $newState');
        if (newState == BluetoothState.stateOn) {
          debugPrint('[BeaconPermissions] ✅ Bluetooth is now ON');
          return true;
        }
      }

      debugPrint('[BeaconPermissions] ❌ Bluetooth still OFF after waiting');
      return false;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error checking Bluetooth state: $e');
      return false;
    }
  }

  static Future<bool> checkPermissions() async {
    final locationStatus = await Permission.locationWhenInUse.status;

    bool bluetoothGranted = true;
    if (Platform.isIOS) {
      final bluetoothStatus = await Permission.bluetooth.status;
      bluetoothGranted = bluetoothStatus.isGranted;
    } else {
      final bluetoothScan = await Permission.bluetoothScan.status;
      final bluetoothConnect = await Permission.bluetoothConnect.status;
      bluetoothGranted = bluetoothScan.isGranted && bluetoothConnect.isGranted;
    }

    return locationStatus.isGranted && bluetoothGranted;
  }

  static Future<void> openSettings() async {
    await openAppSettings();
  }
}