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

import 'beacon_channel.dart';

class BeaconPermissions {
  static Future<bool> requestPermissions() async {
    try {
      // On Android, check native first (fast path)
      if (Platform.isAndroid) {
        final hasPerms = await BeaconChannel.hasPermissions();
        if (hasPerms) {
          debugPrint('[BeaconPermissions] Native check: granted');
          return true;
        }
        debugPrint('[BeaconPermissions] Native check: not granted, requesting...');
      }

      // Request via Flutter plugin (slow but shows system dialogs)
      final locationStatus = await Permission.locationWhenInUse.request();
      debugPrint('[BeaconPermissions] Location: $locationStatus');

      bool bluetoothGranted = true;

      if (Platform.isIOS) {
        final bluetoothStatus = await Permission.bluetooth.request();
        debugPrint('[BeaconPermissions] Bluetooth (iOS): $bluetoothStatus');
        bluetoothGranted = bluetoothStatus.isGranted;
      } else {
        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;
      debugPrint('[BeaconPermissions] All granted: $allGranted');
      return allGranted;
    } catch (e) {
      debugPrint('[BeaconPermissions] Error: $e');
      return false;
    }
  }

  /// Check if Bluetooth is enabled - returns current state without prompting
  static Future<bool> isBluetoothEnabled() async {
    try {
      // Use native channel on Android
      if (Platform.isAndroid) {
        return await BeaconChannel.isBluetoothEnabled();
      }

      // Use Flutter plugin on iOS
      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 isOn = await isBluetoothEnabled();
      debugPrint('[BeaconPermissions] Bluetooth state: ${isOn ? "ON" : "OFF"}');

      if (isOn) {
        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 - short wait first
      for (int i = 0; i < 6; i++) {
        await Future.delayed(const Duration(milliseconds: 500));
        final newState = await isBluetoothEnabled();
        debugPrint('[BeaconPermissions] Polling Bluetooth state ($i): ${newState ? "ON" : "OFF"}');
        if (newState) {
          debugPrint('[BeaconPermissions] Bluetooth is now ON');
          return true;
        }
      }

      // If still off after 3 seconds, try opening Bluetooth settings directly
      debugPrint('[BeaconPermissions] Bluetooth still OFF, opening settings...');
      await openBluetoothSettings();

      // Poll again for up to 15 seconds (user needs time to toggle in settings)
      for (int i = 0; i < 30; i++) {
        await Future.delayed(const Duration(milliseconds: 500));
        final newState = await isBluetoothEnabled();
        debugPrint('[BeaconPermissions] Polling Bluetooth state after settings ($i): ${newState ? "ON" : "OFF"}');
        if (newState) {
          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 {
    // On Android, use native check (much faster)
    if (Platform.isAndroid) {
      return await BeaconChannel.hasPermissions();
    }

    // iOS: use Flutter plugin
    final locationStatus = await Permission.locationWhenInUse.status;
    final bluetoothStatus = await Permission.bluetooth.status;
    return locationStatus.isGranted && bluetoothStatus.isGranted;
  }

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