import { Platform, Alert } from 'react-native';
import messaging, { AuthorizationStatus } from '@react-native-firebase/messaging';
import { request, PERMISSIONS, RESULTS, Permission } from 'react-native-permissions';

export interface PermissionResult {
  granted: boolean;
  status: string;
  needsRequest: boolean;
  platform: string;
  androidVersion?: number;
}

/**
 * Check if the device requires explicit notification permission request
 * Android 13+ (API 33+) requires POST_NOTIFICATIONS permission
 * Older Android versions don't need explicit permission for notifications
 */
export function needsNotificationPermission(): boolean {
  if (Platform.OS === 'ios') {
    return true; // iOS always requires permission
  }
  
  if (Platform.OS === 'android') {
    // Android 13+ (API level 33+) requires POST_NOTIFICATIONS permission
    return Platform.Version >= 33;
  }
  
  return false;
}

/**
 * Get the appropriate notification permission constant based on platform
 */
export function getNotificationPermission(): Permission | null {
  if (Platform.OS === 'android') {
    //@ts-ignore
    return 'android.permission.POST_NOTIFICATIONS';
  }
  
  // iOS uses Firebase messaging permission, not react-native-permissions
  return null;
}

/**
 * Request notification permission for Android 13+
 * Returns permission status information
 */
export async function requestNotificationPermission(): Promise<PermissionResult> {

  
  if (Platform.OS === 'ios') {
    // iOS uses Firebase messaging permission
    try {

      const authStatus = await messaging().requestPermission();
      const granted = authStatus === AuthorizationStatus.AUTHORIZED || 
                     authStatus === AuthorizationStatus.PROVISIONAL;
      

      
      return {
        granted,
        status: AuthorizationStatus[authStatus],
        needsRequest: true,
        platform: 'ios'
      };
    } catch (error) {

      return {
        granted: false,
        status: 'ERROR',
        needsRequest: true,
        platform: 'ios'
      };
    }
  }
  
  if (Platform.OS === 'android') {
    const androidVersion = Platform.Version as number;
    const permission = getNotificationPermission();
    
   
    
    if (!permission) {
      // Older Android versions don't need explicit permission

      return {
        granted: true,
        status: 'GRANTED',
        needsRequest: false,
        platform: 'android',
        androidVersion
      };
    }
    
    try {

      const result = await request(permission);
      

      
      return {
        granted: result === RESULTS.GRANTED,
        status: result,
        needsRequest: true,
        platform: 'android',
        androidVersion
      };
    } catch (error) {

      return {
        granted: false,
        status: 'ERROR',
        needsRequest: true,
        platform: 'android',
        androidVersion
      };
    }
  }
  
  return {
    granted: false,
    status: 'UNSUPPORTED',
    needsRequest: false,
    platform: 'unknown'
  };
}

/**
 * Check current notification permission status
 */
export async function checkNotificationPermission(): Promise<PermissionResult> {

  
  if (Platform.OS === 'ios') {
    try {

      const authStatus = await messaging().hasPermission();
      const granted = authStatus === AuthorizationStatus.AUTHORIZED || 
                     authStatus === AuthorizationStatus.PROVISIONAL;
      

      
      return {
        granted,
        status: AuthorizationStatus[authStatus],
        needsRequest: !granted,
        platform: 'ios'
      };
    } catch (error) {

      return {
        granted: false,
        status: 'ERROR',
        needsRequest: true,
        platform: 'ios'
      };
    }
  }
  
  if (Platform.OS === 'android') {
    const androidVersion = Platform.Version as number;
    const permission = getNotificationPermission();

    
    if (!permission) {
      // Older Android versions - assume granted

      return {
        granted: true,
        status: 'GRANTED',
        needsRequest: false,
        platform: 'android',
        androidVersion
      };
    }
    
    try {

      const { check } = require('react-native-permissions');
      const result = await check(permission);

      

      
      return {
        granted: result === RESULTS.GRANTED,
        status: result,
        needsRequest: result !== RESULTS.GRANTED,
        platform: 'android',
        androidVersion
      };
    } catch (error) {

      return {
        granted: false,
        status: 'ERROR',
        needsRequest: true,
        platform: 'android',
        androidVersion
      };
    }
  }
  
  return {
    granted: false,
    status: 'UNSUPPORTED',
    needsRequest: false,
    platform: 'unknown'
  };
}

/**
 * Show permission explanation dialog for Android
 */
export function showPermissionExplanation(): Promise<boolean> {
  return new Promise((resolve) => {
    Alert.alert(
      'Notification Permission',
      'This app needs notification permission to send you chat messages and updates. You can change this later in your device settings.',
      [
        {
          text: 'Cancel',
          style: 'cancel',
          onPress: () => resolve(false),
        },
        {
          text: 'Allow',
          onPress: () => resolve(true),
        },
      ]
    );
  });
}

/**
 * Show settings redirect dialog when permission is denied
 */
export function showSettingsDialog(): void {
  Alert.alert(
    'Permission Required',
    'Notification permission is required for this app to work properly. Please enable it in your device settings.',
    [
      {
        text: 'Cancel',
        style: 'cancel',
      },
      {
        text: 'Open Settings',
        onPress: () => {
          // You can use react-native-permissions to open settings
          // Linking.openSettings();
        },
      },
    ]
  );
}

/**
 * Debug function to test permission flow
 * Call this from your app to see detailed permission information
 */
export async function debugPermissionFlow(): Promise<void> {

  
  const permission = getNotificationPermission();

  
  const currentStatus = await checkNotificationPermission();

  
  if (!currentStatus.granted && currentStatus.needsRequest) {

    const requestResult = await requestNotificationPermission();
;
  }
  
  console.log('🔧 === END DEBUG ===');
}