HeadsetDetector.h

#import <Foundation/Foundation.h>
#import <React/RCTBridgeModule.h>
#import <React/RCTEventEmitter.h>

@interface HeadsetDetector : RCTEventEmitter <RCTBridgeModule>
@end

HeadsetDetector.m

#import "HeadsetDetector.h"

@implementation HeadsetDetector

RCT_EXPORT_MODULE();

- (NSArray<NSString *> *)supportedEvents
{
  return @[@"HeadsetStatusChange"];
}

[[NSNotificationCenter defaultCenter] addObserver:self
                                       selector:@selector(audioRoutingListenerCallback:)
                                       name:AVAudioSessionRouteChangeNotification
                                       object:nil];

- (void)audioRoutingListenerCallback:(NSNotification*)notification
{
    NSDictionary *interuptionDict = notification.userInfo;

    NSInteger routeChangeReason = [[interuptionDict valueForKey:AVAudioSessionRouteChangeReasonKey] integerValue];

    switch (routeChangeReason) {

        case AVAudioSessionRouteChangeReasonNewDeviceAvailable:

            [self sendEventWithName:@"HeadsetStatusChange" body:@{@"isPlugged": true}];

            break;

        case AVAudioSessionRouteChangeReasonOldDeviceUnavailable:

            [self sendEventWithName:@"HeadsetStatusChange" body:@{@"isPlugged": false}];
        
            break;
    }
}

@end