#import <Foundation/Foundation.h>

#import <Speech/Speech.h>

@interface SpeechListener : NSObject

<SFSpeechRecognitionTaskDelegate,SFSpeechRecognizerDelegate>

@property(nonatomic,strong)SFSpeechRecognizer *listener;

@property(nonatomic,strong)SFSpeechRecognitionTask *currentTask;

@property(nonatomic,assign)SFSpeechRecognizerAuthorizationStatus authorizationStatus;

@property(nonatomic,strong)SFSpeechAudioBufferRecognitionRequest *currentRequest;

@property(nonatomic,assign)BOOL inRecognizer;

@property(nonatomic,copy)void (^haveRecognizerSpeakTextBlock)(NSString *text,NSTimeInterval startLocation,NSTimeInterval length);

-(void)startRecognizer;

-(void)giveBuffer:(CMSampleBufferRef)buffer;

-(void)endRecognizer;

@end

#import "SpeechListener.h"

@interface SpeechListener()

@property(nonatomic,copy)NSString *currentText;

@property(nonatomic,assign)NSTimeInterval beginListenLocation;

@end

@implementation SpeechListener

-(instancetype)init

{

    self = [super init];

    if (self) {

        self.listener = [[SFSpeechRecognizer alloc] initWithLocale:[NSLocale localeWithLocaleIdentifier:@"zh-CN"]];

        [self.listener setDelegate:self];

        [self requestAuthorizationStatus];

    }

    return self;

}

-(void)requestAuthorizationStatus

{

    typeof(self) __weak weakself = self;

    [SFSpeechRecognizer requestAuthorization:^(SFSpeechRecognizerAuthorizationStatus status) {

        typeof(weakself) __strong strongself = weakself;

        strongself.authorizationStatus = status;

    }];

}

-(void)startRecognizer

{

    self.beginListenLocation = CFAbsoluteTimeGetCurrent();

    self.currentRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init];

    [self.currentRequest setShouldReportPartialResults:YES];

    typeof(self) __weak weakself = self;

    self.currentTask = [self.listener recognitionTaskWithRequest:self.currentRequest resultHandler:^(SFSpeechRecognitionResult *result, NSError *error) {

        typeof(weakself) __strong strongself = weakself;

        if (strongself.inRecognizer) {

            if (error != nil) {

                [strongself endRecognizer];

            }

            else

                if(result != nil) {

                if (strongself.inRecognizer) {

                    strongself.currentText = [[result bestTranscription] formattedString];

                }

                if ([result isFinal]) {

                    [strongself endRecognizer];

                }

            }

        }

        if (error) {

        }

    }];

    self.inRecognizer = YES;

}

-(void)endRecognizer

{

    if (self.currentText.length > ) {

        if (self.haveRecognizerSpeakTextBlock) {

            self.haveRecognizerSpeakTextBlock(self.currentText, self.beginListenLocation, CFAbsoluteTimeGetCurrent() - self.beginListenLocation);

        }

    }

    self.inRecognizer = NO;

    if (self.currentTask) {

        [self.currentTask cancel];

        self.currentTask = nil;

    }

    if (self.currentRequest) {

        [self.currentRequest endAudio];

        self.currentRequest = nil;

    }

    self.currentText = @"";

}

-(void)speechRecognizer:(SFSpeechRecognizer *)speechRecognizer availabilityDidChange:(BOOL)available

{

    self.inRecognizer = !available;

}

-(void)giveBuffer:(CMSampleBufferRef)buffer

{

    if (self.currentRequest) {

        [self.currentRequest appendAudioSampleBuffer:buffer];

    }

    if (self.inRecognizer && (CFAbsoluteTimeGetCurrent() - self.beginListenLocation) > ) {

        [self endRecognizer];

        [self startRecognizer];

    }

}

@end