#import "RNLoudness.h"
#import <React/RCTLog.h>
#import <Foundation/Foundation.h>

@implementation RNLoudness
{
    bool hasListeners;
}

-(void)startObserving {
    hasListeners = YES;
}

-(void)stopObserving {
    hasListeners = NO;
}

+ (BOOL)requiresMainQueueSetup
{
    return NO;
}

- (dispatch_queue_t)methodQueue
{
    return dispatch_queue_create("com.rnloudness", DISPATCH_QUEUE_SERIAL);
}

- (id)init {
    if (!(self = [super init])){
        return nil;
    }

    NSError *error;

    // Initialize directory for save and temp files
    saveDirURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory
                                                        inDomain:NSUserDomainMask
                                               appropriateForURL:nil
                                                          create:false
                                                           error:&error];
    tmpDirURL = [NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES];
    // Set this app session to play and record mode
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];

    return self;
}

// To export a module
RCT_EXPORT_MODULE();

RCT_EXPORT_METHOD(start:(NSString * _Nullable)fileName)
{
    NSError *error;
    NSURL *fileURL;
    if (fileName){
        fileURL = [[saveDirURL URLByAppendingPathComponent:fileName] URLByAppendingPathExtension:@"wav"];
    } else {
        fileURL = [[tmpDirURL URLByAppendingPathComponent:@"micTmp"] URLByAppendingPathExtension:@"wav"];
    }

    NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
                              [NSNumber numberWithFloat: 44100.0],AVSampleRateKey,
                              [NSNumber numberWithInt: kAudioFormatLinearPCM],AVFormatIDKey,
                              [NSNumber numberWithInt: 1],AVNumberOfChannelsKey,
                              [NSNumber numberWithInt: AVAudioQualityMax],AVEncoderAudioQualityKey,
                              [NSNumber numberWithInt: 16],AVEncoderBitDepthHintKey,
                              [NSNumber numberWithInt: 16],AVEncoderBitRatePerChannelKey,
                              nil];

    recorder = [[AVAudioRecorder alloc] initWithURL:fileURL settings:settings error:&error];

    if(!recorder){
        RCTLogError(@"Error: %@", [error localizedDescription]);
        return;
    }

    BOOL isStart = [recorder record];
    recorder.meteringEnabled = true;

    dispatch_async(dispatch_get_main_queue(), ^{

        timer = [NSTimer scheduledTimerWithTimeInterval: 0.1
                                        target: self
                                        selector: @selector(onTick:)
                                      userInfo: nil
                                       repeats: YES];

    });

    if (!isStart) RCTLogError(@"Error: Failed to start recording.");
}

RCT_EXPORT_METHOD(stop)
{
    if(!recorder) return;
    [timer invalidate];
    [recorder stop];
    if (hasListeners) { // Only send events if anyone is listening
        [self sendEventWithName:@"onStop" body:nil];
    }
}

RCT_EXPORT_METHOD(getLoudness:(RCTResponseSenderBlock)callback)
{
    if(!recorder) return;

    [recorder updateMeters];
    float avgPower = [recorder averagePowerForChannel:0];
    NSNumber *loudness = [NSNumber numberWithFloat:avgPower];
    callback(@[loudness]);
}

-(void)onTick:(NSTimer*)timer
{
    if(!recorder) return;

    [recorder updateMeters];
    float avgPower = [recorder averagePowerForChannel:0];
    NSNumber *loudness = [NSNumber numberWithFloat:avgPower];

    if (hasListeners) { // Only send events if anyone is listening
        [self sendEventWithName:@"onLoudness" body:@{@"loudness": loudness}];
    }
}

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

@end