ResearchKit/ResearchKitActiveTask/environmentSPLMeter/ORKEnvironmentSPLMeterStepViewController.m

/*
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 are permitted provided that the following conditions are met:
 
 1.  Redistributions of source code must retain the above copyright notice, this
 list of conditions and the following disclaimer.
 
 2.  Redistributions in binary form must reproduce the above copyright notice,
 this list of conditions and the following disclaimer in the documentation and/or
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 3.  Neither the name of the copyright holder(s) nor the names of any contributors
 may be used to endorse or promote products derived from this software without
 specific prior written permission. No license is granted to the trademarks of
 the copyright holders even if such marks are included in this software.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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#import "ORKEnvironmentSPLMeterStepViewController.h"

#import "ORKActiveStepView.h"
#import "ORKStepView.h"
#import "ORKStepContainerView_Private.h"
#import "ORKRoundTappingButton.h"
#import "ORKEnvironmentSPLMeterContentView.h"
#import "ORKRingView.h"

#import "ORKEnvironmentSPLMeterStepViewController_Private.h"
#import "ORKActiveStepViewController_Internal.h"
#import "ORKStepViewController_Internal.h"
#import "ORKTaskViewController_Internal.h"

#import "ORKCollectionResult_Private.h"
#import "ORKEnvironmentSPLMeterResult.h"
#import "ORKEnvironmentSPLMeterStep.h"
#import "ORKNavigationContainerView_Internal.h"
#import "ORKSkin.h"

#import "ORKHelpers_Internal.h"
#import <AVFoundation/AVFoundation.h>
#include <sys/sysctl.h>

static const NSTimeInterval SPL_METER_PLAY_DELAY_VOICEOVER = 3.0;

NSString * const ORKEnvironmentSPLMeterStepViewAccessibilityIdentifier = @"ORKEnvironmentSPLMeterStepView";

@interface ORKEnvironmentSPLMeterStepViewController ()<ORKRingViewDelegate, ORKEnvironmentSPLMeterContentViewVoiceOverDelegate> {
    AVAudioInputNode *_inputNode;
    AVAudioUnitEQ *_eqUnit;
    AVAudioFrameCount _bufferSize;
    uint32_t _sampleRate;
    AVAudioFormat *_inputNodeOutputFormat;
    int _countToFetch;
    NSMutableArray *_rmsBuffer;
    dispatch_semaphore_t _semaphoreRms;
    float _rmsData;
    float _spl;
    double _samplingInterval;
    double _thresholdValue;
    double _sensitivityOffset;
    NSInteger _requiredContiguousSamples;
    int _counter;
    NSMutableArray *_recordedSamples;
    AVAudioSessionCategory _savedSessionCategory;
    AVAudioSessionMode _savedSessionMode;
    AVAudioSessionCategoryOptions _savedSessionCategoryOptions;
    UINotificationFeedbackGenerator *_notificationFeedbackGenerator;
}

@property (nonatomic, strong) ORKEnvironmentSPLMeterContentView *environmentSPLMeterContentView;

@end

@implementation ORKEnvironmentSPLMeterStepViewController

- (instancetype)initWithStep:(ORKStep *)step {
    self = [super initWithStep:step];
    
    if (self) {
        _rmsBuffer = [NSMutableArray new];
        _semaphoreRms = dispatch_semaphore_create(1);
        _rmsData = 0.0;
        _spl = 0.0;
        _counter = 0;
        _samplingInterval = 1.0;
        _requiredContiguousSamples = 1;
        _sensitivityOffset = -23.3;
        _recordedSamples = [NSMutableArray new];
        _audioEngine = [[AVAudioEngine alloc] init];
        _eqUnit = [[AVAudioUnitEQ alloc] initWithNumberOfBands:6];
    }
    
    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    _environmentSPLMeterContentView = [ORKEnvironmentSPLMeterContentView new];
    _environmentSPLMeterContentView.voiceOverDelegate = self;
    _environmentSPLMeterContentView.ringView.delegate = self;
    self.activeStepView.activeCustomView = _environmentSPLMeterContentView;
    
    self.view.accessibilityIdentifier = ORKEnvironmentSPLMeterStepViewAccessibilityIdentifier;
    
    [self.taskViewController setNavigationBarColor:[self.view backgroundColor]];
}

- (void)saveAudioSession {
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    _savedSessionCategory = audioSession.category;
    _savedSessionMode = audioSession.mode;
    _savedSessionCategoryOptions = audioSession.categoryOptions;
}

- (void)setNavigationFooterView {

    self.activeStepView.navigationFooterView.continueButtonItem = self.continueButtonItem;
    self.activeStepView.navigationFooterView.continueEnabled = NO;
    [self.activeStepView.navigationFooterView updateContinueAndSkipEnabled];
}

- (void)setContinueButtonItem:(UIBarButtonItem *)continueButtonItem {
    [super setContinueButtonItem:continueButtonItem];
    _navigationFooterView.continueButtonItem = continueButtonItem;
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    
    [self setNavigationFooterView];
    if (!_audioEngine.isRunning) {
        [self saveAudioSession];
        _sensitivityOffset = [self sensitivityOffsetForDevice];
        [self requestRecordPermissionIfNeeded];
        [self configureAudioSession];
        [self setupFeedbackGenerator];
    }
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    
    [self start];
    
    _samplingInterval = [self environmentSPLMeterStep].samplingInterval;
    _requiredContiguousSamples = [self environmentSPLMeterStep].requiredContiguousSamples;
    _thresholdValue = [self environmentSPLMeterStep].thresholdValue;
    [self configureInputNode];
    [self splWorkBlock];
    
    if (UIAccessibilityIsVoiceOverRunning()) {
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(SPL_METER_PLAY_DELAY_VOICEOVER * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            UIAccessibilityPostNotification(UIAccessibilityAnnouncementNotification, ORKLocalizedString(@"ENVIRONMENTSPL_CALCULATING", nil));
        });
    }
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    [self stopAudioEngine];
    [self resetAudioSession];
}

- (NSString *)deviceType {
    return [[UIDevice currentDevice] model];
}

- (double)sensitivityOffsetForDevice {
    NSDictionary *lookupTable = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle bundleForClass:[self class]] pathForResource:@"splMeter_sensitivity_offset"  ofType:@"plist"]];
    NSString *deviceTypeString = [self deviceType];
    double sensitivity = [[lookupTable valueForKey:deviceTypeString] doubleValue];
    return ( sensitivity ? : _sensitivityOffset);
}

- (ORKStepResult *)result {
    ORKStepResult *sResult = [super result];
    // "Now" is the end time of the result, which is either actually now,
    // or the last time we were in the responder chain.
    NSDate *now = sResult.endDate;
    
    NSMutableArray *results = [NSMutableArray arrayWithArray:sResult.results];
    
    ORKEnvironmentSPLMeterResult *splResult = [[ORKEnvironmentSPLMeterResult alloc] initWithIdentifier:self.step.identifier];
    splResult.startDate = sResult.startDate;
    splResult.endDate = now;
    splResult.sensitivityOffset = _sensitivityOffset;
    splResult.recordedSPLMeterSamples = [_recordedSamples copy];
    
    [results addObject:splResult];
    
    sResult.results = [results copy];
    
    return sResult;
}

- (void)requestRecordPermissionIfNeeded
{
    [self handleRecordPermission:[[AVAudioSession sharedInstance] recordPermission]];
}

- (void)handleRecordPermission:(AVAudioSessionRecordPermission)recordPermission
{
    switch (recordPermission)
    {
        case AVAudioSessionRecordPermissionGranted:
            break;
            
        case AVAudioSessionRecordPermissionDenied:
        {
            ORK_Log_Error("User has denied record permission for a step which requires microphone access.");
            break;
        }
        case AVAudioSessionRecordPermissionUndetermined:
        {
            [[AVAudioSession sharedInstance] requestRecordPermission:^(BOOL granted) {
                [self handleRecordPermission:granted ? AVAudioSessionRecordPermissionGranted : AVAudioSessionRecordPermissionDenied];
            }];
            break;
        }
    }
}

- (void)configureAudioSession {
    NSError *error = nil;
    AVAudioSession * session = [AVAudioSession sharedInstance];
    
    // Stop any existing audio
    [session setCategory:AVAudioSessionCategorySoloAmbient error:&error];
    if (error) {
        ORK_Log_Error("Setting AVAudioSessionCategory failed with error message: \"%@\"", error.localizedDescription);
    }
    
    [session setActive:YES error:&error];
    if (error) {
        ORK_Log_Error("Activating AVAudioSession failed with error message: \"%@\"", error.localizedDescription);
    }
    
    // Force input/output from iOS device
    [session setCategory:AVAudioSessionCategoryPlayAndRecord mode:AVAudioSessionModeMeasurement options:AVAudioSessionCategoryOptionDuckOthers | AVAudioSessionCategoryOptionMixWithOthers | AVAudioSessionCategoryOptionAllowBluetoothA2DP error:&error];
    if (error) {
        ORK_Log_Error("Setting AVAudioSessionCategory failed with error message: \"%@\"", error.localizedDescription);
    }
    
    // When setting the input like this, we do not need to set the input AND the output to the iPhone.
    NSArray<AVAudioSessionPortDescription *> * inputs = [session availableInputs];
    for (AVAudioSessionPortDescription* desc in inputs) {
        if ([desc.portType isEqualToString:AVAudioSessionPortBuiltInMic]) {
            // go ahead and set our preferred input to the built-in mic
            [session setPreferredInput:desc error:&error];
            
            if (error) {
                ORK_Log_Error("Setting AVAudioSession preferred input failed with error message: \"%@\"", error.localizedDescription);
            }
        }
    }
    
    [session setActive:YES error:&error];
    if (error) {
        ORK_Log_Error("Activating AVAudioSession failed with error message: \"%@\"", error.localizedDescription);
    }
}

- (void)configureInputNode {
    _inputNode = [_audioEngine inputNode];
    _inputNodeOutputFormat = [_inputNode inputFormatForBus:0];
    _sampleRate = (uint32_t)_inputNodeOutputFormat.sampleRate;
    _bufferSize = _sampleRate/10;
    _countToFetch = _sampleRate > 0 ? _sampleRate/(int)_bufferSize : 0;
    [self configureEQ];
    [_audioEngine attachNode:_eqUnit];
    [_audioEngine connect:_inputNode to:_eqUnit format:_inputNodeOutputFormat];
}

- (void)configureEQ {
    _eqUnit.globalGain = 0;
    
    // A-weighting EQ
    AVAudioUnitEQFilterParameters *eqCoefficient = _eqUnit.bands[0];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeHighPass;
    eqCoefficient.frequency = 290;
    eqCoefficient.bypass = NO;
    
    eqCoefficient = _eqUnit.bands[1];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeParametric;
    eqCoefficient.frequency = 243;
    eqCoefficient.bandwidth = 1.3882;
    eqCoefficient.gain = -4.5;
    eqCoefficient.bypass = NO;
    
    eqCoefficient = _eqUnit.bands[2];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeParametric;
    eqCoefficient.frequency = 450;
    eqCoefficient.bandwidth = 0.94428;
    eqCoefficient.gain = -1.5;
    eqCoefficient.bypass = NO;
    
    eqCoefficient = _eqUnit.bands[3];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeParametric;
    eqCoefficient.frequency = 2650;
    eqCoefficient.bandwidth = 2.4924;
    eqCoefficient.gain = 1.25;
    eqCoefficient.bypass = NO;
    
    eqCoefficient = _eqUnit.bands[4];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeParametric;
    eqCoefficient.frequency = 10000;
    eqCoefficient.bandwidth = 1.0246;
    eqCoefficient.gain = -1.5;
    eqCoefficient.bypass = NO;
    
    eqCoefficient = _eqUnit.bands[5];
    eqCoefficient.filterType = AVAudioUnitEQFilterTypeLowPass;
    eqCoefficient.frequency = 11800;
    eqCoefficient.bypass = NO;
}

- (void)splWorkBlock {
    // secondaryAudioShouldBeSilencedHint returns true if VoiceOver is running.
    // Since we are killing all audio when configuring the session, here we can make a safe assumption that if VoiceOver is running, allow the user to continue even if the secondaryAudioShouldBeSilencedHint is YES.
    // If VoiceOver is not running, we can still gate based on the secondaryAudioShouldBeSilencedHint.
    
    BOOL otherAudioIsProhibitingMeasurement = [[AVAudioSession sharedInstance] secondaryAudioShouldBeSilencedHint] && !UIAccessibilityIsVoiceOverRunning();
    
    if (!_audioEngine.isRunning && !otherAudioIsProhibitingMeasurement) {
        [_eqUnit installTapOnBus:0
                      bufferSize:_bufferSize
                          format:_inputNodeOutputFormat
                           block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) {
                               if ([AVAudioSession sharedInstance].recordPermission == AVAudioSessionRecordPermissionGranted) {
                                   if (buffer.frameLength != self->_bufferSize) {
                                       self->_bufferSize = buffer.frameLength;
                                   }
                                   int sampleCount = self->_samplingInterval * self->_countToFetch;
                                   float rms = 0.0;
                                   for (int i = 0; i < buffer.frameLength; i++) {
                                       float value = [@(buffer.floatChannelData[0][i]) floatValue];
                                       rms +=  value * value;
                                   }
                                   dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                                       [self->_rmsBuffer addObject:@(rms)];
                                       
                                       // perform averaging based on capture interval
                                       if (self->_rmsBuffer.count >= sampleCount + 1) {
                                           float rmsSum = 0.0;
                                           int i = sampleCount;
                                           NSUInteger j = self->_rmsBuffer.count - 1;
                                           while (i>0) {
                                               rmsSum += [self->_rmsBuffer[j] floatValue];
                                               i --;
                                               j --;
                                           }
                                           self->_rmsData = rmsSum/self->_samplingInterval;
                                           float calValue = self->_sensitivityOffset;
                                           self->_spl = (20 * log10f(sqrtf(self->_rmsData/(float)self->_sampleRate))) - calValue + 94;
                                           [self->_recordedSamples addObject:[NSNumber numberWithFloat:self->_spl]];
                                           dispatch_async(dispatch_get_main_queue(), ^{
                                               [self.environmentSPLMeterContentView setProgressCircle:(self->_spl/self->_thresholdValue)];
                                           });
                                           [self evaluateThreshold:self->_spl];
                                           [self->_rmsBuffer removeAllObjects];
                                       } else {
                                           if (rms > 0.0 && self->_sampleRate > 0.0) {
                                               float spl = (20 * log10f(sqrtf(rms/(float)self->_sampleRate))) - self->_sensitivityOffset + 96;
                                               dispatch_async(dispatch_get_main_queue(), ^{
                                                   [self.environmentSPLMeterContentView setProgressBar:(spl/self->_thresholdValue)];
                                               });
                                           } else {
                                               dispatch_async(dispatch_get_main_queue(), ^{
                                                   [self.environmentSPLMeterContentView setProgressBar:(self->_spl/self->_thresholdValue)];
                                               });
                                           }
                                       }
                                       dispatch_semaphore_signal(self->_semaphoreRms);
                                   });
                                   dispatch_semaphore_wait(self->_semaphoreRms, DISPATCH_TIME_FOREVER);
                               } else if ([AVAudioSession sharedInstance].recordPermission == AVAudioSessionRecordPermissionDenied) {
                                   dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                                       [self->_eqUnit removeTapOnBus:0];
                                       [self->_audioEngine stop];
                                       [self->_rmsBuffer removeAllObjects];
                                   });
                               }
                           }];
        if (!_audioEngine.isRunning && !otherAudioIsProhibitingMeasurement) {
            NSError *error = nil;
            [_audioEngine startAndReturnError:&error];
        } else {
            [self stopAudioEngine];
        }
    }
}

- (void)evaluateThreshold:(float)spl
{
    if (spl < _thresholdValue)
    {
        _counter += 1;
        
        [self.environmentSPLMeterContentView.ringView fillRingWithDuration:(double)_requiredContiguousSamples*_samplingInterval];
    }
    else
    {
        _counter = 0;
        self.environmentSPLMeterContentView.ringView.animationDuration = 0.5;
        [self.environmentSPLMeterContentView setProgress:0.0];
        
        [self sendHapticEvent:UINotificationFeedbackTypeError];
    }
}

- (void)resetAudioSession {
    NSError *error = nil;
    [[AVAudioSession sharedInstance] setCategory:_savedSessionCategory mode:_savedSessionMode options:_savedSessionCategoryOptions error:&error];
    [[AVAudioSession sharedInstance] overrideOutputAudioPort:AVAudioSessionPortOverrideNone error:&error];
    if (error) {
        ORK_Log_Error("Setting AVAudioSessionCategory failed with error message: \"%@\"", error.localizedDescription);
    }
    [[AVAudioSession sharedInstance] setActive:YES error:&error];
    if (error) {
        ORK_Log_Error("Activating AVAudioSession failed with error message: \"%@\"", error.localizedDescription);
    }
}

- (void)stopAudioEngine {
    if ([_audioEngine isRunning]) {
        dispatch_semaphore_signal(_semaphoreRms);
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [self->_eqUnit removeTapOnBus:0];
            [self->_audioEngine stop];
            [self->_rmsBuffer removeAllObjects];
        });
    }
}

- (void)reachedOptimumNoiseLevel {
    [self stopAudioEngine];
    [self sendHapticEvent:UINotificationFeedbackTypeSuccess];
    [self resetAudioSession];
}

- (void)stepDidFinish {
    [super stepDidFinish];
    [self.environmentSPLMeterContentView finishStep:self];
    [self goForward];
}

- (void)start {
    [super start];
}

- (ORKEnvironmentSPLMeterStep *)environmentSPLMeterStep {
    return (ORKEnvironmentSPLMeterStep *)self.step;
}

#pragma mark - ORKRingViewDelegate

- (void)ringViewDidFinishFillAnimation {
    [self reachedOptimumNoiseLevel];
    [self.environmentSPLMeterContentView reachedOptimumNoiseLevel];
    self.activeStepView.navigationFooterView.continueEnabled = YES;
}

#pragma mark - UINotificationFeedbackGenerator

- (void)setupFeedbackGenerator
{
    _notificationFeedbackGenerator = [[UINotificationFeedbackGenerator alloc] init];
    [_notificationFeedbackGenerator prepare];
}

- (void)sendHapticEvent:(UINotificationFeedbackType)eventType
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [self->_notificationFeedbackGenerator notificationOccurred:eventType];
        [self->_notificationFeedbackGenerator prepare];
    });
}

#pragma mark - ORKEnvironmentSPLMeterContentViewVoiceOverDelegate

- (void)contentView:(ORKEnvironmentSPLMeterContentView *)contentView shouldAnnounce:(NSString *)inAnnouncement
{
    UIAccessibilityPostNotification(UIAccessibilityAnnouncementNotification, inAnnouncement);
}

@end