//
//  SCNBarcodePicker.m
//  SCNScanditBarcodeScanner
//
//  Created by Luca Torella on 13.08.17.
//  Copyright © 2017 Scandit. All rights reserved.
//

#import "SCNBarcodePicker.h"
#import <React/RCTLog.h>
#import <UIKit/UIKit.h>
#import <ScanditBarcodeScanner/SBSTextRecognition.h>

@import ScanditBarcodeScanner;

typedef SBSQuadrilateral (^ConversionBlock)(SBSQuadrilateral);

static inline NSDictionary<NSString *, id> *dictionaryFromQuadrilateral(SBSQuadrilateral quadrilateral) {
    return @{
        @"topLeft": @[@(quadrilateral.topLeft.x), @(quadrilateral.topLeft.y)],
        @"topRight": @[@(quadrilateral.topRight.x), @(quadrilateral.topRight.y)],
        @"bottomLeft": @[@(quadrilateral.bottomLeft.x), @(quadrilateral.bottomLeft.y)],
        @"bottomRight": @[@(quadrilateral.bottomRight.x), @(quadrilateral.bottomRight.y)],
    };
}

static inline SBSQuadrilateral convertQuadrilateral(SBSQuadrilateral rect, SBSBarcodePicker *picker) {
    SBSQuadrilateral convertedRect;
    convertedRect.topLeft = [picker convertPointToPickerCoordinates:rect.topLeft];
    convertedRect.topRight = [picker convertPointToPickerCoordinates:rect.topRight];
    convertedRect.bottomLeft = [picker convertPointToPickerCoordinates:rect.bottomLeft];
    convertedRect.bottomRight = [picker convertPointToPickerCoordinates:rect.bottomRight];
    return convertedRect;
}

static NSDictionary<NSString *, id> *dictionaryFromCode(SBSCode *code, NSNumber *identifier) {
    NSMutableArray<NSNumber *> *bytesArray = [NSMutableArray arrayWithCapacity:code.rawData.length];
    if (code.rawData != nil) {
        unsigned char *bytes = (unsigned char *)[code.rawData bytes];
        for (int i = 0; i < code.rawData.length; i++) {
            [bytesArray addObject:@(bytes[i])];
        }
    }

    return @{
        @"id": identifier ?: @(-1),
        @"rawData": bytesArray,
        @"data": code.data ?: @"",
        @"symbology": code.symbologyName,
        @"compositeFlag": @(code.compositeFlag),
        @"isGs1DataCarrier": [NSNumber numberWithBool:code.isGs1DataCarrier],
        @"isRecognized": [NSNumber numberWithBool:code.isRecognized],
        @"location": dictionaryFromQuadrilateral(code.location),
    };
}

static inline NSDictionary *dictionaryFromScanSession(SBSScanSession *session) {
    NSMutableArray *allRecognizedCodes = [NSMutableArray arrayWithCapacity:session.allRecognizedCodes.count];
    for (SBSCode *code in session.allRecognizedCodes) {
        [allRecognizedCodes addObject:dictionaryFromCode(code, nil)];
    }
    NSMutableArray *newlyLocalizedCodes = [NSMutableArray arrayWithCapacity:session.newlyLocalizedCodes.count];
    for (SBSCode *code in session.newlyLocalizedCodes) {
        [newlyLocalizedCodes addObject:dictionaryFromCode(code, nil)];
    }
    NSMutableArray *newlyRecognizedCodes = [NSMutableArray arrayWithCapacity:session.newlyRecognizedCodes.count];
    int i = 0;
    for (SBSCode *code in session.newlyRecognizedCodes) {
        [newlyRecognizedCodes addObject:dictionaryFromCode(code, @(i))];
        i++;
    }
    return @{
        @"allRecognizedCodes": allRecognizedCodes,
        @"newlyLocalizedCodes": newlyLocalizedCodes,
        @"newlyRecognizedCodes": newlyRecognizedCodes,
    };
}

static inline NSMutableArray *dictionaryArrayFromTrackedCodes(NSDictionary<NSNumber *, SBSTrackedCode *> *trackedCodes,
                                                              ConversionBlock convert) {
    NSMutableArray *trackedCodeDictionaries = [NSMutableArray arrayWithCapacity:trackedCodes.count];
    for (NSNumber *identifier in trackedCodes) {
        SBSTrackedCode *trackedCode = trackedCodes[identifier];
        NSMutableDictionary *codeDictionary = [NSMutableDictionary dictionaryWithDictionary:dictionaryFromCode(trackedCode, identifier)];

        codeDictionary[@"predictedLocation"] = dictionaryFromQuadrilateral(trackedCode.predictedLocation);
        codeDictionary[@"deltaTimeForPrediction"] = [NSNumber numberWithDouble:(trackedCode.deltaTimeForPrediction)];
        codeDictionary[@"shouldAnimateFromPreviousToNextState"] = [NSNumber numberWithBool:(trackedCode.shouldAnimateFromPreviousToNextState)];

        SBSQuadrilateral convertedPredictedLocation = convert(trackedCode.predictedLocation);
        codeDictionary[@"convertedPredictedLocation"] = dictionaryFromQuadrilateral(convertedPredictedLocation);

        SBSQuadrilateral convertedLocation = convert(trackedCode.location);
        codeDictionary[@"convertedLocation"] = dictionaryFromQuadrilateral(convertedLocation);

        [trackedCodeDictionaries addObject:codeDictionary];
    }
    return trackedCodeDictionaries;
}

static inline NSDictionary *dictionaryForMatrixScanSession(NSDictionary<NSNumber *,SBSTrackedCode *> *allTrackedCodes,
                                                           NSDictionary<NSNumber *,SBSTrackedCode *> *newlyTrackedCodes,
                                                           ConversionBlock convert) {
    return @{
        @"allTrackedCodes": dictionaryArrayFromTrackedCodes(allTrackedCodes, convert),
        @"newlyTrackedCodes": dictionaryArrayFromTrackedCodes(newlyTrackedCodes, convert),
    };
}

static inline NSDictionary *dictionaryFromBase64FrameString(NSString *base64FrameString) {
    return @{@"base64FrameString": base64FrameString};
}

static inline NSString *base64StringFromFrame(CMSampleBufferRef *frame) {

    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(*frame);
    // Lock the base address of the pixel buffer.
    CVPixelBufferLockBaseAddress(imageBuffer,0);

    // Get the pixel buffer width and height.
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);

    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);

    CVPlanarPixelBufferInfo_YCbCrBiPlanar *bufferInfo = (CVPlanarPixelBufferInfo_YCbCrBiPlanar *)baseAddress;

    int yOffset = CFSwapInt32BigToHost(bufferInfo->componentInfoY.offset);
    int yRowBytes = CFSwapInt32BigToHost(bufferInfo->componentInfoY.rowBytes);
    int cbCrOffset = CFSwapInt32BigToHost(bufferInfo->componentInfoCbCr.offset);
    int cbCrRowBytes = CFSwapInt32BigToHost(bufferInfo->componentInfoCbCr.rowBytes);

    unsigned char *dataPtr = (unsigned char*)baseAddress;
    unsigned char *rgbaImage = (unsigned char*)malloc(4 * width * height);

    for (int x = 0; x < width; x++) {
        for (int y = 0; y < height; y++) {
            int ypIndex = yOffset + (x + y * yRowBytes);

            int yp = (int) dataPtr[ypIndex];

            unsigned char* cbCrPtr = dataPtr + cbCrOffset;
            unsigned char* cbCrLinePtr = cbCrPtr + cbCrRowBytes * (y >> 1);

            unsigned char cb = cbCrLinePtr[x & ~1];
            unsigned char cr = cbCrLinePtr[x | 1];

            // YpCbCr to RGB conversion as used in JPEG and MPEG
            // full-range:
            int r = yp                        + 1.402   * (cr - 128);
            int g = yp - 0.34414 * (cb - 128) - 0.71414 * (cr - 128);
            int b = yp + 1.772   * (cb - 128);

            r = MIN(MAX(r, 0), 255);
            g = MIN(MAX(g, 0), 255);
            b = MIN(MAX(b, 0), 255);
            //printf("x/y %d/%d\n", x, y);
            rgbaImage[(x + y * width) * 4] = (unsigned char) b;
            rgbaImage[(x + y * width) * 4 + 1] = (unsigned char) g;
            rgbaImage[(x + y * width) * 4 + 2] = (unsigned char) r;
            rgbaImage[(x + y * width) * 4 + 3] = (unsigned char) 255;
        }
    }

    // Create a device-dependent RGB color space.
    static CGColorSpaceRef colorSpace = NULL;
    if (colorSpace == NULL) {
        colorSpace = CGColorSpaceCreateDeviceRGB();
        if (colorSpace == NULL) {
            // Handle the error appropriately.
            free(rgbaImage);
            return nil;
        }

    }

    // Create a Quartz direct-access data provider that uses data we supply.
    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbaImage, 4 * width * height, NULL);

    // Create a bitmap image from data supplied by the data provider.
    CGImageRef cgImage = CGImageCreate(width, height, 8, 32, width * 4,
                                       colorSpace, kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little,
                                       dataProvider, NULL, true, kCGRenderingIntentDefault);

    CGDataProviderRelease(dataProvider);

    // Create and return an image object to represent the Quartz image.
    UIImage *image = [UIImage imageWithCGImage:cgImage];

    // Create base64 String from UIImage
    NSString *base64String = [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    CGImageRelease(cgImage);
    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
    free(rgbaImage);

    // Return a String which is easily readable by js side.
    return [@"data:image/png;base64," stringByAppendingString:base64String];
}

static inline NSDictionary *dictionaryFromText(SBSRecognizedText *text) {
    return @{
        @"text": text.text,
        @"rejected": @(text.rejected)
    };
}

@interface SCNBarcodePicker () <SBSScanDelegate, SBSProcessFrameDelegate, SBSWarningsObserver, SBSPropertyObserver, SBSTextRecognitionDelegate>

@property (nonatomic) BOOL shouldStop;
@property (nonatomic) BOOL shouldPause;
@property (nonatomic, nullable) NSArray<NSNumber *> *codesToReject;
@property (nonatomic) dispatch_semaphore_t didScanSemaphore;

// MatrixScan
@property (nonatomic) dispatch_semaphore_t didFinishOnRecognizeNewCodesSemaphore;
@property (nonatomic) dispatch_semaphore_t didFinishOnChangeTrackedCodesSemaphore;
@property (nonatomic) BOOL matrixScanEnabled;
@property (nonatomic, nullable) NSArray<NSNumber *> *idsToVisuallyReject;
@property (nonatomic, nullable) NSSet<NSNumber *> *lastFrameRecognizedIds;

// TextRecognition
@property (nonatomic) dispatch_semaphore_t didRecognizeTextSemaphore;
@property (nonatomic) BOOL shouldRejectText;

@end

@implementation SCNBarcodePicker

- (instancetype)init {
    self = [super init];
    if (self) {
        _matrixScanEnabled = NO;
        SBSScanSettings *scanSettings = [SBSScanSettings defaultSettings];
        _picker = [[SBSBarcodePicker alloc] initWithSettings:scanSettings];
        _picker.scanDelegate = self;
        _picker.processFrameDelegate = self;
        [_picker addWarningsObserver:self];
        [_picker addPropertyObserver:self];
        if ([_picker respondsToSelector:@selector(setTextRecognitionDelegate:)]) {
            _picker.textRecognitionDelegate = self;
        }
        _didScanSemaphore = dispatch_semaphore_create(0);
        _didFinishOnRecognizeNewCodesSemaphore = dispatch_semaphore_create(0);
        _didFinishOnChangeTrackedCodesSemaphore = dispatch_semaphore_create(0);
        _shouldRejectText = NO;
        _didRecognizeTextSemaphore = dispatch_semaphore_create(0);
        [self addSubview:_picker.view];
    }
    return self;
}

- (void)dealloc {
    [_picker removePropertyObserver:self];
}

- (void)layoutSubviews {
    [super layoutSubviews];
    self.picker.view.frame = self.bounds;
}

- (void)setScanSettings:(NSDictionary *)dictionary {
    _scanSettings = dictionary;
    NSError *error = nil;
    SBSScanSettings *scanSettings = [SBSScanSettings settingsWithDictionary:dictionary error:&error];
    if (error != nil) {
        RCTLogError(@"Invalid scan settings: %@", error.localizedDescription);
    } else {
        __weak typeof(self)weakSelf = self;
        self.matrixScanEnabled = scanSettings.matrixScanEnabled;
        [self.picker applyScanSettings:scanSettings completionHandler:^{
            __strong typeof(weakSelf)strongSelf = weakSelf;
            if (strongSelf.onSettingsApplied != nil) {
                NSDictionary *emptyDictionary = [[NSDictionary alloc] init];
                strongSelf.onSettingsApplied(emptyDictionary);
            }
        }];
    }
}

- (void)pauseScanning {
    [self.picker pauseScanning];
    self.shouldPause = YES;
    [self signalSemaphores];
}

- (void)stopScanning {
    [self.picker stopScanning];
    self.shouldStop = YES;
    [self signalSemaphores];
}

- (void)signalSemaphores {
    // It's possible that we are requested to stop/pause the picker while we are waiting for a
    // callback from the JS side. When the JS side asks to stop/pause the picker, this callback is
    // not executed and the signal is not sent to the semaphore. This means that the session queue,
    // that is waiting for the semaphore, will just wait forever. Here by signaling the semaphores,
    // we make sure that the session queue is not blocked and it will finish the code it has to
    // execute.
    dispatch_semaphore_signal(self.didScanSemaphore);
    dispatch_semaphore_signal(self.didFinishOnRecognizeNewCodesSemaphore);
    dispatch_semaphore_signal(self.didFinishOnChangeTrackedCodesSemaphore);
    dispatch_semaphore_signal(self.didRecognizeTextSemaphore);
}

- (void)finishOnScanCallbackShouldStop:(BOOL)shouldStop
                           shouldPause:(BOOL)shouldPause
                         codesToReject:(NSArray<NSNumber *> *)codesToReject {
    self.shouldStop = shouldStop;
    self.shouldPause = shouldPause;
    self.codesToReject = codesToReject;
    dispatch_semaphore_signal(self.didScanSemaphore);
}

- (void)finishOnRecognizeNewCodesShouldStop:(BOOL)shouldStop
                                shouldPause:(BOOL)shouldPause
                        idsToVisuallyReject:(NSArray<NSNumber *> *)idsToVisuallyReject {
    self.shouldStop = shouldStop;
    self.shouldPause = shouldPause;
    self.idsToVisuallyReject = idsToVisuallyReject;
    dispatch_semaphore_signal(self.didFinishOnRecognizeNewCodesSemaphore);
}

- (void)finishOnChangeTrackedCodesShouldStop:(BOOL)shouldStop
                                 shouldPause:(BOOL)shouldPause
                         idsToVisuallyReject:(NSArray<NSNumber *> *)idsToVisuallyReject {
    self.shouldStop = shouldStop;
    self.shouldPause = shouldPause;
    self.idsToVisuallyReject = idsToVisuallyReject;
    dispatch_semaphore_signal(self.didFinishOnChangeTrackedCodesSemaphore);
}

- (void)finishOnTextRecognizedShouldStop:(BOOL)shouldStop
                             shouldPause:(BOOL)shouldPause
                            shouldReject:(BOOL)shouldReject {
    self.shouldStop = shouldStop;
    self.shouldPause = shouldPause;
    self.shouldRejectText = shouldReject;
    dispatch_semaphore_signal(self.didRecognizeTextSemaphore);
}

- (void)setMatrixScanEnabled:(BOOL)matrixScanEnabled {
    if (_matrixScanEnabled != matrixScanEnabled) {
        _matrixScanEnabled = matrixScanEnabled;
        self.picker.processFrameDelegate = matrixScanEnabled ? self : nil;
    }
}

#pragma mark - SBSScanDelegate

- (void)barcodePicker:(SBSBarcodePicker *)picker didScan:(SBSScanSession *)session {
    if (_matrixScanEnabled) {
        return;
    }
    if (self.onScan) {
        self.onScan(dictionaryFromScanSession(session));
    }
    // Suspend the session thread, until finishOnScanCallbackShouldStop:shouldPause:codesToReject: is called from JS
    dispatch_semaphore_wait(self.didScanSemaphore, DISPATCH_TIME_FOREVER);
    if (self.shouldStop) {
        [session stopScanning];
    } else if (self.shouldPause) {
        [session pauseScanning];
    } else {
        for (NSNumber *index in self.codesToReject) {
            if (index.integerValue == -1) {
                continue;
            }
            SBSCode *code = session.newlyRecognizedCodes[index.integerValue];
            [session rejectCode:code];
        }
        self.codesToReject = nil;
    }
}

#pragma mark - SBSTextRecognitionDelegate

- (SBSBarcodePickerState)barcodePicker:(SBSBarcodePicker *)picker
                      didRecognizeText:(SBSRecognizedText *)text {
    if (self.onTextRecognized) {
        self.onTextRecognized(dictionaryFromText(text));
    }
    dispatch_semaphore_wait(self.didRecognizeTextSemaphore, DISPATCH_TIME_FOREVER);
    if (self.shouldRejectText) {
        text.rejected = YES;
        self.shouldRejectText = NO;
    }

    if (self.shouldStop) {
        return SBSBarcodePickerStateStopped;
    } else if (self.shouldPause) {
        return SBSBarcodePickerStatePaused;
    } else {
        return SBSBarcodePickerStateActive;
    }
}

#pragma mark - SBSProcessFrameDelegate

- (void)barcodePicker:(nonnull SBSBarcodePicker *)barcodePicker
      didProcessFrame:(nonnull CMSampleBufferRef)frame
              session:(nonnull SBSScanSession *)session {

    // Call `onBarcodeFrameAvailable` only when new codes have been recognized.
    if (self.shouldPassBarcodeFrame && session.newlyRecognizedCodes.count > 0) {
        NSDictionary *processedFrameDictionary = dictionaryFromBase64FrameString(base64StringFromFrame(&frame));
        if (self.onBarcodeFrameAvailable) {
            self.onBarcodeFrameAvailable(processedFrameDictionary);
        }
    }

    if (session.trackedCodes == nil) {
        return;
    }

    NSMutableSet<NSNumber *> *recognizedCodeIds = [NSMutableSet set];
    NSMutableDictionary<NSNumber *, SBSTrackedCode *> *newlyTrackedCodes = [NSMutableDictionary dictionary];

    for (NSNumber *identifier in session.trackedCodes.allKeys) {
        SBSTrackedCode *code = session.trackedCodes[identifier];
        if (code.isRecognized) {
            [recognizedCodeIds addObject:identifier];
            if (self.lastFrameRecognizedIds == nil || ![self.lastFrameRecognizedIds containsObject:identifier]) {
                newlyTrackedCodes[identifier] = code;
            }
        }
    }

    self.lastFrameRecognizedIds = recognizedCodeIds;

    SBSQuadrilateral (^convert)(SBSQuadrilateral) = ^SBSQuadrilateral(SBSQuadrilateral rect) {
        return convertQuadrilateral(rect, barcodePicker);
    };
    NSDictionary *matrixScanSessionDictionary = dictionaryForMatrixScanSession(session.trackedCodes,
                                                                               newlyTrackedCodes,
                                                                               convert);

    if (self.matrixScanEnabled && self.onChangeTrackedCodes) {
        self.onChangeTrackedCodes(matrixScanSessionDictionary);
        // Suspend the session thread, until finishOnChangeTrackedCodesShouldStop:shouldPause:idsToVisuallyReject: is called from JS
        dispatch_semaphore_wait(self.didFinishOnChangeTrackedCodesSemaphore, DISPATCH_TIME_FOREVER);
        [self handleFinishingSemaphore:session];
    }


    if (newlyTrackedCodes.count > 0 && self.onRecognizeNewCodes) {
        self.onRecognizeNewCodes(matrixScanSessionDictionary);
        // Suspend the session thread, until finishOnRecognizeNewCodesShouldStop:shouldPause:idsToVisuallyReject: is called from JS
        dispatch_semaphore_wait(self.didFinishOnRecognizeNewCodesSemaphore, DISPATCH_TIME_FOREVER);
        [self handleFinishingSemaphore:session];
    }
}

- (void)handleFinishingSemaphore:(SBSScanSession *)session {
    if (self.shouldStop) {
        [session stopScanning];
    } else if (self.shouldPause) {
        [session pauseScanning];
    } else {
        for (NSNumber *identifier in self.idsToVisuallyReject) {
            SBSTrackedCode *code = session.trackedCodes[identifier];
            [session rejectTrackedCode:code];
        }
        self.idsToVisuallyReject = nil;
    }
}

#pragma mark - SBSWarningsObserver

- (void)barcodePicker:(SBSBarcodePicker *)barcodePicker
   didProduceWarnings:(SBSWarning)warnings {
    NSMutableArray<NSNumber *> *result = [NSMutableArray arrayWithCapacity:2];
    if (warnings & SBSWarningTooMuchGlare) {
        // Add 3 which represents `TOO_MUCH_GLARE_WARNING: 3` (check barcodePicker.js)
        [result addObject:@3];
    }
    if (warnings & SBSWarningNotEnoughContrast) {
        // Add 4 which represents `NOT_ENOUGH_CONTRAST_WARNING: 4` (check barcodePicker.js)
        [result addObject:@4];
    }
    if (self.onWarnings) {
        self.onWarnings(@{@"warnings": result});
    }
}

#pragma mark - SBSPropertyObserver

- (void)barcodePicker:(SBSBarcodePicker *)barcodePicker
             property:(NSString *)property
       changedToValue:(NSObject *)value {
    if (![value isKindOfClass:[NSNumber class]]) {
        return;
    }
    NSNumber *number = (NSNumber *)value;
    if ([property isEqualToString:@"torchOn"]) {
        if (number.unsignedIntegerValue == 1) { // torch on
            number = @(2);
        } else if (number.unsignedIntegerValue == 2) { // torch off
            number = @(1);
        }
        NSDictionary *result = @{@"name": property, @"newState": number};
        if (self.onPropertyChanged) {
            self.onPropertyChanged(result);
        }
    } else if ([property isEqualToString:@"relativeZoom"]) {
        number = @(number.floatValue * 1000);
        NSDictionary *result = @{@"name": property, @"newState": number};
        if (self.onPropertyChanged) {
            self.onPropertyChanged(result);
        }
    } else if ([property isEqualToString:@"switchCamera"]) {
        NSDictionary *result = @{@"name": property, @"newState": number};
        if (self.onPropertyChanged) {
            self.onPropertyChanged(result);
        }
    } else if ([property isEqualToString:@"recognitionMode"]) {
        if (number.unsignedIntegerValue == 4) { // text and barcodes
            number = @(3);
        }
        NSDictionary *result = @{@"name": property, @"newState": number};
        if (self.onPropertyChanged) {
            self.onPropertyChanged(result);
        }
    }
}

@end