#import <React/RCTConvert.h>
#import <AssetsLibrary/AssetsLibrary.h>
#import "color-grabber.h"

#define CLAMP(x, low, high) ({\
__typeof__(x) __x = (x); \
__typeof__(low) __low = (low);\
__typeof__(high) __high = (high);\
__x > __high ? __high : (__x < __low ? __low : __x);\
})

@implementation ColorGrabber




RCT_EXPORT_MODULE();

- (NSArray *)getColorsFromImage:(UIImage *)image options:(NSDictionary *)options {
    
    float dimension = [RCTConvert float:options[@"dimension"]]; // 4
    float flexibility = [RCTConvert float:options[@"flexibility"]]; // 5;
    float range = [RCTConvert float:options[@"range"]]; // 40;
    
    NSMutableArray * colours = [NSMutableArray new];
    CGImageRef imageRef = [image CGImage];
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    unsigned char *rawData = (unsigned char*) calloc(dimension * dimension * 4, sizeof(unsigned char));
    NSUInteger bytesPerPixel = 4;
    NSUInteger bytesPerRow = bytesPerPixel * dimension;
    NSUInteger bitsPerComponent = 8;
    CGContextRef context = CGBitmapContextCreate(rawData, dimension, dimension, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
    CGColorSpaceRelease(colorSpace);
    CGContextDrawImage(context, CGRectMake(0, 0, dimension, dimension), imageRef);
    CGContextRelease(context);
    
    float x = 0;
    float y = 0;
    for (int n = 0; n<(dimension*dimension); n++){
        
        int index = (bytesPerRow * y) + x * bytesPerPixel;
        int red   = rawData[index];
        int green = rawData[index + 1];
        int blue  = rawData[index + 2];
        int alpha = rawData[index + 3];
        NSArray * a = [NSArray arrayWithObjects:[NSString stringWithFormat:@"%i",red],[NSString stringWithFormat:@"%i",green],[NSString stringWithFormat:@"%i",blue],[NSString stringWithFormat:@"%i",alpha], nil];
        [colours addObject:a];
        
        y++;
        if (y==dimension){
            y=0;
            x++;
        }
    }
    free(rawData);
    
    // Add some colour flexibility (adds more colours either side of the colours in the image)
    NSArray * copyColours = [NSArray arrayWithArray:colours];
    NSMutableArray * flexibleColours = [NSMutableArray new];
    
    float flexFactor = flexibility * 2 + 1;
    float factor = flexFactor * flexFactor * 3; //(r,g,b) == *3
    for (int n = 0; n<(dimension * dimension); n++){
        
        NSArray * pixelColours = copyColours[n];
        NSMutableArray * reds = [NSMutableArray new];
        NSMutableArray * greens = [NSMutableArray new];
        NSMutableArray * blues = [NSMutableArray new];
        
        for (int p = 0; p<3; p++){
            
            NSString * rgbStr = pixelColours[p];
            int rgb = [rgbStr intValue];
            
            for (int f = -flexibility; f<flexibility+1; f++){
                int newRGB = rgb+f;
                if (newRGB<0){
                    newRGB = 0;
                }
                if (p==0){
                    [reds addObject:[NSString stringWithFormat:@"%i",newRGB]];
                } else if (p==1){
                    [greens addObject:[NSString stringWithFormat:@"%i",newRGB]];
                } else if (p==2){
                    [blues addObject:[NSString stringWithFormat:@"%i",newRGB]];
                }
            }
        }
        
        int r = 0;
        int g = 0;
        int b = 0;
        for (int k = 0; k<factor; k++){
            int red = CLAMP([reds[r] intValue], 0, 255);
            int green = CLAMP([greens[g] intValue], 0, 255);
            int blue = CLAMP([blues[b] intValue], 0, 255);
            //NSLog([NSString stringWithFormat:@"r: %d, g: %d, b: %d",red,green,blue]);
            
            NSString * rgbString = [NSString stringWithFormat:@"%i,%i,%i",red,green,blue];
            [flexibleColours addObject:rgbString];
            
            b++;
            if (b==flexFactor){ b=0; g++; }
            if (g==flexFactor){ g=0; r++; }
        }
    }
    
    // Distinguish the colours
    // orders the flexible colours by their occurrence
    // then keeps them if they are sufficiently disimilar
    
    NSMutableDictionary * colourCounter = [NSMutableDictionary new];
    
    //count the occurences in the array
    NSCountedSet *countedSet = [[NSCountedSet alloc] initWithArray:flexibleColours];
    for (NSString *item in countedSet) {
        NSUInteger count = [countedSet countForObject:item];
        [colourCounter setValue:[NSNumber numberWithInteger:count] forKey:item];
    }
    
    // Sort keys highest occurrence to lowest
    NSArray *orderedKeys = [colourCounter keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2){
        return [obj2 compare:obj1];
    }];
    
    // Checks if the colour is similar to another one already included
    NSMutableArray * ranges = [NSMutableArray new];
    for (NSString * key in orderedKeys){
        NSArray * rgb = [key componentsSeparatedByString:@","];
        int r = [rgb[0] intValue];
        int g = [rgb[1] intValue];
        int b = [rgb[2] intValue];
        bool exclude = false;
        for (NSString * ranged_key in ranges){
            NSArray * ranged_rgb = [ranged_key componentsSeparatedByString:@","];
            
            int ranged_r = [ranged_rgb[0] intValue];
            int ranged_g = [ranged_rgb[1] intValue];
            int ranged_b = [ranged_rgb[2] intValue];
            
            if (r>= ranged_r-range && r<= ranged_r+range){
                if (g>= ranged_g-range && g<= ranged_g+range){
                    if (b>= ranged_b-range && b<= ranged_b+range){
                        exclude = true;
                    }
                }
            }
        }
        
        if (!exclude){ [ranges addObject:key]; }
    }
    

    
    // If you want percentages to colours continue below
    NSMutableDictionary * temp = [NSMutableDictionary new];
    float totalCount = 0.0f;
    for (NSString * rangeKey in ranges){
        NSNumber * count = colourCounter[rangeKey];
        totalCount += [count intValue];
        temp[rangeKey]=count;
    }
    
    // Set percentages
    NSMutableArray * colors = [NSMutableArray new];
    for (NSString * key in temp){
        float count = [temp[key] floatValue];
        float percentage = count/totalCount;
        //NSLog(@"%f",percentage);
        NSArray * rgb = [key componentsSeparatedByString:@","];
        float r = [rgb[0] floatValue];
        float g = [rgb[1] floatValue];
        float b = [rgb[2] floatValue];
      
       
       
        [colors addObject:@{
                            @"color": @{
                                    @"r": @(r),
                                    @"g": @(g),
                                    @"b": @(b)
                                    },
                            @"percentage":@(percentage)
                            }];
       
    }
    return colors;
}

RCT_EXPORT_METHOD(getColors:(NSString *)path options:(NSDictionary *)options resolve:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject)
{
    
    NSURL* aURL = [NSURL URLWithString:path];
    
    if([path hasPrefix: @"/"]) {
        UIImage *image = [UIImage imageWithContentsOfFile:path];
        
        NSArray * colors = [self getColorsFromImage:image options:options];
        resolve(colors);
    } else {
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        
        [library assetForURL:aURL resultBlock:^(ALAsset *asset) {
            UIImage  *image = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage] scale:0.5 orientation:UIImageOrientationUp];
            NSArray * colors = [self getColorsFromImage:image options:options];
            resolve(colors);
            
        }
                failureBlock:^(NSError *error) {
                    reject(@"asset error", @"cant't get colors from asset", error );
                }];
    }
    
    
    
    
}

- (NSString *)hexStringFromColor:(UIColor *)color {
    const CGFloat *components = CGColorGetComponents(color.CGColor);
    
    CGFloat r = components[0];
    CGFloat g = components[1];
    CGFloat b = components[2];
    
    return [NSString stringWithFormat:@"#%02lX%02lX%02lX",
            lroundf(r * 255),
            lroundf(g * 255),
            lroundf(b * 255)];
}


+ (instancetype)sharedInstance {
    static ColorGrabber *instance = nil;
    static dispatch_once_t onceToken;
    
    dispatch_once(&onceToken, ^{
        if (instance == nil) {
            instance = [[self alloc] init];
        }
    });
    return instance;
}


@end