//
//  UIImage+Extenstion.m
//  RNPhotoEditor
//
//  Created by Hanson on 2019/6/29.
//  Copyright © 2019 Facebook. All rights reserved.
//

#import "UIImage+Extenstion.h"
#import <Accelerate/Accelerate.h>

@implementation UIImage (Extenstion)

+ (NSString *)getImageDir {
    //获取Document文件
    NSString * docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *imageDir = [docsDir stringByAppendingPathComponent:@"resultImgs"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL isDir = NO;
    BOOL existed = [fileManager fileExistsAtPath:imageDir isDirectory:&isDir];
    if ( !(isDir == YES && existed == YES) ) {//如果文件夹不存在
        [fileManager createDirectoryAtPath:imageDir withIntermediateDirectories:YES attributes:nil error:nil];
    }
    return imageDir;
}

+ (void)cleanTempImages {
    NSString *filePath = [self getImageDir];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:filePath]) {
        [fileManager removeItemAtPath:filePath error:nil];
    }
}

- (NSString *)saveToDevice {
    // 本地沙盒目录
    NSString *path = [UIImage getImageDir];
    // 得到本地沙盒中名为"MyImage"的路径，"MyImage"是保存的图片名
    NSTimeInterval time = [[NSDate date] timeIntervalSince1970];
    NSString *imgaName = [NSString stringWithFormat:@"img%.0f.png",time];
    NSString *imageFilePath = [path stringByAppendingPathComponent:imgaName];
    [UIImagePNGRepresentation(self) writeToFile:imageFilePath  atomically:YES];
    return imageFilePath;
}

- (instancetype)gaussianBlurWithValue:(CGFloat)blur {
    
    int boxSize = blur;
    if (blur < 1 || blur > 100) {
        boxSize = 30;
    }
    boxSize = boxSize - (boxSize % 2) + 1;
    
    CGImageRef img = self.CGImage;
    
    vImage_Buffer inBuffer, outBuffer;
    vImage_Error error;
    
    void *pixelBuffer;
    
    CGDataProviderRef inProvider = CGImageGetDataProvider(img);
    CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
    
    inBuffer.width = CGImageGetWidth(img);
    inBuffer.height = CGImageGetHeight(img);
    inBuffer.rowBytes = CGImageGetBytesPerRow(img);
    
    inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
    
    pixelBuffer = malloc(CGImageGetBytesPerRow(img) *
                         CGImageGetHeight(img));
    
    if(pixelBuffer == NULL)
        NSLog(@"No pixelbuffer");
    
    outBuffer.data = pixelBuffer;
    outBuffer.width = CGImageGetWidth(img);
    outBuffer.height = CGImageGetHeight(img);
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);
    
    error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
    
    if (error) {
        NSLog(@"error from convolution %ld", error);
    }
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate(
                                             outBuffer.data,
                                             outBuffer.width,
                                             outBuffer.height,
                                             8,
                                             outBuffer.rowBytes,
                                             colorSpace,
                                             kCGImageAlphaNoneSkipLast);
    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
    
    //clean up
    CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);
    
    free(pixelBuffer);
    CFRelease(inBitmapData);
    
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(imageRef);
    
    return returnImage;
}

@end