//
//  UIImage+getSize.m
//  LiDa
//
//  Created by LF on 2017/7/31.
//  Copyright © 2017年 Simon. All rights reserved.
//

#import "UIImage+getSize.h"
#import <ImageIO/ImageIO.h>
@implementation UIImage (getSize)

// 根据图片url获取图片尺寸
+(CGSize )getImageSizeWithUrl:(id)imageURL {
    NSURL * url = nil;
    if ([imageURL isKindOfClass:[NSURL class]]) {
        url = imageURL;
    }
    if ([imageURL isKindOfClass:[NSString class]]) {
        url = [NSURL URLWithString:imageURL];
    }
    if (!imageURL) {
        return CGSizeZero;
    }

    CGImageSourceRef imageSourceRef =     CGImageSourceCreateWithURL((CFURLRef)url, NULL);
    CGFloat width = 0, height = 0;
    if (imageSourceRef) {
        CFDictionaryRef imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef, 0, NULL);
        if (imageProperties != NULL) {
            CFNumberRef widthNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelWidth);
            if (widthNumberRef != NULL) {
                CFNumberGetValue(widthNumberRef, kCFNumberFloat64Type, &width);
            }
            CFNumberRef heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight);
            if (heightNumberRef != NULL) {
                CFNumberGetValue(heightNumberRef, kCFNumberFloat64Type, &height);
            }
            CFRelease(imageProperties);
        }
        CFRelease(imageSourceRef);
    }
    return CGSizeMake(width, height);
//    NSURL* URL = nil;
//    if([imageURL isKindOfClass:[NSURL class]]) {
//        URL = imageURL;
//    }
//    if([imageURL isKindOfClass:[NSString class]]) {
//        URL = [NSURL URLWithString:imageURL];
//    }
//    if(URL == nil) {
//        // url不正确返回CGSizeZero
//        return CGSizeZero;
//    }
//    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:URL];
//    NSString* pathExtendsion = [URL.pathExtension lowercaseString];
//
//    CGSize size = CGSizeZero;
//    if([pathExtendsion isEqualToString:@"png"]) {
//        size =  [self getPNGImageSizeWithRequest:request];
//    }
//    else if([pathExtendsion isEqual:@"gif"])
//    {
//        size =  [self getGIFImageSizeWithRequest:request];
//    }
//    else{
//        size = [self getJPGImageSizeWithRequest:request];
//    }
//    if(CGSizeEqualToSize(CGSizeZero, size)) {
//
//        // 如果获取文件头信息失败,发送异步请求请求原图
//
//        NSData* data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:URL] returningResponse:nil error:nil];
//        UIImage* image = [UIImage imageWithData:data];
//        if(image) {
//            size = image.size;
//        }
//    }
//    return size;
}

//  获取PNG图片的大小
+(CGSize)getPNGImageSizeWithRequest:(NSMutableURLRequest*)request
{
    [request setValue:@"bytes=16-23" forHTTPHeaderField:@"Range"];
    NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    if(data.length == 8)
    {
        int w1 = 0, w2 = 0, w3 = 0, w4 = 0;
        [data getBytes:&w1 range:NSMakeRange(0, 1)];
        [data getBytes:&w2 range:NSMakeRange(1, 1)];
        [data getBytes:&w3 range:NSMakeRange(2, 1)];
        [data getBytes:&w4 range:NSMakeRange(3, 1)];
        int w = (w1 << 24) + (w2 << 16) + (w3 << 8) + w4;
        int h1 = 0, h2 = 0, h3 = 0, h4 = 0;
        [data getBytes:&h1 range:NSMakeRange(4, 1)];
        [data getBytes:&h2 range:NSMakeRange(5, 1)];
        [data getBytes:&h3 range:NSMakeRange(6, 1)];
        [data getBytes:&h4 range:NSMakeRange(7, 1)];
        int h = (h1 << 24) + (h2 << 16) + (h3 << 8) + h4;
        return CGSizeMake(w, h);
    }
    return CGSizeZero;
}

//  获取gif图片的大小
+(CGSize)getGIFImageSizeWithRequest:(NSMutableURLRequest*)request
{
    [request setValue:@"bytes=6-9" forHTTPHeaderField:@"Range"];
    NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    if(data.length == 4)
    {
        short w1 = 0, w2 = 0;
        [data getBytes:&w1 range:NSMakeRange(0, 1)];
        [data getBytes:&w2 range:NSMakeRange(1, 1)];
        short w = w1 + (w2 << 8);
        short h1 = 0, h2 = 0;
        [data getBytes:&h1 range:NSMakeRange(2, 1)];
        [data getBytes:&h2 range:NSMakeRange(3, 1)];
        short h = h1 + (h2 << 8);
        return CGSizeMake(w, h);
    }
    return CGSizeZero;
}

//  获取jpg图片的大小
+(CGSize)getJPGImageSizeWithRequest:(NSMutableURLRequest*)request
{
    [request setValue:@"bytes=0-209" forHTTPHeaderField:@"Range"];
    NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    
    if ([data length] <= 0x58) {
        return CGSizeZero;
    }
    
    if ([data length] < 210) {// 肯定只有一个DQT字段
        short w1 = 0, w2 = 0;
        [data getBytes:&w1 range:NSMakeRange(0x60, 0x1)];
        [data getBytes:&w2 range:NSMakeRange(0x61, 0x1)];
        short w = (w1 << 8) + w2;
        short h1 = 0, h2 = 0;
        [data getBytes:&h1 range:NSMakeRange(0x5e, 0x1)];
        [data getBytes:&h2 range:NSMakeRange(0x5f, 0x1)];
        short h = (h1 << 8) + h2;
        return CGSizeMake(w, h);
    } else {
        short word = 0x0;
        [data getBytes:&word range:NSMakeRange(0x15, 0x1)];
        if (word == 0xdb) {
            [data getBytes:&word range:NSMakeRange(0x5a, 0x1)];
            if (word == 0xdb) {// 两个DQT字段
                short w1 = 0, w2 = 0;
                [data getBytes:&w1 range:NSMakeRange(0xa5, 0x1)];
                [data getBytes:&w2 range:NSMakeRange(0xa6, 0x1)];
                short w = (w1 << 8) + w2;
                short h1 = 0, h2 = 0;
                [data getBytes:&h1 range:NSMakeRange(0xa3, 0x1)];
                [data getBytes:&h2 range:NSMakeRange(0xa4, 0x1)];
                short h = (h1 << 8) + h2;
                return CGSizeMake(w, h);
            } else {// 一个DQT字段
                short w1 = 0, w2 = 0;
                [data getBytes:&w1 range:NSMakeRange(0x60, 0x1)];
                [data getBytes:&w2 range:NSMakeRange(0x61, 0x1)];
                short w = (w1 << 8) + w2;
                short h1 = 0, h2 = 0;
                [data getBytes:&h1 range:NSMakeRange(0x5e, 0x1)];
                [data getBytes:&h2 range:NSMakeRange(0x5f, 0x1)];
                short h = (h1 << 8) + h2;
                return CGSizeMake(w, h);
            }
        } else {
            return CGSizeZero;
        }
    }
}

@end