//
//  UIImage+Extension.swift
//  MuchinfoSignUp
//
//  Created by zhongyuan on 2017/4/11.
//  Copyright © 2018年 zhongyuan. All rights reserved.
//

import UIKit

// MARK: - 图片拓展类
extension UIImage {
    
    // MARK: - 降低质量
    /// 根据指定体积大小来压缩图片的方法
    ///
    /// - Parameter maxSize: 指定压缩大小
    /// - Returns: 压缩后的图片数据
    func resetSizeOfImageData(maxSize: Int) -> Data {
        
        //先判断当前质量是否满足要求，不满足再进行压缩
        var finallImageData = UIImage.jpegData(self)(compressionQuality: 1.0)
        let sizeOrigin      = finallImageData?.count
        let sizeOriginKB    = sizeOrigin! / 1024
        if sizeOriginKB <= maxSize {
            return finallImageData!
        }
        
        //先调整分辨率
        var defaultSize = CGSize(width: 1024, height: 1024)
        let newImage = self.newSizeImage(size: defaultSize, source_image: self)
        
        finallImageData = UIImage.jpegData(newImage)(compressionQuality: 1.0)
        
        //保存压缩系数
        let compressionQualityArr = NSMutableArray()
        let avg = CGFloat(1.0/250)
        var value = avg
        
        var i = 250
        repeat {
            i -= 1
            value = CGFloat(i)*avg
            compressionQualityArr.add(value)
        } while i >= 1
        
        /*
         调整大小
         说明：压缩系数数组compressionQualityArr是从大到小存储。
         */
        //思路：使用二分法搜索
        finallImageData = self.halfFuntion(arr: compressionQualityArr.copy() as! [CGFloat], image: newImage, sourceData: finallImageData!, maxSize: maxSize)
        //如果还是未能压缩到指定大小，则进行降分辨率
        while finallImageData?.count == 0 {
            //每次降100分辨率
            if defaultSize.width-100 <= 0 || defaultSize.height-100 <= 0 {
                break
            }
            defaultSize = CGSize(width: defaultSize.width-100, height: defaultSize.height-100)
            
            let image = self.newSizeImage(size: defaultSize, source_image: UIImage(data: UIImage.jpegData(newImage)(compressionQuality: compressionQualityArr.lastObject as! CGFloat)!)!)
            finallImageData = self.halfFuntion(arr: compressionQualityArr.copy() as! [CGFloat], image: image, sourceData: UIImage.jpegData(image)(compressionQuality: 1.0)!, maxSize: maxSize)
        }
        
        return finallImageData!
    }
    
    /// 根据指定的分辨率大小来等比率压缩图片的方法
    ///
    /// - Parameters:
    ///   - size: 指定大小
    ///   - source_image: 目标图片数据
    /// - Returns: 压缩后的图片数据
    func newSizeImage(size: CGSize, source_image: UIImage) -> UIImage {
        var newSize = CGSize(width: source_image.size.width, height: source_image.size.height)
        let tempHeight = newSize.height / size.height
        let tempWidth = newSize.width / size.width
        
        if tempWidth > 1.0 && tempWidth > tempHeight {
            newSize = CGSize(width: source_image.size.width / tempWidth, height: source_image.size.height / tempWidth)
        } else if tempHeight > 1.0 && tempWidth < tempHeight {
            newSize = CGSize(width: source_image.size.width / tempHeight, height: source_image.size.height / tempHeight)
        }
        
        UIGraphicsBeginImageContext(newSize)
        source_image.draw(in: CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height))
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage!
    }
    
    // MARK: - 二分法
    func halfFuntion(arr: [CGFloat], image: UIImage, sourceData finallImageData: Data, maxSize: Int) -> Data? {
        var tempFinallImageData = finallImageData
        
        var tempData = Data.init()
        var start = 0
        var end = arr.count - 1
        var index = 0
        
        var difference = Int.max
        while start <= end {
            index = start + (end - start)/2
            
            tempFinallImageData = UIImage.jpegData(image)(compressionQuality: arr[index])!
            let sizeOrigin = tempFinallImageData.count
            let sizeOriginKB = sizeOrigin / 1024
            
            if sizeOriginKB > maxSize {
                start = index + 1
            } else if sizeOriginKB < maxSize {
                if maxSize-sizeOriginKB < difference {
                    difference = maxSize-sizeOriginKB
                    tempData = tempFinallImageData
                }
                end = index - 1
            } else {
                break
            }
        }
        return tempData
    }
    
    //图片压缩 1000kb以下的图片控制在100kb-200kb之间
    func compressImageSize() -> Data{
        
        var zipImageData = UIImage.jpegData(self)(compressionQuality: 1.0)!//UIImageJPEGRepresentation(self, 1.0)!
        let originalImgSize = zipImageData.count/1024 as Int  //获取图片大小
        
        if originalImgSize>1500 {
            zipImageData = UIImage.jpegData(self)(compressionQuality: 0.2)!//UIImageJPEGRepresentation(self,0.2)!
        } else if originalImgSize>600 {
            zipImageData = UIImage.jpegData(self)(compressionQuality: 0.4)!//UIImageJPEGRepresentation(self,0.4)!
        } else if originalImgSize>400 {
            zipImageData = UIImage.jpegData(self)(compressionQuality: 0.6)!//UIImageJPEGRepresentation(self,0.6)!
        } else if originalImgSize>300 {
            zipImageData = UIImage.jpegData(self)(compressionQuality: 0.7)!//UIImageJPEGRepresentation(self,0.7)!
        } else if originalImgSize>200 {
            zipImageData = UIImage.jpegData(self)(compressionQuality: 0.8)!//UIImageJPEGRepresentation(self,0.8)!
        }
        return zipImageData
    }
    
    func resizeImage() -> UIImage{
        
        //prepare constants
        let width = self.size.width
        let height = self.size.height
        let scale = width/height
        
        var sizeChange = CGSize()
        
        if width <= 1280 && height <= 1280{ //a，图片宽或者高均小于或等于1280时图片尺寸保持不变，不改变图片大小
            return self
        } else if width > 1280 || height > 1280 {//b,宽或者高大于1280，但是图片宽度高度比小于或等于2，则将图片宽或者高取大的等比压缩至1280
            
            if scale <= 2 && scale >= 1 {
                let changedWidth:CGFloat = 1280
                let changedheight:CGFloat = changedWidth / scale
                sizeChange = CGSize(width: changedWidth, height: changedheight)
                
            } else if scale >= 0.5 && scale <= 1 {
                
                let changedheight:CGFloat = 1280
                let changedWidth:CGFloat = changedheight * scale
                sizeChange = CGSize(width: changedWidth, height: changedheight)
                
            } else if width > 1280 && height > 1280 {//宽以及高均大于1280，但是图片宽高比大于2时，则宽或者高取小的等比压缩至1280
                
                if scale > 2 {//高的值比较小
                    
                    let changedheight:CGFloat = 1280
                    let changedWidth:CGFloat = changedheight * scale
                    sizeChange = CGSize(width: changedWidth, height: changedheight)
                    
                } else if scale < 0.5{//宽的值比较小
                    
                    let changedWidth:CGFloat = 1280
                    let changedheight:CGFloat = changedWidth / scale
                    sizeChange = CGSize(width: changedWidth, height: changedheight)
                    
                }
            } else {//d, 宽或者高，只有一个大于1280，并且宽高比超过2，不改变图片大小
                return self
            }
        }
        
        UIGraphicsBeginImageContext(sizeChange)
        
        //draw resized image on Context
        self.draw(in: CGRect(origin: CGPoint.zero, size: CGSize(width: sizeChange.width, height: sizeChange.height)))
        
        //create UIImage
        let resizedImg = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        return resizedImg!
        
    }
    
    /// 传入图片image回传对应的base64字符串,默认不带有data标识,
    func imageToBase64String() -> String? {
        
        /// 根据图片得到对应的二进制编码
        guard let imageData = self.pngData() else {
            return nil
        }
        
        /// 根据二进制编码得到对应的base64字符串
        var base64String = imageData.base64EncodedString(options: .endLineWithCarriageReturn)
        /// 根据格式拼接数据头 添加header信息，扩展名信息
        base64String = "data:image/png;base64," + base64String
        return base64String
    }
    
    /// 图片旋转
    /// - Parameter orientation: 角度
    func transRotation(_ orientation: UIImage.Orientation) -> UIImage? {
        
        var rotate: Double = 0.0
        var rect: CGRect = CGRect.zero
        var translateX: CGFloat = 0.0;
        var translateY: CGFloat = 0.0;
        var scaleX: CGFloat = 1.0;
        var scaleY: CGFloat = 1.0;
        
        switch orientation {
        case .left:
            rotate = .pi/2
            rect = CGRect(x: 0.0, y: 0.0, width: self.size.height, height: self.size.width)
            translateX = 0
            translateY = -rect.size.width
            scaleY = rect.size.width/rect.size.height
            scaleX = rect.size.height/rect.size.width
        case .right:
            rotate = 33 * .pi/2
            rect = CGRect(x: 0, y: 0, width: self.size.height, height:self.size.width)
            translateX = -rect.size.height
            translateY = 0
            scaleY = rect.size.width/rect.size.height
            scaleX = rect.size.height/rect.size.width
        case .down:
            rotate = .pi
            rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
            translateX = -rect.size.width
            translateY = -rect.size.height
        default:
            rotate = 0.0
            rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
            translateX = 0
            translateY = 0
        }
        
        UIGraphicsBeginImageContext(rect.size);
        let context = UIGraphicsGetCurrentContext()
        
        /// 做CTM变换
        context!.translateBy(x: 0.0, y: rect.size.height)
        context!.scaleBy(x: 1.0, y: -1.0)
        context!.rotate(by: CGFloat(rotate))
        context!.translateBy(x: translateX, y: translateY)
        context!.scaleBy(x: scaleX, y: scaleY)
        
        /// 绘制图片
        context?.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: rect.size.width, height: rect.size.height))
        return UIGraphicsGetImageFromCurrentImageContext()
    }
    
    /// 按照尺寸大小压缩图片
    /// - Parameter size: size
    func reSizeImage(_ size: CGSize)-> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale);
        self.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height));
        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext() ?? UIImage();
        UIGraphicsEndImageContext();
        return image;
    }
    
    static func image(_ color: UIColor, _ size: CGSize) -> UIImage {
        let rect = CGRect(x: 0.0, y: 0.0, width: size.width, height: size.height)
        UIGraphicsBeginImageContext(rect.size )
        let context = UIGraphicsGetCurrentContext()
        context?.setFillColor(color.cgColor)
        context?.fill(rect)
        
        guard let image = UIGraphicsGetImageFromCurrentImageContext() else { return UIImage() }
        UIGraphicsEndImageContext()
        
        return image
    }
}