FireBoltt_ios/FireBoltt/FB_Modules/FB_Device/ViewModel/WeChatSportViewModels.swift

//
//  WeChatSportViewModelss.swift
//  FireBoltt
//
//  Created by lemo. on 2020/10/27.
//  Copyright © 2020 Sheldon. All rights reserved.
//

import UIKit
import RxSwift

class WeChatSportViewModelss: ViewModel, ViewModelType {

    struct Input {
        let saveQrCode: Observable<Void>
    }
    
    struct Output {
        let qrCodeImage: BehaviorRelay<UIImage?>
        
    }
    
    func transform(input: Input) -> Output {
        // 获取二维码
        let qrCodeImage = BehaviorRelay<UIImage?>(value: nil)
        if let deviceInfo = UserDefaultsManagerFrieBoltt.getDeviceInfo() {
            SVProgressHUD.show()
            ProviderRequest(.wechatGetCode(deviceMac: deviceInfo.MACString))
                .subscribe(onNext: { [weak self] json in
                    SVProgressHUD.dismiss()
                    if let url = json["data"].string {
                        let image = self?.creatQrcode(url: url)
                        qrCodeImage.accept(image)
                    }
                })
                .disposed(by: rx.disposeBag)
        }
        // 保存到相册
        input.saveQrCode
            .subscribe(onNext: { [weak self] _ in
                if let image = qrCodeImage.value {
                    SystemAuthorityFireBoltt.shared.getPhotoAuthority { [weak self] (result) in
                        if result {
                            // 保存图片至相册
                            UIImageWriteToSavedPhotosAlbum(image, self, nil, nil)
                            SVProgressHUD.showSuccess(withStatus: MultiLanguageKey_FB.saveQrCodeSuccessFB.localized)
                        }
                    }
                }
            })
            .disposed(by: rx.disposeBag)
        
        return Output(qrCodeImage: qrCodeImage)
    }
    
    private func creatQrcode(url: String) -> UIImage {
        /// CIFilter
        let filter = CIFilter.init(name: "CIQRCodeGenerator")
        filter?.setDefaults()
        /// Add Data
        let data = url.data(using: .utf8)
        filter?.setValue(data, forKeyPath: "inputMessage")
        /// Out Put
        let outputImage = filter?.outputImage
        /// Show QRCode
        return createUIImageFromCIImages(image: outputImage!, size: 200)
    }
    
    // 高清处理
    private func createUIImageFromCIImages(image: CIImage, size: CGFloat) -> UIImage {
        let extent = image.extent.integral
        let scale = min(size / extent.width, size / extent.height)
        /// Create bitmap
        let width: size_t = size_t(extent.width * scale)
        let height: size_t = size_t(extent.height * scale)
        let cs: CGColorSpace = CGColorSpaceCreateDeviceGray()
        let bitmap: CGContext = CGContext(data: nil, width: width, height: height, bitsPerComponent: 8, bytesPerRow: 0, space: cs, bitmapInfo: 1)!
        let context = CIContext.init()
        let bitmapImage = context.createCGImage(image, from: extent)
        bitmap.interpolationQuality = .none
        bitmap.scaleBy(x: scale, y: scale)
        bitmap.draw(bitmapImage!, in: extent)
        let scaledImage = bitmap.makeImage()
        return UIImage.init(cgImage: scaledImage!)
    }
    
}