space-ios/iOSClient/Main/Create cloud/NCUploadScanDocument.swift

//
//  NCUploadScanDocument.swift
//  Nextcloud
//
//  Created by Marino Faggiana on 28/12/22.
//  Copyright © 2022 Marino Faggiana. All rights reserved.
//
//  Author Marino Faggiana <marino.faggiana@nextcloud.com>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

import SwiftUI
import NextcloudKit
import Vision
import VisionKit
import Photos
import PDFKit

class NCHostingUploadScanDocumentView: NSObject {

    @objc func makeShipDetailsUI(images: [UIImage], account: String, serverUrl: String) -> UIViewController {
        let uploadScanDocument = NCUploadScanDocument(images: images)
        let details = UploadScanDocumentView(uploadScanDocument)
        let vc = UIHostingController(rootView: details)
        vc.title = NSLocalizedString("_save_settings_", comment: "")
        return vc
    }
}

class NCUploadScanDocument: ObservableObject {

    @Published var isTextRecognition: Bool = false
    @Published var url: URL = Bundle.main.url(forResource: "Reasons to use Nextcloud", withExtension: "pdf")!

    var images: [UIImage] = []

    init(images: [UIImage]) {
        self.images = images
        createPDF()
    }

    func createPDF(password: String = "", textRecognition: Bool = false, quality: Double = 1) {

        guard !images.isEmpty else { return }
        let pdfData = NSMutableData()

        if password.isEmpty {
            UIGraphicsBeginPDFContextToData(pdfData, CGRect.zero, nil)
        } else {
            for char in password.unicodeScalars {
                if !char.isASCII {
                    NCActivityIndicator.shared.stop()
                    let error = NKError(errorCode: NCGlobal.shared.errorForbidden, errorDescription: "_password_ascii_")
                    NCContentPresenter.shared.showError(error: error)
                    return
                }
            }
            let info: [AnyHashable: Any] = [kCGPDFContextUserPassword as String: password, kCGPDFContextOwnerPassword as String: password]
            UIGraphicsBeginPDFContextToData(pdfData, CGRect.zero, info)
        }

        for var image in images {

            image = changeCompressionImage(image, quality: quality)
            let bounds = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)
            if textRecognition {

            } else {
                UIGraphicsBeginPDFPageWithInfo(bounds, nil)
                image.draw(in: bounds)
            }
        }
        UIGraphicsEndPDFContext()

        do {
            url = URL(fileURLWithPath: NSTemporaryDirectory() + "scandocument.pdf")
            try pdfData.write(to: url, options: .atomic)
        } catch {
            print("error catched")
        }
    }

    func changeCompressionImage(_ image: UIImage, quality: Double) -> UIImage {

        var compressionQuality: CGFloat = 0.5
        var baseHeight: Float = 595.2    // A4
        var baseWidth: Float = 841.8     // A4

        switch quality {
        case 0:
            baseHeight *= 1
            baseWidth *= 1
            compressionQuality = 0.3
        case 1:
            baseHeight *= 2
            baseWidth *= 2
            compressionQuality = 0.6
        case 2:
            baseHeight *= 4
            baseWidth *= 4
            compressionQuality = 0.9
        default:
            break
        }

        var newHeight = Float(image.size.height)
        var newWidth = Float(image.size.width)
        var imgRatio: Float = newWidth / newHeight
        let baseRatio: Float = baseWidth / baseHeight

        if newHeight > baseHeight || newWidth > baseWidth {
            if imgRatio < baseRatio {
                imgRatio = baseHeight / newHeight
                newWidth = imgRatio * newWidth
                newHeight = baseHeight
            } else if imgRatio > baseRatio {
                imgRatio = baseWidth / newWidth
                newHeight = imgRatio * newHeight
                newWidth = baseWidth
            } else {
                newHeight = baseHeight
                newWidth = baseWidth
            }
        }

        let rect = CGRect(x: 0.0, y: 0.0, width: CGFloat(newWidth), height: CGFloat(newHeight))
        UIGraphicsBeginImageContext(rect.size)
        image.draw(in: rect)
        let img = UIGraphicsGetImageFromCurrentImageContext()
        let imageData = img?.jpegData(compressionQuality: CGFloat(compressionQuality))
        UIGraphicsEndImageContext()
        return UIImage(data: imageData!) ?? image
    }
}

extension NCUploadScanDocument: NCSelectDelegate {

    func dismissSelect(serverUrl: String?, metadata: tableMetadata?, type: String, items: [Any], overwrite: Bool, copy: Bool, move: Bool) {
    }
}

extension NCUploadScanDocument: NCCreateFormUploadConflictDelegate {

    func dismissCreateFormUploadConflict(metadatas: [tableMetadata]?) {
    }
}

// MARK: - Preview / Test

struct UploadScanDocumentView: View {

    @State var currentValue = 1.0
    @State var password: String = ""
    @State var isSecured: Bool = true
    @ObservedObject var uploadScanDocument: NCUploadScanDocument

    init(_ uploadScanDocument: NCUploadScanDocument) {
        self.uploadScanDocument = uploadScanDocument
    }

    var body: some View {

        GeometryReader { geo in

            VStack {
                List {
                    Section(header: Text(NSLocalizedString("_save_path_", comment: ""))) {

                        HStack {
                            Label {
                                Text("/")
                                    .frame(maxWidth: .infinity, alignment: .trailing)
                            } icon: {
                                Image("folder")
                                    .renderingMode(.template)
                                    .resizable()
                                    .scaledToFit()
                                    .frame(width: NCBrandSettings.shared.settingsSizeImage, height: NCBrandSettings.shared.settingsSizeImage)
                                    .foregroundColor(Color(NCBrandColor.shared.brand))
                            }
                            Spacer()
                        }
                        .contentShape(Rectangle())
                        .onTapGesture {
                            //
                        }
                    }

                    Section(header: Text(NSLocalizedString("_quality_image_title_", comment: ""))) {

                        VStack {
                            Text("Current slider value")
                            Slider(value: $currentValue, in: 0...2, step: 1) { _ in
                                uploadScanDocument.createPDF(quality: currentValue)
                            }
                            // Slider(value: $currentValue, in: 0...2, step: 1).onChange(of: currentValue, perform: { currentValue in
                            //    uploadScanDocument.createPDF(quality: currentValue)
                            // })
                            .accentColor(Color(NCBrandColor.shared.brand))
                        }
                    }

                    Section(header: Text(NSLocalizedString("_preview_", comment: ""))) {

                        PDFKitRepresentedView(uploadScanDocument.url)
                            .frame(maxWidth: .infinity, minHeight: geo.size.height / 3)
                    }

                    Section(header: Text(NSLocalizedString("_file_creation_", comment: ""))) {

                        HStack {
                            Group {
                                Text(NSLocalizedString("_password_", comment: ""))
                                if isSecured {
                                    SecureField(NSLocalizedString("_enter_password_", comment: ""), text: $password)
                                        .multilineTextAlignment(.trailing)
                                } else {
                                    TextField(NSLocalizedString("_enter_password_", comment: ""), text: $password)
                                        .multilineTextAlignment(.trailing)
                                }
                            }
                            Button(action: {
                                isSecured.toggle()
                            }) {
                                Image(systemName: self.isSecured ? "eye.slash" : "eye")
                                    .accentColor(.gray)
                            }
                        }

                        HStack {
                            Toggle(NSLocalizedString("_text_recognition_", comment: ""), isOn: $uploadScanDocument.isTextRecognition)
                                .toggleStyle(SwitchToggleStyle(tint: Color(NCBrandColor.shared.brand)))
                                .onChange(of: uploadScanDocument.isTextRecognition) { newValue in

                                }
                        }

                        HStack {
                            Text(NSLocalizedString("_filename_", comment: ""))
                            TextField(NSLocalizedString("_enter_filename_", comment: ""), text: $password)
                                .multilineTextAlignment(.trailing)
                        }
                    }
                }
            }
        }
        .background(Color(UIColor.systemGroupedBackground))
    }
}

struct PDFKitRepresentedView: UIViewRepresentable {

    let url: URL

    init(_ url: URL) {
        self.url = url
    }

    func makeUIView(context: UIViewRepresentableContext<PDFKitRepresentedView>) -> PDFKitRepresentedView.UIViewType {
        let pdfView = PDFView()
        pdfView.document = PDFDocument(url: self.url)
        pdfView.autoScales = true
        pdfView.backgroundColor = .clear
        pdfView.displayMode = .singlePage
        pdfView.displayDirection = .vertical
        return pdfView
    }

    func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PDFKitRepresentedView>) {
    }
}

struct UploadScanDocumentView_Previews: PreviewProvider {
    static var previews: some View {
        let uploadScanDocument = NCUploadScanDocument(images: [])
        UploadScanDocumentView(uploadScanDocument)
            // .previewDevice(PreviewDevice(rawValue: "iPhone 14 Pro"))
            // .previewDisplayName("iPhone 14")
    }
}