import SwiftUI

struct SwiftUIView: View {
    
    let filename = "tmp.txt"
    @State var savedContent: String = ""
    @State var readContent: String = ""
    
    
    var body: some View {
        
        VStack {
            HStack {
                TextField("Type something to save", text: $savedContent)
                Spacer()
                Text("Save")
                    .onTapGesture {
                        save()
                    }
            }
            .padding()
            .background(Color.green)
            
            HStack {
                Text(readContent)
                Spacer()
                Text("Read")
                    .onTapGesture {
                        read()
                    }
            }
            .padding()
            .background(Color.yellow)
            
        }
        
    }
    
    
    
    func getDocumentsDirectory() -> URL {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        return paths[0]
    }
    
    func read() {
        
        let fullPath = getDocumentsDirectory().appendingPathComponent(filename)
        do {
            let data = try Data(contentsOf: fullPath)
            do {
                readContent = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as! String
                
            } catch {
                print("Couldn't read file.")
            }
            
        } catch {
            print("couldn't read the data")
        }
        
    }
    
    func save() {
        
        let fullPath = getDocumentsDirectory().appendingPathComponent(filename)

        do {
            let data = try NSKeyedArchiver.archivedData(withRootObject: savedContent, requiringSecureCoding: false)
            try data.write(to: fullPath)
        } catch {
            print("Couldn't write file")
        }
    }
  
    
}