import UIKit
import SwiftUI
import Combine

struct DoneTextField: View, UIViewRepresentable {


    var placeholder: String
    @Binding var text: String

    func makeUIView(context: Context) -> DoneUITextField {

        let field = DoneUITextField()
        field.placeholder = placeholder
        field.keyboardType = .numberPad
        field.textBinding = $text
        field.configure()

        return field

    }

    func updateUIView(_ uiView: DoneUITextField, context: Context) {
    }

    static func dismantleUIView(_ uiView: DoneUITextField, coordinator: ()) {
        uiView.subscription?.cancel()
    }
    
}

class DoneUITextField: UITextField, UITextFieldDelegate, ObservableObject {

    var toolbar: UIToolbar?

    var textBinding: Binding<String>? {
        didSet {
            text = textBinding?.wrappedValue
        }
    }

    var subscription: AnyCancellable?

    func configure() {
        if toolbar == nil {
            toolbar = UIToolbar(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 44.0))
            let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(handleDone))
            toolbar?.items = [doneButton]
            self.inputAccessoryView = toolbar
        }

        self.delegate = self

        subscription = NotificationCenter.default.publisher(for: UITextField.textDidChangeNotification, object: self)
            .sink { _ in
                if (self.text?.count ?? 0) >= 10 {
                    self.text = String(self.text?.prefix(10) ?? "")
                }
                self.textBinding?.wrappedValue = self.text ?? ""
        }
    }

    @objc func handleDone() {
        self.resignFirstResponder()
    }

}