import SwiftUI

struct TextViewWrapper: UIViewRepresentable {

  init(text: Binding<String?>, focused: Binding<Bool>, contentHeight: Binding<CGFloat>) {
    self._text = text
    self._focused = focused
    self._contentHeight = contentHeight
  }

  @Binding var text: String?
  @Binding var focused: Bool
  @Binding var contentHeight: CGFloat

  // MARK: - UIViewRepresentable

  func makeUIView(context: Context) -> UITextView {
    let textView = UITextView()
    textView.delegate = context.coordinator
    textView.font = .systemFont(ofSize: 16)
    textView.backgroundColor = .clear
    textView.autocorrectionType = .no
    return textView
  }

  func makeCoordinator() -> Coordinator {
    Coordinator(text: $text, focused: $focused, contentHeight: $contentHeight)
  }

  func updateUIView(_ uiView: UITextView, context: Context) {
    uiView.text = text
  }

  class Coordinator: NSObject, UITextViewDelegate {

    init(text: Binding<String?>, focused: Binding<Bool>, contentHeight: Binding<CGFloat>) {
      self._text = text
      self._focused = focused
      self._contentHeight = contentHeight
    }

    @Binding private var text: String?
    @Binding private var focused: Bool
    @Binding private var contentHeight: CGFloat

    // MARK: - UITextViewDelegate

    func textViewDidChange(_ textView: UITextView) {
      text = textView.text
      contentHeight = textView.contentSize.height
    }

    func textViewDidBeginEditing(_ textView: UITextView) {
      focused = true
    }

    func textViewDidEndEditing(_ textView: UITextView) {
      focused = false
      contentHeight = text == nil ? 0 : textView.contentSize.height
    }
  }
}

#if DEBUG
struct TextViewWrapper_Previews: PreviewProvider {
    @State static var text:String?

  static var previews: some View {
    TextViewWrapper(text: $text, focused: .constant(false), contentHeight: .constant(0))
  }
}
#endif