my-files-sample/Modules/Sources/Browse/UI/Components/InputAlertView.swift

//
//  InputAlertView.swift
//  Browse
//
//  Created by Javier Cicchelli on 16/12/2022.
//  Copyright © 2022 Röck+Cöde. All rights reserved.
//

import DataModels
import SwiftUI
import UIKit

struct InputAlertView: UIViewControllerRepresentable {
    
    // MARK: Bindings
    
    @Binding private var isPresenting: Bool
    @Binding private var textFieldString: String
    
    // MARK: Properties
    
    private let title: String
    private let message: String
    private let textFieldPlaceholder: String
    private let actions: [UIAlertAction]
    
    // MARK: Initialisers
    
    init(
        isPresenting: Binding<Bool>,
        title: String,
        message: String,
        textFieldPlaceholder: String,
        textFieldString: Binding<String>,
        actions: [UIAlertAction]
    ) {
        self.title = title
        self.message = message
        self.textFieldPlaceholder = textFieldPlaceholder
        self.actions = actions
        
        self._isPresenting = isPresenting
        self._textFieldString = textFieldString
    }

    // MARK: Functions
    
    func makeUIViewController(
        context: UIViewControllerRepresentableContext<InputAlertView>
    ) -> UIViewController {
        .init()
    }
    
    func updateUIViewController(
        _ viewController: UIViewController,
        context: UIViewControllerRepresentableContext<InputAlertView>
    ) {
        guard
            context.coordinator.alert == nil,
            isPresenting
        else { return }
        
        let alertController = {
            let alert = UIAlertController(
                title: title,
                message: message,
                preferredStyle: .alert
            )
            
            alert.addTextField { textField in
                textField.placeholder = textFieldPlaceholder
                textField.text = textFieldString
                textField.delegate = context.coordinator
            }

            actions.forEach { action in
                alert.addAction(action)
            }
            
            return alert
        }()
        
        context.coordinator.alert = alertController
        
        Task { @MainActor in
            viewController.present(
                alertController,
                animated: true
            ) {
                isPresenting = false
                context.coordinator.alert = nil
            }
        }
    }
    
    func makeCoordinator() -> InputAlertView.Coordinator {
        Coordinator(self)
    }
    
}

// MARK: - Coordinator

extension InputAlertView {
    class Coordinator: NSObject, UITextFieldDelegate {
        
        // MARK: Properties
        
        var alert: UIAlertController?
        
        private let component: InputAlertView
        
        // MARK: Initialisers

        init(_ component: InputAlertView) {
            self.component = component
        }
        
        // MARK: UITextFieldDelegate
        
        func textField(
            _ textField: UITextField,
            shouldChangeCharactersIn range: NSRange,
            replacementString string: String
        ) -> Bool {
            component.textFieldString = {
                if let text = textField.text as NSString? {
                    return text
                        .replacingCharacters(in: range, with: string)
                        .trimmingCharacters(in: .newlines)
                } else {
                    return .empty
                }
            }()

            return true
        }

    }
}