vds_ios_sample/VDSSample/ViewControllers/TestViewController.swift

//
//  TestViewController.swift
//  VDSSample
//
//  Created by Matt Bruce on 8/12/22.
//

import Foundation
import UIKit
import Combine
import VDS

struct User {
   var firstName: String
   var lastName: String

  init(firstName: String, lastName: String) {
    self.firstName = firstName
    self.lastName = lastName
  }
}

public protocol Bindable {
    associatedtype ModelType
    var model: ModelType { get set }
    var subject: CurrentValueSubject<ModelType, Never>? { get set }
    func createBinding(with subject: CurrentValueSubject<ModelType, Never>, storeIn subscriptions: inout Set<AnyCancellable>)
}

extension Bindable {
    public func send() {
        subject?.send(model)
    }
}

class TextFieldBindingCell: UIView, Bindable {
    //bindable
    var model: User
    var subject: CurrentValueSubject<User, Never>?

    let firstNameTextField = TextField()
    let lastNameTextField = TextField()
        
    init(model: User) {
        self.model = model
        super.init(frame: .zero)
    
        translatesAutoresizingMaskIntoConstraints = false
        firstNameTextField.translatesAutoresizingMaskIntoConstraints = false
        lastNameTextField.translatesAutoresizingMaskIntoConstraints = false
        
        addSubview(firstNameTextField)
        addSubview(lastNameTextField)
        print("\(model.firstName) \(model.lastName)")

        firstNameTextField.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        firstNameTextField.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        firstNameTextField.topAnchor.constraint(equalTo: topAnchor).isActive = true
        firstNameTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true

        lastNameTextField.topAnchor.constraint(equalTo: firstNameTextField.bottomAnchor, constant: 20).isActive = true
        lastNameTextField.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        lastNameTextField.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        lastNameTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
        lastNameTextField.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true

    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func createBinding(with subject: CurrentValueSubject<User, Never>, storeIn subscriptions: inout Set<AnyCancellable>) {
        self.model = subject.value
        self.subject = subject

        //add the logic
        let firstNameSubject = CurrentValueSubject<String, Never>(model.firstName)
        firstNameTextField.createBinding(with: firstNameSubject, storeIn: &subscriptions)
        firstNameSubject.assign(to: \.model.firstName, on: self).store(in: &subscriptions)
        firstNameSubject.sink {[weak self] value in
            self?.send()
        }.store(in: &subscriptions)

        let lastNameSubject = CurrentValueSubject<String, Never>(model.lastName)
        lastNameTextField.createBinding(with: lastNameSubject, storeIn: &subscriptions)
        lastNameSubject.assign(to: \.model.lastName, on: self).store(in: &subscriptions)
        lastNameSubject.sink {[weak self] value in
            guard let self = self else { return }
            self.send()
        }.store(in: &subscriptions)

    }
}

@objcMembers class TestViewController: UIViewController, Initable {
    
    var user = User(firstName: "Joe", lastName: "User")
    private var subscriptions = Set<AnyCancellable>()

    required init() {
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        
        let subject = CurrentValueSubject<User, Never>(user)
        subject.assign(to: \.user, on: self).store(in: &subscriptions)
        
        let nameTextField = TextFieldBindingCell(model: user)
        nameTextField.createBinding(with: subject, storeIn: &subscriptions)
        
        let button = UIButton()
        
        button.translatesAutoresizingMaskIntoConstraints = false
        
        view.addSubview(nameTextField)
        view.addSubview(button)
        nameTextField.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 20).isActive = true
        nameTextField.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -20).isActive = true
        nameTextField.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
        button.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 20).isActive = true
        button.topAnchor.constraint(equalTo: nameTextField.bottomAnchor, constant: 20).isActive = true
        button.heightAnchor.constraint(equalToConstant: 50).isActive = true
        button.widthAnchor.constraint(equalToConstant: 100).isActive = true
        button.backgroundColor = .blue
        button.setTitle("Print", for: .normal)
        
        button.addAction(UIAction(title: "", handler: { [weak self] action in
            if let user = self?.user {
                print("\(user.firstName) \(user.lastName)")
            }
        }), for: .touchUpInside)
    }
}


extension UITextField {
    
    public func textPublisher() -> AnyPublisher<String, Never> {
        NotificationCenter.default
            .publisher(for: UITextField.textDidChangeNotification, object: self)
            .compactMap({ ($0.object as? UITextField)?.text })
            .eraseToAnyPublisher()
    }
    
    public func createBinding(with subject: CurrentValueSubject<String, Never>,
                       storeIn subscriptions: inout Set<AnyCancellable>) {
        
        subject.sink { [weak self] (value) in
            if value != self?.text {
                self?.text = value
            }
        }.store(in: &subscriptions)
        
        self.textPublisher().sink { (value) in
            if value != subject.value {
                subject.send(value)
            }
        }.store(in: &subscriptions)
    }
}

class TextField: UITextField {
    var textPadding = UIEdgeInsets(
        top: 10,
        left: 20,
        bottom: 10,
        right: 20
    )

    override func textRect(forBounds bounds: CGRect) -> CGRect {
        layer.borderColor = UIColor.black.cgColor
        layer.borderWidth = 1
        let rect = super.textRect(forBounds: bounds)
        return rect.inset(by: textPadding)
    }

    override func editingRect(forBounds bounds: CGRect) -> CGRect {
        layer.borderColor = UIColor.black.cgColor
        layer.borderWidth = 1
        let rect = super.editingRect(forBounds: bounds)
        return rect.inset(by: textPadding)
    }
}