import Foundation

import RxSwift

protocol ViewModelType {

    associatedtype Input
    associatedtype Output

    var disposeBag: DisposeBag { get set }

    func transform(input: Input) -> Output
}

import Foundation

import RxSwift
import RxCocoa

final class BeforeNAfterViewModel: ViewModelType {
   
    struct Input {
        let didBeforeAddButtonTapped: Signal<Void>
        let didAfterAddButtonTapped: Signal<Void>
        
    }
    
    struct Output {
        let isBeforeButtonHidden: Driver<Bool>
        let isAfterButtonHidden: Driver<Bool>
    }
    
    var disposeBag = DisposeBag()
    
    private let isBeforeButtonHidden = BehaviorRelay<Bool>(value: false)
    private let isAlbumHidden = BehaviorRelay<Bool>(value: false)
    
    private let isAfterButtonHidden = BehaviorRelay<Bool>(value: false)

    func transform(input: Input) -> Output {
        input.didBeforeAddButtonTapped
            .emit(onNext: { [weak self] in
                guard let self = self else { return }
                self.isBeforeButtonHidden.accept(!self.isBeforeButtonHidden.value)
            })
            .disposed(by: disposeBag)
        
        input.didAfterAddButtonTapped
            .emit(onNext: { [weak self] in
                guard let self = self else { return }
                self.isAfterButtonHidden.accept(!self.isAfterButtonHidden.value)
            })
            .disposed(by: disposeBag)
        
        isBeforeButtonHidden
            .subscribe(onNext: { [weak self] isSelected in
                if isSelected {
                    self?.isAlbumHidden.accept(false)
                }
            })
            .disposed(by: disposeBag)
        
        isAfterButtonHidden
            .subscribe(onNext: { [weak self] isSelected in
                if isSelected {
                    self?.isAlbumHidden.accept(false)
                }
            })
            .disposed(by: disposeBag)
        
        return Output (
            isBeforeButtonHidden: isBeforeButtonHidden.asDriver(),
            isAfterButtonHidden: isAfterButtonHidden.asDriver()
        )
    }
}

  private lazy var input = BeforeNAfterViewModel.Input (
        didBeforeAddButtonTapped: beforeNAfterView.beforeAddButton.rx.tap.asSignal(),
        didAfterAddButtonTapped: beforeNAfterView.afterAddButton.rx.tap.asSignal()
    )

  private func bind() {
        output.isBeforeButtonHidden.drive(onNext: {
            self.beforeNAfterView.beforeAddButton.isHidden = $0
            self.beforeNAfterView.beforeAlbumButton.isHidden = !$0
            self.beforeNAfterView.beforeCameraButton.isHidden = !$0
        })
            .disposed(by: disposeBag)
        
        output.isAfterButtonHidden.drive(onNext: {
            self.beforeNAfterView.afterAddButton.isHidden = $0
            self.beforeNAfterView.afterAlbumButton.isHidden = !$0
            self.beforeNAfterView.afterCameraButton.isHidden = !$0
        })
            .disposed(by: disposeBag)
            
    }