vds_ios/VDS/Components/SelectorBase/SelectorGroup.swift

//
//  RadioButtonGroup.swift
//  VDS
//
//  Created by Matt Bruce on 8/8/22.
//

import Foundation
import UIKit


public protocol SelectorGroupModel<SelectorType>: Modelable, FormFieldable {
    associatedtype SelectorType: SelectorModel
    var selectors: [SelectorType] { get set }
}

public struct DefaultSelectorGroupModel<SelectorType: SelectorModel>: SelectorGroupModel {
    public var id: UUID = UUID()
    public var inputId: String?
    public var value: AnyHashable?
    public var surface: Surface = .light
    public var disabled: Bool = false
    public var selectors: [SelectorType]
    public init() { selectors = [] }
    public init(selectors: [SelectorType]){
        self.selectors = selectors
    }
}

open class SelectorGroup<SelectorType, SelectorGroupType: SelectorGroupModel<SelectorType>, SelectorHandlerType: SelectorBase<SelectorType>>: View<SelectorGroupType>, Changable {
    
    public var selectorViews: [SelectorHandlerType] = []
    public var selectedModel: SelectorType?
    public var onChange: Blocks.ActionBlock?

    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var mainStackView: UIStackView = {
       let stackView = UIStackView()
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.alignment = .top
        stackView.axis = .vertical
        stackView.spacing = 10
        return stackView
    }()

    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    override public var disabled: Bool {
        didSet {
            let selectors = model.selectors.compactMap { existing in
                return updated(existing){
                    $0.disabled = disabled
                }
            }
            model.selectors = selectors
        }
    }

    override public var surface: Surface {
        didSet {
            let selectors = model.selectors.compactMap { existing in
                return updated(existing){
                    $0.surface = surface
                }
            }
            model.selectors = selectors
        }
    }

    open override func setup() {
        super.setup()

        isAccessibilityElement = true
        accessibilityTraits = .button
        addSubview(mainStackView)

        mainStackView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        mainStackView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        mainStackView.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        mainStackView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
    }

    open override func shouldUpdateView(viewModel: ModelType) -> Bool {
        return true
    }

    open override func updateView(viewModel: ModelType) {
        print("Selector Group update:")
        func findSelectorView(inputId: String) -> SelectorHandlerType? {
            return selectorViews.first(where: { existingSelectorView in
                return existingSelectorView.model.inputId == inputId 
            })
        }
        
        for selectorModel in viewModel.selectors {
            //see if view is there for the model
            if let inputId = selectorModel.inputId, let foundSelectorView = findSelectorView(inputId: inputId) {
                foundSelectorView.set(with: selectorModel)
            } else {
                
                //create view
                let newSelectorView = SelectorHandlerType(with: selectorModel)
                
                //add the selectedPublisher for the change
                newSelectorView.selectedPublisher().sink { [weak self] model in
                    self?.didSelect(selected: model)
                }.store(in: &cancellables)
                
                newSelectorView.$model.sink { [weak self] model in
                    //should replace
                    if let cached = self?.getCachedSelector(viewModel: model), newSelectorView.shouldUpdateView(viewModel: cached) {
                        self?.replace(viewModel: model)
                    }
                }.store(in: &cancellables)
                
                self.selectorViews.append(newSelectorView)
                mainStackView.addArrangedSubview(newSelectorView)
            }
        }
        
    }
   
    public func getCachedSelector(viewModel: SelectorType) -> SelectorType? {
        if let  index = model.selectors.firstIndex(where: { element in
            return element.id == viewModel.id
        }) {
            return model.selectors[index]
        } else {
            return nil
        }
    }
    
    public func replace(viewModel: SelectorType){
        if let  index = model.selectors.firstIndex(where: { element in
            return element.id == viewModel.id
        }) {
            model.selectors[index] = viewModel
        }
    }
    
    open func didSelect(selected: SelectorType) { }
}