vds_ios/VDS/Classes/CollectionView.swift

//
//  CollectionView.swift
//  VDS
//
//  Created by Matt Bruce on 8/25/22.
//

import Foundation
import UIKit
import Combine

open class CollectionView<ModelType: Modelable>: UICollectionView, ModelHandlerable, ViewProtocol, Resettable {
    
    //--------------------------------------------------
    // MARK: - Combine Properties
    //--------------------------------------------------
    @Published public var model: ModelType = ModelType()
    public var modelPublisher: Published<ModelType>.Publisher { $model }
    public var subscribers = Set<AnyCancellable>()
    
    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    private var initialSetupPerformed = false

    @Proxy(\.model.surface)
    open var surface: Surface
    
    @Proxy(\.model.disabled)
    open var disabled: Bool {
        didSet {
            self.isEnabled = !disabled
        }
    }
    
    open var isEnabled: Bool {
        get { !model.disabled }
        set {
            //create local vars for clear coding
            let disabled = !newValue
            if model.disabled != disabled {
                model.disabled = disabled
            }
        }
    }
    
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
        initialSetup()
    }
    
    public required init(with model: ModelType) {
        super.init(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
        initialSetup()
        set(with: model)
    }

    public required init(with model: ModelType, collectionViewLayout layout: UICollectionViewLayout) {
        super.init(frame: .zero, collectionViewLayout: layout)
        initialSetup()
        set(with: model)
    }
    
    public override init(frame: CGRect, collectionViewLayout layout: UICollectionViewLayout) {
        super.init(frame: frame, collectionViewLayout: layout)
        initialSetup()
        set(with: model)
    }

    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        initialSetup()
    }
    
    //--------------------------------------------------
    // MARK: - Setup
    //--------------------------------------------------
    
    public func initialSetup() {
        if !initialSetupPerformed {
            initialSetupPerformed = true
            setupUpdateView()
            setup()
        }
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    open func updateView(viewModel: ModelType) {
        fatalError("Implement updateView")
    }
        
    open func reset() {
        backgroundColor = .clear
        if let model = model as? Resettable {
            model.reset()
        }
    }
    
    // MARK: - ViewProtocol    
    /// Will be called only once.
    open func setup() {
        translatesAutoresizingMaskIntoConstraints = false
        insetsLayoutMarginsFromSafeArea = false
    }
}