vds_ios/VDS/Components/Tilelet/TileletGroup/TileletGroup.swift

//
//  TileletGroup.swift
//  VDS
//
//  Created by Matt Bruce on 10/8/24.
//

import Foundation
import UIKit
import VDSCoreTokens
import Combine

open class TileletGroup: View {
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    
    /// CollectionView to show the rows and columns
    private lazy var matrixView = SelfSizingCollectionView(frame: .zero, collectionViewLayout: flowLayout).with {
        $0.register(TileletGroupCellItem.self, forCellWithReuseIdentifier: TileletGroupCellItem.Identifier)
        $0.dataSource = self
        $0.delegate = self
        $0.translatesAutoresizingMaskIntoConstraints = false
        $0.allowsSelection = false
        $0.showsVerticalScrollIndicator = false
        $0.showsHorizontalScrollIndicator = false
        $0.isAccessibilityElement = true
        $0.backgroundColor = .clear
    }
    
    /// Custom flow layout to manage the height of the cells
    private lazy var flowLayout = TileletGroupFlowLayout().with {
        $0.delegate = self
        $0.scrollDirection = .horizontal
    }

    /// Parameter to show the all table rows
    private var rows: [[Tilelet]] = [] { didSet { setNeedsUpdate() } }    
    //--------------------------------------------------
    // MARK: - Enums
    //--------------------------------------------------
    
    /// Enums used to define the padding for the cell edge spacing.
    public enum Padding: String, CaseIterable {
        case standard, compact
        
        private func value() -> CGFloat {
            switch self {
            case .standard:
                return UIDevice.isIPad ? 40.0 : VDSLayout.space3X
            case .compact:
                return UIDevice.isIPad ? VDSLayout.space6X : VDSLayout.space3X
            }
        }
        
        func horizontalValue() -> CGFloat { value() }
        
        func verticalValue() -> CGFloat { value() }
    }
    
    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
        /// Parameter to set the padding for the cell
    open var padding: Padding = .standard { didSet { setNeedsUpdate() } }
                
    /// An object containing number of Button components per row for iPhones
    open var rowQuantityPhone: Int = 2 { didSet { updateRows() } }
    
    /// An object containing number of Button components per row for iPads
    open var rowQuantityTablet: Int = 4 { didSet { updateRows() } }
    
    /// An object containing number of Button components per row
    open var rowQuantity: Int { UIDevice.isIPad ? rowQuantityTablet : rowQuantityPhone }
    
    open var tilelets: [Tilelet] = [] { didSet { updateRows() } }

    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    
    ///Called upon initializing the table view
    open override func setup() {
        super.setup()
        addSubview(matrixView)
        matrixView.pinToSuperView()
    }
    
    /// Will update the table view, when called becasue of any changes in component parameters
    open override func updateView() {
        super.updateView()
        flowLayout.verticalPadding = padding.verticalValue()
        flowLayout.horizontalPadding = padding.horizontalValue()
        matrixView.reloadData()
        matrixView.collectionViewLayout.invalidateLayout()
    }
    
    open override func setDefaults() {
        super.setDefaults()
        padding = .standard
        rows = [[]]
    }

    func updateRows() {
        var tempRows: [[Tilelet]] = []
        for i in stride(from: 0, to: tilelets.count, by: rowQuantity) {
            let endIndex = min(i + rowQuantity, tilelets.count)
            let row = Array(tilelets[i..<endIndex])
            tempRows.append(row)
        }
        rows = tempRows
    }
}

extension TileletGroup: UICollectionViewDelegate, UICollectionViewDataSource, TiletGroupCollectionViewLayoutDataDelegate {
    
    //--------------------------------------------------
    // MARK: - UICollectionViewDelegate & UICollectionViewDataSource
    //--------------------------------------------------
    
    public func numberOfSections(in collectionView: UICollectionView) -> Int {
        return rows.count
    }
    public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return rows[section].count
    }
    
    public func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: TileletGroupCellItem.Identifier, for: indexPath) as? TileletGroupCellItem else { return UICollectionViewCell() }
        let currentItem = rows[indexPath.section][indexPath.row]
        cell.updateCell(component: currentItem)
//        let rowColors: (UIColor,UIColor) = indexPath.section % 2 == 0 ? (.green, .yellow) : (.blue, .brown)
//        cell.backgroundColor = indexPath.row % 2 == 0 ? rowColors.0 : rowColors.1
        return cell
    }
    
    //--------------------------------------------------
    // MARK: - TableCollectionViewLayoutDataDelegate
    //--------------------------------------------------
    
    internal func collectionView(_ collectionView: UICollectionView, dataForItemAt indexPath: IndexPath) -> Tilelet {
        return rows[indexPath.section][indexPath.row]
    }
}

final class TileletGroupCellItem: UICollectionViewCell {
    
    /// Identifier for TableCellItem
    static let Identifier: String = String(describing: TileletGroupCellItem.self)
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    
    /// Main view which holds the content of the cell
    private let containerView = View()
        
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupCell()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setupCell()
    }
    
    private func setupCell() {
        contentView.backgroundColor = .clear
        addSubview(containerView)
        containerView.pinToSuperView()
    }
    
    //--------------------------------------------------
    // MARK: - Public Methods
    //--------------------------------------------------
    
    public func updateCell(component: Tilelet) {
        containerView.subviews.forEach({ $0.removeFromSuperview() })
        containerView.addSubview(component)
        component.pinToSuperView()
    }
}