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

import Foundation
import UIKit
import Combine

@objc(VDSRadioSwatchGroup)
open class RadioSwatchGroup: SelectorGroupSelectedHandlerBase<RadioSwatch>, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout, UICollectionViewDelegate {

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    public override var selectorViews: [RadioSwatch] {
        didSet {
            collectionView.reloadData()
        }
    }
    
    open var selectorModels: [RadioSwatchModel]? {
        didSet {
            if let selectorModels {
                selectorViews = selectorModels.map { model in
                    return RadioSwatch().with {
                        $0.accessibilityLabel = model.accessibileText
                        $0.text = model.text
                        $0.fillImage = model.fillImage
                        $0.primaryColor = model.primaryColor
                        $0.secondaryColor = model.secondaryColor
                        $0.strikethrough = model.strikethrough
                        $0.disabled = model.disabled
                        $0.surface = model.surface
                        $0.inputId = model.inputId
                        $0.value = model.value
                        $0.isSelected = model.selected
                    }
                }
            }
        }
    }

    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    open var label = Label()
    private let cellSize: CGFloat = 48.0
    private let labelSpacing: CGFloat = 24.0
    private let labelHeight: CGFloat = 16.0
    private let lineSpacing: CGFloat = 12.0
    private let itemSpacing: CGFloat = 16.0

    fileprivate lazy var collectionView: SelfSizingCollectionView = {
        let layout = UICollectionViewFlowLayout().with {
            $0.minimumLineSpacing = lineSpacing
            $0.minimumInteritemSpacing = itemSpacing
        }
        return SelfSizingCollectionView(frame: .zero, collectionViewLayout: layout).with {
            $0.backgroundColor = .clear
            $0.showsHorizontalScrollIndicator = false
            $0.showsVerticalScrollIndicator = false
            $0.isScrollEnabled = false
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "collectionViewCell")
        }
    }()
        
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    /// Whether this object is disabled or not
    override public var disabled: Bool {
        didSet {
            for selector in selectorViews {
                selector.disabled = disabled
            }
            collectionView.reloadData()
        }
    }
    /// Current Surface and this is used to pass down to child objects that implement Surfacable
    override public var surface: Surface {
        didSet {
            for selector in selectorViews {
                selector.surface = surface
            }
            collectionView.reloadData()
        }
    }
        
    open override func setup() {
        super.setup()

        addSubview(label)
        addSubview(collectionView)
        
        label
            .pinTop()
            .pinLeading()
            .pinTrailing()
            .height(labelHeight)
        
        collectionView
            .pinTop(label.bottomAnchor, labelSpacing)
            .pinLeading()
            .pinTrailing()
            .pinBottom()
        
    }
    
    open override func layoutSubviews() {
        super.layoutSubviews()
        // Accounts for any collection size changes
        DispatchQueue.main.async {
            self.collectionView.collectionViewLayout.invalidateLayout()
        }
    }

    public override func initialSetup() {
        super.initialSetup()
        collectionView.delegate = self
        collectionView.dataSource = self
    }
    
    /// Function used to make changes to the View based off a change events or from local properties.
    open override func updateView() {
        super.updateView()
        
        label.textPosition = .left
        label.textStyle = .bodySmall
        label.text = selectedHandler?.text ?? " "
        label.surface = surface
        label.disabled = disabled
        collectionView.reloadData()
    }
    
    public func reload() {
        collectionView.reloadData()
    }
    
    //--------------------------------------------------
    // MARK: - UICollectionViewDelegateFlowLayout
    //--------------------------------------------------
    open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: cellSize, height: cellSize)
    }
    
    //--------------------------------------------------
    // MARK: - UICollectionViewDelegate
    //--------------------------------------------------
    open func collectionView(_ collectionView: UICollectionView, shouldSelectItemAt indexPath: IndexPath) -> Bool {
        return !selectorViews[indexPath.row].disabled
    }
    
    open func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        didSelect(selector: selectorViews[indexPath.row])
    }
    
    //--------------------------------------------------
    // MARK: - UICollectionViewDataSource
    //--------------------------------------------------
    public func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 1
    }
    
    public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return selectorViews.count
    }
    
    var cellsubs: [Int: AnyCancellable] = [:]

    public func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionViewCell", for: indexPath)
        let handler = selectorViews[indexPath.row]
        handler.onClick = { [weak self] handler in
            self?.didSelect(selector: handler)
        }
        cell.subviews.forEach { $0.removeFromSuperview() }
        cell.addSubview(handler)
        handler.pinToSuperView()
        return cell
    }
    
    public func didSelect(selector: RadioSwatch) {
        selectedHandler?.toggle()
        selector.toggle()
        label.text = selector.text
        setNeedsUpdate()
        valueChanged()
    }
}

extension RadioSwatchGroup {
    public struct RadioSwatchModel: Surfaceable, Disabling, Initable {
        /// Whether this object is disabled or not
        public var disabled: Bool = false
        /// Current Surface and this is used to pass down to child objects that implement Surfacable
        public var surface: Surface
        public var inputId: String?
        public var value: AnyHashable?
        public var selected: Bool = false
        public var text: String
        public var fillImage: UIImage?
        public var primaryColor: UIColor?
        public var secondaryColor: UIColor?
        public var strikethrough: Bool = false
        public var accessibileText: String?
        
        public init(disabled: Bool, surface: Surface = .light, inputId: String? = nil, value: AnyHashable? = nil, selected: Bool = false,
                    text: String = "", fillImage: UIImage? = nil, primaryColor: UIColor? = nil, secondaryColor: UIColor? = nil,
                    strikethrough: Bool = false, accessibileText: String? = nil) {
            self.disabled = disabled
            self.surface = surface
            self.inputId = inputId
            self.value = value
            self.selected = selected
            self.text = text
            self.fillImage = fillImage
            self.primaryColor = primaryColor
            self.secondaryColor = secondaryColor
            self.strikethrough = strikethrough
            self.accessibileText = accessibileText
        }
        
        public init() {
            self.init(disabled: false)
        }
    }
}