vds_ios/VDS/Components/InputStepper/InputStepper.swift

//
//  InputStepper.swift
//  VDS
//
//  Created by Kanamarlapudi, Vasavi on 24/06/24.
//

import Foundation
import UIKit
import VDSCoreTokens
import Combine

/// A stepper is a two-segment control that people use to increase or decrease an incremental value.
@objc(VDSInputStepper)
open class InputStepper: EntryFieldBase {
    
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
    }
    
    public override init(frame: CGRect) {
        super.init(frame: .zero)
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
    
    //--------------------------------------------------
    // MARK: - Enums
    //--------------------------------------------------
    
    /// Enum used to describe the control width of Input Stepper.
    public enum controlWidth: String, CaseIterable {
        case auto, value
    }
    
    /// Enum used to describe the size of Input Stepper.
    public enum Size: String, CaseIterable {
        case large, small
    }

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    /// Accepts a string or number value to control the width of input stepper to a fixed pixel or percentage value.
    open var controlWidth: CGFloat? { didSet { setNeedsUpdate() } }
    
    /// Maximum value of the input stepper, defaults to '99'.
    open var maxValue:  Int? {
        get { return _maxValue }
        set {
            if let newValue, newValue < 100 && newValue > 0 {
                _maxValue = newValue
            } else {
                _maxValue = 99
            }
            setNeedsUpdate()
        }
    }
    
    /// Minimum value of the input stepper, defaults to '0'.
    open var minValue: Int? {
        get { return _minValue }
        set {
            if let newValue, newValue >= 0 && newValue < 99 {
                _minValue = newValue
            } else {
                _minValue = 0
            }
            setNeedsUpdate()
        }
    }
        
    /// The size of the input stepper. Defaults to 'large'.
    open var size: Size {
        get { return _size }
        set {
            _size = newValue
            setNeedsUpdate()
        }
    }
    
    /// Accepts any text or character to appear next to input stepper value.
    open var trailingText: String? { didSet { setNeedsUpdate() } }

    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    internal var _maxValue: Int = 99
    internal var _minValue: Int = 0
    internal var _size: Size = .large

    private var stepperWidthConstraint: NSLayoutConstraint?
    private var stepperHeightConstraint: NSLayoutConstraint?
    
    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    open override func initialSetup() {
        super.initialSetup()
    }
    
    open override func setup() {
        super.setup()
        isAccessibilityElement = false
        accessibilityLabel = "Input Stepper"

        containerView.isEnabled = false
    }
    
    open override func getFieldContainer() -> UIView {
        // stackview for controls in EntryFieldBase.controlContainerView
        let controlStackView = UIStackView().with {
            $0.translatesAutoresizingMaskIntoConstraints = false
            $0.axis = .horizontal
            $0.spacing = VDSLayout.space3X
            $0.backgroundColor = .clear
        }
        let view = View().with {
            $0.clipsToBounds = true
            $0.backgroundColor = .clear
        }
        
        let controlView = View().with {
            $0.clipsToBounds = true
            $0.backgroundColor = .clear
        }
        
        let label = Label().with {
            $0.text = "Label"
        }
        
        let minusButton = ButtonIcon().with {
            $0.kind = .ghost
            $0.iconName = .leftCaret
            $0.iconOffset = .init(x: -2, y: 0)
            $0.customContainerSize = 40
            $0.icon.customSize = 16
        }
        
        let plusButton = ButtonIcon().with {
            $0.kind = .ghost
            $0.iconName = .rightCaret
            $0.iconOffset = .init(x: 2, y: 0)
            $0.customContainerSize = 40
            $0.icon.customSize = 16
        }
        
        controlStackView.addArrangedSubview(minusButton)
        controlStackView.addArrangedSubview(label)
        controlStackView.addArrangedSubview(plusButton)
        controlView.addSubview(controlStackView)
        controlStackView.pinToSuperView()

        view.addSubview(controlView)
        controlView.pinToSuperView()
        view.pinToSuperView()
        return view
    }
    
    open override func updateView() {
        super.updateView()
        updateContainerView(flag: false)
    }
}