//
//  TextLink.swift
//  VDS
//
//  Created by Matt Bruce on 11/1/22.
//

import Foundation
import UIKit
import VDSColorTokens
import VDSFormControlsTokens
import Combine

@objc(VDSTextLink)
open class TextLink: ButtonBase {
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var heightConstraint: NSLayoutConstraint?
    private var lineHeightConstraint: NSLayoutConstraint?

    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    open var size: ButtonSize = .large { didSet { didChange() }}
        
    open override var availableSizes: [ButtonSize] { [.large, .small] }

    open override var typograpicalStyle: TypographicalStyle {
        size == .large ? TypographicalStyle.BodyLarge : TypographicalStyle.BodySmall
    }
        
    open override var textColor: UIColor {
        textColorConfiguration.getColor(self)
    }
    
    private var textColorConfiguration = HighlightDisabledSurfaceColorConfiguration().with {
        $0.disabled.lightColor = VDSColor.elementsSecondaryOnlight
        $0.disabled.darkColor = VDSColor.elementsSecondaryOndark
        $0.enabled.lightColor = VDSColor.elementsPrimaryOnlight
        $0.enabled.darkColor = VDSColor.elementsPrimaryOndark
        
        $0.highlighted.lightColor = VDSColor.interactiveActiveOnlight
        $0.highlighted.darkColor = VDSColor.interactiveActiveOndark

    }
    
    private var height: CGFloat {
        switch size {
        case .large:
            return 44
        case .small:
            return 32
        }
    }

    //--------------------------------------------------
    // 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)
    }
    
    private var line = UIView().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
    }
    
    //--------------------------------------------------
    // MARK: - Public Functions
    //--------------------------------------------------
    open override func setup() {
        super.setup()
        
        if let titleLabel {
            addSubview(line)
            line.pinLeading(titleLabel.leadingAnchor)
            line.pinTrailing(titleLabel.trailingAnchor)
            line.pinTop(titleLabel.bottomAnchor, 1)
            lineHeightConstraint = line.heightAnchor.constraint(equalToConstant: 1.0)
            lineHeightConstraint?.isActive = true
        }
                             
        heightConstraint = heightAnchor.constraint(equalToConstant: height)
        heightConstraint?.isActive = true
    }

    open override func reset() {
        super.reset()
        size = .large        
        accessibilityCustomActions = []
        accessibilityTraits = .staticText
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    open override func updateView() {
        //need to set the properties so the super class
        //can render out the label correctly
        heightConstraint?.constant = height
        lineHeightConstraint?.constant = isHighlighted ? 2.0 : 1.0
        line.backgroundColor = textColor
        
        //always call last so the label is rendered
        super.updateView()
    }

}

class HighlightDisabledSurfaceColorConfiguration: ObjectColorable {
    typealias ObjectType = Buttonable
    public var highlighted = SurfaceColorConfiguration()
    public var disabled = SurfaceColorConfiguration()
    public var enabled = SurfaceColorConfiguration()
    
    required public init(){}
    
    public func getColor(_ object: any ObjectType) -> UIColor {
        if object.isHighlighted {
            return highlighted.getColor(object)
        } else {
            return object.disabled ? disabled.getColor(object) : enabled.getColor(object)
        }
    }
}