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

import Foundation
import UIKit
import VDSCoreTokens
import Combine

/// A text link is an interactive element that navigates a customer to pages within an experience, like a “Bill details” page, or triggers a secondary action,
/// like canceling a task.  This class can be used within a ``ButtonGroup``.
///
/// If you are using AutoLayoutConstraints you have a combination of Leading/Left and Trailing/Right NSLayoutConstraints,
/// you need to ensure that one of these Horizontal Contraints is not constraint of "equatTo".  If you are to pin the left/right edges
/// to its parent this object will stretch to the parent's width.
@objcMembers
@objc(VDSTextLink)
open class TextLink: ButtonBase {
    //--------------------------------------------------
    // 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 size.
    public enum Size: String, CaseIterable {
        case large
        case small
    }
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    private var lineHeightConstraint: NSLayoutConstraint?
    
    private var line = UIView().with {
        $0.translatesAutoresizingMaskIntoConstraints = false
    }

    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    /// The ButtonSize available.
    open var size: Size = .large { didSet { setNeedsUpdate() } }
       
    open override var textStyle: TextStyle {
        size == .large ? TextStyle.bodyLarge : TextStyle.bodySmall
    }
        
    /// UIColor used on the titleLabel text.
    open override var textColor: UIColor {
        textColorConfiguration.getColor(self)
    }
        
    private var textColorConfiguration = ControlColorConfiguration().with {
        $0.setSurfaceColors(VDSColor.elementsPrimaryOnlight, VDSColor.elementsPrimaryOndark, forState: .normal)
        $0.setSurfaceColors(VDSColor.interactiveDisabledOnlight, VDSColor.interactiveDisabledOndark, forState: .disabled)
        $0.setSurfaceColors(VDSColor.interactiveActiveOnlight, VDSColor.interactiveActiveOndark, forState: .highlighted)
    }
            
    /// The natural size for the receiving view, considering only properties of the view itself.
    open override var intrinsicContentSize: CGSize {
        guard let titleLabel else { return super.intrinsicContentSize }
        // Calculate the titleLabel's intrinsic content size
        let labelSize = titleLabel.sizeThatFits(CGSize(width: self.frame.width, height: CGFloat.greatestFiniteMagnitude))
        // Adjust the size if needed (add any additional padding if your design requires)
        let adjustedSize = CGSize(width: labelSize.width + contentEdgeInsets.left + contentEdgeInsets.right,
                                  height: labelSize.height + contentEdgeInsets.top + contentEdgeInsets.bottom)
        return adjustedSize
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    /// Called once when a view is initialized and is used to Setup additional UI or other constants and configurations.
    open override func setup() {
        super.setup()
        isAccessibilityElement = true
        accessibilityTraits = .link
        
        //left align titleLabel in case this is pinned leading/trailing
        //default is always set to center
        contentHorizontalAlignment = .left
        
        if let titleLabel {
            addSubview(line)
            line.pinLeading(titleLabel.leadingAnchor)
            line.pinTrailing(titleLabel.trailingAnchor)
            line.pinTop(titleLabel.bottomAnchor)
            line.pinBottom(bottomAnchor, 0, .defaultHigh)
            lineHeightConstraint = line.height(constant: 1)
            lineHeightConstraint?.isActive = true
        }
        
        bridge_accessibilityHintBlock = { [weak self] in
            guard let self else { return "" }
            return !isEnabled ? "" : "Double tap to open."
        }
        
    }

    /// Used to make changes to the View based off a change events or from local properties.
    open override func updateView() {
        //need to set the properties so the super class
        //can render out the label correctly
        line.backgroundColor = textColor
        
        //always call last so the label is rendered
        super.updateView()
    }
    
    /// Resets to default settings.
    open override func reset() {
        super.reset()
        shouldUpdateView = false
        text = nil
        size = .large
        accessibilityCustomActions = []
        isAccessibilityElement = true
        accessibilityTraits = .link
        shouldUpdateView = true
        setNeedsUpdate()
    }
    
}