//
//  Checkbox.swift
//  VDS
//
//  Created by Matt Bruce on 7/22/22.
//

import Foundation
import UIKit
import VDSColorTokens
import VDSFormControlsTokens
import Combine

public class Checkbox: CheckboxBase<DefaultCheckboxModel>{}

open class CheckboxBase<ModelType: CheckboxModel>: SelectorBase<ModelType> {
    //--------------------------------------------------
    // MARK: - Configuration Properties
    //--------------------------------------------------
    public let checkboxSize = CGSize(width: 20, height: 20)
    
    private var checkboxBackgroundColorConfiguration: CheckboxErrorColorConfiguration = {
        return CheckboxErrorColorConfiguration().with {
            $0.forTrue.enabled.lightColor = VDSColor.elementsPrimaryOnlight
            $0.forTrue.enabled.darkColor = VDSColor.elementsPrimaryOndark
            $0.forTrue.disabled.lightColor = VDSColor.interactiveDisabledOnlight
            $0.forTrue.disabled.darkColor = VDSColor.interactiveDisabledOndark
            //error doesn't care enabled/disable
            $0.error.forTrue.lightColor = VDSColor.elementsPrimaryOnlight
            $0.error.forTrue.darkColor = VDSColor.elementsPrimaryOndark
            $0.error.forFalse.lightColor = VDSColor.feedbackErrorBackgroundOnlight
            $0.error.forFalse.darkColor = VDSColor.feedbackErrorBackgroundOndark
        }
    }()
    
    private var checkboxBorderColorConfiguration: CheckboxErrorColorConfiguration = {
        return CheckboxErrorColorConfiguration().with {
            $0.forTrue.enabled.lightColor = VDSColor.elementsPrimaryOnlight
            $0.forTrue.enabled.darkColor = VDSColor.elementsPrimaryOndark
            $0.forFalse.enabled.lightColor = VDSFormControlsColor.borderOnlight
            $0.forFalse.enabled.darkColor = VDSFormControlsColor.borderOndark
            $0.forTrue.disabled.lightColor = VDSColor.interactiveDisabledOnlight
            $0.forTrue.disabled.darkColor = VDSColor.interactiveDisabledOndark
            $0.forFalse.disabled.lightColor = VDSColor.interactiveDisabledOnlight
            $0.forFalse.disabled.darkColor = VDSColor.interactiveDisabledOndark
            //error doesn't care enabled/disable
            $0.error.forTrue.lightColor = VDSColor.elementsPrimaryOnlight
            $0.error.forTrue.darkColor = VDSColor.elementsPrimaryOndark
            $0.error.forFalse.lightColor = VDSColor.feedbackErrorOnlight
            $0.error.forFalse.darkColor = VDSColor.feedbackErrorOndark
        }
    }()

    private var checkboxCheckColorConfiguration: BinarySurfaceColorConfiguration<ModelType> = {
        return BinarySurfaceColorConfiguration<ModelType>().with {
            $0.forTrue.lightColor = VDSColor.elementsPrimaryOndark
            $0.forTrue.darkColor = VDSColor.elementsPrimaryOnlight
        }
    }()
        
    //--------------------------------------------------
    // MARK: - Checkbox View
    //--------------------------------------------------
    /// Manages the appearance of the checkbox.
    private var shapeLayer: CAShapeLayer?
    
    open override func getSelectorSize() -> CGSize {
        return checkboxSize
    }
    
    open override func updateSelector(_ viewModel: ModelType) {
        //get the colors
        let backgroundColor = checkboxBackgroundColorConfiguration.getColor(viewModel)
        let borderColor = checkboxBorderColorConfiguration.getColor(viewModel)
        let checkColor = checkboxCheckColorConfiguration.getColor(viewModel)

        if let shapeLayer = shapeLayer, let sublayers = layer.sublayers, sublayers.contains(shapeLayer) {
            shapeLayer.removeFromSuperlayer()
            self.shapeLayer = nil
        }

        selectorView.backgroundColor = backgroundColor
        selectorView.layer.borderColor = borderColor.cgColor
        selectorView.layer.cornerRadius = 2.0
        selectorView.layer.borderWidth = 1.0

        if shapeLayer == nil {
            let bounds = selectorView.bounds
            let length = max(bounds.size.height, bounds.size.width)
            guard length > 0.0, shapeLayer == nil else { return }
            
            //draw the checkmark layer
            let xInsetLeft = length * 0.25
            let yInsetTop = length * 0.3
            let innerWidth = length - (xInsetLeft + length * 0.25) // + Right X Inset
            let innerHeight = length - (yInsetTop + length * 0.35) // + Bottom Y Inset
            
            let startPoint = CGPoint(x: xInsetLeft, y: yInsetTop + (innerHeight / 2))
            let pivotOffSet = CGPoint(x: xInsetLeft + (innerWidth * 0.33), y: yInsetTop + innerHeight)
            let endOffset = CGPoint(x: xInsetLeft + innerWidth, y: yInsetTop)
            
            let bezierPath = UIBezierPath()
            bezierPath.move(to: startPoint)
            bezierPath.addLine(to: pivotOffSet)
            bezierPath.addLine(to: endOffset)

            let shapeLayer = CAShapeLayer()
            self.shapeLayer = shapeLayer
            shapeLayer.frame = bounds
            layer.addSublayer(shapeLayer)
            shapeLayer.strokeColor = checkColor.cgColor
            shapeLayer.fillColor = UIColor.clear.cgColor
            shapeLayer.path = bezierPath.cgPath
            shapeLayer.lineJoin = .miter
            shapeLayer.lineWidth = 2
            CATransaction.withDisabledAnimations {
                shapeLayer.strokeEnd = model.selected ? 1 : 0
            }
        }
    }
    
    //--------------------------------------------------
    // MARK: - Color Class Configurations
    //--------------------------------------------------
    private class CheckboxErrorColorConfiguration: BinaryDisabledSurfaceColorConfiguration<ModelType> {
        public let error = BinarySurfaceColorConfiguration<ModelType>()
        override func getColor(_ viewModel: ModelType) -> UIColor {
            //only show error is enabled and showError == true
            let showErrorColor = !viewModel.disabled && viewModel.hasError
            
            if showErrorColor {
                return error.getColor(viewModel)
            } else {
                return super.getColor(viewModel)
            }
        }
    }
        
}