//
//  RadioButton.swift
//  PrivadoVPN
//
//  Created by Murad Shabanov on 23.07.2021.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

import Foundation

public class RadioButton: RadioBaseButton {
    
    public var backgroundColor: NSColor = .gray {
        didSet {
            self.setupLayer()
        }
    }
    
    public var innerCircleColor: NSColor = .white {
        didSet {
            self.setupLayer()
        }
    }
    
    public var outerCircleColor: NSColor = .white {
        didSet {
            self.setupLayer()
        }
    }
    
    public override var isEnabled: Bool {
        didSet {
            self.backLayer.opacity = self.isEnabled ? 1.0 : 0.5
        }
    }
    
    public var textFont: NSFont? = NSFont.systemFont(ofSize: 14) {
        didSet {
            self.setupLayer()
        }
    }
    
    public var fontSize: CGFloat?
    
    public var textYoffset: CGFloat = 8 {
        didSet {
            self.setupLayer()
        }
    }
    
    public var radioBoxSize: CGSize?
    
    public var innerSelectedColor: NSColor = .gray
    
    public weak var delegate: RadioButtonDelegate?
    
    public override func layout() {
        super.layout()
        self.layer?.frame = self.frame
        self.calculateRadioboxRect(width: self.frame.width, height: self.frame.height)
        self.backLayer.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.innerCircle.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.outerCircle.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.textLayer?.frame = CGRect(x: self.radioSquare.width + 5, y: self.textYoffset, width: self.bounds.width - self.radioSquare.width, height: self.bounds.height)
    }
        
    private lazy var backLayer = CAShapeLayer()
    
    private lazy var outerCircle = CAShapeLayer()
    
    private lazy var innerCircle = CAShapeLayer()
    
    private var textLayer: CATextLayer?
    
    private var radioSquare = CGRect.zero
        
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        self.setup()
    }
    
    init(frame frameRect: NSRect, title: String) {
        super.init(frame: frameRect)
        self.textLayer = CATextLayer()
        self.textLayer?.string = title
        self.setup()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func setup() {
        let layer = CALayer()
        self.wantsLayer = true
        self.layer = layer
        self.layer?.bounds = CGRect(origin: .zero, size: CGSize(width: self.frame.width, height: self.frame.height))
        self.layer?.addSublayer(backLayer)
        self.backLayer.addSublayer(outerCircle)
        self.backLayer.addSublayer(innerCircle)
        if let titleLayer = self.textLayer {
            self.backLayer.addSublayer(titleLayer)
        }
        
        super.setup()
    }
    
    public override func layoutSubtreeIfNeeded() {
        self.calculateRadioboxRect(width: self.bounds.width, height: self.bounds.height)
        self.setupBackLayer()
        self.setupOuterCircleLayer()
        self.setupInnerCircleLayer()
        self.setupTitleLayer()
    }
    
    override func setupLayer() {
        self.calculateRadioboxRect(width: self.bounds.width, height: self.bounds.height)
        self.setupBackLayer()
        self.setupOuterCircleLayer()
        self.setupInnerCircleLayer()
        self.setupTitleLayer()
        super.setupLayer()
    }
    
    private func setupTitleLayer() {
        guard let titleLayer = self.textLayer else { return }
        titleLayer.foregroundColor = .white
        titleLayer.backgroundColor = .clear
        titleLayer.frame =  CGRect(x: self.radioSquare.width + 5, y: self.textYoffset, width: self.bounds.width - self.radioSquare.width, height: self.bounds.height)
        titleLayer.font = self.textFont
        titleLayer.fontSize = self.fontSize ?? 160
    }
    
    private func setupBackLayer() {
        let path = NSBezierPath()
        let radius = (self.radioSquare.width / 2) * 0.75
        path.appendArc(withCenter: self.radioSquare.center, radius: radius, startAngle: 0, endAngle: 360)
        self.backLayer.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.backLayer.path = path.CGPath
        self.backLayer.fillColor = self.backgroundColor.cgColor
        self.backLayer.lineWidth = 4
        self.backLayer.opacity = self.isEnabled ? 1.0 : 0.5
    }
    
    private func setupOuterCircleLayer() {
        let path = NSBezierPath()
        let radius = (self.radioSquare.width / 2) * 0.75
        path.appendArc(withCenter: self.radioSquare.center, radius: radius, startAngle: 0, endAngle: 360)
        self.outerCircle.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.outerCircle.path = path.CGPath
        self.outerCircle.fillColor = self.outerCircleColor.cgColor
        self.outerCircle.strokeColor = self.outerCircleColor.cgColor
        self.outerCircle.lineWidth = 0
        self.outerCircle.opacity = 0
    }
    
    private func setupInnerCircleLayer() {
        let path = NSBezierPath()
        let radius = (self.radioSquare.width / 4) * 0.75
        path.appendArc(withCenter: self.radioSquare.center, radius: radius, startAngle: 0, endAngle: 360)
        self.innerCircle.frame = CGRect(origin: .zero, size: CGSize(width: self.radioSquare.width, height: self.radioSquare.height))
        self.innerCircle.path = path.CGPath
        self.innerCircle.fillColor = self.innerCircleColor.cgColor
        self.innerCircle.strokeColor = NSColor.clear.cgColor
        self.innerCircle.opacity = 0
    }
    
    func animateSelection() {
        let animation = CABasicAnimation(keyPath: "opacity")
        animation.duration = 0.2
        animation.fromValue = 0.0
        animation.toValue = 1.0
        animation.isRemovedOnCompletion = false
        animation.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
        let colorAnimation = CABasicAnimation(keyPath: "fillColor")
        colorAnimation.fromValue = self.backgroundColor
        colorAnimation.toValue = self.innerSelectedColor
        self.outerCircle.opacity = 1
        self.innerCircle.opacity = 1
        self.outerCircle.add(animation, forKey: "opacity")
        self.innerCircle.add(animation, forKey: "opacity")
        self.backLayer.add(colorAnimation, forKey: "fillColor")
        self.backLayer.fillColor = self.innerSelectedColor.cgColor
    }
    
    func animateDeselction() {
        let animation = CABasicAnimation(keyPath: "opacity")
        animation.duration = 0.2
        animation.fromValue = 1.0
        animation.toValue = 0.0
        animation.isRemovedOnCompletion = false
        animation.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
        let colorAnimation = CABasicAnimation(keyPath: "fillColor")
        colorAnimation.fromValue = self.innerSelectedColor
        colorAnimation.toValue = self.backgroundColor
        colorAnimation.duration = 0.2
        self.outerCircle.opacity = 0
        self.innerCircle.opacity = 0
        self.outerCircle.add(animation, forKey: "opacity")
        self.innerCircle.add(animation, forKey: "opacity")
        self.backLayer.add(colorAnimation, forKey: "fillColor")
        self.backLayer.fillColor = self.backgroundColor.cgColor
    }
    
    private func calculateRadioboxRect(width: CGFloat, height: CGFloat) {
        
        var width = Int(width)
        var height = Int(height)
        
        if height > width {
            height -= height - width
        } else if height < width {
            width -= width - height
        }
        
        if let square = self.radioBoxSize {
            self.radioSquare = CGRect(origin: .zero, size: square)
        } else {
            self.radioSquare = CGRect(origin: .zero, size: CGSize(width: CGFloat(width), height: CGFloat(height)))
        }
    }
    
    override func updateActiveLayer() {
        self.animateSelection()
    }
    
    override func updateInactiveLayer() {
        self.animateDeselction()
    }
    
    override func callDelegate() {
        if self.isOn {
            self.delegate?.radioButtonDidSelect(self)
        } else {
            self.delegate?.radioButtonDidDeselect(self)
        }
    }
    
}

// MARK: - RadioButtonDelegate
public protocol RadioButtonDelegate: AnyObject {
    
    /// Delegate called when radio button is Selected
    ///
    /// - Parameter button: RadioButton
    func radioButtonDidSelect(_ button: RadioButton)
    
    /// Delegate called when radio button is deselected
    /// It will call automatically when user choose different radio button than selected
    ///
    /// - Parameter button: RadioButton
    func radioButtonDidDeselect(_ button: RadioButton)
    
}