#if os(macOS)

import AppKit
import AutoCatCore
import SwiftUI

extension CGRect {
    
    func inset(by insets: NSEdgeInsets) -> CGRect {
        
        CGRect(origin: CGPoint(x: origin.x + insets.left,
                               y: origin.y + insets.bottom),
               size: CGSize(width: size.width - insets.left - insets.right,
                            height: size.height - insets.top - insets.bottom))
    }
}

extension NSScreen {
    
    static var mainScreenScale: CGFloat {
        main?.backingScaleFactor ?? 1
    }
}

class FlagLayer: CALayer {
    let pixelWidth = 1/NSScreen.mainScreenScale
    
    // Flag colors - https://ru.wikipedia.org/wiki/%D0%A4%D0%BB%D0%B0%D0%B3_%D0%A0%D0%BE%D1%81%D1%81%D0%B8%D0%B8
    let blue = NSColor(srgbRed: 0, green: 57/256.0, blue: 166/256.0, alpha: 1)
    let red = NSColor(srgbRed: 213/256.0, green: 43/256.0, blue: 30/256.0, alpha: 1)
    
    override func draw(in ctx: CGContext) {
        ctx.saveGState()
        super.draw(in: ctx)
        
        ctx.setStrokeColor(NSColor.black.cgColor)
        ctx.setLineWidth(0)
        
        ctx.setFillColor(NSColor.white.cgColor)
        ctx.fill(bounds.inset(by: NSEdgeInsets(top: 0, left: 0, bottom: bounds.height*2/3, right: 0)))
        
        ctx.setFillColor(self.blue.cgColor)
        ctx.fill(bounds.insetBy(dx: 0, dy: bounds.height/3))
        
        ctx.setFillColor(self.red.cgColor)
        ctx.fill(bounds.inset(by: NSEdgeInsets(top: bounds.height*2/3, left: 0, bottom: 0, right: 0)))
        
        ctx.setLineWidth(pixelWidth)
        ctx.stroke(bounds.insetBy(dx: pixelWidth/2, dy: pixelWidth/2))
        
        ctx.restoreGState()
    }
}

class PlateView: NSView {
    // Some driver plate parameters from "ГОСТ Р 50577-93"
    // http://docs.cntd.ru/document/gost-r-50577-93
    private static let aspectRatio: CGFloat = 112.0/520.0
    private static let fontHeightCoeff: CGFloat = 58.0/76.0
    
    private var bgLayer = CALayer()
    private var mainBgLayer = CALayer()
    private var regionBgLayer = CALayer()
    private var numberLayer = CenterTextLayer(coeff: fontHeightCoeff)
    private var regionLayer = CenterTextLayer(coeff: fontHeightCoeff)
    private var countryLayer = CenterTextLayer()
    private var flagLayer = FlagLayer()
    
    var number: PlateNumber? {
        didSet {
            self.layout()
            self.setAccessibilityLabel(number?.asString())
        }
    }
    
    var foreground: NSColor? {
        didSet {
            self.layout()
        }
    }
    
    var fontSize: CGFloat = 10 {
        didSet {
            self.layout()
        }
    }
    
    var onChange: (() -> Void)?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }
    
    func setup() {
        self.wantsLayer = true
        self.layer?.backgroundColor = NSColor.clear.cgColor
        
        self.bgLayer.cornerRadius = 6 //self.bounds.height/8
        self.layer?.addSublayer(self.bgLayer)
        
        self.mainBgLayer.cornerRadius = 4
        self.layer?.addSublayer(self.mainBgLayer)
        
        self.regionBgLayer.cornerRadius = 4
        self.layer?.addSublayer(self.regionBgLayer)
        
        self.numberLayer.alignmentMode = .center
        self.numberLayer.contentsScale = NSScreen.mainScreenScale
        self.layer?.addSublayer(self.numberLayer)
        
        self.regionLayer.alignmentMode = .center
        self.regionLayer.contentsScale = NSScreen.mainScreenScale
        self.layer?.addSublayer(self.regionLayer)
        
        self.countryLayer.contentsScale = NSScreen.mainScreenScale
        self.countryLayer.string = "RUS"
        self.countryLayer.alignmentMode = .center
        self.layer?.addSublayer(self.countryLayer)
        
        self.flagLayer.contentsScale = NSScreen.mainScreenScale
        self.layer?.addSublayer(self.flagLayer)
        
        self.setAccessibilityElement(true)
    }
    
    private func pathForFlag(in rect: CGRect) -> CGPath {
        let path = CGMutablePath()
        let rect = CGPath(rect: rect, transform: nil)
        path.addPath(rect)
        return path
    }
    
    override func layout() {
        super.layout()
        
        guard let number = self.number else { return }
        guard let fgColorMain = NSColor(named: "PlateForeground")?.cgColor else { return }
        guard let bgColor = NSColor(named: "PlateBackground")?.cgColor else { return }
        
        let fgColor = self.foreground?.cgColor ?? fgColorMain
        
        self.bgLayer.backgroundColor = fgColor
        self.bgLayer.frame = self.bounds
        
        self.mainBgLayer.backgroundColor = bgColor
        self.regionBgLayer.backgroundColor = bgColor
        self.mainBgLayer.frame = self.bounds.inset(by: NSEdgeInsets(top: 2, left: 2, bottom: 2, right: self.bounds.width*0.27 + 1))
        self.regionBgLayer.frame = self.bounds.inset(by: NSEdgeInsets(top: 2, left: self.bounds.width*0.73 + 1, bottom: 2, right: 2))
        
        self.numberLayer.frame = self.mainBgLayer.frame.insetBy(dx: 4, dy: 0)
        let font = NSFont(name: "RoadNumbers", size: self.mainBgLayer.frame.height*1.1) ?? NSFont.boldSystemFont(ofSize: 24)
        let attributes: [NSAttributedString.Key: Any] = [
            .kern: 3,
            .font: font,
            .foregroundColor: fgColor
        ]
        let attributed = NSAttributedString(string: number.mainPart(), attributes: attributes)
        self.numberLayer.string = attributed
        
        let rbgSize = self.regionBgLayer.frame.size
        
        self.regionLayer.frame = self.regionBgLayer.frame.inset(by: NSEdgeInsets(top: 2, left: 2, bottom: rbgSize.height*0.35, right: 2))
        let regionFont = NSFont(name: "RoadNumbers", size: rbgSize.height*0.8) ?? NSFont.boldSystemFont(ofSize: 24)
        let regionAttrs: [NSAttributedString.Key: Any] = [
            .kern: 1,
            .font: regionFont,
            .foregroundColor: fgColor
        ]
        let attributedRegion = NSAttributedString(string: number.region(), attributes: regionAttrs)
        self.regionLayer.string = attributedRegion
        
        self.countryLayer.foregroundColor = fgColor
        self.countryLayer.frame = self.regionBgLayer.frame.inset(by: NSEdgeInsets(top: rbgSize.height*0.64,
                                                                                  left: rbgSize.width*0.08,
                                                                                  bottom: rbgSize.height*0.07,
                                                                                  right: rbgSize.width*0.42))
        self.countryLayer.fontSize = self.countryLayer.frame.size.height
        
        let top = (self.regionBgLayer.frame.origin.y + rbgSize.height*0.04).rounded(.toNearestOrAwayFromZero)
        let left = (self.regionBgLayer.frame.origin.x + rbgSize.width*0.62).rounded(.toNearestOrAwayFromZero)
        let w = (rbgSize.width*0.34).rounded(.toNearestOrAwayFromZero)
        let h = (rbgSize.height*0.28).rounded(.toNearestOrAwayFromZero)
        self.flagLayer.frame = CGRect(x: left, y: top, width: w, height: h)
        self.flagLayer.setNeedsDisplay()
    }
    
    override var intrinsicContentSize: CGSize {
        
        let height = fontSize/1.1 + 4
        let width = height/PlateView.aspectRatio
        return CGSize(width: width, height: height)
    }
}

struct PlateNumberView: NSViewRepresentable {

    var number: PlateNumber
    var unrecognized: Bool
    var outdated: Bool
    var fontSize: CGFloat

    func makeNSView(context: Context) -> PlateView {
        let view = PlateView(frame: .zero)
        view.fontSize = fontSize
        return view
    }

    func updateNSView(_ nsView: PlateView, context: Context) {
        nsView.number = number
        nsView.setContentHuggingPriority(.defaultHigh, for: .horizontal)
        nsView.setContentHuggingPriority(.defaultHigh, for: .vertical)
    }
}

struct PlateNumberView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            PlateNumberView(number: PlateNumber("Е201АМ761"), unrecognized: false, outdated: false, fontSize: 50)
            PlateNumberView(number: PlateNumber("Е201АМ761"), unrecognized: true, outdated: false, fontSize: 50)
            PlateNumberView(number: PlateNumber("Е201АМ761"), unrecognized: false, outdated: true, fontSize: 50)
        }
    }
}


#endif