MultiColoredPie.swift

//
//  MultiColoredPie.swift
//
//  Created by Himal Madhushan
//

import UIKit
import CoreGraphics

class MultiColoredPie: UIView {
    
    private var commonPath: UIBezierPath {
        get {
            let x = self.frame.width/2
            let y = self.frame.height/2
            let center = CGPoint(x: x, y: y)
            let path = UIBezierPath(arcCenter: center, radius: CGFloat(x - lineWidth/2), startAngle: -90.degreesToRadians, endAngle: 270.degreesToRadians, clockwise: true)
            path.close()
            return path
        }
    }
    
    private lazy var shapeLayer: CAShapeLayer = {
        var layer = CAShapeLayer()
        layer.fillColor = nil
        layer.strokeColor = UIColor.pieChartNonFillPath.cgColor
        layer.lineCap = CAShapeLayerLineCap.square
//        layer.path = commonPath.cgPath
        return layer
    }()
    
    @IBInspectable var lineWidth: CGFloat = 40
    
    var data: [MultiPieData]?
    
    private lazy var pathLayers: [PieLayer] = {
        
        guard let data = self.data else { return [] }

        var previousPercentage: CGFloat = 0
        let sorted = data.sorted(by: { (data1, data2) -> Bool in
            return data1.percentage < data2.percentage
        })

        var layers: [PieLayer] = []
        for (index, item) in sorted.enumerated() {
            previousPercentage += item.percentage
            let layer = PieLayer()
            layer.index = index
            layer.lineCap = CAShapeLayerLineCap.square
            layer.fillColor = nil
            layer.strokeColor = item.color.cgColor
            layer.strokeEnd = previousPercentage //item.percentage
            layer.percentage = previousPercentage //item.percentage
            layers.append(layer)
        }
        return layers
    }()
    
//    private lazy var pathLayers: [PieLayer] = []
    
    override init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        self.addShapes()
    }
    
    func addShapes() {
        shapeLayer.path = commonPath.cgPath
        shapeLayer.lineWidth = lineWidth
        self.layer.addSublayer(shapeLayer)
        
        for layer in pathLayers.reversed() {
            print("\(layer.index) - \(layer.percentage)")
            layer.lineWidth = lineWidth
            layer.path = commonPath.cgPath
            self.layer.addSublayer(layer)
        }
        
    }
    
    func getPath() -> UIBezierPath {
        var path = UIBezierPath()
        path = UIBezierPath(ovalIn: CGRect(x: lineWidth/2, y: lineWidth/2, width: self.frame.width-lineWidth, height: self.frame.height-lineWidth))
        path.close()
        return path
    }
    
}


class MultiPieData {
    var color: UIColor = .navigationBarColor
    var percentage: CGFloat = 0.0
    var label: String = ""
    
    init(label: String, percentage: CGFloat, color: UIColor) {
        self.color = color
        self.label = label
        self.percentage = percentage
    }
}


class PieLayer: CAShapeLayer {
    var index: Int = 0
    var percentage: CGFloat = 0.0
}