//
//  DoughnutChart.swift
//  MVMCoreUI
//
//  Created by Murugan, Vimal on 07/01/20.
//  Copyright © 2020 Verizon Wireless. All rights reserved.
//

import UIKit

open class DoughnutChart: View, MVMCoreUIViewConstrainingProtocol {
 
     var containerView = MVMCoreUICommonViewsUtility.commonView()
     var containerLayer = CALayer()
     var titleLabel = Label.commonLabelH3(true)
     var subTitleLabel = Label.commonLabelB2(true)
     var doughnutChartModel: DoughnutChartModel? {
        get { return model as? DoughnutChartModel }
     }
     var labelContainer = ViewConstrainingView.empty()
     var heightConstraint: NSLayoutConstraint?
        
     private var sizeObject = MFStyler.sizeObjectGeneric(forCurrentDevice: 150)!
        
     var height: CGFloat = 150 {
        didSet {
            if height != oldValue {
                sizeObject = MFStyler.sizeObjectGeneric(forCurrentDevice: height)!
                updateContainer()
                drawGraph()
            }
        }
     }
      
     open override func updateView(_ size: CGFloat) {
         super.updateView(size)
         titleLabel.updateView(size)
         subTitleLabel.updateView(size)
         updateContainer()
         drawGraph()
     }
     
     open override func reset() {
         super.reset()
         titleLabel.reset()
         subTitleLabel.reset()
         clearLayers()
     }
     
    public override func setAsMolecule() {
         titleLabel.setAsMolecule()
         subTitleLabel.setAsMolecule()
     }
     
     open override func setupView() {
         super.setupView()
         guard containerView.superview == nil else {
             return
         }
         addSubview(containerView)
         addSubview(labelContainer)
         
         labelContainer.addSubview(titleLabel)
         labelContainer.addSubview(subTitleLabel)
         titleLabel.textAlignment = .center
         subTitleLabel.textAlignment = .center
        
         //Make label font size to adjust width if label content is high
         titleLabel.numberOfLines = 1
         titleLabel.adjustsFontSizeToFitWidth = true
         
         containerView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
         containerView.topAnchor.constraint(equalTo: topAnchor).isActive = true
         bottomAnchor.constraint(equalTo: containerView.bottomAnchor).isActive = true
         trailingAnchor.constraint(equalTo: containerView.trailingAnchor).isActive = true
         containerView.layer.addSublayer(containerLayer)
         heightConstraint = containerView.heightAnchor.constraint(equalToConstant:
            sizeObject.getValueBasedOnApplicationWidth())
         heightConstraint?.isActive = true
         containerView.widthAnchor.constraint(equalTo: containerView.heightAnchor).isActive = true
         
         labelContainer.leftPin = labelContainer.leftAnchor.constraint(greaterThanOrEqualTo: containerView.leftAnchor, constant: lineWidth())
         labelContainer.leftPin?.isActive = true
         labelContainer.topPin = labelContainer.topAnchor.constraint(greaterThanOrEqualTo: containerView.topAnchor, constant: lineWidth())
         labelContainer.topPin?.isActive = true
         labelContainer.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true
         labelContainer.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
         
         NSLayoutConstraint.constraintPinSubview(titleLabel, pinTop: true, pinBottom: false, pinLeft: true, pinRight: true)
         NSLayoutConstraint.constraintPinSubview(subTitleLabel, pinTop: false, pinBottom: true, pinLeft: true, pinRight: true)
         _ = NSLayoutConstraint(pinFirstView: titleLabel, toSecondView: subTitleLabel, withConstant: 0, directionVertical: true)
         //Rotate view for initial draw
         containerLayer.transform = CATransform3DMakeRotation(1 * .pi, 0.0, 0.0, 1.0)
        
    }
    
    open override func setWithModel(_ model: MoleculeProtocol?, _ delegateObject: MVMCoreUIDelegateObject?, _ additionalData: [AnyHashable : Any]?) {
        super.setWithModel(model, delegateObject, additionalData)
        clearLayers()
        guard let doughnutChartModel = model as? DoughnutChartModel else {
            return
        }
        titleLabel.setWithModel(doughnutChartModel.title, delegateObject, additionalData)
        subTitleLabel.setWithModel(doughnutChartModel.subtitle, delegateObject, additionalData)
        titleLabel.textAlignment = .center
        subTitleLabel.textAlignment = .center
        updateLabelContainer()
        drawGraph()
    }
    
    func drawGraph() {
         clearLayers()
         let widthHeight = sizeObject.getValueBasedOnApplicationWidth()
         containerLayer.frame = CGRect(x: 0, y: 0,
                                       width: widthHeight,
                                       height: widthHeight)
         if let doughnutChart = doughnutChartModel {
             var prevPercent: CGFloat = 0.0
             for model in doughnutChart.sections {
                prevPercent += drawBar(model, prevPercent)
             }
         }
      }
     
    func drawBar(_ chartModel: ChartItemModel, _ prevPercent: CGFloat) -> CGFloat {
         
         let shapeLayer = CAShapeLayer()
         shapeLayer.frame = containerLayer.frame
         shapeLayer.lineWidth = lineWidth()
         shapeLayer.fillColor = nil
         shapeLayer.strokeColor = UIColor.mfGet(forHex: chartModel.color).cgColor
         
         let arcCenter = shapeLayer.position
        let radius = shapeLayer.bounds.size.width / 2.0 - lineWidth()/2.0
            //lineSizeObject.getValueBasedOnApplicationWidth() / 2.0
         let clockwise = true
         
         let value: CGFloat = chartModel.percent
         let gap: CGFloat = spaceReuired() ? lineGap() : 0.0
         let startAngle =  ((prevPercent / 100.0) * 2 * .pi) - (0.5 * .pi)
         let endAngle = ((value / 100.0) * 2 * .pi) + startAngle - gap
         let circlePath = UIBezierPath(arcCenter: arcCenter,
                                       radius: radius,
                                       startAngle: startAngle,
                                       endAngle: endAngle,
                                       clockwise: clockwise)
         
         shapeLayer.path = circlePath.cgPath
         containerLayer.addSublayer(shapeLayer)
         return value
     }
     
     func clearLayers() {
         containerLayer.sublayers?.forEach({ $0.removeFromSuperlayer() })
     }
    
     func updateContainer() {
         heightConstraint?.constant = sizeObject.getValueBasedOnApplicationWidth()
         updateLabelContainer()
         setNeedsDisplay()
     }
    
     func lineWidth() -> CGFloat {
        return doughnutChartModel?.lineWidth ?? 30
     }
    
     func lineGap() -> CGFloat {
        //If array is having the single item then no space required
        return doughnutChartModel?.sections.count == 1 ? 0.0 : 0.05
     }
    
     func spaceReuired() -> Bool {
        return doughnutChartModel?.spaceRequired ?? true
     }
    
    func updateLabelContainer() {
        labelContainer.layoutIfNeeded()
        let radius = sizeObject.getValueBasedOnApplicationWidth()/2 - lineWidth()
        let labelheight = labelContainer.frame.height/2
        let padding = sizeObject.getValueBasedOnApplicationWidth()/2 - sqrt(pow(radius, 2) - pow(labelheight, 2))
        
        labelContainer.leftPin?.constant = padding
        labelContainer.topPin?.constant = padding
        labelContainer.setNeedsDisplay()
    }

}