using System;

using UIKit;

using System.Drawing;

using CoreAnimation;

namespace PMM

{

    public class ProgressCircleView : UIView

    {

        protected CAShapeLayer _progressCircle;

        protected CAShapeLayer PageGrayCircle;

        public override CoreGraphics.CGRect Bounds {

            get

            {

                return base.Bounds;

            }

            set {

                base.Bounds = value;

                GrayCircle ();

            }

        }

        public ProgressCircleView ()

        {

            GrayCircle ();

        }

        /// <summary>

        /// Redraws the progress circle. If the circle is already on the screen, it removes that one and creates a new one using the

        /// current properties of the view

        /// </summary>

        void RedrawCircle ()

        {

            var centerPoint = new PointF ((float)this.Bounds.Width , (float)this.Bounds.Height );

            UIBezierPath circlePath = UIBezierPath.FromArc (centerPoint, this.Bounds.Width * .5f, (float)(-. * Math.PI), (float)(1.5 * Math.PI), true);

            _progressCircle = new CAShapeLayer ();

            _progressCircle.Path = circlePath.CGPath;

            _progressCircle.StrokeColor = UIColor.Red.CGColor;

            _progressCircle.FillColor = UIColor.Clear.CGColor;

            _progressCircle.LineWidth = 5f;

            _progressCircle.LineCap = CAShapeLayer.CapRound;

            _progressCircle.StrokeStart = 0f;

            _progressCircle.StrokeEnd = 0f;

            this.Layer.AddSublayer (_progressCircle);

        }

        void GrayCircle()

        {

            if (_progressCircle != null && _progressCircle.SuperLayer != null) {

                _progressCircle.RemoveFromSuperLayer ();

            }

            var centerPoint = new PointF ((float)this.Bounds.Width , (float)this.Bounds.Height );

            UIBezierPath circlePath = UIBezierPath.FromArc (centerPoint, this.Bounds.Width * .5f, (float)(1.5 * Math.PI), (float)(-. * Math.PI), false);

            PageGrayCircle = new CAShapeLayer ();

            PageGrayCircle.Path = circlePath.CGPath;

            PageGrayCircle.StrokeColor = UIColor.Gray.CGColor;

            PageGrayCircle.FillColor = UIColor.Clear.CGColor;

            PageGrayCircle.LineWidth = 4f;

            PageGrayCircle.LineCap = CAShapeLayer.CapRound;

            PageGrayCircle.StrokeStart = 0f;

            PageGrayCircle.StrokeEnd = 0f;

            this.Layer.AddSublayer (PageGrayCircle);

            RedrawCircle ();

        }

        /// <summary>

        /// Updates the progress circle.

        /// </summary>

        /// <param name="progressPercent">The percentage of the progress. Should be a value between 0.0 and 1.0</param>

        public void UpdateProgress(float progressPercent) {

            _progressCircle.StrokeEnd = progressPercent;

            PageGrayCircle.StrokeEnd =  - progressPercent;

        }

    }

}