/* Commented code above each section is code (Swift) that the derived code is converted from */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Foundation;
using UIKit;

namespace XamarinFormsApp1.Extensions
{
    public class AlertController : UIAlertController
    {
        private string originalTitle;
        private string spaceAdjustedTitle;
        private UIImageView imageView = null;
        private CoreGraphics.CGSize previousImgViewSize = CoreGraphics.CGSize.Empty;
        public override UIAlertControllerStyle PreferredStyle
        {
            get
            {
                return UIAlertControllerStyle.Alert;
            }
        }


        public override string Title
        {
            //didSet
            //{
            //    // Keep track of original title
            //    if title != spaceAdjustedTitle {
            //        originalTitle = title
            //    }
            //}
            get
            {
                return originalTitle;
            }
            set
            {
                if (Title != spaceAdjustedTitle ||
                    string.IsNullOrEmpty(Title) || string.IsNullOrEmpty(spaceAdjustedTitle))
                {
                    originalTitle = value;
                }
            }
        }

        public void setTitleImage(UIImage image)
        {
            //guard let imageView = self.imageView else {
            //    let imageView = UIImageView(image: image)
            //self.view.addSubview(imageView)
            //self.imageView = imageView
            //return
            //}
            //imageView.image = image

            if (this.imageView == null)
            {
                UIImageView imageView = new UIImageView(image);
                this.View.AddSubview(imageView);
                this.imageView = imageView;
                return;
            }
            imageView.Image = image;
        }

        public override void ViewDidLayoutSubviews()
        {
            //guard let imageView = imageView else {
            //    super.viewDidLayoutSubviews()
            //    return
            //}
            //    // Adjust title if image size has changed
            //    if previousImgViewSize != imageView.bounds.size {
            //        previousImgViewSize = imageView.bounds.size
            //        adjustTitle(for: imageView)
            //}
            //    // Position `imageView`
            //    let linesCount = newLinesCount(for: imageView)
            //        let padding = Constants.padding(for: preferredStyle)
            //        imageView.center.x = view.bounds.width / 2.0
            //        imageView.center.y = padding + linesCount * lineHeight / 2.0
            //super.viewDidLayoutSubviews()

            if (imageView == null)
            {
                base.ViewDidLayoutSubviews();
                return;
            }
            //  Adjust title if image size has changed
            if (previousImgViewSize != imageView.Bounds.Size)
            {
                previousImgViewSize = imageView.Bounds.Size;
                adjustTitle(imageView);
            }
            //  Position `imageView`
            var linesCount = newLinesCount(imageView);
            var padding = Constants.Padding(PreferredStyle);
            var x = View.Bounds.Width / 2.0;
            var y = padding + linesCount * lineHeight / 2.0;
            CoreGraphics.CGPoint cgPoint = imageView.Center;
            cgPoint.X = (nfloat)x;
            cgPoint.Y = (nfloat)y;
            imageView.Center = cgPoint;
            base.ViewDidLayoutSubviews();
        }

        ///// Adds appropriate number of "\n" to `title` text to make space for `imageView`
        //private func adjustTitle(for imageView: UIImageView)
        //{
        //    let linesCount = Int(newLinesCount(for: imageView))
        //    let lines = (0..< linesCount).map({ _ in "\n" }).reduce("", +)
        //    spaceAdjustedTitle = lines + (originalTitle ?? "")
        //    title = spaceAdjustedTitle
        //}
        private void adjustTitle(UIImageView imageView)
        {
            var linesCount = (int)newLinesCount(imageView);
            var lines = Enumerable
                .Range(1, linesCount)
                .Select(i => "\n")
                .Aggregate((c, n) => $"{c}{n}");
            spaceAdjustedTitle = lines + (originalTitle ?? "");
            Title = spaceAdjustedTitle;
        }


        ///// - Return: Number new line chars needed to make enough space for `imageView`
        //private func newLinesCount(for imageView: UIImageView) -> CGFloat {
        //    return ceil(imageView.bounds.height / lineHeight)
        //}
        private double newLinesCount(UIImageView imageView)
        {
            return Math.Ceiling(imageView.Bounds.Height / lineHeight);
        }

        /// Calculated based on system font line height
        //private lazy var lineHeight: CGFloat = {
        //    let style: UIFontTextStyle = self.preferredStyle == .alert ? .headline : .callout
        //    return UIFont.preferredFont(forTextStyle: style).pointSize
        //}()
        private float lineHeight {
            get
            {
                UIFontTextStyle style = this.PreferredStyle == UIAlertControllerStyle.Alert ? UIFontTextStyle.Headline : UIFontTextStyle.Callout;
                return (float)UIFont.GetPreferredFontForTextStyle(style).PointSize;
            }
        }

        //struct Constants {
        //    static var paddingAlert: CGFloat = 22
        //    static var paddingSheet: CGFloat = 11
        //    static func padding(for style: UIAlertControllerStyle) -> CGFloat {
        //        return style == .alert ? Constants.paddingAlert : Constants.paddingSheet
        //    }
        //}
        struct Constants
        {
            static float paddingAlert = 22;
            static float paddingSheet = 11;
            public static float Padding(UIAlertControllerStyle style)
            {
                return style == UIAlertControllerStyle.Alert ? Constants.paddingAlert : Constants.paddingSheet;
            }
        }

    }
}