Wino-Mail/Wino.Mail/Controls/ImagePreviewControl.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using Fernandezja.ColorHashSharp;
using Windows.UI;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using Windows.UI.Xaml.Shapes;
using Wino.Core.UWP.Services;

namespace Wino.Controls
{
    public partial class ImagePreviewControl : Control
    {
        private const string PART_EllipseInitialsGrid = "EllipseInitialsGrid";
        private const string PART_InitialsTextBlock = "InitialsTextBlock";
        private const string PART_KnownHostImage = "KnownHostImage";
        private const string PART_Ellipse = "Ellipse";

        #region Dependency Properties

        public static readonly DependencyProperty FromNameProperty = DependencyProperty.Register(nameof(FromName), typeof(string), typeof(ImagePreviewControl), new PropertyMetadata(string.Empty, OnAddressInformationChanged));
        public static readonly DependencyProperty FromAddressProperty = DependencyProperty.Register(nameof(FromAddress), typeof(string), typeof(ImagePreviewControl), new PropertyMetadata(string.Empty, OnAddressInformationChanged));
        public static readonly DependencyProperty SenderContactPictureProperty = DependencyProperty.Register(nameof(SenderContactPicture), typeof(string), typeof(ImagePreviewControl), new PropertyMetadata(string.Empty, new PropertyChangedCallback(OnAddressInformationChanged)));

        /// <summary>
        /// Gets or sets base64 string of the sender contact picture.
        /// </summary>
        public string SenderContactPicture
        {
            get { return (string)GetValue(SenderContactPictureProperty); }
            set { SetValue(SenderContactPictureProperty, value); }
        }

        public string FromName
        {
            get { return (string)GetValue(FromNameProperty); }
            set { SetValue(FromNameProperty, value); }
        }

        public string FromAddress
        {
            get { return (string)GetValue(FromAddressProperty); }
            set { SetValue(FromAddressProperty, value); }
        }

        #endregion

        private Ellipse Ellipse;
        private Grid InitialsGrid;
        private TextBlock InitialsTextblock;
        private Image KnownHostImage;
        private CancellationTokenSource contactPictureLoadingCancellationTokenSource;

        public ImagePreviewControl()
        {
            DefaultStyleKey = nameof(ImagePreviewControl);
        }

        protected override void OnApplyTemplate()
        {
            base.OnApplyTemplate();

            InitialsGrid = GetTemplateChild(PART_EllipseInitialsGrid) as Grid;
            InitialsTextblock = GetTemplateChild(PART_InitialsTextBlock) as TextBlock;
            KnownHostImage = GetTemplateChild(PART_KnownHostImage) as Image;
            Ellipse = GetTemplateChild(PART_Ellipse) as Ellipse;

            UpdateInformation();
        }

        private static void OnAddressInformationChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
        {
            if (obj is ImagePreviewControl control)
                control.UpdateInformation();
        }

        private async void UpdateInformation()
        {
            if (KnownHostImage == null || InitialsGrid == null || InitialsTextblock == null || (string.IsNullOrEmpty(FromName) && string.IsNullOrEmpty(FromAddress)))
                return;

            // Cancel active image loading if exists.
            if (!contactPictureLoadingCancellationTokenSource?.IsCancellationRequested ?? false)
            {
                contactPictureLoadingCancellationTokenSource.Cancel();
            }

            var host = ThumbnailService.GetHost(FromAddress);

            bool isKnownHost = false;

            if (!string.IsNullOrEmpty(host))
            {
                var tuple = ThumbnailService.CheckIsKnown(host);

                isKnownHost = tuple.Item1;
                host = tuple.Item2;
            }

            if (isKnownHost)
            {
                // Unrealize others.

                KnownHostImage.Visibility = Visibility.Visible;
                InitialsGrid.Visibility = Visibility.Collapsed;

                // Apply company logo.
                KnownHostImage.Source = new BitmapImage(new Uri(ThumbnailService.GetKnownHostImage(host)));
            }
            else
            {
                KnownHostImage.Visibility = Visibility.Collapsed;
                InitialsGrid.Visibility = Visibility.Visible;

                if (!string.IsNullOrEmpty(SenderContactPicture))
                {
                    contactPictureLoadingCancellationTokenSource = new CancellationTokenSource();

                    try
                    {
                        var brush = await GetContactImageBrushAsync();

                        if (!contactPictureLoadingCancellationTokenSource?.Token.IsCancellationRequested ?? false)
                        {
                            Ellipse.Fill = brush;
                            InitialsTextblock.Text = string.Empty;
                        }
                    }
                    catch (Exception)
                    {
                        // Log exception.
                        Debugger.Break();
                    }
                }
                else
                {
                    var colorHash = new ColorHash();
                    var rgb = colorHash.Rgb(FromAddress);

                    Ellipse.Fill = new SolidColorBrush(Color.FromArgb(rgb.A, rgb.R, rgb.G, rgb.B));
                    InitialsTextblock.Text = ExtractInitialsFromName(FromName);
                }
            }
        }

        private async Task<ImageBrush> GetContactImageBrushAsync()
        {
            // Load the image from base64 string.
            var bitmapImage = new BitmapImage();

            var imageArray = Convert.FromBase64String(SenderContactPicture);
            var imageStream = new MemoryStream(imageArray);
            var randomAccessImageStream = imageStream.AsRandomAccessStream();

            randomAccessImageStream.Seek(0);


            await bitmapImage.SetSourceAsync(randomAccessImageStream);

            return new ImageBrush() { ImageSource = bitmapImage };
        }

        public string ExtractInitialsFromName(string name)
        {
            // Change from name to from address in case of name doesn't exists.
            if (string.IsNullOrEmpty(name))
            {
                name = FromAddress;
            }

            // first remove all: punctuation, separator chars, control chars, and numbers (unicode style regexes)
            string initials = Regex.Replace(name, @"[\p{P}\p{S}\p{C}\p{N}]+", "");

            // Replacing all possible whitespace/separator characters (unicode style), with a single, regular ascii space.
            initials = Regex.Replace(initials, @"\p{Z}+", " ");

            // Remove all Sr, Jr, I, II, III, IV, V, VI, VII, VIII, IX at the end of names
            initials = Regex.Replace(initials.Trim(), @"\s+(?:[JS]R|I{1,3}|I[VX]|VI{0,3})$", "", RegexOptions.IgnoreCase);

            // Extract up to 2 initials from the remaining cleaned name.
            initials = Regex.Replace(initials, @"^(\p{L})[^\s]*(?:\s+(?:\p{L}+\s+(?=\p{L}))?(?:(\p{L})\p{L}*)?)?$", "$1$2").Trim();

            if (initials.Length > 2)
            {
                // Worst case scenario, everything failed, just grab the first two letters of what we have left.
                initials = initials.Substring(0, 2);
            }

            return initials.ToUpperInvariant();
        }
    }
}