ImageView.cs

//
// Copyright Fela Ameghino 2015-2025
//
// Distributed under the GNU General Public License v3.0. (See accompanying
// file LICENSE or copy at https://www.gnu.org/licenses/gpl-3.0.txt)
//
using System;
using Telegram.Common;
using Telegram.Services;
using Telegram.Td.Api;
using Telegram.ViewModels;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;

namespace Telegram.Controls
{
    public partial class ImageView : HyperlinkButton
    {
        protected FrameworkElement Holder;

        public ImageView()
        {
            DefaultStyleKey = typeof(ImageView);
        }

        protected override void OnApplyTemplate()
        {
            Holder = (FrameworkElement)GetTemplateChild("Holder");
            Holder.Loaded += Holder_Loaded;

            if (Holder is Image image)
            {
                image.ImageFailed += Holder_ImageFailed;
                image.ImageOpened += Holder_ImageOpened;
            }
        }

        private void Holder_Loaded(object sender, RoutedEventArgs e)
        {
            OnSourceChanged(Source, null);
        }

        private void Holder_ImageFailed(object sender, ExceptionRoutedEventArgs e)
        {
            ImageFailed?.Invoke(this, e);
        }

        private void Holder_ImageOpened(object sender, RoutedEventArgs e)
        {
            ImageOpened?.Invoke(this, e);
        }

        #region Source

        public ImageSource Source
        {
            get => (ImageSource)GetValue(SourceProperty);
            set => SetValue(SourceProperty, value);
        }

        public static readonly DependencyProperty SourceProperty =
            DependencyProperty.Register("Source", typeof(ImageSource), typeof(ImageView), new PropertyMetadata(null, OnSourceChanged));

        private static void OnSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ((ImageView)d).OnSourceChanged((ImageSource)e.NewValue, (ImageSource)e.OldValue);
        }

        private void OnSourceChanged(ImageSource newValue, ImageSource oldValue)
        {
            if (newValue is WriteableBitmap bitmap && bitmap.PixelWidth > 0 && bitmap.PixelHeight > 0)
            {
                ImageOpened?.Invoke(this, null);
            }
        }

        #endregion

        #region Stretch

        public Stretch Stretch
        {
            get => (Stretch)GetValue(StretchProperty);
            set => SetValue(StretchProperty, value);
        }

        public static readonly DependencyProperty StretchProperty =
            DependencyProperty.Register("Stretch", typeof(Stretch), typeof(ImageView), new PropertyMetadata(Stretch.Uniform));

        #endregion

        #region Constraint

        public object Constraint
        {
            get => GetValue(ConstraintProperty);
            set => SetValue(ConstraintProperty, value);
        }

        public static readonly DependencyProperty ConstraintProperty =
            DependencyProperty.Register("Constraint", typeof(object), typeof(ImageView), new PropertyMetadata(null, OnConstraintChanged));

        private static void OnConstraintChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ((ImageView)d).InvalidateMeasure();
        }

        #endregion

        protected override Size MeasureOverride(Size availableSize)
        {
            if (Constraint == null)
            {
                return base.MeasureOverride(availableSize);
            }

            var availableWidth = Math.Min(availableSize.Width, Math.Min(double.IsNaN(Width) ? double.PositiveInfinity : Width, MaxWidth));
            var availableHeight = Math.Min(availableSize.Height, Math.Min(double.IsNaN(Height) ? double.PositiveInfinity : Height, MaxHeight));

            var width = 0.0;
            var height = 0.0;

            var constraint = Constraint;
            if (constraint is MessageViewModel viewModel)
            {
                //ttl = viewModel.SelfDestructTime > 0;
                constraint = viewModel.Content;
            }
            else if (constraint is Message message)
            {
                //ttl = message.SelfDestructTime > 0;
                constraint = message.Content;
            }

            if (constraint is MessageAnimation animationMessage)
            {
                constraint = animationMessage.Animation;
            }
            else if (constraint is MessageInvoice invoiceMessage)
            {
                if (invoiceMessage.PaidMedia is PaidMediaPhoto paidMediaPhoto)
                {
                    constraint = paidMediaPhoto.Photo;
                }
                else if (invoiceMessage.PaidMedia is PaidMediaVideo paidMediaVideo)
                {
                    constraint = paidMediaVideo.Video;
                }
                else if (invoiceMessage.PaidMedia is PaidMediaPreview paidMediaPreview)
                {
                    width = paidMediaPreview.Width;
                    height = paidMediaPreview.Height;
                }
                else
                {
                    constraint = invoiceMessage.ProductInfo.Photo;
                }
            }
            else if (constraint is MessageGame gameMessage)
            {
                if (gameMessage.Game.Animation != null)
                {
                    constraint = gameMessage.Game.Animation;
                }
                else if (gameMessage.Game.Photo != null)
                {
                    constraint = gameMessage.Game.Photo;
                }
            }
            else if (constraint is MessageLocation locationMessage)
            {
                constraint = locationMessage.Location;
            }
            else if (constraint is MessagePhoto photoMessage)
            {
                constraint = photoMessage.Photo;
            }
            else if (constraint is MessageSticker stickerMessage)
            {
                constraint = stickerMessage.Sticker;
            }
            else if (constraint is MessageText textMessage)
            {
                if (textMessage?.LinkPreview?.Type is LinkPreviewTypeBackground)
                {
                    width = 900;
                    height = 1600;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeAnimation previewAnimation)
                {
                    constraint = previewAnimation.Animation;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeDocument previewDocument)
                {
                    constraint = previewDocument.Document;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeEmbeddedAnimationPlayer previewEmbeddedAnimationPlayer)
                {
                    width = previewEmbeddedAnimationPlayer.Width;
                    height = previewEmbeddedAnimationPlayer.Height;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeEmbeddedVideoPlayer previewEmbeddedVideoPlayer)
                {
                    width = previewEmbeddedVideoPlayer.Width;
                    height = previewEmbeddedVideoPlayer.Height;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypePhoto previewPhoto)
                {
                    constraint = previewPhoto.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeSticker previewSticker)
                {
                    constraint = previewSticker.Sticker;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeVideo previewVideo)
                {
                    constraint = previewVideo.Video;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeVideoNote videoNote)
                {
                    constraint = videoNote.VideoNote;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeApp app)
                {
                    constraint = app.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeArticle article)
                {
                    constraint = article.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeChannelBoost channelBoost)
                {
                    constraint = channelBoost.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeChat chat)
                {
                    constraint = chat.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeSupergroupBoost supergroupBoost)
                {
                    constraint = supergroupBoost.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeUser user)
                {
                    constraint = user.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeVideoChat videoChat)
                {
                    constraint = videoChat.Photo;
                }
                else if (textMessage?.LinkPreview?.Type is LinkPreviewTypeWebApp webApp)
                {
                    constraint = webApp.Photo;
                }
            }
            else if (constraint is MessageVenue venueMessage)
            {
                constraint = venueMessage.Venue;
            }
            else if (constraint is MessageVideo videoMessage)
            {
                constraint = videoMessage.Video;
            }
            else if (constraint is MessageVideoNote videoNoteMessage)
            {
                constraint = videoNoteMessage.VideoNote;
            }
            else if (constraint is MessageChatChangePhoto chatChangePhoto)
            {
                constraint = chatChangePhoto.Photo;
            }
            else if (constraint is PaidMediaPreview paidMediaPreview)
            {
                width = paidMediaPreview.Width;
                height = paidMediaPreview.Height;
            }

            if (constraint is Animation animation)
            {
                width = animation.Width;
                height = animation.Height;
            }
            else if (constraint is Location location)
            {
                width = 320;
                height = 200;
            }
            else if (constraint is Photo photo)
            {
                var size = photo.Sizes.Count > 0 ? photo.Sizes[^1] : null;
                if (size != null)
                {
                    width = size.Width;
                    height = size.Height;
                }
            }
            else if (constraint is ChatPhoto chatPhoto)
            {
                var size = chatPhoto.Sizes.Count > 0 ? chatPhoto.Sizes[^1] : null;
                if (size != null)
                {
                    width = size.Width;
                    height = size.Height;
                }
            }
            else if (constraint is Sticker sticker)
            {
                width = sticker.Width;
                height = sticker.Height;
            }
            else if (constraint is Venue venue)
            {
                width = 320;
                height = 200;
            }
            else if (constraint is Video video)
            {
                width = video.Width;
                height = video.Height;
            }
            else if (constraint is VideoNote videoNote)
            {
                width = 200;
                height = 200;
            }

            if (constraint is PhotoSize photoSize)
            {
                width = photoSize.Width;
                height = photoSize.Height;
            }

            if (constraint is PageBlockMap map)
            {
                width = map.Width;
                height = map.Height;
            }

            if (constraint is Background wallpaper)
            {
                width = 900;
                height = 1600;
            }



        Calculate:
            if (width > availableWidth || height > availableHeight)
            {
                var ratioX = availableWidth / width;
                var ratioY = availableHeight / height;
                var ratio = Math.Min(ratioX, ratioY);

                //if (Holder != null)
                //{
                //    Holder.Width = width * ratio;
                //    Holder.Height = height * ratio;
                //}

                return new Size(width * ratio, height * ratio);
            }
            else
            {
                return new Size(width, height);
            }
        }

        public event ExceptionRoutedEventHandler ImageFailed;

        public event RoutedEventHandler ImageOpened;

        #region Bitmap

        private IClientService _clientService;
        private File _file;
        private int _width;
        private int _height;

        private long _fileToken;

        public void SetSource(IClientService clientService, File file, int width = 0, int height = 0)
        {
            _clientService = clientService;
            _file = file;
            _width = width;
            _height = height;

            Source = GetSource(clientService, file, width, height, true);
        }

        private ImageSource GetSource(IClientService clientService, File file, int width, int height, bool download)
        {
            if (file.Local.IsDownloadingCompleted)
            {
                return UriEx.ToBitmap(file.Local.Path, width, height);
            }
            else if (download)
            {
                UpdateManager.Subscribe(this, clientService, file, ref _fileToken, UpdateSource, true);

                if (file.Local.CanBeDownloaded && !file.Local.IsDownloadingActive)
                {
                    clientService.DownloadFile(file.Id, 16);
                }
            }

            return null;
        }

        private void UpdateSource(object target, File file)
        {
            Source = GetSource(_clientService, _file, _width, _height, false);
        }

        #endregion
    }
}