CreateChatPhotoViewModel.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 Rg.DiffUtils;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using Telegram.Navigation;
using Telegram.Navigation.Services;
using Telegram.Services;
using Telegram.Td.Api;
using Windows.UI.Xaml.Navigation;

namespace Telegram.ViewModels
{
    public partial class CreateChatPhotoViewModel : ViewModelBase
    {
        public CreateChatPhotoViewModel(IClientService clientService, ISettingsService settingsService, IEventAggregator aggregator)
            : base(clientService, settingsService, aggregator)
        {
            Items = new ObservableCollection<BackgroundFill>
            {
                new BackgroundFillFreeformGradient(new[] { 0x5A7FFF, 0x2CA0F2, 0x4DFF89, 0x6BFCEB }),
                new BackgroundFillFreeformGradient(new[] { 0xFF011D, 0xFF530D, 0xFE64DC, 0xFFDC61 }),
                new BackgroundFillFreeformGradient(new[] { 0xFE64DC, 0xFF6847, 0xFFDD02, 0xFFAE10 }),
                new BackgroundFillFreeformGradient(new[] { 0x84EC00, 0x00B7C2, 0x00C217, 0xFFE600 }),
                new BackgroundFillFreeformGradient(new[] { 0x86B0FF, 0x35FFCF, 0x69FFFF, 0x76DEFF }),
                new BackgroundFillFreeformGradient(new[] { 0xFAE100, 0xFF54EE, 0xFC2B78, 0xFF52D9 }),
                new BackgroundFillFreeformGradient(new[] { 0x73A4FF, 0x5F55FF, 0xFF49F8, 0xEC76FF }),
                new BackgroundFillFreeformGradient(new[] { 0x73A4FF, 0x5F55FF, 0xFF49F8, 0xEC76FF }),
            };

            SelectedBackground = Items[0];
        }

        protected override async Task OnNavigatedToAsync(object parameter, NavigationMode mode, NavigationState state)
        {
            var foreground = await ClientService.SendAsync(new GetAnimatedEmoji("\U0001F916")) as AnimatedEmoji;
            if (foreground != null)
            {
                SelectedForeground = foreground.Sticker;
            }
        }

        private Sticker _selectedForeground;
        public Sticker SelectedForeground
        {
            get => _selectedForeground;
            set => Set(ref _selectedForeground, value);
        }

        private BackgroundFill _selectedBackground;
        public BackgroundFill SelectedBackground
        {
            get => _selectedBackground;
            set => Set(ref _selectedBackground, value);
        }

        public ObservableCollection<BackgroundFill> Items { get; private set; }

        public InputChatPhoto Send()
        {
            if (SelectedForeground is not Sticker foreground || SelectedBackground is not BackgroundFill background)
            {
                return null;
            }
            else
            {
                ChatPhotoStickerType stickerType = foreground.FullType is StickerFullTypeCustomEmoji customEmoji
                    ? new ChatPhotoStickerTypeCustomEmoji(customEmoji.CustomEmojiId)
                    : new ChatPhotoStickerTypeRegularOrMask(foreground.SetId, foreground.Id);
                InputChatPhoto inputPhoto = new InputChatPhotoSticker(new ChatPhotoSticker(stickerType, background));
                return inputPhoto;
            }
        }
    }

    public partial class BackgroundDiffHandler : IDiffHandler<Background>
    {
        public bool CompareItems(Background oldItem, Background newItem)
        {
            return oldItem.Id == newItem.Id;
        }

        public void UpdateItem(Background oldItem, Background newItem)
        {

        }
    }
}