use season number as season placeholder

ErsatzTV.Application/MediaCards/Mapper.cs

@@ -18,7 +18,8 @@ namespace ErsatzTV.Application.MediaCards
                 GetSeasonName(televisionSeason.Number),
                 string.Empty,
                 GetSeasonName(televisionSeason.Number),
-                televisionSeason.Poster);
+                televisionSeason.Poster,
+                televisionSeason.Number == 0 ? "S" : televisionSeason.Number.ToString());
 
         internal static MovieCardViewModel ProjectToViewModel(MovieMediaItem movie) =>
             new(

ErsatzTV.Application/MediaCards/TelevisionSeasonCardViewModel.cs

@@ -1,7 +1,7 @@
 namespace ErsatzTV.Application.MediaCards
 {
     public record TelevisionSeasonCardViewModel
-        (int TelevisionSeasonId, string Title, string Subtitle, string SortTitle, string Poster) : MediaCardViewModel(
+        (int TelevisionSeasonId, string Title, string Subtitle, string SortTitle, string Poster, string Placeholder) : MediaCardViewModel(
             Title,
             Subtitle,
             SortTitle,

ErsatzTV/Pages/TelevisionSeasons.razor

@@ -1,4 +1,5 @@
 @page "/media/tv/shows/{ShowId:int}"
+@using static LanguageExt.Prelude
 @using ErsatzTV.Application.Television
 @using ErsatzTV.Application.Television.Queries
 @using ErsatzTV.Application.MediaCards
@@ -30,7 +31,7 @@
 <MudContainer MaxWidth="MaxWidth.Large" Class="media-card-grid">
     @foreach (TelevisionSeasonCardViewModel card in _data.Cards)
     {
-        <MediaCard Data="@card" Link="@($"/media/tv/shows/{ShowId}/seasons/{card.TelevisionSeasonId}")" DataRefreshed="@(() => RefreshData())"/>
+        <MediaCard Data="@card" CustomPlaceholder="@SeasonPlaceholder" Link="@($"/media/tv/shows/{ShowId}/seasons/{card.TelevisionSeasonId}")" DataRefreshed="@(() => RefreshData())"/>
     }
 </MudContainer>
 
@@ -56,4 +57,8 @@
         _data = await Mediator.Send(new GetTelevisionSeasonCards(ShowId, _pageNumber, _pageSize));
     }
 
+    private string SeasonPlaceholder(string sortTitle) =>
+        Optional(_data.Cards.SingleOrDefault(d => d.SortTitle == sortTitle))
+            .Match(vm => vm.Placeholder, () => sortTitle.Substring(0, 1).ToUpperInvariant());
+
 }

ErsatzTV/Shared/MediaCard.razor

@@ -45,9 +45,17 @@
 
     [Parameter]
     public EventCallback<Unit> DataRefreshed { get; set; }
+    
+    [Parameter]
+    public Func<string, string> CustomPlaceholder { get; set; }
 
     private string Placeholder(string sortTitle)
     {
+        if (CustomPlaceholder != null)
+        {
+            return CustomPlaceholder(sortTitle);
+        }
+        
         string first = sortTitle.Substring(0, 1).ToUpperInvariant();
         return int.TryParse(first, out _) ? "#" : first;
     }