Improve selection

Author: KirovAir

Muxarr.Data/Entities/AuditableEntity.cs

@@ -3,6 +3,11 @@
 
 namespace Muxarr.Data.Entities;
 
+public interface IHasId
+{
+    int Id { get; }
+}
+
 public abstract class AuditableEntity
 {
     public DateTime CreatedDate { get; set; }

Muxarr.Data/Entities/MediaConversion.cs

@@ -5,7 +5,7 @@
 
 namespace Muxarr.Data.Entities;
 
-public class MediaConversion : AuditableEntity
+public class MediaConversion : AuditableEntity, IHasId
 {
     public int Id { get; set; }
     public int? MediaFileId { get; set; }

Muxarr.Data/Entities/MediaFile.cs

@@ -3,7 +3,7 @@
 
 namespace Muxarr.Data.Entities;
 
-public class MediaFile : AuditableEntity
+public class MediaFile : AuditableEntity, IHasId
 {
     public int Id { get; set; }
     public int ProfileId { get; set; }

Muxarr.Data/Extensions/PaginationExtensions.cs

@@ -1,11 +1,26 @@
 using System.Linq.Expressions;
 using System.Reflection;
 using Microsoft.EntityFrameworkCore;
+using Muxarr.Data.Entities;
 
 namespace Muxarr.Data.Extensions;
 
 public static class PagingExtensions
 {
+    // EF expands Contains to one parameter per id and SQLite caps a statement
+    // at 32766, so large id sets load in chunks.
+    public static async Task<List<T>> WhereIdsAsync<T>(this IQueryable<T> query, IReadOnlyCollection<int> ids)
+        where T : class, IHasId
+    {
+        var result = new List<T>(ids.Count);
+        foreach (var chunk in ids.Chunk(10_000))
+        {
+            result.AddRange(await query.Where(e => chunk.Contains(e.Id)).ToListAsync());
+        }
+
+        return result;
+    }
+
     public static async Task<(IQueryable<T> Data, int Total, int TotalPages)> FindPagedAsync<T>(
         this IQueryable<T> collection,
         int pageNumber,

Muxarr.Web/Components/Pages/Conversions/Index.razor

@@ -118,11 +118,11 @@
     }
 
     <div class="row mb-3 g-2 mux-filter-row">
-        @if (SelectedItems.Count > 0)
+        @if (SelectedIds.Count > 0)
         {
             <div class="col-auto">
                 <button class="btn btn-danger btn-sm" @onclick="OnDeleteSelected">
-                    <i class="bi bi-trash me-1"></i>Delete @SelectedItems.Count selected
+                    <i class="bi bi-trash me-1"></i>Delete @SelectedIds.Count selected
                 </button>
             </div>
         }
@@ -353,24 +353,28 @@
 
     private async Task OnDeleteSelected()
     {
-        var deletable = SelectedItems.Where(c => c.State != ConversionState.Processing).ToList();
-        if (deletable.Count == 0)
+        // Check the state at delete time; the selected rows may be stale.
+        var ids = SelectedIds.ToList();
+        await using var context = await ContextFactory.CreateDbContextAsync();
+        var deletable = await context.MediaConversions
+            .CountAsync(c => ids.Contains(c.Id) && c.State != ConversionState.Processing);
+        if (deletable == 0)
         {
             return;
         }
 
         if (!await ModalService.ShowConfirm(
-                $"Are you sure you want to delete {deletable.Count} conversion(s)? This will affect conversion statistics.", "Delete Conversions"))
+                $"Are you sure you want to delete {deletable} conversion(s)? This will affect conversion statistics.", "Delete Conversions"))
         {
             return;
         }
 
-        var ids = deletable.Select(c => c.Id).ToList();
-        await using var context = await ContextFactory.CreateDbContextAsync();
-        await context.MediaConversions.Where(c => ids.Contains(c.Id)).ExecuteDeleteAsync();
-        SelectedItems.Clear();
+        var deleted = await context.MediaConversions
+            .Where(c => ids.Contains(c.Id) && c.State != ConversionState.Processing)
+            .ExecuteDeleteAsync();
+        SelectedIds.Clear();
         await UpdateList();
-        ToastService.ShowSuccess($"Deleted {deletable.Count} conversion(s).");
+        ToastService.ShowSuccess($"Deleted {deleted} conversion(s).");
     }
 
     private void OnQueueStateChanged()

Muxarr.Web/Components/Pages/Library/BatchEdit.razor

@@ -346,15 +346,7 @@
 
         await using (var context = await ContextFactory.CreateDbContextAsync())
         {
-            // EF expands Contains to one SQL parameter per id and SQLite caps a
-            // statement at 32766, so a whole-library selection arrives in batches.
-            foreach (var chunk in ids.Chunk(10000))
-            {
-                _files.AddRange(await context.MediaFiles
-                    .Where(f => chunk.Contains(f.Id))
-                    .WithTracksAndProfile()
-                    .ToListAsync());
-            }
+            _files = await context.MediaFiles.WithTracksAndProfile().WhereIdsAsync(ids);
         }
 
         _slots = Aggregate(_files);

Muxarr.Web/Components/Pages/Library/Index.razor

@@ -43,7 +43,7 @@
     </div>
 
     <div class="row mb-3 g-2 mux-filter-row">
-        @if (SelectedItems.Count > 0)
+        @if (SelectedIds.Count > 0)
         {
             <div class="col-auto">
                 <button @onclick="QueueSelected" class="btn btn-success btn-sm" type="button"
@@ -56,13 +56,13 @@
                     {
                         <i class="bi bi-plus-circle me-1"></i>
                     }
-                    Queue @SelectedItems.Count to conversion
+                    Queue @SelectedIds.Count to conversion
                 </button>
             </div>
             <div class="col-auto">
                 <button @onclick="BatchEditSelected" class="btn btn-outline-primary btn-sm" type="button"
                         disabled="@_isQueueing">
-                    <i class="bi bi-sliders me-1"></i>Edit tracks on @SelectedItems.Count
+                    <i class="bi bi-sliders me-1"></i>Edit tracks on @SelectedIds.Count
                 </button>
             </div>
         }
@@ -375,9 +375,6 @@
     private bool _isQueueing;
     private bool _disposed;
 
-    // Ticks handed back by the batch editor. Consumed by the first list load,
-    // then dropped so paging and filtering don't keep re-ticking rows.
-    private HashSet<int>? _restoreIds;
     private LibraryStatsConfig? _filterOptions;
     private List<ProfileSummary> _profileSummaries = [];
 
@@ -416,7 +413,12 @@
         IsAscending = false;
 
         MediaScanner.ScanningStateChanged += OnScanningStateChanged;
-        _restoreIds = Selections.Get(SelectionToken);
+
+        // Ticks handed back by the batch editor; ids, so no page needs to be loaded.
+        if (Selections.Get(SelectionToken) is { } restored)
+        {
+            SelectedIds.UnionWith(restored);
+        }
 
         await LoadFilters();
 
@@ -425,9 +427,6 @@
             await UpdateList();
         }
 
-        // The restore above has run; from here the ticks are the user's business again.
-        _restoreIds = null;
-
         await using var context = await ContextFactory.CreateDbContextAsync();
         _filterOptions = context.Configs.Get<LibraryStatsConfig>();
         await LoadProfileSummaries(context);
@@ -481,15 +480,6 @@
         TotalItems = result.Total;
         TotalPages = result.TotalPages;
         Items = await result.Data.WithTracks().ToListAsync().ConfigureAwait(false);
-
-        // Ticks come back after a trip to the batch editor, which only ever holds ids.
-        if (_restoreIds != null)
-        {
-            foreach (var file in Items.Where(f => _restoreIds.Contains(f.Id)))
-            {
-                SelectedItems.Add(file);
-            }
-        }
     }
 
     private IQueryable<MediaFile> ApplyFilters(IQueryable<MediaFile> query)
@@ -621,8 +611,15 @@
         StateHasChanged();
         try
         {
-            await QueueFiles(SelectedItems);
-            SelectedItems.Clear();
+            // Selected rows may span pages and reloads, so fetch them fresh.
+            List<MediaFile> files;
+            await using (var context = await ContextFactory.CreateDbContextAsync())
+            {
+                files = await context.MediaFiles.WithTracksAndProfile().WhereIdsAsync(SelectedIds);
+            }
+
+            await QueueFiles(files);
+            SelectedIds.Clear();
         }
         finally
         {
@@ -671,12 +668,10 @@
         }
     }
 
-    private Task BatchEditSelected()
+    private void BatchEditSelected()
     {
-        // SelectedItems is compared by reference, so paging away and back leaves
-        // stale duplicates of the same row. Go back to the ids.
-        var ids = SelectedItems.Select(f => f.Id).Distinct().ToList();
-        return BatchEditTracks(q => q.Where(f => ids.Contains(f.Id)));
+        // The selection already is the id set the editor needs.
+        NavigationManager.NavigateTo($"/library/batch?sel={Selections.Put(SelectedIds)}");
     }
 
     private Task BatchEditAllFiltered()

Muxarr.Web/Components/Shared/Selection/SelectAllCheckbox.razor

@@ -1,4 +1,5 @@
-@typeparam TType where TType : class
+@using Muxarr.Data.Entities
+@typeparam TType where TType : class, IHasId
 
 <div class="form-check">
     <input type="checkbox"
@@ -10,7 +11,7 @@
 @code {
     [Parameter] [EditorRequired] public required SelectablePaginatedListComponent<TType> Parent { get; set; }
 
-    private bool IsAllSelected => Parent.Items.All(item => Parent.SelectedItems.Contains(item));
+    private bool IsAllSelected => Parent.Items.All(item => Parent.SelectedIds.Contains(item.Id));
 
     private async Task HandleSelectionChange(ChangeEventArgs args)
     {
@@ -21,14 +22,14 @@
 
         if (selected)
         {
-            foreach (var baseEntity in Parent.Items)
+            foreach (var item in Parent.Items)
             {
-                Parent.SelectedItems.Add(baseEntity);
+                Parent.SelectedIds.Add(item.Id);
             }
         }
         else
         {
-            Parent.SelectedItems.Clear();
+            Parent.SelectedIds.Clear();
         }
 
         await Parent.OnSelectAll();

Muxarr.Web/Components/Shared/Selection/SelectablePaginatedListComponent.cs

@@ -1,44 +1,20 @@
-using Microsoft.AspNetCore.Components;
+using Muxarr.Data.Entities;
 
 namespace Muxarr.Web.Components.Shared.Selection;
 
-public abstract class SelectablePaginatedListComponent<T> : PaginatedListComponent<T> where T : class
+// Selection is a set of ids, not entity references: rows are reloaded on every
+// page or filter change, and two loads of the same row must count as one.
+public abstract class SelectablePaginatedListComponent<T> : PaginatedListComponent<T> where T : class, IHasId
 {
-    public readonly HashSet<T> SelectedItems = new(new EntityComparer<T>());
-
-    [Parameter]
-    public EventCallback<IEnumerable<T>> OnSelectionChanged { get; set; }
-
-    public bool ShowMultiSelect { get; set; }
+    public readonly HashSet<int> SelectedIds = [];
 
     public async Task OnSelectAll()
     {
         await InvokeStateHasChanged();
-        await OnSelectionChanged.InvokeAsync(SelectedItems);
     }
 
     public async Task OnSelect()
     {
         await InvokeStateHasChanged();
-        await OnSelectionChanged.InvokeAsync(SelectedItems);
-    }
-}
-
-// Todo: check if this works.
-public class EntityComparer<T> : IEqualityComparer<T> where T : class
-{
-    public bool Equals(T? x, T? y)
-    {
-        if (x == null || y == null)
-        {
-            return x == y;
-        }
-
-        return x == y;
-    }
-
-    public int GetHashCode(T obj)
-    {
-        return obj.GetHashCode();
     }
 }

Muxarr.Web/Components/Shared/Selection/SelectionCheckbox.razor

@@ -1,8 +1,9 @@
-@typeparam TType where TType : class
+@using Muxarr.Data.Entities
+@typeparam TType where TType : class, IHasId
 <div class="form-check">
     <input type="checkbox"
            class="form-check-input"
-           checked="@Parent.SelectedItems.Contains(Item)"
+           checked="@Parent.SelectedIds.Contains(Item.Id)"
            @onchange="HandleSelectionChange"/>
 </div>
 
@@ -16,11 +17,11 @@
         {
             if (selected)
             {
-                Parent.SelectedItems.Add(Item);
+                Parent.SelectedIds.Add(Item.Id);
             }
             else
             {
-                Parent.SelectedItems.Remove(Item);
+                Parent.SelectedIds.Remove(Item.Id);
             }
 
             await Parent.OnSelect();