Implement search providers

Emby.Server.Implementations/Library/Search/SqlSearchProvider.cs

@@ -0,0 +1,200 @@
+#pragma warning disable RS0030 // Do not use banned APIs
+#pragma warning disable CA1862 // Use the 'StringComparison' method overloads to perform case-insensitive string comparisons
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Data.Enums;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Extensions;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Persistence;
+using MediaBrowser.Model.Configuration;
+using Microsoft.EntityFrameworkCore;
+
+namespace Emby.Server.Implementations.Library.Search;
+
+/// <summary>
+/// Built-in SQL-based search provider that queries the library database directly.
+/// </summary>
+public class SqlSearchProvider : IInternalSearchProvider
+{
+    private const int DefaultSearchLimit = 100;
+    private const float ExactMatchScore = 100f;
+    private const float PrefixMatchScore = 80f;
+    private const float WordPrefixMatchScore = 75f;
+    private const float ContainsMatchScore = 50f;
+
+    private static readonly Guid _placeholderId = Guid.Parse("00000000-0000-0000-0000-000000000001");
+
+    private readonly IDbContextFactory<JellyfinDbContext> _dbProvider;
+    private readonly IItemTypeLookup _itemTypeLookup;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SqlSearchProvider"/> class.
+    /// </summary>
+    /// <param name="dbProvider">The database context factory.</param>
+    /// <param name="itemTypeLookup">The item type lookup.</param>
+    public SqlSearchProvider(IDbContextFactory<JellyfinDbContext> dbProvider, IItemTypeLookup itemTypeLookup)
+    {
+        _dbProvider = dbProvider;
+        _itemTypeLookup = itemTypeLookup;
+    }
+
+    /// <inheritdoc/>
+    public string Name => "Database";
+
+    /// <inheritdoc/>
+    public MetadataPluginType Type => MetadataPluginType.SearchProvider;
+
+    /// <inheritdoc/>
+    public int Priority => 100; // Low priority - runs as fallback
+
+    /// <inheritdoc/>
+    public bool CanSearch(SearchProviderQuery query)
+    {
+        // SQL search can always handle any query
+        return true;
+    }
+
+    /// <inheritdoc/>
+    public async Task<IReadOnlyList<SearchResult>> SearchAsync(SearchProviderQuery query, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(query);
+        ArgumentException.ThrowIfNullOrWhiteSpace(query.SearchTerm);
+
+        var rawSearchTerm = query.SearchTerm.Trim().RemoveDiacritics();
+        if (string.IsNullOrEmpty(rawSearchTerm))
+        {
+            return [];
+        }
+
+        var cleanSearchTerm = rawSearchTerm.GetCleanValue();
+        if (string.IsNullOrEmpty(cleanSearchTerm))
+        {
+            return [];
+        }
+
+        var cleanPrefix = cleanSearchTerm + " ";
+        // OriginalTitle is stored mixed-case and isn't pre-normalized like CleanName,
+        // so match it via a case-insensitive LIKE rather than a per-row case conversion
+        // that may not translate to SQL on every provider.
+        var likeOriginal = $"%{rawSearchTerm}%";
+        var limit = query.Limit ?? DefaultSearchLimit;
+
+        var dbContext = await _dbProvider.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+        await using (dbContext.ConfigureAwait(false))
+        {
+            // Lightweight projection: select only what's needed to score and identify items.
+            var dbQuery = dbContext.BaseItems
+                .AsNoTracking()
+                .Where(e => e.Id != _placeholderId)
+                .Where(e => !e.IsVirtualItem)
+                .Where(e => e.CleanName!.Contains(cleanSearchTerm)
+                    || (e.OriginalTitle != null && EF.Functions.Like(e.OriginalTitle, likeOriginal)));
+
+            dbQuery = ApplyTypeFilter(dbQuery, query.IncludeItemTypes, query.ExcludeItemTypes);
+            dbQuery = ApplyMediaTypeFilter(dbQuery, query.MediaTypes);
+            dbQuery = ApplyParentFilter(dbQuery, query.ParentId);
+
+            // Compute the score in SQL: the ternary translates to a CASE WHEN. CleanName is
+            // the pre-normalized (lowercase, diacritic-stripped) form, so we score against it
+            // directly without any per-row case conversion. Items that match only via
+            // OriginalTitle fall through to the Contains tier.
+            // Tie-break by Id for deterministic ordering so the explicit OrderBy + Take
+            // satisfies EF Core's row-limiting-with-OrderBy requirement.
+            var scored = dbQuery.Select(e => new
+            {
+                e.Id,
+                Score =
+                    (e.CleanName == cleanSearchTerm) ? ExactMatchScore
+                    : e.CleanName!.StartsWith(cleanSearchTerm) ? PrefixMatchScore
+                    : e.CleanName!.Contains(cleanPrefix) ? WordPrefixMatchScore
+                    : ContainsMatchScore
+            });
+
+            var top = await scored
+                .OrderByDescending(x => x.Score)
+                .ThenBy(x => x.Id)
+                .Take(limit)
+                .ToListAsync(cancellationToken)
+                .ConfigureAwait(false);
+
+            var results = new List<SearchResult>(top.Count);
+            foreach (var row in top)
+            {
+                results.Add(new SearchResult(row.Id, row.Score));
+            }
+
+            return results;
+        }
+    }
+
+    private IQueryable<BaseItemEntity> ApplyTypeFilter(
+        IQueryable<BaseItemEntity> query,
+        BaseItemKind[] includeItemTypes,
+        BaseItemKind[] excludeItemTypes)
+    {
+        if (includeItemTypes.Length > 0)
+        {
+            var includeTypeNames = MapKindsToTypeNames(includeItemTypes);
+            if (includeTypeNames.Count > 0)
+            {
+                query = query.Where(e => includeTypeNames.Contains(e.Type));
+            }
+        }
+        else if (excludeItemTypes.Length > 0)
+        {
+            var excludeTypeNames = MapKindsToTypeNames(excludeItemTypes);
+            if (excludeTypeNames.Count > 0)
+            {
+                query = query.Where(e => !excludeTypeNames.Contains(e.Type));
+            }
+        }
+
+        return query;
+    }
+
+    private static IQueryable<BaseItemEntity> ApplyMediaTypeFilter(
+        IQueryable<BaseItemEntity> query,
+        MediaType[] mediaTypes)
+    {
+        if (mediaTypes.Length == 0)
+        {
+            return query;
+        }
+
+        var mediaTypeNames = mediaTypes.Select(m => m.ToString()).ToArray();
+        return query.Where(e => e.MediaType != null && mediaTypeNames.Contains(e.MediaType));
+    }
+
+    private static IQueryable<BaseItemEntity> ApplyParentFilter(
+        IQueryable<BaseItemEntity> query,
+        Guid? parentId)
+    {
+        if (!parentId.HasValue || parentId.Value.IsEmpty())
+        {
+            return query;
+        }
+
+        var pid = parentId.Value;
+        return query.Where(e => e.ParentId == pid || e.Parents!.Any(p => p.ParentItemId == pid));
+    }
+
+    private List<string> MapKindsToTypeNames(BaseItemKind[] kinds)
+    {
+        var list = new List<string>(kinds.Length);
+        foreach (var kind in kinds)
+        {
+            if (_itemTypeLookup.BaseItemKindNames.TryGetValue(kind, out var name) && name is not null)
+            {
+                list.Add(name);
+            }
+        }
+
+        return list;
+    }
+}