Added basic search engine functionality

1 files changed, 46 insertions, 0 deletions

diff --git a/Services/SearchService.cs b/Services/SearchService.cs
new file mode 100644
index 0000000..8a109ea
--- /dev/null
+++ b/Services/SearchService.cs
@@ -0,0 +1,46 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace HyperBooru.Services;
+
+public interface ISearchService {
+    public Media[] Search(string query);
+}
+
+public class SearchService : ISearchService {
+    private IDbContextFactory<HBContext> dbFactory;
+
+    public SearchService(IDbContextFactory<HBContext> dbFactory) =>
+        this.dbFactory = dbFactory;
+
+    public Media[] Search(string query) {
+        var db = dbFactory.CreateDbContext();
+
+        query = query.ToLower();
+
+        var matchedTag = db.TagDefinitions
+            .FirstOrDefault(td => td.Name.ToLower() == query)?.Guid;
+
+        Guid[] guids;
+
+        if(matchedTag is not null) {
+            guids = new[] { (Guid) matchedTag };
+        } else {
+            guids = db.TagDefinitions
+                .Where(td => td.Name.ToLower().Contains(query))
+                .Select(td => td.Guid)
+                .ToArray();
+        }
+
+        return db.Media
+            .Include(m => m.Tags)
+            .ThenInclude(m => m.TagDefinition)
+            .AsEnumerable()
+            .Where(m => m.Tags.IntersectBy(guids, t => t.TagDefinition.Guid).Any())
+            .Concat(db.Media
+                .Where(m =>
+                    (m.ShortDescription != null && m.ShortDescription.ToLower().Contains(query)) ||
+                    (m.LongDescription != null && m.LongDescription.ToLower().Contains(query))))
+            .DistinctBy(m => m.Guid)
+            .ToArray();
+    }
+}