1 files changed, 78 insertions, 0 deletions
diff --git a/Services/FeedService.cs b/Services/FeedService.cs
new file mode 100644
index 0000000..c66b9ee
--- /dev/null
+++ b/Services/FeedService.cs
@@ -0,0 +1,78 @@
+using Microsoft.EntityFrameworkCore;
+using System.Data.Common;
+
+namespace HyperBooru.Services;
+
+public enum FeedOrder {
+    Chronological,
+    Rating
+}
+
+public interface IFeedService {
+    public IEnumerable<Media> Feed { get; }
+
+    public void InitializeFeed(
+        FeedOrder order = FeedOrder.Chronological,
+        bool descending = true,
+        bool randomPosition = false);
+}
+
+public class FeedService : IFeedService {
+    private FeedConfiguration? feedConfig;
+
+    private IDbContextFactory<HBContext> dbFactory;
+
+    public FeedService(IDbContextFactory<HBContext> dbFactory) =>
+        this.dbFactory = dbFactory;
+
+    public void InitializeFeed(
+        FeedOrder order,
+        bool descending,
+        bool randomPosition) {
+
+        feedConfig = new() {
+            Order          = order,
+            Descending     = descending,
+            RandomPosition = randomPosition
+        };
+    }
+
+    public IEnumerable<Media> Feed {
+        get {
+            if(feedConfig is null)
+                throw new InvalidOperationException("Feed must be initialized first");
+
+            while(true) {
+                var db = dbFactory.CreateDbContext();
+
+                IOrderedQueryable<Media> media;
+
+                switch(feedConfig.Order) {
+                    default:
+                    case FeedOrder.Chronological:
+                        if(feedConfig.Descending)
+                            media = db.Media.OrderByDescending(m => m.ObjectId);
+                        else
+                            media = db.Media.OrderBy(m => m.ObjectId);
+                        break;
+                }
+
+                Media[] mediaArray = media.Take(50).ToArray();
+
+                db.Dispose();
+
+                if(mediaArray.Count() == 0)
+                    break;
+
+                foreach(var m in mediaArray)
+                    yield return m;
+            }
+        }
+    }
+
+    private record FeedConfiguration {
+        public FeedOrder Order          { get; set; }
+        public bool      Descending     { get; set; }
+        public bool      RandomPosition { get; set; }
+    }
+}