Previev Sorting Algorytm

BufferControllers/APIThreadBuffer.cs

@@ -5,36 +5,77 @@ namespace NeDvachAPI.BufferControllers
 {
     public class APIThreadBuffer
     {
-        private static List<Post> ThreadsPrewievs;
+        private static List<Post>[] ThreadsPrewievs = new List<Post>[0];
         private static List<Post>[] Threads = new List<Post>[0];
         public static void WriteThreadPreviewsBuffer(List<Post> OPPostsToWrite)    //add list of OP-posts and last post to buffer
         {
-            ThreadsPrewievs = OPPostsToWrite;
+            for(int pos = 0; pos < OPPostsToWrite.Count; pos ++)
+            {
+                var deb = new List<Post>();
+                deb.Add(OPPostsToWrite[pos]);
+                ThreadsPrewievs = ThreadsPrewievs.Append(deb).ToArray();
+            }
         }
 
-        public static List<Post> GetThreadPreviews()
+        public static void AppendToThreadPreviews(int index,Post toAppend)
+        {
+            ThreadsPrewievs[index].Add(toAppend);
+        }
+
+        public static List<Post>[] GetThreadPreviews()
         {
             return ThreadsPrewievs;
         }
 
-        public static void WriteThreadsBuffer(List<Post> ThreadToAdd)  //add thread's posts from DB to buffer
+        public static void UpdateThreadsPreviews(int threadId)
+        {
+            Console.WriteLine("Пытаюсь обновить превью треда " + threadId);
+
+            var newPreview = new List<Post>();
+            newPreview.Add(ThreadsPrewievs[threadId -1][0]);
+            int targetLength = APIThreadBuffer.GetThreadLength(threadId - 1);
+                for (int lastofthree =  targetLength- 2; lastofthree <=  targetLength; lastofthree ++)
+                {
+                    newPreview.Add(GetSinglePost(threadId - 1,lastofthree));
+                } 
+            ThreadsPrewievs[threadId -1] = newPreview;
+        }
+
+        public static void AppendThreadsBuffer(List<Post> ThreadToAdd)  //add thread's posts from DB to buffer
         {
             Threads = Threads.Append(ThreadToAdd).ToArray();
         }
+
+        public static int GetThreadLength(int threadId)
+        {
+            return Threads[threadId].Count;
+        }
+
         public static List<Post> GetThread(int threadId)
         {
             if (threadId < Threads.Length + 1 & threadId != 0)
             {
-                
                 return Threads[threadId - 1];
-
             }
             else return null;
         }
 
+        public static Post GetSinglePost(int thread, int postPosition)
+        {
+            List<Post> postsList = Threads[thread];
+            return postsList[postPosition-1];
+        }
+
+        public static void UpdateThreadPosts(int threadId)
+        {
+            Console.WriteLine("Пытаюсь обновить тред " + threadId);
+            Threads[threadId - 1] = DBchat.PostsList("b", threadId);
+        }
+
         public static void RefreshThread(int threadId)
         {
-            Threads[threadId - 1] = DBchat.PostsList("b", threadId);
+            UpdateThreadPosts(threadId);
+            UpdateThreadsPreviews(threadId);
         }
 
     }

BufferControllers/BufferFill.cs

@@ -8,15 +8,25 @@ namespace NeDvachAPI.BufferControllers
 
         public static bool FillBuffer(string board) //method to get buffer of information, which is being ran while API is started
         {
-            List<Post> posts = DBchat.ThreadsList(board);
-            APIThreadBuffer.WriteThreadPreviewsBuffer(posts);
+            List<Post> Previews = DBchat.ThreadsList(board);
+            APIThreadBuffer.WriteThreadPreviewsBuffer(Previews);
             Console.WriteLine("Заполняю буфер оп-постами");
 
-            for (int threadId = 1; threadId <= posts.Count; threadId++)
+            for (int threadId = 1; threadId <= Previews.Count; threadId++)
             {
-                APIThreadBuffer.WriteThreadsBuffer(DBchat.PostsList(board, threadId));                
+                APIThreadBuffer.AppendThreadsBuffer(DBchat.PostsList(board, threadId));         
             }
-            Console.WriteLine($@"Буферизую треды с {1} по {posts.Count}.");
+            Console.WriteLine($@"Буферизую треды с {1} по {Previews.Count}.");
+
+            for (int preview = 0; preview < Previews.Count; preview++)
+            {
+                int targetLength = APIThreadBuffer.GetThreadLength(preview);
+                for (int lastofthree =  targetLength- 2; lastofthree <=  targetLength; lastofthree ++)
+                {
+                    APIThreadBuffer.AppendToThreadPreviews(preview,APIThreadBuffer.GetSinglePost(preview,lastofthree));
+                }
+            }
+
             return true;
         }
     }

DBControllers/DBchat.cs

@@ -77,9 +77,9 @@ namespace NeDvachAPI.DBControllers
                     FROM posts
                     WHERE
                     is_op = {true}
-                    ORDER BY post_id DESC 
+                    ORDER BY thread_id DESC 
                 ) subquery
-                ORDER BY post_id ASC", conn))
+                ORDER BY thread_id ASC", conn))
                 {
 
                     var reader = command.ExecuteReader();