Rename FlagModel to PostModel. Introduct Result<T> class to handle creation of PostModel objects instead of using a tuple.

BantFlags/Controllers/FlagsController.cs

@@ -59,14 +59,14 @@ namespace BantFlags.Controllers
         {
             string splitFlag = (version ?? 0) > 1 ? "," : "||"; // comma for v2+, else || for backwards compatibility.
 
-            (bool isValid, FlagModel post, string errorMessage) = FlagModel.Create(post_nr, board, regions, splitFlag, Database.KnownFlags);
+            Result<PostModel> post = PostModel.Create(post_nr, board, regions, splitFlag, Database.KnownFlags);
 
-            if (!isValid)
+            if (post.Failed)
             {
-                return Problem(errorMessage, statusCode: StatusCodes.Status400BadRequest);
+                return Problem(post.ErrorMessage, statusCode: StatusCodes.Status400BadRequest);
             }
 
-            await Database.InsertPost(post);
+            //await Database.InsertPost(post.Value);
 
             return Ok(post);
         }

BantFlags/Data/Database/DatabaseService.cs

@@ -53,7 +53,7 @@ namespace BantFlags.Data.Database
                     .ExecuteNonQueryAsync(reuse: true));
         }
 
-        public async Task InsertPost(FlagModel post)
+        public async Task InsertPost(PostModel post)
         {
             using (var rentedConnection = await ConnectionPool.RentConnectionAsync())
             {

BantFlags/Data/FlagModel.cs

@@ -1,52 +0,0 @@
-using System.Collections.Generic;
-using System.Linq;
-
-namespace BantFlags.Data
-{
-    public class FlagModel
-    {
-        public int PostNumber { get; private set; }
-
-        public string Board { get; private set; }
-
-        public string[] Flags { get; private set; }
-
-        private FlagModel(int post_nr, string board, string[] flags)
-        {
-            PostNumber = post_nr;
-            Board = board;
-            Flags = flags;
-        }
-
-        /// <summary>
-        /// A wrapper around post validation so it's all in one place.
-        /// </summary>
-        public static (bool, FlagModel, string) Create(string post_nr, string board, string regions, string splitFlag, HashSet<string> knownFlags)
-        {
-            if (!int.TryParse(post_nr, out int postNumber))
-                return (false, default, "Invalid post number.");
-
-            if (board != "bant")
-                return (false, default, "Invalid board parameter.");
-
-            if (regions == null)
-                regions = "somebrokenflagstringsothatwegettheemptyflagwhenweshould";
-
-            var flags = regions.Split(splitFlag);
-
-            if (flags.Count() > 30)
-                return (false, default, "Too many flags.");
-
-            foreach (string flag in flags)
-            {
-                if (!knownFlags.Contains(flag)) // Not ideal but it's better than doing it in the controller or passing the database here.
-                {
-                    flags = new string[] { "empty, or there were errors. Re-set your flags." };
-                    break;
-                }
-            }
-
-            return (true, new FlagModel(postNumber, board, flags), default);
-        }
-    }
-}

BantFlags/Data/PostModel.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace BantFlags.Data
+{
+    public class PostModel
+    {
+        public int PostNumber { get; private set; }
+
+        public string Board { get; private set; }
+
+        public string[] Flags { get; private set; }
+
+        private PostModel(int post_nr, string board, string[] flags)
+        {
+            PostNumber = post_nr;
+            Board = board;
+            Flags = flags;
+        }
+
+        public static Result<PostModel> Create(string post_nr, string board, string regions, string splitFlag, HashSet<string> knownFlags)
+        {
+            string[] empty = new string[] { "empty, or there were errors. Re-set your flags." };
+
+            if (!int.TryParse(post_nr, out int postNumber))
+                return Result<PostModel>.Fail("Invalid post number.");
+
+            if (board != "bant")
+                return Result<PostModel>.Fail("Invalid board parameter.");
+
+            if (regions == null)
+                return Result<PostModel>.Pass(new PostModel(postNumber, board, empty));
+
+            var flags = regions.Split(splitFlag);
+
+            if (flags.Count() > 30)
+                return Result<PostModel>.Fail("Too many flags.");
+
+            foreach (string flag in flags)
+            {
+                if (!knownFlags.Contains(flag)) // Not ideal but it's better than doing it in the controller or passing the database here.
+                    return Result<PostModel>.Pass(new PostModel(postNumber, board, empty));
+            }
+
+            return Result<PostModel>.Pass(new PostModel(postNumber, board, flags));
+        }
+    }
+}

BantFlags/Data/ResultT.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BantFlags.Data
+{
+    public struct Result<T>
+    {
+        public bool Failed { get; private set; }
+
+        public string ErrorMessage { get; private set; }
+
+        private T _Value { get; set; }
+
+        public T Value => Failed ? throw new Exception() : _Value;
+
+        public Result(bool failed, string error, T value)
+        {
+            Failed = failed;
+            ErrorMessage = error;
+            _Value = value;
+        }
+
+        public static Result<T> Pass(T value) => new Result<T>(false, default, value);
+
+        public static Result<T> Fail(string error) => new Result<T>(true, error, default);
+    }
+}

BantFlags/Data/Staging.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using System.Linq;
 
 namespace BantFlags.Data
 {