From 461b3b3c20ca716440baee05aa7a14fe5b7eac37 Mon Sep 17 00:00:00 2001
From: maxime <maximebatista18@gmail.com>
Date: Wed, 6 Mar 2024 23:04:35 +0100
Subject: [PATCH] fix concurrency issue when adding a new step to the same
 tactic

---
 DbServices/DbTacticService.cs | 37 ++++++++++++++++++++++-------------
 WebAPI.sln                    |  4 ++++
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/DbServices/DbTacticService.cs b/DbServices/DbTacticService.cs
index 72910e9..42d70e1 100644
--- a/DbServices/DbTacticService.cs
+++ b/DbServices/DbTacticService.cs
@@ -9,6 +9,7 @@ namespace DbServices;
 
 public class DbTacticService(AppContext.AppContext context) : ITacticService
 {
+
     public Task<IEnumerable<Tactic>> ListTacticsOf(int userId)
     {
         return Task.FromResult(
@@ -111,25 +112,33 @@ public class DbTacticService(AppContext.AppContext context) : ITacticService
 
     public async Task<int?> AddTacticStep(int tacticId, int parentStepId, string initialJson)
     {
-        if (!context.Tactics.Any(t => t.Id == tacticId))
+
+        var tactic = await context.Tactics.FirstOrDefaultAsync(t => t.Id == tacticId);
+        if (tactic == null)
         {
             return null;
         }
 
-        var nextStepId = context.TacticSteps
-            .Where(s => s.TacticId == tacticId)
-            .Max(s => s.StepId) + 1;
-
-        var entity = new TacticStepEntity
+        TacticStepEntity entity;
+        int nextStepId;
+        lock (tactic)
         {
-            JsonContent = initialJson,
-            ParentId = parentStepId,
-            TacticId = tacticId,
-            StepId = nextStepId
-        };
-    
-        await context.AddAsync(entity);
-        await context.SaveChangesAsync();
+            nextStepId = context.TacticSteps
+                .Where(s => s.TacticId == tacticId)
+                .Max(s => s.StepId) + 1;
+
+            entity = new TacticStepEntity
+            {
+                JsonContent = initialJson,
+                ParentId = parentStepId,
+                TacticId = tacticId,
+                StepId = nextStepId
+            };
+
+            context.Add(entity);
+            context.SaveChanges();
+        }
+
 
         return entity.StepId;
     }
diff --git a/WebAPI.sln b/WebAPI.sln
index 4cb00ad..0e5f8c6 100644
--- a/WebAPI.sln
+++ b/WebAPI.sln
@@ -54,5 +54,9 @@ Global
 		{465819A9-7158-4612-AC57-ED2C7A0F243E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{465819A9-7158-4612-AC57-ED2C7A0F243E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{465819A9-7158-4612-AC57-ED2C7A0F243E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9C5EAD2F-FA50-43C2-BB86-1065ED661C52}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9C5EAD2F-FA50-43C2-BB86-1065ED661C52}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9C5EAD2F-FA50-43C2-BB86-1065ED661C52}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9C5EAD2F-FA50-43C2-BB86-1065ED661C52}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal