From 0e0daae17288897ef778a75485048589d8e1e872 Mon Sep 17 00:00:00 2001
From: Rutherther <fandabohacek@gmail.com>
Date: Sat, 19 Feb 2022 13:50:38 +0100
Subject: [PATCH] fix(combat): make skill cancellation tokens actions async

---
 .../CombatManager.cs                          | 75 +++++++++++++------
 .../Operations/UseSkillOperation.cs           | 16 +++-
 .../Responders/CancelResponder.cs             |  2 +-
 .../Responders/SuResponder.cs                 |  2 +-
 4 files changed, 67 insertions(+), 28 deletions(-)

diff --git a/Extensions/NosSmooth.Extensions.Combat/CombatManager.cs b/Extensions/NosSmooth.Extensions.Combat/CombatManager.cs
index d59cd8a7a6789aa10fb0c9cf95a80e172105577f..173e92be86bc3e90124e46a42cf7a5c1376743ae 100644
--- a/Extensions/NosSmooth.Extensions.Combat/CombatManager.cs
+++ b/Extensions/NosSmooth.Extensions.Combat/CombatManager.cs
@@ -20,7 +20,7 @@ namespace NosSmooth.Extensions.Combat;
 public class CombatManager : IStatefulEntity
 {
     private readonly List<CancellationTokenSource> _tokenSource;
-    private readonly Semaphore _semaphore;
+    private readonly SemaphoreSlim _semaphore;
     private readonly INostaleClient _client;
     private readonly Game.Game _game;
 
@@ -31,7 +31,7 @@ public class CombatManager : IStatefulEntity
     /// <param name="game">The game.</param>
     public CombatManager(INostaleClient client, Game.Game game)
     {
-        _semaphore = new Semaphore(1, 1);
+        _semaphore = new SemaphoreSlim(1, 1);
         _tokenSource = new List<CancellationTokenSource>();
         _client = client;
         _game = game;
@@ -136,43 +136,74 @@ public class CombatManager : IStatefulEntity
     /// Register the given cancellation token source to be cancelled on skill use/cancel.
     /// </summary>
     /// <param name="tokenSource">The token source to register.</param>
-    public void RegisterSkillCancellationToken(CancellationTokenSource tokenSource)
+    /// <param name="ct">The cancellation token for cancelling the operation.</param>
+    /// <returns>A task.</returns>
+    public async Task RegisterSkillCancellationTokenAsync(CancellationTokenSource tokenSource, CancellationToken ct)
     {
-        _semaphore.WaitOne();
-        _tokenSource.Add(tokenSource);
-        _semaphore.Release();
+        await _semaphore.WaitAsync(ct);
+        try
+        {
+            _tokenSource.Add(tokenSource);
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
     }
 
     /// <summary>
     /// Unregister the given cancellation token registered using <see cref="RegisterSkillCancellationToken"/>.
     /// </summary>
     /// <param name="tokenSource">The token source to unregister.</param>
-    public void UnregisterSkillCancellationToken(CancellationTokenSource tokenSource)
+    /// <param name="ct">The cancellation token for cancelling the operation.</param>
+    /// <returns>A task.</returns>
+    public async Task UnregisterSkillCancellationTokenAsync(CancellationTokenSource tokenSource, CancellationToken ct)
     {
-        _semaphore.WaitOne();
-        _tokenSource.Remove(tokenSource);
-        _semaphore.Release();
+        if (_cancelling)
+        {
+            return;
+        }
+
+        await _semaphore.WaitAsync(ct);
+        try
+        {
+            _tokenSource.Remove(tokenSource);
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
     }
 
     /// <summary>
     /// Cancel all of the skill tokens.
     /// </summary>
-    internal void CancelSkillTokens()
+    /// <param name="ct">The cancellation token for cancelling the operation.</param>
+    /// <returns>A task.</returns>
+    internal async Task CancelSkillTokensAsync(CancellationToken ct)
     {
-        _semaphore.WaitOne();
-        foreach (var tokenSource in _tokenSource)
+        await _semaphore.WaitAsync(ct);
+        _cancelling = true;
+        try
         {
-            try
-            {
-                tokenSource.Cancel();
-            }
-            catch
+            foreach (var tokenSource in _tokenSource)
             {
-                // ignored
+                try
+                {
+                    tokenSource.Cancel();
+                }
+                catch
+                {
+                    // ignored
+                }
             }
-        }
 
-        _tokenSource.Clear();
-        _semaphore.Release();
+            _tokenSource.Clear();
+        }
+        finally
+        {
+            _cancelling = false;
+            _semaphore.Release();
+        }
     }
 }
\ No newline at end of file
diff --git a/Extensions/NosSmooth.Extensions.Combat/Operations/UseSkillOperation.cs b/Extensions/NosSmooth.Extensions.Combat/Operations/UseSkillOperation.cs
index cec4553caf58eaa4e8bfbcac027351cf38374d8e..ff571a6639738ebec6e802f380ae6ae205ac021f 100644
--- a/Extensions/NosSmooth.Extensions.Combat/Operations/UseSkillOperation.cs
+++ b/Extensions/NosSmooth.Extensions.Combat/Operations/UseSkillOperation.cs
@@ -49,6 +49,8 @@ public record UseSkillOperation(Skill Skill, ILivingEntity Target) : ICombatOper
         }
 
         // TODO: support for area skills, support skills that use x, y coordinates (like dashes or teleports)
+        var linkedSource = CancellationTokenSource.CreateLinkedTokenSource(ct);
+        await combatState.CombatManager.RegisterSkillCancellationTokenAsync(linkedSource, ct);
         var sendResponse = await combatState.Client.SendPacketAsync
         (
             new UseSkillPacket
@@ -64,13 +66,19 @@ public record UseSkillOperation(Skill Skill, ILivingEntity Target) : ICombatOper
 
         if (!sendResponse.IsSuccess)
         {
+            await combatState.CombatManager.UnregisterSkillCancellationTokenAsync(linkedSource, ct);
             return sendResponse;
         }
 
-        var linkedSource = CancellationTokenSource.CreateLinkedTokenSource(ct);
-        combatState.CombatManager.RegisterSkillCancellationToken(linkedSource);
-        await Task.Delay(Skill.Info.CastTime * 200 * 5, linkedSource.Token);
-        combatState.CombatManager.UnregisterSkillCancellationToken(linkedSource);
+        try
+        {
+            await Task.Delay(Skill.Info.CastTime * 200 * 5, linkedSource.Token);
+        }
+        catch (TaskCanceledException)
+        {
+            // ignored
+        }
+        await combatState.CombatManager.UnregisterSkillCancellationTokenAsync(linkedSource, ct);
 
         return Result.FromSuccess();
     }
diff --git a/Extensions/NosSmooth.Extensions.Combat/Responders/CancelResponder.cs b/Extensions/NosSmooth.Extensions.Combat/Responders/CancelResponder.cs
index 33a85bd3572aa476f5d02ed9e02f2117b9a62f23..582a58d4f22bf973a7949482ecc6531d0ef97823 100644
--- a/Extensions/NosSmooth.Extensions.Combat/Responders/CancelResponder.cs
+++ b/Extensions/NosSmooth.Extensions.Combat/Responders/CancelResponder.cs
@@ -29,7 +29,7 @@ public class CancelResponder : IPacketResponder<CancelPacket>
     /// <inheritdoc />
     public Task<Result> Respond(PacketEventArgs<CancelPacket> packetArgs, CancellationToken ct = default)
     {
-        _combatManager.CancelSkillTokens();
+        _combatManager.CancelSkillTokensAsync(ct);
         return Task.FromResult(Result.FromSuccess());
     }
 }
\ No newline at end of file
diff --git a/Extensions/NosSmooth.Extensions.Combat/Responders/SuResponder.cs b/Extensions/NosSmooth.Extensions.Combat/Responders/SuResponder.cs
index 05190aa9c25c5e5bc7c436145073354534b35521..933d0b9f6955a282e8594b329f6caefe2c44b1d1 100644
--- a/Extensions/NosSmooth.Extensions.Combat/Responders/SuResponder.cs
+++ b/Extensions/NosSmooth.Extensions.Combat/Responders/SuResponder.cs
@@ -29,7 +29,7 @@ public class SuResponder : IPacketResponder<SuPacket>
     /// <inheritdoc />
     public Task<Result> Respond(PacketEventArgs<SuPacket> packetArgs, CancellationToken ct = default)
     {
-        _combatManager.CancelSkillTokens();
+        _combatManager.CancelSkillTokensAsync(ct);
         return Task.FromResult(Result.FromSuccess());
     }
 }
\ No newline at end of file