feat: RemovingTarget event for 096

EXILED/Exiled.Events/EventArgs/Scp096/RemovingTargetEventArgs.cs

@@ -0,0 +1,59 @@
+// -----------------------------------------------------------------------
+// <copyright file="RemovingTargetEventArgs.cs" company="ExMod Team">
+// Copyright (c) ExMod Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Exiled.Events.EventArgs.Scp096
+{
+    using API.Features;
+
+    using Interfaces;
+
+    using Scp096Role = API.Features.Roles.Scp096Role;
+
+    /// <summary>
+    /// Contains all information after removing a target from SCP-096.
+    /// </summary>
+    public class RemovingTargetEventArgs : IScp096Event, IDeniableEvent
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RemovingTargetEventArgs" /> class.
+        /// </summary>
+        /// <param name="scp096">
+        /// <inheritdoc cref="Player" />
+        /// </param>
+        /// <param name="target">
+        /// <inheritdoc cref="Target" />
+        /// </param>
+        /// <param name="isAllowed">
+        /// <inheritdoc cref="IsAllowed" />
+        /// </param>
+        public RemovingTargetEventArgs(Player scp096, Player target, bool isAllowed = true)
+        {
+            Player = scp096;
+            Scp096 = scp096.Role.As<Scp096Role>();
+            Target = target;
+            IsAllowed = isAllowed;
+        }
+
+        /// <summary>
+        /// Gets the <see cref="Player" /> that is controlling SCP-096.
+        /// </summary>
+        public Player Player { get; }
+
+        /// <inheritdoc/>
+        public Scp096Role Scp096 { get; }
+
+        /// <summary>
+        /// Gets the <see cref="Player" /> being removed as a target.
+        /// </summary>
+        public Player Target { get; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether the target is allowed to be removed.
+        /// </summary>
+        public bool IsAllowed { get; set; }
+    }
+}

EXILED/Exiled.Events/Handlers/Scp096.cs

@@ -32,6 +32,11 @@ public static class Scp096
         /// </summary>
         public static Event<AddingTargetEventArgs> AddingTarget { get; set; } = new();
 
+        /// <summary>
+        /// Invoked before removing a target from SCP-096.
+        /// </summary>
+        public static Event<RemovingTargetEventArgs> RemovingTarget { get; set; } = new();
+
         /// <summary>
         /// Invoked before SCP-096 begins prying open a gate.
         /// </summary>
@@ -65,6 +70,12 @@ public static class Scp096
         /// <param name="ev">The <see cref="AddingTargetEventArgs" /> instance.</param>
         public static void OnAddingTarget(AddingTargetEventArgs ev) => AddingTarget.InvokeSafely(ev);
 
+        /// <summary>
+        /// Called before removing a target from SCP-096.
+        /// </summary>
+        /// <param name="ev">The <see cref="RemovingTargetEventArgs" /> instance.</param>
+        public static void OnRemovingTarget(RemovingTargetEventArgs ev) => RemovingTarget.InvokeSafely(ev);
+
         /// <summary>
         /// Called before SCP-096 begins prying open a gate.
         /// </summary>

EXILED/Exiled.Events/Patches/Events/Scp096/RemovingTarget.cs

@@ -0,0 +1,149 @@
+// -----------------------------------------------------------------------
+// <copyright file="RemovingTarget.cs" company="ExMod Team">
+// Copyright (c) ExMod Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Exiled.Events.Patches.Events.Scp096
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Diagnostics;
+    using System.Reflection.Emit;
+
+    using API.Features;
+    using API.Features.Pools;
+    using Exiled.Events.Attributes;
+    using Exiled.Events.EventArgs.Scp096;
+    using HarmonyLib;
+    using PlayerRoles.PlayableScps.Scp096;
+    using PlayerRoles.Subroutines;
+
+    using static HarmonyLib.AccessTools;
+
+    /// <summary>
+    /// Patches <see cref="Scp096TargetsTracker.RemoveTarget(ReferenceHub)" /> and <see cref="Scp096TargetsTracker.ClearAllTargets()" />.
+    /// Adds the <see cref="Scp096.RemovingTarget" /> event.
+    /// </summary>
+    [EventPatch(typeof(Handlers.Scp096), nameof(Handlers.Scp096.RemovingTarget))]
+    [HarmonyPatch(typeof(Scp096TargetsTracker))]
+    internal static class RemovingTarget
+    {
+        [HarmonyPatch(nameof(Scp096TargetsTracker.RemoveTarget))]
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions, ILGenerator generator)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            Label retFalseLabel = generator.DefineLabel();
+            Label runLabel = generator.DefineLabel();
+
+            // make game check contains instead of removing then forcibly running our event (so no spam event calls and is still deniable)
+            newInstructions.Find(instruction => instruction.Calls(Method(typeof(HashSet<ReferenceHub>), nameof(HashSet<ReferenceHub>.Remove)))).operand = Method(typeof(HashSet<ReferenceHub>), nameof(HashSet<ReferenceHub>.Contains));
+
+            int index = newInstructions.FindIndex(instruction => instruction.opcode == OpCodes.Ret) - 1;
+
+            newInstructions[index].WithLabels(retFalseLabel);
+
+            index -= 1;
+
+            // integrate our condition into first if statement
+            newInstructions.RemoveAt(index);
+
+            newInstructions.InsertRange(
+                index,
+                new CodeInstruction[]
+                {
+                    // integrate our condition into first if statement
+                    new(OpCodes.Brfalse, retFalseLabel),
+
+                    // Player.Get(base.Owner)
+                    new(OpCodes.Ldarg_0),
+                    new(OpCodes.Call, PropertyGetter(typeof(StandardSubroutine<Scp096Role>), nameof(StandardSubroutine<Scp096Role>.Owner))),
+                    new(OpCodes.Call, Method(typeof(Player), nameof(Player.Get), new[] { typeof(ReferenceHub) })),
+
+                    // Player.Get(target)
+                    new(OpCodes.Ldarg_1),
+                    new(OpCodes.Call, Method(typeof(Player), nameof(Player.Get), new[] { typeof(ReferenceHub) })),
+
+                    // true
+                    new(OpCodes.Ldc_I4_1),
+
+                    // RemovingTargetEventArgs ev = new(scp096, target, isAllowed)
+                    new(OpCodes.Newobj, GetDeclaredConstructors(typeof(RemovingTargetEventArgs))[0]),
+                    new(OpCodes.Dup),
+
+                    // Handlers.Scp096.OnRemovingTarget(ev)
+                    new(OpCodes.Call, Method(typeof(Handlers.Scp096), nameof(Handlers.Scp096.OnRemovingTarget))),
+
+                    // if (!ev.IsAllowed)
+                    //   return;
+                    new(OpCodes.Callvirt, PropertyGetter(typeof(RemovingTargetEventArgs), nameof(RemovingTargetEventArgs.IsAllowed))),
+                    new(OpCodes.Brtrue, runLabel),
+                });
+
+            index = newInstructions.FindIndex(instruction => instruction.opcode == OpCodes.Ret) + 1;
+
+            // if allowed, remove target
+            newInstructions.InsertRange(index, new[]
+            {
+                new CodeInstruction(OpCodes.Ldarg_0).MoveLabelsFrom(newInstructions[index]).WithLabels(runLabel),
+                new(OpCodes.Ldfld, Field(typeof(Scp096TargetsTracker), nameof(Scp096TargetsTracker.Targets))),
+                new(OpCodes.Ldarg_1),
+                new(OpCodes.Callvirt, Method(typeof(HashSet<ReferenceHub>), nameof(HashSet<ReferenceHub>.Remove))),
+                new(OpCodes.Pop),
+            });
+
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+
+        [HarmonyPatch(nameof(Scp096TargetsTracker.ClearAllTargets))]
+        [HarmonyTranspiler]
+        private static IEnumerable<CodeInstruction> Transpiler2(IEnumerable<CodeInstruction> instructions)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            object continueLabel = newInstructions.Find(instruction => instruction.opcode == OpCodes.Br_S).operand;
+
+            const int offset = 1;
+            int index = newInstructions.FindIndex(instruction => instruction.opcode == OpCodes.Stloc_1) + offset;
+
+            newInstructions.InsertRange(
+                index,
+                new[]
+                {
+                    // Player.Get(base.Owner)
+                    new CodeInstruction(OpCodes.Ldarg_0).MoveLabelsFrom(newInstructions[index]),
+                    new(OpCodes.Call, PropertyGetter(typeof(StandardSubroutine<Scp096Role>), nameof(StandardSubroutine<Scp096Role>.Owner))),
+                    new(OpCodes.Call, Method(typeof(Player), nameof(Player.Get), new[] { typeof(ReferenceHub) })),
+
+                    // Player.Get(target)
+                    new(OpCodes.Ldloc_1),
+                    new(OpCodes.Call, Method(typeof(Player), nameof(Player.Get), new[] { typeof(ReferenceHub) })),
+
+                    // true
+                    new(OpCodes.Ldc_I4_1),
+
+                    // RemovingTargetEventArgs ev = new(scp096, target, isAllowed)
+                    new(OpCodes.Newobj, GetDeclaredConstructors(typeof(RemovingTargetEventArgs))[0]),
+                    new(OpCodes.Dup),
+
+                    // Handlers.Scp096.OnRemovingTarget(ev)
+                    new(OpCodes.Call, Method(typeof(Handlers.Scp096), nameof(Handlers.Scp096.OnRemovingTarget))),
+
+                    // if (!ev.IsAllowed)
+                    //   continue;
+                    new(OpCodes.Callvirt, PropertyGetter(typeof(RemovingTargetEventArgs), nameof(RemovingTargetEventArgs.IsAllowed))),
+                    new(OpCodes.Brfalse, continueLabel),
+                });
+
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+    }
+}