TriggerOnMeleeHit and more (#39826)

Co-authored-by: iaada <iaada@users.noreply.github.com>
Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>

Content.Shared/Trigger/Components/Triggers/TriggerOnMeleeHitComponent.cs

@@ -0,0 +1,25 @@
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Trigger.Components.Triggers;
+
+/// <summary>
+/// Triggers when this entity is swung as a melee weapon and hits at least one target.
+/// </summary>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
+public sealed partial class TriggerOnMeleeHitComponent : BaseTriggerOnXComponent
+{
+    /// <summary>
+    /// If true, this trigger will activate individually for each entity hit.
+    /// If false, this trigger will always activate only once.
+    /// </summary>
+    [DataField, AutoNetworkedField]
+    public bool TriggerEveryHit;
+
+    /// <summary>
+    /// If true, the "user" of the trigger is the entity hit by the melee.
+    /// If false, user is the entity which attacked with the melee weapon.
+    /// </summary>
+    /// <remarks>If TriggerEveryHit is false, the user is randomly chosen from hit entities.</remarks>
+    [DataField, AutoNetworkedField]
+    public bool TargetIsUser;
+}