NPC refactor (#10122)

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Server/NPC/HTN/PrimitiveTasks/Operators/NPCCombatOperator.cs

@@ -0,0 +1,82 @@
+using System.Threading.Tasks;
+using Content.Server.Interaction;
+using Content.Server.NPC.Systems;
+using Content.Shared.MobState;
+using Content.Shared.MobState.Components;
+using Robust.Shared.Map;
+
+namespace Content.Server.NPC.HTN.PrimitiveTasks.Operators;
+
+public abstract class NPCCombatOperator : HTNOperator
+{
+    [Dependency] protected readonly IEntityManager EntManager = default!;
+    private AiFactionTagSystem _tags = default!;
+    protected InteractionSystem Interaction = default!;
+
+    [ViewVariables, DataField("key")] public string Key = "CombatTarget";
+
+    /// <summary>
+    /// The EntityCoordinates of the specified target.
+    /// </summary>
+    [ViewVariables, DataField("keyCoordinates")]
+    public string KeyCoordinates = "CombatTargetCoordinates";
+
+    public override void Initialize(IEntitySystemManager sysManager)
+    {
+        base.Initialize(sysManager);
+        _tags = sysManager.GetEntitySystem<AiFactionTagSystem>();
+        Interaction = sysManager.GetEntitySystem<InteractionSystem>();
+    }
+
+    public override async Task<(bool Valid, Dictionary<string, object>? Effects)> Plan(NPCBlackboard blackboard)
+    {
+        var targets = GetTargets(blackboard);
+
+        if (targets.Count == 0)
+        {
+            return (false, null);
+        }
+
+        // TODO: Need some level of rng in ratings (outside of continuing to attack the same target)
+        var selectedTarget = targets[0].Entity;
+
+        var effects = new Dictionary<string, object>()
+        {
+            {Key, selectedTarget},
+            {KeyCoordinates, new EntityCoordinates(selectedTarget, Vector2.Zero)}
+        };
+
+        return (true, effects);
+    }
+
+    private List<(EntityUid Entity, float Rating)> GetTargets(NPCBlackboard blackboard)
+    {
+        var owner = blackboard.GetValue<EntityUid>(NPCBlackboard.Owner);
+        var radius = blackboard.GetValueOrDefault<float>(NPCBlackboard.VisionRadius, EntManager);
+        var targets = new List<(EntityUid Entity, float Rating)>();
+
+        blackboard.TryGetValue<EntityUid>(Key, out var existingTarget);
+        var xformQuery = EntManager.GetEntityQuery<TransformComponent>();
+        var mobQuery = EntManager.GetEntityQuery<MobStateComponent>();
+        var canMove = blackboard.GetValueOrDefault<bool>(NPCBlackboard.CanMove, EntManager);
+
+        // TODO: Need a perception system instead
+        foreach (var target in _tags
+                     .GetNearbyHostiles(owner, radius))
+        {
+            if (mobQuery.TryGetComponent(target, out var mobState) &&
+                mobState.CurrentState > DamageState.Alive)
+            {
+                continue;
+            }
+
+            targets.Add((target, GetRating(blackboard, target, existingTarget, canMove, xformQuery)));
+        }
+
+        targets.Sort((x, y) => y.Rating.CompareTo(x.Rating));
+        return targets;
+    }
+
+    protected abstract float GetRating(NPCBlackboard blackboard, EntityUid uid, EntityUid existingTarget, bool canMove,
+        EntityQuery<TransformComponent> xformQuery);
+}