Add utility AI (#806)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>
Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Content.Server/GameObjects/EntitySystems/AI/AiSystem.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Collections.Generic;
+using Content.Server.AI.Utility.AiLogic;
+using Content.Server.GameObjects.Components.Movement;
+using Content.Server.Interfaces.GameObjects.Components.Movement;
+using JetBrains.Annotations;
+using Robust.Server.AI;
+using Robust.Server.Interfaces.Console;
+using Robust.Server.Interfaces.Player;
+using Robust.Server.Interfaces.Timing;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Reflection;
+using Robust.Shared.IoC;
+using Robust.Shared.Utility;
+
+namespace Content.Server.GameObjects.EntitySystems.AI
+{
+    [UsedImplicitly]
+    internal class AiSystem : EntitySystem
+    {
+#pragma warning disable 649
+        [Dependency] private readonly IPauseManager _pauseManager;
+        [Dependency] private readonly IDynamicTypeFactory _typeFactory;
+        [Dependency] private readonly IReflectionManager _reflectionManager;
+#pragma warning restore 649
+
+        private readonly Dictionary<string, Type> _processorTypes = new Dictionary<string, Type>();
+
+        /// <inheritdoc />
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            // register entity query
+            EntityQuery = new TypeEntityQuery(typeof(AiControllerComponent));
+
+            var processors = _reflectionManager.GetAllChildren<AiLogicProcessor>();
+            foreach (var processor in processors)
+            {
+                var att = (AiLogicProcessorAttribute)Attribute.GetCustomAttribute(processor, typeof(AiLogicProcessorAttribute));
+                if (att != null)
+                {
+                    _processorTypes.Add(att.SerializeName, processor);
+                }
+            }
+        }
+
+        /// <inheritdoc />
+        public override void Update(float frameTime)
+        {
+
+            var entities = EntityManager.GetEntities(EntityQuery);
+            foreach (var entity in entities)
+            {
+                if (_pauseManager.IsEntityPaused(entity))
+                {
+                    continue;
+                }
+
+                var aiComp = entity.GetComponent<AiControllerComponent>();
+                ProcessorInitialize(aiComp);
+
+                var processor = aiComp.Processor;
+
+                processor.Update(frameTime);
+            }
+        }
+
+        /// <summary>
+        /// Will start up the controller's processor if not already done so
+        /// </summary>
+        /// <param name="controller"></param>
+        public void ProcessorInitialize(AiControllerComponent controller)
+        {
+            if (controller.Processor != null) return;
+            controller.Processor = CreateProcessor(controller.LogicName);
+            controller.Processor.SelfEntity = controller.Owner;
+            controller.Processor.VisionRadius = controller.VisionRadius;
+            controller.Processor.Setup();
+        }
+
+        private UtilityAi CreateProcessor(string name)
+        {
+            if (_processorTypes.TryGetValue(name, out var type))
+            {
+                return (UtilityAi)_typeFactory.CreateInstance(type);
+            }
+
+            // processor needs to inherit AiLogicProcessor, and needs an AiLogicProcessorAttribute to define the YAML name
+            throw new ArgumentException($"Processor type {name} could not be found.", nameof(name));
+        }
+
+        public bool ProcessorTypeExists(string name) => _processorTypes.ContainsKey(name);
+
+
+        private class AddAiCommand : IClientCommand
+        {
+            public string Command => "addai";
+            public string Description => "Add an ai component with a given processor to an entity.";
+            public string Help => "Usage: addai <processorId> <entityId>"
+                                + "\n    processorId: Class that inherits AiLogicProcessor and has an AiLogicProcessor attribute."
+                                + "\n    entityID: Uid of entity to add the AiControllerComponent to. Open its VV menu to find this.";
+
+            public void Execute(IConsoleShell shell, IPlayerSession player, string[] args)
+            {
+                if(args.Length != 2)
+                {
+                    shell.SendText(player, "Wrong number of args.");
+                    return;
+                }
+
+                var processorId = args[0];
+                var entId = new EntityUid(int.Parse(args[1]));
+                var ent = IoCManager.Resolve<IEntityManager>().GetEntity(entId);
+                var aiSystem = EntitySystem.Get<AiSystem>();
+
+                if (!aiSystem.ProcessorTypeExists(processorId))
+                {
+                    shell.SendText(player, "Invalid processor type. Processor must inherit AiLogicProcessor and have an AiLogicProcessor attribute.");
+                    return;
+                }
+                if (ent.HasComponent<AiControllerComponent>())
+                {
+                    shell.SendText(player, "Entity already has an AI component.");
+                    return;
+                }
+
+                if (ent.HasComponent<IMoverComponent>())
+                {
+                    ent.RemoveComponent<IMoverComponent>();
+                }
+
+                var comp = ent.AddComponent<AiControllerComponent>();
+                comp.LogicName = processorId;
+                shell.SendText(player, "AI component added.");
+            }
+        }
+    }
+}