ECS vapors (#4308)

* ECS vapors

* tweak

* Reviews

* man my git must be laggin is yours laggin

Content.Server/Chemistry/EntitySystems/VaporSystem.cs

@@ -1,17 +1,122 @@
-using Content.Server.Chemistry.Components;
+using System.Linq;
+using Content.Server.Chemistry.Components;
+using Content.Shared.Chemistry.Reagent;
+using Content.Shared.Chemistry.Solution;
+using Content.Shared.Physics;
 using JetBrains.Annotations;
 using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+using Robust.Shared.Physics.Dynamics;
+using Robust.Shared.Prototypes;
 
 namespace Content.Server.Chemistry.EntitySystems
 {
     [UsedImplicitly]
-    public class VaporSystem : EntitySystem
+    internal sealed class VaporSystem : EntitySystem
     {
+        [Dependency] private readonly IMapManager _mapManager = default!;
+        [Dependency] private readonly IPrototypeManager _protoManager = default!;
+
+        private const float ReactTime = 0.125f;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            SubscribeLocalEvent<VaporComponent, StartCollideEvent>(HandleCollide);
+        }
+
+        private void HandleCollide(EntityUid uid, VaporComponent component, StartCollideEvent args)
+        {
+            if (!ComponentManager.TryGetComponent(uid, out SolutionContainerComponent? contents)) return;
+
+            contents.Solution.DoEntityReaction(args.OtherFixture.Body.Owner, ReactionMethod.Touch);
+
+            // Check for collision with a impassable object (e.g. wall) and stop
+            if ((args.OtherFixture.CollisionLayer & (int) CollisionGroup.Impassable) != 0 && args.OtherFixture.Hard)
+            {
+               EntityManager.QueueDeleteEntity(uid);
+            }
+        }
+
+        public void Start(VaporComponent vapor, Vector2 dir, float speed, EntityCoordinates target, float aliveTime)
+        {
+            vapor.Active = true;
+            vapor.Target = target;
+            vapor.AliveTime = aliveTime;
+            // Set Move
+            if (vapor.Owner.TryGetComponent(out PhysicsComponent? physics))
+            {
+                physics.BodyStatus = BodyStatus.InAir;
+                physics.ApplyLinearImpulse(dir * speed);
+            }
+        }
+
+        internal bool TryAddSolution(VaporComponent vapor, Solution solution)
+        {
+            if (solution.TotalVolume == 0)
+            {
+                return false;
+            }
+
+            if (!vapor.Owner.TryGetComponent(out SolutionContainerComponent? contents))
+            {
+                return false;
+            }
+
+            var result = contents.TryAddSolution(solution);
+
+            if (!result)
+            {
+                return false;
+            }
+
+            return true;
+        }
+
         public override void Update(float frameTime)
         {
-            foreach (var vaporComp in ComponentManager.EntityQuery<VaporComponent>(true))
+            foreach (var (vaporComp, solution) in ComponentManager.EntityQuery<VaporComponent, SolutionContainerComponent>(true))
             {
-                vaporComp.Update(frameTime);
+                Update(frameTime, vaporComp, solution);
+            }
+        }
+
+        private void Update(float frameTime, VaporComponent vapor, SolutionContainerComponent contents)
+        {
+            if (!vapor.Active)
+                return;
+
+            var entity = vapor.Owner;
+
+            vapor.Timer += frameTime;
+            vapor.ReactTimer += frameTime;
+
+            if (vapor.ReactTimer >= ReactTime && vapor.Owner.Transform.GridID.IsValid())
+            {
+                vapor.ReactTimer = 0;
+                var mapGrid = _mapManager.GetGrid(entity.Transform.GridID);
+
+                var tile = mapGrid.GetTileRef(entity.Transform.Coordinates.ToVector2i(EntityManager, _mapManager));
+                foreach (var reagentQuantity in contents.ReagentList.ToArray())
+                {
+                    if (reagentQuantity.Quantity == ReagentUnit.Zero) continue;
+                    var reagent = _protoManager.Index<ReagentPrototype>(reagentQuantity.ReagentId);
+                    contents.TryRemoveReagent(reagentQuantity.ReagentId, reagent.ReactionTile(tile, (reagentQuantity.Quantity / vapor.TransferAmount) * 0.25f));
+                }
+            }
+
+            // Check if we've reached our target.
+            if(!vapor.Reached && vapor.Target.TryDistance(EntityManager, entity.Transform.Coordinates, out var distance) && distance <= 0.5f)
+            {
+                vapor.Reached = true;
+            }
+
+            if (contents.CurrentVolume == 0 || vapor.Timer > vapor.AliveTime)
+            {
+                // Delete this
+                entity.QueueDelete();
             }
         }
     }