module relations and module staging

Assets/Engine/Runtime/Modules/Module.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using EscapeRoomEngine.Engine.Runtime.Requirements;
 using EscapeRoomEngine.Engine.Runtime.Utilities;
 using UnityEngine;
 using Logger = EscapeRoomEngine.Engine.Runtime.Utilities.Logger;
@@ -21,6 +22,9 @@ namespace EscapeRoomEngine.Engine.Runtime.Modules
             Orientation.North, Orientation.East, Orientation.South, Orientation.West
         });
 
+        public readonly List<Module> relatedModules = new();
+
+        public ModuleState State { get; private set; }
         /// <summary>
         /// Get the space relative (<i>SR</i>) position of this module.
         /// </summary>
@@ -29,7 +33,6 @@ namespace EscapeRoomEngine.Engine.Runtime.Modules
         /// Get the room relative (<i>RR</i>) position of this module.
         /// </summary>
         internal Vector2Int RrPosition => space.ToRoomRelative(SrPosition);
-        internal ModuleState State { get; private set; }
 
         internal readonly ModuleDescription description;
         internal Orientation orientation;
@@ -52,6 +55,13 @@ namespace EscapeRoomEngine.Engine.Runtime.Modules
             return description.types.Contains(type);
         }
 
+        internal bool CheckRequirements()
+        {
+            return PreconditionRequirement.CheckPreconditions(this, space) &&
+                   PlacementRequirement.TryPlacing(this, space) &&
+                   OrientationRequirement.TryOrienting(this, space);
+        }
+
         /// <summary>
         /// Place this module with a position relative to the room.
         /// </summary>

Assets/Engine/Runtime/Requirements/NoOverlap.cs

@@ -16,7 +16,7 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
         {
             var candidates = space.rrDimensions.EveryPosition;
             
-            space.Modules.ForEach(m =>
+            space.AllModules.ForEach(m =>
             {
                 candidates.Remove(m.SrPosition);
                 m.description.placementRequirements

Assets/Engine/Runtime/Requirements/OrientationRequirement.cs

@@ -32,7 +32,7 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
             // ReSharper disable once RedundantIfElseBlock
             else
             {
-                Logger.Log("Could not find suitable orientation for module", LogType.ModulePlacement);
+                Logger.Log("Could not find suitable orientation for module", LogType.RequirementResolution);
                 return false;
             }
         }

Assets/Engine/Runtime/Requirements/PlacementRequirement.cs

@@ -35,7 +35,7 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
             // ReSharper disable once RedundantIfElseBlock
             else
             {
-                Logger.Log($"Could not find suitable placement for {module}", LogType.ModulePlacement);
+                Logger.Log($"Could not find suitable placement for {module}", LogType.RequirementResolution);
                 return false;
             }
         }

Assets/Engine/Runtime/Requirements/PreconditionRequirement.cs

@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using EscapeRoomEngine.Engine.Runtime.Modules;
-using UnityEngine;
 using Logger = EscapeRoomEngine.Engine.Runtime.Utilities.Logger;
 using LogType = EscapeRoomEngine.Engine.Runtime.Utilities.LogType;
 
@@ -14,7 +13,6 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
 
         public static bool CheckPreconditions(Module module, Space space)
         {
-            Debug.Log($"{module}, {module.description.preconditionRequirements}");
             if (module.description.preconditionRequirements.Count == 0)
             {
                 // don't evaluate requirements if there are none
@@ -31,7 +29,7 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
                 preconditionsMet
                     ? $"Preconditions for {module} satisfied"
                     : $"Could not satisfy preconditions for {module}",
-                LogType.ModulePlacement);
+                LogType.RequirementResolution);
 
             return preconditionsMet;
         }

Assets/Engine/Runtime/Requirements/RelatedModule.cs

@@ -14,7 +14,10 @@ namespace EscapeRoomEngine.Engine.Runtime.Requirements
         
         protected override IEnumerable<bool> GenerateCandidates(Module module, Space space)
         {
-            return new []{ space.AddModuleWithRequirements(Module.CreateModuleByType(space, relatedModule)) };
+            var newModule = Module.CreateModuleByType(space, relatedModule);
+            module.relatedModules.Add(newModule);
+            
+            return new []{ space.StageModuleWithRequirements(newModule) };
         }
     }
 }

Assets/Engine/Runtime/Space.cs

@@ -15,10 +15,30 @@ namespace EscapeRoomEngine.Engine.Runtime
         /// The room relative (<i>RR</i>) dimensions of this space.
         /// </summary>
         internal readonly Dimensions rrDimensions;
-        internal List<Module> Modules { get; } = new(2);
         internal readonly Room room;
         
+        /// <summary>
+        /// A list of all modules.
+        /// </summary>
+        internal List<Module> Modules { get; } = new(2);
+        /// <summary>
+        /// A list of all staged and added modules.
+        /// </summary>
+        internal List<Module> AllModules
+        {
+            get
+            {
+                var modules = new List<Module>(Modules);
+                if (_stagedModules.Count > 0)
+                {
+                    modules.AddRange(_stagedModules);
+                }
+                return modules;
+            }
+        }
+        
         private GameObject _spaceObject, _spaceTiles;
+        private List<Module> _stagedModules = new();
 
         internal Space(Room room, Passage entrance)
         {
@@ -31,24 +51,41 @@ namespace EscapeRoomEngine.Engine.Runtime
             // connect the space to its passage
             entrance.ConnectTo(new DoorModule(this,
                 ((DoorModuleDescription)entrance.fromOut.description).connectedDoorDescription));
-            AddModule(entrance.toIn);
+            Modules.Add(entrance.toIn);
-        }
-
-        internal void AddModule(Module module)
-        {
-            Modules.Add(module);
         }
 
         internal bool AddModuleWithRequirements(Module module)
         {
-            var requirementsFulfilled =
+            var requirementsFulfilled = module.CheckRequirements();
-                PreconditionRequirement.CheckPreconditions(module, this) &&
-                PlacementRequirement.TryPlacing(module, this) &&
-                OrientationRequirement.TryOrienting(module, this);
-
             if (requirementsFulfilled)
             {
-                AddModule(module);
+                // add all previously staged modules first ...
+                for (var i = _stagedModules.Count - 1; i >= 0; i--)
+                {
+                    Modules.Add(_stagedModules[i]);
+                }
+                
+                // ... and then add the module itself
+                Modules.Add(module);
+            }
+            
+            // always clear the staged modules. if a module isn't added, its corresponding staged modules should be discarded
+            _stagedModules = new List<Module>();
+
+            return requirementsFulfilled;
+        }
+
+        /// <summary>
+        /// Stage a module if its requirements are currently met. It will be added as soon as the next module is added by <see cref="AddModuleWithRequirements"/>.
+        /// </summary>
+        /// <param name="module">The module to stage</param>
+        /// <returns>Whether the requirements were met and the module was staged</returns>
+        internal bool StageModuleWithRequirements(Module module)
+        {
+            var requirementsFulfilled = module.CheckRequirements();
+            if (requirementsFulfilled)
+            {
+                _stagedModules.Add(module);
             }
 
             return requirementsFulfilled;