Data-oriented Construction System (#2152)

- Powerful
- Data-oriented
- Approved by PJB
- Powered by node graphs and AI pathfinding
- Coded by the same nerd who brought you atmos

Co-authored-by: Exp <theexp111@gmail.com>

Content.Shared/Construction/ConstructionGraphNode.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using Content.Shared.Interfaces;
+using Robust.Shared.IoC;
+using Robust.Shared.Serialization;
+using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
+using YamlDotNet.RepresentationModel;
+using ObjectSerializer = Robust.Shared.Serialization.ObjectSerializer;
+
+namespace Content.Shared.Construction
+{
+    [Serializable]
+    public class ConstructionGraphNode
+    {
+        private List<IGraphAction> _actions = new List<IGraphAction>();
+        private List<ConstructionGraphEdge> _edges = new List<ConstructionGraphEdge>();
+
+        [ViewVariables]
+        public string Name { get; private set; }
+
+        [ViewVariables]
+        public IReadOnlyList<ConstructionGraphEdge> Edges => _edges;
+
+        [ViewVariables]
+        public IReadOnlyList<IGraphAction> Actions => _actions;
+
+        [ViewVariables]
+        public string Entity { get; private set; }
+
+        public void ExposeData(ObjectSerializer serializer)
+        {
+            var moduleManager = IoCManager.Resolve<IModuleManager>();
+
+            serializer.DataField(this, x => x.Name, "node", string.Empty);
+            serializer.DataField(this, x => x.Entity, "entity",string.Empty);
+            if (!moduleManager.IsServerModule) return;
+            serializer.DataField(ref _actions, "actions", new List<IGraphAction>());
+        }
+
+        public void LoadFrom(YamlMappingNode mapping)
+        {
+            var serializer = YamlObjectSerializer.NewReader(mapping);
+            ExposeData(serializer);
+
+            if (!mapping.TryGetNode("edges", out YamlSequenceNode edgesMapping)) return;
+
+            foreach (var yamlNode in edgesMapping)
+            {
+                var edgeMapping = (YamlMappingNode) yamlNode;
+                var edge = new ConstructionGraphEdge();
+                edge.LoadFrom(edgeMapping);
+                _edges.Add(edge);
+            }
+        }
+
+        public ConstructionGraphEdge GetEdge(string target)
+        {
+            foreach (var edge in _edges)
+            {
+                if (edge.Target == target)
+                    return edge;
+            }
+
+            return null;
+        }
+    }
+}