feat: goap ai for faction and ship

2026-03-18 00:09:39 -04:00
parent b3508d9d08
commit ad5f733b3e
14 changed files with 945 additions and 349 deletions
--- a/apps/backend/Simulation/AI/GoapCore.cs
+++ b/apps/backend/Simulation/AI/GoapCore.cs
@@ -0,0 +1,91 @@
+namespace SpaceGame.Simulation.Api.Simulation;
+
+public abstract class GoapAction<TState>
+{
+  public abstract string Name { get; }
+  public abstract float Cost { get; }
+  public abstract bool CheckPreconditions(TState state);
+  public abstract TState ApplyEffects(TState state);
+  public abstract void Execute(SimulationEngine engine, SimulationWorld world, CommanderRuntime commander);
+}
+
+public abstract class GoapGoal<TState>
+{
+  public abstract string Name { get; }
+  public abstract bool IsSatisfied(TState state);
+  public abstract float ComputePriority(TState state, SimulationWorld world, CommanderRuntime commander);
+}
+
+public sealed class GoapPlan<TState>
+{
+  public static readonly GoapPlan<TState> Empty = new() { Actions = [], TotalCost = 0f };
+
+  public required IReadOnlyList<GoapAction<TState>> Actions { get; init; }
+  public required float TotalCost { get; init; }
+  public int CurrentStep { get; set; }
+
+  public GoapAction<TState>? CurrentAction => CurrentStep < Actions.Count ? Actions[CurrentStep] : null;
+  public bool IsComplete => CurrentStep >= Actions.Count;
+  public void Advance() => CurrentStep++;
+}
+
+public sealed class GoapPlanner<TState>
+{
+  private readonly Func<TState, TState> cloneState;
+
+  public GoapPlanner(Func<TState, TState> cloneState)
+  {
+    this.cloneState = cloneState;
+  }
+
+  public GoapPlan<TState>? Plan(
+      TState initialState,
+      GoapGoal<TState> goal,
+      IReadOnlyList<GoapAction<TState>> availableActions)
+  {
+    if (goal.IsSatisfied(initialState))
+    {
+      return GoapPlan<TState>.Empty;
+    }
+
+    var openSet = new PriorityQueue<PlanNode, float>();
+    openSet.Enqueue(new PlanNode(cloneState(initialState), [], 0f), 0f);
+
+    const int MaxIterations = 256;
+    var iterations = 0;
+
+    while (openSet.Count > 0 && iterations++ < MaxIterations)
+    {
+      var current = openSet.Dequeue();
+
+      if (goal.IsSatisfied(current.State))
+      {
+        return new GoapPlan<TState>
+        {
+          Actions = current.Actions,
+          TotalCost = current.Cost,
+        };
+      }
+
+      foreach (var action in availableActions)
+      {
+        if (!action.CheckPreconditions(current.State))
+        {
+          continue;
+        }
+
+        var newState = action.ApplyEffects(cloneState(current.State));
+        var newCost = current.Cost + action.Cost;
+        var newActions = new List<GoapAction<TState>>(current.Actions) { action };
+        openSet.Enqueue(new PlanNode(newState, newActions, newCost), newCost);
+      }
+    }
+
+    return null;
+  }
+
+  private sealed record PlanNode(
+      TState State,
+      IReadOnlyList<GoapAction<TState>> Actions,
+      float Cost);
+}