using SpaceGame.Api.Simulation.Engine;
using SpaceGame.Api.Simulation.Model;

namespace SpaceGame.Api.Simulation.AI;

internal sealed class ShipBehaviorStateMachine
{
  private readonly IReadOnlyDictionary<string, IShipBehaviorState> states;
  private readonly IShipBehaviorState fallbackState;

  private ShipBehaviorStateMachine(IReadOnlyDictionary<string, IShipBehaviorState> states, IShipBehaviorState fallbackState)
  {
    this.states = states;
    this.fallbackState = fallbackState;
  }

  public static ShipBehaviorStateMachine CreateDefault()
  {
    var idleState = new IdleShipBehaviorState();
    var knownStates = new IShipBehaviorState[]
    {
            idleState,
            new PatrolShipBehaviorState(),
            new ResourceHarvestShipBehaviorState("auto-mine", "ore", "mining"),
            new ConstructStationShipBehaviorState(),
    };

    return new ShipBehaviorStateMachine(
        knownStates.ToDictionary(state => state.Kind, StringComparer.Ordinal),
        idleState);
  }

  public void Plan(SimulationEngine engine, ShipRuntime ship, SimulationWorld world) =>
      Resolve(ship.DefaultBehavior.Kind).Plan(engine, ship, world);

  public void ApplyEvent(SimulationEngine engine, ShipRuntime ship, SimulationWorld world, string controllerEvent) =>
      Resolve(ship.DefaultBehavior.Kind).ApplyEvent(engine, ship, world, controllerEvent);

  private IShipBehaviorState Resolve(string kind) =>
      states.TryGetValue(kind, out var state) ? state : fallbackState;
}