#if HAVE_NODECANVAS

using System;

using UnityEngine;

using ParadoxNotion.Design;
using NodeCanvas.Framework;

namespace Framework.Dialogue {

  /// <summary>Clears the dialogue choice index stored on blackboard</summary>
  [Category("Dialogue")]
  [Icon("Dialogue")]
  [Description("Clear dialogue choice index stored on blackboard")]
  public class ClearChoiceTask : ActionTask {

    /// <summary>Provides a summary description of what this action does</summary>
    protected override string info {
      get { return "Clear stored dialogue choice"; }
    }

    /// <summary>Called once when the action is executed</summary>
    protected override void OnExecute() {
      removeChoiceIndexOnBlackboard();
      EndAction();
    }

    /// <summary>Removes the index of the selected dialogue choice from the blackboard</summary>
    private void removeChoiceIndexOnBlackboard() {
      const string ChoiceIndexVariableName = "DialogueChoiceIndex";

      IBlackboard choiceBlackboard = ownerBlackboard;
      if(choiceBlackboard == null) {
        Debug.LogError(
          "DialogueChoiceCondition could not find a blackboard in its state machine. " +
          "A blackboard is required to store the choices made by the player. " +
          "Conditions on multiple choice dialogue will not work."
        );
        return;
      }

      // If it's null, we'll already have complaine in OnInit()!
      Variable choiceIndexVariable = choiceBlackboard.GetVariable(
        ChoiceIndexVariableName, typeof(int)
      );
      if(choiceIndexVariable != null) {
        choiceBlackboard.RemoveVariable(ChoiceIndexVariableName);
      }
    }

  }

} // namespace Framework.Dialogue

#endif // HAVE_NODECANVAS