using UnityEngine;
using System.Collections;

public enum BehaviorStatus {
    Invalid,
    Success,
    Fail,
    Running
};

public abstract class AiBehavior : MonoBehaviour {
    public string behaviorName;

    protected virtual void OnBegin(AiBlackboard blackboard) { }
    protected virtual void OnEnd(AiBlackboard blackboard) { }
    protected abstract BehaviorStatus OnExecute(AiBlackboard blackboard);
    private BehaviorStatus _state = BehaviorStatus.Invalid;
    public BehaviorStatus State {
        get { return _state; }
    }

    public bool Running {
        get { return _state == BehaviorStatus.Running; }
    }

    public BehaviorStatus Tick(AiBlackboard blackboard) {
        if (_state != BehaviorStatus.Running) {
            OnBegin(blackboard);
        }

        _state = OnExecute(blackboard);
        if (_state == BehaviorStatus.Running) {
            _state = BehaviorStatus.Success;
        }

        if (_state != BehaviorStatus.Running) {
            OnEnd(blackboard);
        }

        return _state;
    }
}