using System;

namespace DefaultNamespace.BehaviorTree
{
    public class Sequence : Composite
    {
        protected int _currentIndex;
        protected Node _currentNode;

        public override void Start()
        {
            _currentIndex = 0;
            _currentNode = _currentIndex >= _nodes.Count ? null : _nodes[_currentIndex];
            _currentNode?.Start();
        }

        public override Status Update()
        {
            if (_currentNode == null) return Status.Failure;
            
            Status status = _currentNode.Update();

            switch (status)
            {
                case Status.Success:
                    _currentNode.End();
                    _currentIndex++;
                    if (_currentIndex >= _nodes.Count) return Status.Success;
                    _currentNode = _nodes[_currentIndex];
                    _currentNode.Start();
                    return Status.Running;
                case Status.Failure:
                    _currentNode.End();
                    return Status.Failure;
                case Status.Running:
                    return Status.Running;
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }
    }
}