using System;
using System.Collections.Generic;

namespace BehaviorTree
{
    public class Selector : Composite
    {
        private int _currentIndex;
        private Node _currentNode;

        public Selector(List<Node> _nodes)
        {
            nodes = _nodes;
        }

        public override Status Start()
        {
            if (nodes == null || nodes.Count == 0)
            {
                return Status.Failure;
            }
            
            _currentIndex = 0;
            _currentNode = nodes[_currentIndex];
            _currentNode.Start();
            
            return Status.Running;
        }
        
        public override Status Update()
        {
            Status status = _currentNode?.Update() ?? Status.Failure;

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