using System;
using System.Collections.Generic;

namespace DefaultNamespace.BehaviorTree
{
    public class Sequence : Composite
    {
        private int _currentIndex;
        private Node _currentNode;
        
        public Sequence(List<Node> children) : base(children)
        {
        }

        public override Status OnStart()
        {
            if (Children.Count == 0) return Status.Failure;
            
            _currentIndex = 0;
            _currentNode = Children[_currentIndex];
            return _currentNode?.OnStart() ?? Status.Failure;
        }

        public override Status OnUpdate()
        {
            Status status = _currentNode?.OnUpdate() ?? Status.Failure;

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