using System;
using System.Collections.Generic;

namespace NBF.Setting
{
    public interface IMultiOption : IOptionBase
    {
        List<string> GetOptionNames();
        int GetIndex();
        void SetIndex(int index);
        string GetName();
    }

    public abstract class MultiOption<T> : OptionBase, IMultiOption
    {
        private int _index;

        protected OptionTable<T> OptionTable = new OptionTable<T>();
        
        /// <summary>
        /// 默认值
        /// </summary>
        protected abstract T DefaultValue { get; }

        protected override void OnLoad()
        {
            
        }

        protected void AddOption(string name, T value)
        {
            OptionTable.Add(name, value);
        }

        public List<string> GetOptionNames() => OptionTable.GetNames();

        public string GetName()
        {
            return OptionTable.GetName(_index);
        }

        public int GetIndex()
        {
            return _index;
        }

        public void SetIndex(int index)
        {
            _index = index;
        }

        protected void SelectOption(T value, int defaultIndex = 0)
        {
            SetIndex(TryGetIndex(value, out var index) ? index : defaultIndex);
        }

        protected void SelectOption(Predicate<T> predicate, int defaultIndex = 0)
        {
            SetIndex(TryGetIndex(predicate, out var index) ? index : defaultIndex);
        }

        protected bool TryGetIndex(T option, out int index)
        {
            return TryGetIndex(entry => entry.Equals(option), out index);
        }

        protected bool TryGetIndex(Predicate<T> predicate, out int index)
        {
            index = -1;

            var entries = OptionTable.GetValues();

            for (var i = 0; i < entries.Count; i++)
            {
                if (!predicate(entries[i])) continue;
                index = i;
                return true;
            }

            return false;
        }

        public T GetSelectedOption() => OptionTable.GetValue(_index);
    }
}