using System;
using System.Collections.Generic;

namespace AnP.Utils{
    public class Options{
        
        public const int OVERWRITING = 0;
        public static readonly int OVERWRITE = 1 * (int)Math.Pow(3, OVERWRITING);
        public static readonly int NO_OVERWRITE = 2 * (int)Math.Pow(3, OVERWRITING);

        public const int NULLISH = 1;
        public static readonly int ALLOW_NULLS = 1 * (int)Math.Pow(3, NULLISH);
        public static readonly int NO_NULLS = 2 * (int)Math.Pow(3, NULLISH);

        public static readonly Options DEFAULT = new Options(NO_OVERWRITE + ALLOW_NULLS);

        public static bool? get(int value, int option){

            int ternary = value / (int)Math.Pow(3, option) % 3;

            return (
                ternary == 1 ? true : 
                ternary == 2 ? false : 
            null);
        }

        public bool? overwrite = null;
        public bool? allow_null = null;

        public Options(int value = 0, Options? _default = null){
            
            if(_default == null)
                _default = DEFAULT;

            overwrite = get(value, OVERWRITING) ?? _default?.overwrite;
            allow_null = get(value, NULLISH) ?? _default?.allow_null;

        }

        public int get(){

            int code = 0;

            foreach(KeyValuePair<int, bool?> pair in new Dictionary<int, bool?>{
                {OVERWRITING, overwrite},
                {NULLISH, allow_null}
            })
                code += (
                    pair.Value == true ? 1 : 
                    pair.Value == false ? 2 : 
                0) * (int)Math.Pow(3, pair.Key);
            
            return code;
        }
        
    }
}