using Edge.Core.Parser.BinaryParser.Util;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ShellChina_EPS_Project_CarPlatePay_EpsClient_App.MessageEntity
{
    public static class BitMapHelper
    {
        /// <summary>
        /// create 8 bytes map.
        /// </summary>
        /// <returns></returns>
        public static byte[] CreateMap()
        {
            byte[] map = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0 };
            return map;
        }

        /// <summary>
        /// create 8 bytes map with fields enabled(correlated bit set to 1)
        /// </summary>
        /// <param name="enablingFieldIndexes">1 based, means the first field's index is 1</param>
        /// <returns></returns>
        public static byte[] CreateMap(params int[] enablingFieldIndexes)
        {
            if (enablingFieldIndexes.Any(i => i < 1)) throw new ArgumentOutOfRangeException("fields' index must >=1");
            byte[] map = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0 };
            return map.Enable(enablingFieldIndexes);
        }

        public static byte[] Enable(this byte[] map, params int[] enablingFieldIndexes)
        {
            for (int i = 0; i < enablingFieldIndexes.Length; i++)
            {
                var fieldIndex = enablingFieldIndexes[i] - 1;
                var groupIndex = fieldIndex / 8;
                var groupInternalIndex = fieldIndex % 8;
                map[groupIndex] = map[groupIndex].SetBit(7 - groupInternalIndex, 7 - groupInternalIndex, 1);
            }

            return map;
        }

        public static byte[] Disable(this byte[] map, params int[] disablingFieldIndexes)
        {
            for (int i = 0; i < disablingFieldIndexes.Length; i++)
            {
                var fieldIndex = disablingFieldIndexes[i] - 1;
                var groupIndex = fieldIndex / 8;
                var groupInternalIndex = fieldIndex % 8;
                map[groupIndex] = map[groupIndex].SetBit(7 - groupInternalIndex, 7 - groupInternalIndex, 0);
            }

            return map;
        }

        /// <summary>
        /// check if target field presents in map
        /// </summary>
        /// <param name="map"></param>
        /// <param name="fieldIndex">0 based</param>
        /// <returns>true for present, otherwise, ommit</returns>
        public static bool Determine(this IList<byte> map, int fieldIndex)
        {
            var groupIndex = (fieldIndex - 1) / 8;
            var groupInternalIndex = (fieldIndex - 1) % 8;
            return map[groupIndex].GetBit(7 - groupInternalIndex) == 1;
        }

        public static List<int> Determine(this IList<byte> map)
        {
            var result = new List<int>();
            for (int i = 0; i < map.Count; i++)
            {
                for (int j = 7; j >= 0; j--)
                {
                    if (map[i].GetBit(j) == 1)
                        result.Add(i * 8 + 7 - j + 1);
                }
            }

            return result;
        }
    }
}