using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        for (int i = 0; i < 500; ++i) {

            string list = String.Join(",", _indexes);

            Console.WriteLine(string.Format("After {0}: Match = {1}, Current = {2}, Array = {3}", i, MatchColorIndex, CurrentColorIndex, list));

​

            GetRandomCabinetLightDataIndex();

        }

    }

​

    public static int MatchColorIndex = -1;

    public static int CurrentColorIndex = -1;

    static readonly List<int> _indexes = new List<int>() { 0, 1, 2, 3, 4, 5, 6, };

    static readonly Random _nativeRandom = new Random();

​

    public static int GetRandomCabinetLightDataIndex()

    {

        int currentOdds = 10;

​

        // Check if RNG has chosen an index

        if (MatchColorIndex >= 0 && MatchColorIndex != CurrentColorIndex) {

            int randomNumber = _nativeRandom.Next(1, 100 + 1);

​

            if (randomNumber <= currentOdds) {

                UpdateOdds(MatchColorIndex);

                return MatchColorIndex;

            }

        }

​

        int index;

​

        // If the colour hasn't been selected, and this is the first colour to choose, choose anything

        if (CurrentColorIndex == -1 && MatchColorIndex == -1) {

            index = _nativeRandom.Next(0, _indexes.Count);

        } else if (MatchColorIndex == -1 || MatchColorIndex == CurrentColorIndex) {

            // We never want to show the same colour twice in a row, so move CurrentColorIndex to the end of the list.

            MoveIndex(CurrentColorIndex, _indexes.Count - 1);

​

            // Exclude the last element

            index = _nativeRandom.Next(0, _indexes.Count - 1);

​

            // Return the CurrentColorIndex to its original position

            MoveIndex(CurrentColorIndex, CurrentColorIndex);

        } else {

            // We never want to show the same colour twice in a row, and RNG has told us not to use MatchColorIndex

            MoveIndex(CurrentColorIndex, _indexes.Count - 1);

            MoveIndex(MatchColorIndex, _indexes.Count - 2);

​

            // Exclude the last two elements

            index = _nativeRandom.Next(0, _indexes.Count - 2);

​

            MoveIndex(MatchColorIndex, MatchColorIndex);

            MoveIndex(CurrentColorIndex, CurrentColorIndex);

        }

​

        UpdateOdds(index);

        return index;

    }

​

    static void MoveIndex(int indexToMove, int positionToMoveTo)

    {

        int indexOfIndex = _indexes.IndexOf(indexToMove);

​

        int valueAtPosition = _indexes[positionToMoveTo];

        _indexes[positionToMoveTo] = indexToMove;

        _indexes[indexOfIndex] = valueAtPosition;

    }

​

    static void UpdateOdds(int index)

    {

        CurrentColorIndex = index;

        if (MatchColorIndex == -1) {

            MatchColorIndex = CurrentColorIndex;    

        }

    }

}