CommandInterpreter

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CommandInterpreter
{
    class CommandInterpreter
    {
        public static List<string> collection;

        static void Main(string[] args)
        {
            collection = Console.ReadLine().
                Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).ToList();

            string inputLine = Console.ReadLine();
            while (!inputLine.Equals("end"))
            {
                string[] commandInfo =
                    inputLine.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).ToArray();

                if (commandInfo.Length == 5)
                {
                    if ((int.Parse(commandInfo[2]) < 0 || int.Parse(commandInfo[2]) >= collection.Count) ||
                        (int.Parse(commandInfo[4]) < 0 ||
                        (int.Parse(commandInfo[2]) + int.Parse(commandInfo[4]) > collection.Count)))
                    {
                        Console.WriteLine("Invalid input parameters.");
                        inputLine = Console.ReadLine();
                        continue;
                    }

                    if (commandInfo[0] == "reverse")
                    {
                       ReverseTheCollection(commandInfo);
                    }
                    else if (commandInfo[0] == "sort")
                    {
                        SortTheCollection(commandInfo);
                    }
                }
                else
                {
                    if (int.Parse(commandInfo[1]) < 0)
                    {
                        Console.WriteLine("Invalid input parameters.");
                        inputLine = Console.ReadLine();
                        continue;
                    }

                    if (commandInfo[0] == "rollLeft")
                    {
                        RollCollectionToTheLeft(commandInfo);
                    }
                    else if (commandInfo[0] == "rollRight")
                    {
                        RollCollectionToTheRight(commandInfo);
                    }
                }

                inputLine = Console.ReadLine();
            }

            Console.WriteLine($"[{string.Join(", ", collection)}]");
        }

        private static void RollCollectionToTheRight(string[] commandInfo)
        {
            int rollTimes = int.Parse(commandInfo[1]);

            for (int currRotation = 0; currRotation < rollTimes; currRotation++)
            {
                string elementHolder = collection[collection.Count - 1];
                collection.RemoveAt(collection.Count - 1);
                collection.Insert(0, elementHolder);
            }
        }

        private static void RollCollectionToTheLeft(string[] commandInfo)
        {
            int rollTimes = int.Parse(commandInfo[1]);

            for (int currRotation = 0; currRotation < rollTimes; currRotation++)
            {
                string elementHolder = collection[0];
                collection.RemoveAt(0);
                collection.Insert(collection.Count, elementHolder);
            }
        }

        private static void SortTheCollection(string[] commandInfo)
        {
            int startPos = int.Parse(commandInfo[2]);
            int count = int.Parse(commandInfo[4]);
            int endPos = int.Parse(commandInfo[2]) + int.Parse(commandInfo[4]);

            List<string> sortedSection = new List<string>();

            for (int currElement = startPos; currElement < endPos; currElement++)
            {
                sortedSection.Add(collection[currElement]);
            }

            sortedSection = sortedSection.OrderBy(x => x).ToList();

            collection.RemoveRange(startPos, count);
            collection.InsertRange(startPos, sortedSection);
        }

        private static void ReverseTheCollection(string[] commandInfo)
        {
            int startPos = int.Parse(commandInfo[2]);
            int count = int.Parse(commandInfo[4]);
            int endPos = int.Parse(commandInfo[2]) + int.Parse(commandInfo[4]);

            List<string> reversedSection = new List<string>();

            for (int currElement = endPos - 1; currElement >= startPos; currElement--)
            {
                reversedSection.Add(collection[currElement]);
            }

            collection.RemoveRange(startPos, count);
            collection.InsertRange(startPos, reversedSection);
        }
    }
}