Array Manipulator

using System;
using System.Linq;

namespace Array_Manipulator_Second_Try
{
    class Program
    {
        static void Main()
        {
            int[] initialArray = Console.ReadLine()
                .Split()
                .Select(int.Parse)
                .ToArray();

            string[] commands = Console.ReadLine().Split().ToArray();

            while (commands[0] != "end")
            {
                switch (commands[0])
                {
                    case "exchange":
                        {
                            int indexForSwitch = int.Parse(commands[1]);
                            if (indexForSwitch >= initialArray.Length || indexForSwitch < 0)
                                Console.WriteLine("Invalid index");

                            else
                            {
                                initialArray = ExchangePositions(initialArray, indexForSwitch);
                            }
                            //Console.WriteLine(string.Join(' ', initialArray));

                            break;
                        }
                    case "min":
                        {
                            int minIndex = PrintMinIndex(initialArray, commands[1]);

                            if (minIndex == -1)
                            {
                                Console.WriteLine("No matches");
                            }

                            else
                            {
                                Console.WriteLine(minIndex);
                            }

                            break;
                        }
                    case "max":
                        {
                            int maxIndex = PrintMaxIndex(initialArray, commands[1]);

                            if (maxIndex == -1)
                            {
                                Console.WriteLine("No matches");
                            }

                            else
                            {
                                Console.WriteLine(maxIndex);
                            }

                            break;
                        }
                    case "first":
                        {
                            int count = int.Parse(commands[1]);
                            if (count <= 0 || count > initialArray.Length)
                            {
                                Console.WriteLine("Invalid count");
                            }

                            else
                            {
                                string elements = PrintFirstElements(initialArray, count, commands[2]);
                                if(elements != "")
                                {
                                    int[] firstElements = elements
                                        .Split()
                                        .Select(int.Parse)
                                        .ToArray();

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

                            break;
                        }
                    case "last":
                        {
                            int count = int.Parse(commands[1]);
                            if (count <= 0 || count > initialArray.Length)
                            {
                                Console.WriteLine("Invalid count");
                            }

                            else
                            {
                                string elements = PrintLastElements(initialArray, count, commands[2]);
                                if (elements != "")
                                {
                                    int[] lastElements = elements
                                        .Split()
                                        .Select(int.Parse)
                                        .ToArray();

                                    Array.Reverse(lastElements);

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

                            break;
                        }
                }

                commands = Console.ReadLine().Split().ToArray();
            }

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

        static bool isEven(int number)
        {
            return number % 2 == 0;
        }

        static int[] ExchangePositions(int[] array, int index)
        {
            //skip the numbers from certain index, since array counts from 0, add 1 to the index
            var newEnd = array.Skip(index + 1).ToArray();

            //take the numbers from certain index
            var arrBegin = array.Take(array.Length - newEnd.Length).ToArray();

            newEnd.CopyTo(array, 0);
            arrBegin.CopyTo(array, newEnd.Length);

            return array;
        }

        static int PrintMaxIndex(int[] array, string command)
        {
            int maxIndex = -1;
            int maxValue = int.MinValue;

            if (command == "even")
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (isEven(array[i]))
                        if (maxValue <= array[i])
                        {
                            maxValue = array[i];
                            maxIndex = i;
                        }
                }
            }

            else if (command == "odd")
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (!isEven(array[i]))
                        if (maxValue <= array[i])
                        {
                            maxValue = array[i];
                            maxIndex = i;
                        }
                }
            }

            return maxIndex;
        }

        static int PrintMinIndex(int[] array, string command)
        {
            int minIndex = -1;
            int minValue = int.MaxValue;

            if (command == "even")
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (isEven(array[i]))
                        if (minValue >= array[i])
                        {
                            minValue = array[i];
                            minIndex = i;
                        }
                }
            }

            else if (command == "odd")
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (!isEven(array[i]))
                        if (minValue >= array[i])
                        {
                            minValue = array[i];
                            minIndex = i;
                        }
                }
            }

            return minIndex;

        }

        static string PrintFirstElements(int[] array, int count, string command)
        {
            string elements = "";

            if (command == "even" && EvenOddExists(array, command))
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (isEven(array[i]))
                    {
                        elements += $"{array[i]} ";
                        count--;
                    }
                    if (count == 0)
                        break;
                }
            }

            else if (command == "even" && !EvenOddExists(array, command))
                Console.WriteLine("[]");

            else if (command == "odd" && EvenOddExists(array, command))
            {
                for (int i = 0; i < array.Length; i++)
                {
                    if (!isEven(array[i]))
                    {
                        elements += $"{array[i]} ";
                        count--;
                    }
                    if (count == 0)
                        break;
                }
            }

            else if (command == "odd" && !EvenOddExists(array, command))
                Console.WriteLine("[]");

            return elements.TrimEnd();
        }

        static string PrintLastElements(int[] array, int count, string command)
        {
            //Array.Reverse(array);
            string elements = "";

            if (command == "even" && EvenOddExists(array, command))
            {
                for (int i = array.Length-1; i >=0; i--)
                {
                    if (isEven(array[i]))
                    {
                        elements += $"{array[i]} ";
                        count--;
                    }
                    if (count == 0)
                        break;
                }
            }

            else if (command == "even" && !EvenOddExists(array, command))
                Console.WriteLine("[]");

            else if (command == "odd" && EvenOddExists(array, command))
            {
                for (int i = array.Length - 1; i >= 0; i--)
                {
                    if (!isEven(array[i]))
                    {
                        elements += $"{array[i]} ";
                        count--;
                    }
                    if (count == 0)
                        break;
                }
            }

            else if (command == "odd" && !EvenOddExists(array, command))
                Console.WriteLine("[]");

            return elements.TrimEnd();
        }
        static bool EvenOddExists(int[] array, string command)
        {
            bool b = true;
            if (command == "even")
            {
                b = Array.Exists(array, element => element % 2 == 0);
            }

            else if (command == "odd")
            {
                b = Array.Exists(array, element => element % 2 != 0);
            }

            return b;
        }

    }
}