SoftUni Course Planning

using System;
using System.Collections.Generic;
using System.Linq;

namespace Softuni_course_planning
{
    class Program
    {
        static void Main()
        {
            List<string> scheduleSoftUni = Console.ReadLine()
                .Split(", ")
                .ToList();

            while (true)
            {
                string changes = Console.ReadLine();

                if (changes == "course start")
                    break;

                else
                {
                    string[] changesInfo = changes.Split(':').ToArray();
                    string lesson = changesInfo[1];

                    switch (changesInfo[0])
                    {
                        case "Add":
                            {
                                AddLesson(scheduleSoftUni, lesson);

                                break;
                            }

                        case "Insert":
                            {
                                int index = int.Parse(changesInfo[2]);
                                InsertLesson(scheduleSoftUni, lesson, index);
                                break;
                            }

                        case "Remove":
                            {
                                RemoveLesson(scheduleSoftUni, lesson);
                                RemoveLesson(scheduleSoftUni, $"{lesson}-Exercise");

                                break;
                            }

                        case "Swap":
                            {
                                string lesson2 = changesInfo[2];

                                if (scheduleSoftUni.Contains(lesson) && scheduleSoftUni.Contains(lesson2))
                                {
                                    int index = scheduleSoftUni.IndexOf(lesson);
                                    int index2 = scheduleSoftUni.IndexOf(lesson2);

                                    scheduleSoftUni[index] = lesson2;
                                    scheduleSoftUni[index2] = lesson;

                                    MoveExercise(scheduleSoftUni, lesson, index2);

                                    MoveExercise(scheduleSoftUni, lesson2, index);

                                }


                                break;
                            }

                        case "Exercise":
                        {
                            string exercise = $"{lesson}-Exercise";
                                if (scheduleSoftUni.Contains(lesson) && !scheduleSoftUni.Contains(exercise))
                                {
                                    if (scheduleSoftUni.IndexOf(lesson) < scheduleSoftUni.Count - 1)
                                        scheduleSoftUni.Insert(scheduleSoftUni.IndexOf(lesson) + 1, exercise);
                                    else
                                        scheduleSoftUni.Add(exercise);
                                }

                                else if (!scheduleSoftUni.Contains(lesson) && !scheduleSoftUni.Contains(exercise))
                                {
                                    scheduleSoftUni.Add(lesson);
                                    scheduleSoftUni.Add(exercise);
                                }
                                break;
                            }
                    }

                }


            }

            for (int i = 0; i < scheduleSoftUni.Count; i++)
            {
                Console.WriteLine($"{i + 1}.{scheduleSoftUni[i]}");
            }

        }

        static void MoveExercise(List<string> schedule, string course, int position)
        {
            if (schedule.Contains($"{course}-Exercise"))
            {
                schedule.Remove($"{course}-Exercise");
                if (position < schedule.Count - 1)
                    schedule.Insert(position + 1, $"{course}-Exercise");
                else
                    schedule.Add($"{course}-Exercise");
            }
        }

        private static void InsertLesson(List<string> schedule, string course, int position)
        {
            if (!DoesExists(schedule, course) && position >= 0 && position < schedule.Count)
            {
                schedule.Insert(position, course);
            }
        }
        static void AddLesson(List<string> schedule, string course)
        {
            if (!DoesExists(schedule, course))
            {
                schedule.Add(course);
            }
        }

        static void RemoveLesson(List<string> schedule, string course)
        {
            if (DoesExists(schedule, course))
            {
                schedule.Remove(course);
            }
        }

        static bool DoesExists(List<string> schedule, string course)
        {
            return schedule.Contains(course);
        }

    }
}