DirectoryScanner

namespace Shine.Models.Scanners
{
    using System;
    using System.Collections.Generic;
    using System.IO;

    public class Scanner
    {
        private string filePath = @"folders.txt";
        private string movieFolderPath = @"D:\Test\Movies";

        public void ScanDirectory()
        {
            if (!this.CheckIfFileExists())
            {
                this.WriteFoldersToDatabase();
            }
            else
            {
                var oldDirectories = this.GetDirectoriesFromDatabase();
                var newDirectories = this.GetDirectoris();

                foreach (var newDir in newDirectories)
                {
                    if (!oldDirectories.Contains(newDir))
                    {
                        Console.WriteLine("New Folder was created: {0}", newDir);
                    }
                }

                foreach (var oldDir in oldDirectories)
                {
                    if (!newDirectories.Contains(oldDir))
                    {
                        Console.WriteLine("A folder was deleted: {0}", oldDir);
                    }
                }

                this.WriteFoldersToDatabase();
            }
        }

        private bool CheckIfFileExists()
        {
            bool result = File.Exists(this.filePath);

            return result;
        }

        private HashSet<string> GetDirectoris()
        {
            var directories = Directory.GetDirectories(this.movieFolderPath);

            HashSet<string> directoryList = new HashSet<string>();

            foreach (var dir in directories)
            {
                var directoryInfo = new DirectoryInfo(dir);

                directoryList.Add(directoryInfo.Name);
            }

            return directoryList;
        }

        private HashSet<string> GetDirectoriesFromDatabase()
        {
            HashSet<string> directories = new HashSet<string>();

            var result = File.ReadAllLines(this.filePath);

            foreach (var dir in result)
            {
                directories.Add(dir);
            }

            return directories;
        }

        private void WriteFoldersToDatabase()
        {
            var directories = this.GetDirectoris();

            File.WriteAllLines(this.filePath, directories);
        }
    }
}