Program.cs

using System;
using System.IO;
using McMaster.Extensions.CommandLineUtils;
namespace shinny_ssg
{
    class Program
    {
      
        static void Main(string[] args)
        {
            
            string DESTINATION = @".\dist";
            //initialize new CLI application
            var app= new CommandLineApplication<Program>();
            Console.WriteLine("Hello World!");
            //help option
            app.HelpOption();
            app.VersionOption("-v|--version", "0.1", "Shinny SSG 0.1");
            var inputFileOption = app.Option<string>("-i|--input", "Input file/folder to convert to HTML", CommandOptionType.SingleValue)
                                   .IsRequired();
            var outputOption = app.Option<string>("-o|--output", "Output folder for converted file", CommandOptionType.SingleValue);
            var cssOption = app.Option<string>("---stylesheet| -s", "Style Sheet for the HTML file", CommandOptionType.SingleValue);
            //on excute
            app.OnExecute(() =>
            {
                try
                {
                    var inputname = inputFileOption.Value();
                    var cssString = cssOption.HasValue() ? cssOption.Value() : null;
                    if (outputOption.HasValue() && Directory.Exists(outputOption.Value()))
                    {
                        DESTINATION = outputOption.Value();
                    }
                    else
                    {
                        //It will delete all file even though the read or write process fail
                        System.IO.DirectoryInfo di = new DirectoryInfo(DESTINATION);

                        foreach (FileInfo file in di.GetFiles())
                        {
                            file.Delete();
                        }
                        foreach (DirectoryInfo dir in di.GetDirectories())
                        {
                            dir.Delete(true);
                        }
                        
                    }
                    if (File.Exists(inputname))
                    {
                        //add try catch block here
                        //if file can write and read ok we can delete old folder and write new file
                        FileText temp = new FileText(inputname, DESTINATION, cssString);
                        temp.saveFile();
                    }
                    else if (Directory.Exists(inputname))
                    {
                        var f = new Subfolder();
                        f.createFolder(inputname, DESTINATION, cssString);
                    }
                    else
                    {
                        Console.WriteLine("File Name is not valid");
                    }

                    Console.WriteLine($"File is in folder {DESTINATION}");
                }catch(Exception ex)
                {
                    Console.WriteLine("There is an error with file\\folder path");
                }
            });

            app.Execute(args);
        }
    
    
    
    }
}