yes.blog/Yes.Application/Admins/Themes/DownloadThemeCommandHandler.cs

namespace Yes.Application.Admins.Themes
{
    public record DownloadThemeCommand(string ThemeName) : IRequest<DownloadThemeCommandResponse>;

    public record DownloadThemeCommandResponse(string Filepath);
    public class DownloadThemeCommandHandler(
        IWebHostEnvironment env,
        BlogDbContext db,
        IIdentityContext identity,
        IOptionsMonitor<BlogSettings> options) : IRequestHandler<DownloadThemeCommand, DownloadThemeCommandResponse>
    {
        private readonly IWebHostEnvironment _env = env;
        private readonly BlogSettings _settings = options.CurrentValue;
        private readonly BlogDbContext _db = db;
        private readonly IIdentityContext _identity = identity;

        public async Task<DownloadThemeCommandResponse> Handle(DownloadThemeCommand request, CancellationToken cancellationToken)
        {
            var identityUser = await _db.Users.FindAsync(_identity.Id);
            if (identityUser == null)
            {
                throw new UserNotExistsException(_identity.Id);
            }

            if (!identityUser.IsSystemUser())
            {
                throw new AccessDeniedException();
            }


            try
            {
                var themeName = request.ThemeName;


                var targetDirectory = Path.Combine(_env.ContentRootPath, "files", "themes", themeName);
                var zipPath = Path.Combine(_env.ContentRootPath, "files", "themes", $"{themeName}.zip");

                ZipHelper.CompressFolderToZip(targetDirectory, zipPath);


                return new DownloadThemeCommandResponse(zipPath);
            }
            catch (Exception ex) when (ex is OverflowException)
            {
                throw new FileOverflowException();
            }
            catch (Exception ex) when (ex is InvalidDataException)
            {
                throw new FileNotSupportedException(ex.Message);
            }
        }
    }
}