Lidarr/src/Lidarr.Api.V1/Artist/ArtistFolderAsRootFolderValidator.cs

using System;
using System.IO;
using FluentValidation.Validators;
using NzbDrone.Common.Extensions;
using NzbDrone.Core.Organizer;

namespace Lidarr.Api.V1.Artist
{
    public class ArtistFolderAsRootFolderValidator : PropertyValidator
    {
        private readonly IBuildFileNames _fileNameBuilder;

        public ArtistFolderAsRootFolderValidator(IBuildFileNames fileNameBuilder)
        {
            _fileNameBuilder = fileNameBuilder;
        }

        protected override string GetDefaultMessageTemplate() => "Root folder path '{rootFolderPath}' contains artist folder '{artistFolder}'";

        protected override bool IsValid(PropertyValidatorContext context)
        {
            if (context.PropertyValue == null)
            {
                return true;
            }

            if (context.InstanceToValidate is not ArtistResource artistResource)
            {
                return true;
            }

            var rootFolderPath = context.PropertyValue.ToString();

            if (rootFolderPath.IsNullOrWhiteSpace())
            {
                return true;
            }

            var rootFolder = new DirectoryInfo(rootFolderPath!).Name;
            var artist = artistResource.ToModel();
            var artistFolder = _fileNameBuilder.GetArtistFolder(artist);

            context.MessageFormatter.AppendArgument("rootFolderPath", rootFolderPath);
            context.MessageFormatter.AppendArgument("artistFolder", artistFolder);

            if (artistFolder == rootFolder)
            {
                return false;
            }

            var distance = artistFolder.LevenshteinDistance(rootFolder);

            return distance >= Math.Max(1, artistFolder.Length * 0.2);
        }
    }
}