using System.IO;
using System.Text;

namespace CommonLibrary
{
    public static class Extensions
    {
        public static string PathCombineL(params string[] paths)
        {
            var directorySeparatorChar = System.IO.Path.AltDirectorySeparatorChar.ToString();
            return PathCombine(directorySeparatorChar, paths).Replace("\\", "/");
        }

        public static string PathCombineW(params string[] paths)
        {
            var directorySeparatorChar = System.IO.Path.DirectorySeparatorChar.ToString();
            return PathCombine(directorySeparatorChar, paths).Replace("/", "\\");
        }

        static string PathCombine(string directorySeparator, params string[] paths)
        {
            if (paths.Length == 0) return string.Empty;

            var path = new StringBuilder();
            path.Append(paths[0]);

            for (int i = 1; i < paths.Length; i++)
            {
                if (path.ToString().Substring(path.Length - 1, 1) == directorySeparator)
                {
                    if (paths[i].Substring(0, 1) == directorySeparator)
                    {
                        path.Append(paths[i].Substring(1, paths[i].Length - 1));
                    }
                    else
                    {
                        path.Append(paths[i]);
                    }
                }
                else
                {
                    if (paths[i].Substring(0, 1) == directorySeparator)
                    {
                        path.Append(paths[i]);
                    }
                    else
                    {
                        path.Append(directorySeparator);
                        path.Append(paths[i]);
                    }
                }
            }

            return path.ToString();
        }

        public static bool IsDefault<T>(ref this T data) where T : struct
=> default(T).Equals(data);

        public static void DeepMove(this DirectoryInfo sourceDirectoryInfo, DirectoryInfo targetDirectoryInfo)
        {
            if (!sourceDirectoryInfo.Exists) return;

            if (sourceDirectoryInfo.Root.Name == targetDirectoryInfo.Root.Name)
            {
                sourceDirectoryInfo.MoveTo(targetDirectoryInfo.FullName);
            }
            else
            {
                var fileInfos = sourceDirectoryInfo.GetFiles("*", SearchOption.AllDirectories);

                foreach (var file in fileInfos)
                {
                    var targetDirectory = new DirectoryInfo(file.DirectoryName.Replace(sourceDirectoryInfo.FullName, targetDirectoryInfo.FullName));
                    targetDirectory.Create();
                    var targetFileName = System.IO.Path.Combine(targetDirectory.FullName, file.Name);

                    file.CopyTo(targetFileName, true);
                }

                sourceDirectoryInfo.Delete(true);
            }
        }
    }
}