using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Ips.Library.Basic
{
    public static class DirectoryUtil
    {
        public static void CreateIfNotExists(string directory)
        {
            if (!Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }
        }

        public static void DeleteIfExists(string directory)
        {
            if (Directory.Exists(directory))
            {
                Directory.Delete(directory, true);
            }
        }

        public static void DeleteIfExists(string directory, bool recursive)
        {
            if (Directory.Exists(directory))
            {
                Directory.Delete(directory, recursive);
            }
        }

        public static void DeleteIfEmpty(string directory)
        {
            if (Directory.Exists(directory) && !Directory.EnumerateFiles(directory, "*", SearchOption.AllDirectories).Any())
            {
                Directory.Delete(directory, true);
            }
        }

        public static bool DeleteFiles(string diretory, string searchPattern = "*", SearchOption searchOption = SearchOption.TopDirectoryOnly)
        {
            bool result = true;
            if (Directory.Exists(diretory))
            {
                var fileNames = Directory.GetFiles(diretory, searchPattern, searchOption);
                foreach (var fileName in fileNames)
                {
                    try
                    {
                        File.Delete(fileName);
                    }
                    catch
                    {
                        result = false;
                    }
                }
            }

            return result;
        }

        public static void CreateIfNotExists(DirectoryInfo directory)
        {
            if (!directory.Exists)
            {
                directory.Create();
            }
        }

        public static bool IsSubDirectoryOf(string parentDirectoryPath, string childDirectoryPath)
        {
            return IsSubDirectoryOf(
                new DirectoryInfo(parentDirectoryPath),
                new DirectoryInfo(childDirectoryPath)
            );
        }

        public static bool IsSubDirectoryOf(DirectoryInfo parentDirectory, DirectoryInfo childDirectory)
        {
            if (parentDirectory.FullName == childDirectory.FullName)
            {
                return true;
            }

            var parentOfChild = childDirectory.Parent;
            if (parentOfChild == null)
            {
                return false;
            }

            return IsSubDirectoryOf(parentDirectory, parentOfChild);
        }

        public static IDisposable ChangeCurrentDirectory(string targetDirectory)
        {
            var currentDirectory = Directory.GetCurrentDirectory();

            if (currentDirectory.Equals(targetDirectory, StringComparison.OrdinalIgnoreCase))
            {
                return NullDisposable.Instance;
            }

            Directory.SetCurrentDirectory(targetDirectory);

            return new DisposeAction(() => { Directory.SetCurrentDirectory(currentDirectory); });
        }
    }
}