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

namespace Stone.Common
{

/// <summary>
/// 文件排序类
/// </summary>
public class MyFileSort : IComparer
{
    private FileOrder _fileorder;
    private FileAsc _fileasc;

    /// <summary>
    /// 构造函数
    /// </summary>
    public MyFileSort()
        : this(FileOrder.Name, FileAsc.Asc)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="fileorder"></param>
    public MyFileSort(FileOrder fileorder)
        : this(fileorder, FileAsc.Asc)
    { }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="fileorder"></param>
    /// <param name="fileasc"></param>
    public MyFileSort(FileOrder fileorder, FileAsc fileasc)
    {
        _fileorder = fileorder;
        _fileasc = fileasc;
    }

    /// <summary>
    /// 比较函数
    /// </summary>
    /// <param name="x"></param>
    /// <param name="y"></param>
    /// <returns></returns>
    public int Compare(object x, object y)
    {
        FileInfo file1 = x as FileInfo;
        FileInfo file2 = y as FileInfo;
        FileInfo file3;

        if (file1 == null || file2 == null)
            throw new ArgumentException("参数不是FileInfo类实例.");

        if (_fileasc == FileAsc.Desc)
        {
            file3 = file1;
            file1 = file2;
            file2 = file3;
        }

        switch (_fileorder)
        {
            case FileOrder.Name:
                return file1.Name.CompareTo(file2.Name);
            case FileOrder.Length:
                return file1.Length.CompareTo(file2.Length);
            case FileOrder.Extension:
                return file1.Extension.CompareTo(file2.Extension);
            case FileOrder.CreationTime:
                return file1.CreationTime.CompareTo(file2.CreationTime);
            case FileOrder.LastAccessTime:
                return file1.LastAccessTime.CompareTo(file2.LastAccessTime);
            case FileOrder.LastWriteTime:
                return file1.LastWriteTime.CompareTo(file2.LastWriteTime);
            default:
                return 0;
        }
    }
}

/// <summary>
/// 排序依据
/// </summary>
public enum FileOrder
{
    /// <summary>
    /// 文件名
    /// </summary>
    Name,
    /// <summary>
    /// 大小
    /// </summary>
    Length,
    /// <summary>
    /// 类型
    /// </summary>
    Extension,
    /// <summary>
    /// 创建时间
    /// </summary>
    CreationTime,
    /// <summary>
    /// 访问时间
    /// </summary>
    LastAccessTime,
    /// <summary>
    /// 修改时间
    /// </summary>
    LastWriteTime
}

/// <summary>
/// 升序降序
/// </summary>
public enum FileAsc
{
    /// <summary>
    /// 升序
    /// </summary>
    Asc,
    /// <summary>
    /// 降序
    /// </summary>
    Desc
}
}