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

namespace iWare_SCADA_BusinessLogical.Utils
{
    /// <summary>
    /// 
    /// </summary>
    /// <remarks>
    /// 调用Win32API方法 FindFirstFile , FindNextFile， FindClose 
    /// </remarks>
    public class FileDirectoryEnumerator : System.Collections.IEnumerator
    {
        #region 属性
        /// <summary>
        /// 当前对象文件
        /// </summary>
        private object objCurrentObject = null;
        private bool bolIsEmpty = false;
        /// <summary>
        /// 是否找不到文件
        /// </summary>
        public bool IsEmpty
        {
            get { return bolIsEmpty; }
        }
        private int intSearchedCount = 0;
        /// <summary>
        /// 找到的文件数
        /// </summary>
        public int SearchedCount
        {
            get { return intSearchedCount; }
        }
        private bool bolIsFile = true;
        /// <summary>
        /// 是否为文件
        /// </summary>
        public bool IsFile
        {
            get { return bolIsFile; }
        }
        private int intLastErrorCode = 0;
        /// <summary>
        /// 错误代码Win32
        /// </summary>
        public int LastErrorCode
        {
            get { return intLastErrorCode; }
        }
        /// <summary>
        /// 文件名称
        /// </summary>
        public string Name
        {
            get
            {
                if (this.objCurrentObject != null)
                {
                    if (objCurrentObject is string)
                        return (string)this.objCurrentObject;
                    else
                        return ((System.IO.FileSystemInfo)this.objCurrentObject).Name;
                }
                return null;
            }
        }
        /// <summary>
        /// 文件属性
        /// </summary>
        public System.IO.FileAttributes Attributes
        {
            get { return (System.IO.FileAttributes)myData.dwFileAttributes; }
        }
        /// <summary>
        /// 文件创建时间
        /// </summary>
        public System.DateTime CreationTime
        {
            get
            {
                //long time = ToLong(myData.ftCreationTime_dwHighDateTime,
                //    myData.ftCreationTime_dwLowDateTime);
                //System.DateTime dtm = System.DateTime.FromFileTimeUtc(time);
                //return dtm.ToLocalTime();

                return ToDateTime(myData.ftCreationTime);
            }
        }

        /// <summary>
        /// 文件最后访问时间
        /// </summary>
        public System.DateTime LastAccessTime
        {
            get
            {
                //long time = ToLong(myData.ftLastAccessTime_dwHighDateTime,
                //    myData.ftLastAccessTime_dwLowDateTime);
                //System.DateTime dtm = System.DateTime.FromFileTimeUtc(time);
                //return dtm.ToLocalTime();
                return ToDateTime(myData.ftLastAccessTime);
            }
        }
        /// <summary>
        /// 文件最后写入时间
        /// </summary>
        public System.DateTime LastWriteTime
        {
            get
            {
                //long time = ToLong(myData.ftLastWriteTime_dwHighDateTime,
                //    myData.ftLastWriteTime_dwLowDateTime);
                //System.DateTime dtm = System.DateTime.FromFileTimeUtc(time);
                //return dtm.ToLocalTime();

                return ToDateTime(myData.ftLastWriteTime);
            }
        }
        /// <summary>
        /// 文件大小
        /// </summary>
        public long FileLength
        {
            get
            {
                if (this.bolIsFile)
                    return ToLong(myData.nFileSizeHigh, myData.nFileSizeLow);
                else
                    return 0;
            }
        }
        #endregion
        #region 查询属性
        private bool bolThrowIOException = true;
        /// <summary>
        /// 是否抛出异常
        /// </summary>
        public bool ThrowIOException
        {
            get { return this.bolThrowIOException; }
            set { this.bolThrowIOException = value; }
        }
        private bool bolReturnStringType = true;
        /// <summary>
        /// 返回类型
        /// </summary>
        public bool ReturnStringType
        {
            get { return bolReturnStringType; }
            set { bolReturnStringType = value; }
        }
        private string strSearchPattern = "*";
        /// <summary>
        /// 查询文件名
        /// </summary>
        public string SearchPattern
        {
            get { return strSearchPattern; }
            set { strSearchPattern = value; }
        }
        private string strSearchPath = null;
        /// <summary>
        /// 查询路径
        /// </summary>
        public string SearchPath
        {
            get { return strSearchPath; }
            set { strSearchPath = value; }
        }
        private bool bolSearchForFile = true;
        /// <summary>
        /// 查询文件
        /// </summary>
        public bool SearchForFile
        {
            get { return bolSearchForFile; }
            set { bolSearchForFile = value; }
        }
        private bool bolSearchForDirectory = true;
        /// <summary>
        /// 查询文件夹
        /// </summary>
        public bool SearchForDirectory
        {
            get { return bolSearchForDirectory; }
            set { bolSearchForDirectory = value; }
        }
        //private int? searchCreationTime_High;
        //private int? searchCreationTime_Low;
        private DateTime? searchCreationTime;
        /// <summary>
        /// 查询文件创建时间在设置时间之后的文件
        /// </summary>
        public DateTime? SearchCreationTime
        {
            get { return searchCreationTime; }
            set
            {
                searchCreationTime = value;
            }
        }


        private DateTime? searchCreationEndTime;
        /// <summary>
        /// 查询文件创建时间在设置时间之前的文件
        /// </summary>
        public DateTime? SearchCreationEndTime
        {
            get { return searchCreationEndTime; }
            set
            {
                searchCreationEndTime = value;
            }
        }

        private DateTime? searchModifyTime;
        /// <summary>
        /// 查询文件修改时间在设置时间之后的文件
        /// </summary>
        public DateTime? SearchModifyTime
        {
            get { return searchModifyTime; }
            set
            {
                searchModifyTime = value;
            }
        }


        private DateTime? searchModifyEndTime;
        /// <summary>
        /// 查询文件修改时间在设置时间之前的文件
        /// </summary>
        public DateTime? SearchModifyEndTime
        {
            get { return searchModifyEndTime; }
            set
            {
                searchModifyEndTime = value;
            }
        }
        #endregion
        /// <summary>
        /// 关闭文件
        /// </summary>
        public void Close()
        {
            this.CloseHandler();
        }
        #region IEnumerator
        /// <summary>
        /// 当前文件
        /// </summary>
        public object Current
        {
            get { return objCurrentObject; }
        }
        /// <summary>
        /// 查询下一文件
        /// </summary>
        /// <returns>是否成功</returns>
        public bool MoveNext()
        {
            bool success = false;
            while (true)
            {
                if (this.bolStartSearchFlag)
                    success = this.SearchNext();
                else
                    success = this.StartSearch();

                if (success)
                {
                    var time = ToDateTime(myData.ftCreationTime);
                    if (searchCreationTime.HasValue)
                        if (time <= searchCreationTime.Value)
                            continue;
                    if (searchCreationEndTime.HasValue)
                        if (time > searchCreationEndTime.Value)
                            continue;


                    time = ToDateTime(myData.ftLastWriteTime);
                    if (searchModifyTime.HasValue)
                        if (time <= searchModifyTime.Value)
                            continue;
                    if (searchModifyEndTime.HasValue)
                        if (time > searchModifyEndTime.Value)
                            continue;

                    if (this.UpdateCurrentObject())
                        return true;
                }
                else
                {
                    this.objCurrentObject = null;
                    return false;
                }
            }
        }
        /// <summary>
        /// 重设
        /// </summary>
        public void Reset()
        {
            if (this.strSearchPath == null)
                throw new System.ArgumentNullException("SearchPath can not null");
            if (this.strSearchPattern == null || this.strSearchPattern.Length == 0)
                this.strSearchPattern = "*";
            this.intSearchedCount = 0;
            this.objCurrentObject = null;
            this.CloseHandler();
            this.bolStartSearchFlag = false;
            this.bolIsEmpty = false;
            this.intLastErrorCode = 0;
        }
        #endregion
        #region WIN32API
        //[Serializable, System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Auto), System.Runtime.InteropServices.BestFitMapping(false)]
        //private struct WIN32_FIND_DATA
        //{
        //    public int dwFileAttributes;
        //    public int ftCreationTime_dwLowDateTime;
        //    public int ftCreationTime_dwHighDateTime;
        //    public int ftLastAccessTime_dwLowDateTime;
        //    public int ftLastAccessTime_dwHighDateTime;
        //    public int ftLastWriteTime_dwLowDateTime;
        //    public int ftLastWriteTime_dwHighDateTime;
        //    public int nFileSizeHigh;
        //    public int nFileSizeLow;
        //    public int dwReserved0;
        //    public int dwReserved1;
        //    [System.Runtime.InteropServices.MarshalAs
        //    (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
        //    SizeConst = 260)]
        //    public string cFileName;
        //    [System.Runtime.InteropServices.MarshalAs
        //    (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
        //    SizeConst = 14)]
        //    public string cAlternateFileName;
        //}
        [Serializable, System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Auto), System.Runtime.InteropServices.BestFitMapping(false)]
        public struct FILETIME
        {
            public int dwLowDateTime;
            public int dwHighDateTime;
        }


        //[Serializable, System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Auto), System.Runtime.InteropServices.BestFitMapping(false)]
        //public struct WIN32_FIND_DATA
        //{
        //    public int dwFileAttributes;
        //    public FILETIME ftCreationTime;
        //    public FILETIME ftLastAccessTime;
        //    public FILETIME ftLastWriteTime;
        //    public int nFileSizeHigh;
        //    public int nFileSizeLow;
        //    public int dwOID;
        //    [System.Runtime.InteropServices.MarshalAs
        //   (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
        //   SizeConst = 260)]
        //    public string cFileName;
        //    [System.Runtime.InteropServices.MarshalAs
        //    (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
        //    SizeConst = 14)]
        //    public string cAlternateFileName;
        //}
        [Serializable, System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet = System.Runtime.InteropServices.CharSet.Auto), System.Runtime.InteropServices.BestFitMapping(false)]
        public struct WIN32_FIND_DATA
        {
            public int dwFileAttributes;
            public FILETIME ftCreationTime;
            public FILETIME ftLastAccessTime;
            public FILETIME ftLastWriteTime;
            public int nFileSizeHigh;
            public int nFileSizeLow;
            public int dwReserved0;
            public int dwReserved1;
            [System.Runtime.InteropServices.MarshalAs
            (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
            SizeConst = 260)]
            public string cFileName;
            [System.Runtime.InteropServices.MarshalAs
            (System.Runtime.InteropServices.UnmanagedType.ByValTStr,
            SizeConst = 14)]
            public string cAlternateFileName;
        }


        [System.Runtime.InteropServices.DllImport("kernel32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto, SetLastError = true)]
        private static extern IntPtr FindFirstFile(IntPtr pFileName, ref WIN32_FIND_DATA pFindFileData);
        [System.Runtime.InteropServices.DllImport("kernel32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto, SetLastError = true)]
        private static extern bool FindNextFile(IntPtr hndFindFile, ref WIN32_FIND_DATA lpFindFileData);
        [System.Runtime.InteropServices.DllImport("kernel32.dll", SetLastError = true)]
        private static extern bool FindClose(IntPtr hndFindFile);
        private static long ToLong(int height, int low)
        {
            long v = (uint)height;
            v = v << 0x20;
            v = v | ((uint)low);
            return v;
        }

        public static DateTime ToDateTime(FILETIME time)
        {
            return DateTime.FromFileTime(ToLong(time.dwHighDateTime, time.dwLowDateTime));
        }
        private static void WinIOError(int errorCode, string str)
        {
            switch (errorCode)
            {
                case 80:
                    throw new System.IO.IOException("IO_FileExists :" + str);
                case 0x57:
                    throw new System.IO.IOException("IOError:" + MakeHRFromErrorCode(errorCode));
                case 0xce:
                    throw new System.IO.PathTooLongException("PathTooLong:" + str);
                case 2:
                    throw new System.IO.FileNotFoundException("FileNotFound:" + str);
                case 3:
                    throw new System.IO.DirectoryNotFoundException("PathNotFound:" + str);
                case 5:
                    throw new UnauthorizedAccessException("UnauthorizedAccess:" + str);
                case 0x20:
                    throw new System.IO.IOException("IO_SharingViolation:" + str);
            }
            throw new System.IO.IOException("IOError:" + MakeHRFromErrorCode(errorCode));
        }
        private static int MakeHRFromErrorCode(int errorCode)
        {
            return (-2147024896 | errorCode);
        }

        private static readonly IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
        /// <summary>
        /// 无效句柄
        /// </summary>
        private System.IntPtr intSearchHandler = INVALID_HANDLE_VALUE;
        private WIN32_FIND_DATA myData = new WIN32_FIND_DATA();
        /// <summary>
        /// 是否已经开始查询
        /// </summary>
        private bool bolStartSearchFlag = false;
        /// <summary>
        /// 关闭
        /// </summary>
        private void CloseHandler()
        {
            if (this.intSearchHandler != INVALID_HANDLE_VALUE)
            {
                FindClose(this.intSearchHandler);
                this.intSearchHandler = INVALID_HANDLE_VALUE;
            }
        }
        /// <summary>
        /// 开始查询
        /// </summary>
        /// <returns></returns>
        private bool StartSearch()
        {
            bolStartSearchFlag = true;
            bolIsEmpty = false;
            objCurrentObject = null;
            intLastErrorCode = 0;
            string strPath = System.IO.Path.Combine(strSearchPath, this.strSearchPattern);
            this.CloseHandler();
            intSearchHandler = FindFirstFile(System.Runtime.InteropServices.Marshal.StringToHGlobalAuto(strPath), ref myData);
            if (intSearchHandler == INVALID_HANDLE_VALUE)
            {
                intLastErrorCode = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
                if (intLastErrorCode == 2)
                {
                    bolIsEmpty = true;
                    return false;
                }
                if (this.bolThrowIOException)
                    WinIOError(intLastErrorCode, strSearchPath);
                else
                    return false;
            }
            return true;
        }
        /// <summary>
        /// 查询下一文件
        /// </summary>
        /// <returns></returns>
        private bool SearchNext()
        {
            if (bolStartSearchFlag == false)
                return false;
            if (bolIsEmpty)
                return false;
            if (intSearchHandler == INVALID_HANDLE_VALUE)
                return false;
            intLastErrorCode = 0;
            if (FindNextFile(intSearchHandler, ref myData) == false)
            {
                intLastErrorCode = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
                this.CloseHandler();
                if (intLastErrorCode != 0 && intLastErrorCode != 0x12)
                {
                    if (this.bolThrowIOException)
                        WinIOError(intLastErrorCode, strSearchPath);
                    else
                        return false;
                }
                return false;
            }
            return true;
        }

        /// <summary>
        /// 更新当前文件信息
        /// </summary>
        /// <returns></returns>
        private bool UpdateCurrentObject()
        {
            if (intSearchHandler == INVALID_HANDLE_VALUE)
                return false;
            bool Result = false;
            this.objCurrentObject = null;
            if ((myData.dwFileAttributes & 0x10) == 0)
            {
                // 
                this.bolIsFile = true;
                if (this.bolSearchForFile)
                    Result = true;
            }
            else
            {
                // 
                this.bolIsFile = false;
                if (this.bolSearchForDirectory)
                {
                    if (myData.cFileName == "." || myData.cFileName == "..")
                        Result = false;
                    else
                        Result = true;
                }
            }
            if (Result)
            {
                if (this.bolReturnStringType)
                    this.objCurrentObject = myData.cFileName;
                else
                {
                    string p = System.IO.Path.Combine(this.strSearchPath, myData.cFileName);
                    if (this.bolIsFile)
                    {
                        this.objCurrentObject = new System.IO.FileInfo(p);
                    }
                    else
                    {
                        this.objCurrentObject = new System.IO.DirectoryInfo(p);
                    }
                }
                this.intSearchedCount++;
            }
            return Result;
        }
        #endregion
    }

}