using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Runtime.InteropServices;
using System.IO;
using System.Globalization;
using System.Text;

namespace FoxTricks
{
    /// <summary>
    /// The ExtendedProcedures partial class wraps all the extended stored procedures from SQL 2000 we are implementing in SQL 2005.
    /// We suppress the "Microsoft.Design : Remove the public constructors from 'ExtendedProcedures'." Code analysis warning because 
    /// the public constructor sits in the other part of the partial class....
    /// </summary>
    public partial class ExtendedProcedures
    {
        /// <summary>
        /// Class containing all constants in use.
        /// </summary>
        private struct Constant
        {
            internal const string DATEFORMAT = "yyyyMMdd";
            internal const string TIMEFORMAT = "Hmmss";
            internal const string VERSION_TOKEN = "version";
        }

        /// <summary>
        /// Return a resultset containing the properties of the file passed as parameter
        /// 
        /// When the filePath parameter has the value 'version' we will display the build number of this component. 
        /// Instead of path information. This option will greatly improve deployment problems and the chance that 
        /// somebody enters that value for a path name is marginal. 
        /// </summary>
        /// <param name="filePath">The path to the file we want to analyze</param>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes"), 
         Microsoft.SqlServer.Server.SqlProcedure(Name="xp_getfiledetails")]
        public static void GetFileDetails(string filePath)
        {
            
                // Validate the parameter.
                if (string.IsNullOrEmpty(filePath))
                {
                    throw new ArgumentNullException("filePath");
                }

                #region "List of columns in the recordset."
                SqlMetaData colAlternateName = new SqlMetaData("Alternate Name", SqlDbType.NVarChar, 4000);
                SqlMetaData colSize = new SqlMetaData("Size", SqlDbType.BigInt);
                SqlMetaData colCreationDate = new SqlMetaData("Creation Date", SqlDbType.NChar, 8);
                SqlMetaData colCreationTime = new SqlMetaData("Creation Time", SqlDbType.NChar, 6);
                SqlMetaData colLastWrittenDate = new SqlMetaData("Last Written Date", SqlDbType.NChar, 8);
                SqlMetaData colLastWrittenTime = new SqlMetaData("Last Written Time", SqlDbType.NChar, 6);
                SqlMetaData colLastAccessedDate = new SqlMetaData("Last Accessed Date", SqlDbType.NChar, 8);
                SqlMetaData colLastAccessedTime = new SqlMetaData("Last Accessed Time", SqlDbType.NChar, 6);
                SqlMetaData colAttributes = new SqlMetaData("Attributes", SqlDbType.Int);

                //Define a recordset based on the column metadata
                SqlDataRecord record = new SqlDataRecord(new SqlMetaData[] {
                colAlternateName,
                colSize,
                colCreationDate,
                colCreationTime,
                colLastWrittenDate,
                colLastWrittenTime,
                colLastAccessedDate,
                colLastAccessedTime,
                colAttributes});
                #endregion


                //Check if the filePath is pointing to a file or a folder.
                if (Directory.Exists(filePath))
                {
                    #region "Directory treatment"
                    // Get a FileInfo object which will tell us everything we want to know
                    DirectoryInfo myDirectory = new DirectoryInfo(filePath);

                    record.SetInt64(1, 0);
                    record.SetString(2, myDirectory.CreationTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                    record.SetString(3, (myDirectory.CreationTime.Add(ExplorerBias(myDirectory.CreationTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                    record.SetString(4, myDirectory.LastWriteTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                    record.SetString(5, (myDirectory.LastWriteTime.Add(ExplorerBias(myDirectory.LastWriteTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                    record.SetString(6, myDirectory.LastAccessTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                    record.SetString(7, (myDirectory.LastAccessTime.Add(ExplorerBias(myDirectory.LastAccessTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                    record.SetInt32(8, (int)myDirectory.Attributes);
                    #endregion
                }
                else
                {
                    #region "File treatment"
                    if (File.Exists(filePath))
                    {
                        // Get a FileInfo object which will tell us everything we want to know about the file
                        FileInfo myFile = new FileInfo(filePath);

                        //Only return a value for "Alternate Name" when the filename is longer then 8 
                        if ((myFile.Name.Length - myFile.Extension.Length) > 8 || myFile.Extension.Length > 4)
                        {
                            StringBuilder shortPath = new StringBuilder(255);
                            NativeMethods.GetShortPathName(filePath, shortPath, shortPath.Capacity);
                            record.SetString(0, Path.GetFileName(shortPath.ToString()));
                        }

                        record.SetInt64(1, myFile.Length);
                        record.SetString(2, myFile.CreationTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                        record.SetString(3, (myFile.CreationTime.Add(ExplorerBias(myFile.CreationTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                        record.SetString(4, myFile.LastWriteTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                        record.SetString(5, (myFile.LastWriteTime.Add(ExplorerBias(myFile.LastWriteTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                        record.SetString(6, myFile.LastAccessTime.ToString(Constant.DATEFORMAT, CultureInfo.InvariantCulture));
                        record.SetString(7, (myFile.LastAccessTime.Add(ExplorerBias(myFile.LastAccessTime))).ToString(Constant.TIMEFORMAT, CultureInfo.InvariantCulture));
                        record.SetInt32(8, (int)myFile.Attributes);

                    }
                    #endregion
                }
                //Send the resulting record to SQL Server 
                SqlContext.Pipe.SendResultsStart(record);
                SqlContext.Pipe.SendResultsRow(record);
                SqlContext.Pipe.SendResultsEnd();
             
        }

        #region "Helper Functions"

        /// <summary>
        /// This function gives the offset caused by daylight savings time. Apparently Windows explorer and the original xp_getfiledetails 
        /// are smart enough to account for daylight saving. But .Net just adjusts UTC for this based on the current daylight saving situation. 
        /// Of course for file properties this causes all kinds of funky offsets.
        /// When you call this function it will return the Daylight savings offset to be added to the timestamp to reach the original timestamp of the file.
        /// </summary>
        /// <param name="timeStamp">The timestamp to calculate the offset for.</param>
        /// <returns></returns>
        private static TimeSpan ExplorerBias(DateTime timeStamp)
        {
            TimeSpan bias = new TimeSpan(0);
            if (TimeZone.CurrentTimeZone.IsDaylightSavingTime(DateTime.Now) != TimeZone.CurrentTimeZone.IsDaylightSavingTime(timeStamp))
            {
                bias = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now) - TimeZone.CurrentTimeZone.GetUtcOffset(timeStamp);
            }
            return bias;
        }
        #endregion

    };

    /// <summary>
    /// internal class containing all Marshalled Native methods.
    /// </summary>
    internal static class NativeMethods
    {
        /// <summary>
        /// Import the GetShortPathName API through interop. This api is used to determine the 8.3 filename of a file 
        /// that has a funky name.
        /// </summary>
        /// <param name="path">the full path with the long filename</param>
        /// <param name="shortPath">the full path including the short filename</param>
        /// <param name="shortPathLength">the length of the returned short path. </param>
        /// <returns>status code if the call was successfull.</returns>
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        internal static extern int GetShortPathName([MarshalAs(UnmanagedType.LPTStr)] string path,
                                                    [MarshalAs(UnmanagedType.LPTStr)] StringBuilder shortPath,
                                                    int shortPathLength);

    };

}