using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml;

// ReSharper disable UnusedMember.Local
// ReSharper disable UnusedVariable

namespace DTS.Common.Utils
{
    [SuppressMessage("ReSharper", "InconsistentNaming")]
    public static class FileUtils
    {
        [Flags]
        enum MoveFileFlags
        {
            MOVEFILE_REPLACE_EXISTING = 0x00000001,
            MOVEFILE_COPY_ALLOWED = 0x00000002,
            MOVEFILE_DELAY_UNTIL_REBOOT = 0x00000004,
            MOVEFILE_WRITE_THROUGH = 0x00000008,
            MOVEFILE_CREATE_HARDLINK = 0x00000010,
            MOVEFILE_FAIL_IF_NOT_TRACKABLE = 0x00000020
        }

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
        private static extern bool MoveFileEx(string lpExistingFileName, string lpNewFileName, MoveFileFlags dwFlags);

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool DeleteFile(string lpFileName);
        public const double DataPROPre20XmlVersion = 2.0D;
        public const double DataPRO20XmlVersion = 3.0D;
        public const double DataPRO21XmlVersion = 4.0D;
        public const double DataPRO22XmlVersion = 5.0D;
        //FB 13120 Added FilterClass and deleted CFC in version 6.0 
        //15390 Store the ZMO in EU in the DataPRO DB in version 7.0, adds top level field SensorChangeHistory
        //13065 Sensor "First Use" Date, version 8, adds LatestCalibrationId, CalibrationId and FirstUse tags
        //15727Building and Replacing Racks/Mods - version 9, adds TestId,GroupId, StandIn to hardware and Id to tests
        //Version 10 adds TSR Air settings
        public const double CurrentXmlVersion = 10.0D;
        

        public static XmlElement GetImportXmlNode(string filename, string xmlDoc, out double importVersion)
        {
            var doc = new XmlDocument();
            importVersion = 0D;

            if (!string.IsNullOrWhiteSpace(xmlDoc))
            {
                doc.LoadXml(xmlDoc);
            }
            else
            {
                doc.Load(filename);
            }

            foreach (var node in doc.ChildNodes)
            {
                if (node is XmlDeclaration) continue;
                if (!(node is XmlElement)) continue;
                if ((node as XmlElement).Name != "ExportFile") continue;

                var itemsToComplete = Convert.ToDouble(((XmlElement) node).GetAttribute("TotalItems"),
                    System.Globalization.CultureInfo.InvariantCulture);
                importVersion = Convert.ToDouble(((XmlElement) node).GetAttribute("Version"),
                    System.Globalization.CultureInfo.InvariantCulture);
                if (importVersion > CurrentXmlVersion)
                {
                    throw new NotSupportedException("Unsupported version: " + importVersion);
                }

                return (XmlElement) node;
            }

            throw new Exception("Invalid Import XML");
        }

        /// <summary>
        /// This API can accept a parameter “MOVEFILE_DELAY_UNTIL_REBOOT ” to remove the file only after reboot. 
        /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365240(v=vs.85).aspx
        /// </summary>
        /// <param name="filePath">Entire path of the file we want to move</param>
        public static void moveFileEx(string filePath)
        {
            MoveFileEx(filePath, null, MoveFileFlags.MOVEFILE_DELAY_UNTIL_REBOOT);
        }

        /// <summary>
        /// FB16400: ISO exports error in 3rd Party Software, related to FB15801
        /// By default, C# returns UTF-8 Encoding with Byte-Order Mark turned on. Need to explicitly call the overloaded constructor to turn it off:
        /// https://docs.microsoft.com/en-us/dotnet/api/system.text.encoding.utf8?view=netcore-3.1
        /// </summary>
        /// <param name="codepage"></param>
        /// <returns></returns>
        public static Encoding GetEncoding(int codepage)
        {
            var encoding = Encoding.GetEncoding(codepage);
            if (encoding is UTF8Encoding) { encoding = new UTF8Encoding(false); }
            return encoding;
        }

        public static XmlWriter GetExportWriter(int count, double version, string software, string softwareVersion, LogDelegate logDelegate, out StringBuilder sb)
        {
            sb = new StringBuilder(5000000);

            var xSet = new XmlWriterSettings { Indent = true, CheckCharacters = true };
            var writer = XmlWriter.Create(sb, xSet);

            writer.WriteStartDocument();

            writer.WriteStartElement("ExportFile");

            writer.WriteAttributeString("TotalItems", count.ToString(System.Globalization.CultureInfo.InvariantCulture));
            writer.WriteAttributeString("Version", version.ToString(System.Globalization.CultureInfo.InvariantCulture));
            writer.WriteAttributeString("Software", software);
            writer.WriteAttributeString("SoftwareVersion", softwareVersion);
            return writer;
        }
        /// <summary>
        /// This API deletes an existing file.
        /// https://msdn.microsoft.com/en-us/library/windows/desktop/aa363915(v=vs.85).aspx
        /// </summary>
        /// <param name="filePath">Entire path of the file to be deleted.</param>
        /// <param name="lastError">Error if failed to delete file 
        /// If the function succeeds, the return value is nonzero.
        /// If the function fails, the return value is zero (0). 
        /// To get extended error information, call GetLastError.</param>
        public static bool deleteFile(string filePath, ref int lastError)
        {
            if (!File.Exists(filePath)) return true;

            var deleted = DeleteFile(filePath);
            if (!deleted)
            {
                lastError = Marshal.GetLastWin32Error();
            }
            return deleted;
        }
        public delegate void LogDelegate(params object[] paramlist);
        public static void DeleteFileOrMove(string filepath, LogDelegate logfunction)
        {
            var lastError = 0;
            if (!deleteFile(filepath, ref lastError))
            {
                logfunction("failed to delete file: ", filepath, " error: ", lastError);
                moveFileEx(filepath);
            }
        }

        /// <summary>
        /// One time sql script conversion from SQLite syntax to MS SQL Server 
        /// all you need to know about Regex is here - http://rubular.com/r/kcqDdLJBpx
        /// </summary>
        /// <param name="script">SQLite script file path</param>
        /// <returns></returns>
        public static string ScriptFromSQLiteToSQL(string script)
        {
            if (string.IsNullOrEmpty(script)) return script;

            const string BLOB = "BLOB";
            const string NVCHAR = "NVCHAR";
            const string NVARCHAR = "NVARCHAR";
            const string COLLATE_NOCASE = "COLLATE NOCASE";
            const string Couldnt =  "Couldn't";
            const string Couldnot = "Could not";
            const string IDENTITY = "IDENTITY(1,1)";
            const string AUTOINCREMENT = "AUTOINCREMENT";
            const string varbinary_max = "varbinary(max)";
            const string varchar_max = "varchar(max)";
            const string max = "(max)";
            const string BigInt = "bigint";
            const string Integer = "integer";
            const string Int = "int";
            const string _2048 = "(2048)";
            const string _5000 = "(5000)";

            var sql = new StringBuilder();
            long count = 0;
            using (var inputStream = File.OpenRead(script))
            {
                using (var inputReader = new StreamReader(inputStream))
                {
                    string tempLineValue;

                    while (null != (tempLineValue = inputReader.ReadLine()))
                    {
                        Debug.Print("Line: " + count++);
                        var addGo = false;
                        const string dropTable = "DROP TABLE IF EXISTS";
                        const string dropTableNew = @"if exists(SELECT * FROM sysobjects where name = '{0}') DROP TABLE [dbo].[{0}];" ;
                        const string insertInto = "INSERT INTO";
                        const string convert = "convert(varbinary(max), {0})";

                        if (tempLineValue.StartsWith(dropTable))
                        {
                            var tableName = tempLineValue.Replace(dropTable, string.Empty).Replace("\"", string.Empty).Replace(";", string.Empty).Trim();
                            tempLineValue = string.Format(dropTableNew, tableName);
                            addGo = true;
                        }
                        else if (tempLineValue.StartsWith(insertInto))
                        {

                            //find SQLite (or C#) date (Format: '2016-06-06 15:15:38.0630927' )
                            const string patternSQLiteDate = @"(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2}).\d{3,7}";
                            var regexSQLiteDate = new Regex(patternSQLiteDate, RegexOptions.IgnoreCase);
                            var matchSQLiteDate = regexSQLiteDate.Match(tempLineValue);

                            while (matchSQLiteDate.Success)
                            {
                                var foundSQLiteDate = matchSQLiteDate.Value;

                                //find SQL date in SQLite date (Format: '2016-06-06 15:15:38.063' )
                                const string patternSQLDate = @"(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})";
                                var rDate = new Regex(patternSQLDate, RegexOptions.IgnoreCase);

                                var mDate = rDate.Match(foundSQLiteDate);
                                if (mDate.Success)
                                {
                                    //replace date
                                    tempLineValue = tempLineValue.Replace(foundSQLiteDate, mDate.Value);

                                }
                                matchSQLiteDate = matchSQLiteDate.NextMatch();

                            }
                            
                            const string patternBinary = @"[X]'\w+'";
                            var regexBinary = new Regex(patternBinary, RegexOptions.IgnoreCase);
                            var matchBinary = regexBinary.Match(tempLineValue);
                            while (matchBinary.Success)
                            {
                                var matchValue = matchBinary.Value;
                                var newValue = string.Format(convert, matchValue.Replace("X", string.Empty).Replace(",", string.Empty));
                                tempLineValue = tempLineValue.Replace(matchValue, newValue);
                                matchBinary = matchBinary.NextMatch();
                            }
                            addGo = true;
                        }
                        else
                        {
                            const string patternText = @"text\s{0,}\(\w+\)";
                            var regexText = new Regex(patternText, RegexOptions.IgnoreCase);
                            var matchText = regexText.Match(tempLineValue);
                            if (matchText.Success)
                            {
                                tempLineValue = tempLineValue.Replace(matchText.Value, varchar_max);
                            }

                            const string patternMaxMemory = @"\[MaxMemory\]\sinteger,";
                            var regexMaxMemory = new Regex(patternMaxMemory, RegexOptions.IgnoreCase);
                            var matchMaxMemory = regexMaxMemory.Match(tempLineValue);
                            if (matchMaxMemory.Success)
                            {
                                tempLineValue = tempLineValue.Replace(Integer, BigInt);
                            }

                        }
                        sql.AppendLine(tempLineValue);
                        if (addGo) sql.AppendLine("GO");
                    }
                }
            }
            return sql
                .Replace(AUTOINCREMENT, string.Empty)
                .Replace(Couldnt, Couldnot)
                .Replace(_2048, max)
                .Replace(_5000, max)
                .Replace(Integer, Int)
                .Replace(COLLATE_NOCASE, string.Empty)
                .Replace(BLOB, varbinary_max)
                .Replace(BLOB.ToLower(), varbinary_max)
                .Replace(NVCHAR, NVARCHAR)
                .Replace(NVCHAR.ToLower(), NVARCHAR).ToString(); 
        }

        #region File List
        private static List<string> _fileList = new List<string>();

        public static List<string> FileList { get => _fileList; set => _fileList = value; }

        private static List<string> _newFileList = new List<string>();

        public static List<string> NewFileList { get => _newFileList; set => _newFileList = value; }

        /// <summary>
        /// recursively search directory and subdirectories and return a list of files
        /// </summary>
        /// <param name="path"></param>
        /// <param name="pattern">*.dts</param>
        /// <returns></returns>
        public static void FindFiles(string path, string pattern)
        {
            _fileList.AddRange(FindFiles(path, pattern, SearchOption.AllDirectories));

        }
        /// <summary>
        /// Search directory and return a list of files
        /// </summary>
        /// <param name="path"></param>
        /// <param name="pattern">*.dts</param>
        /// <returns></returns>
        public static List<string> FindFilesInDirectory(string path, string pattern)
        {
            return FindFiles(path, pattern, SearchOption.TopDirectoryOnly);
        }

        private static List<string> FindFiles(string path, string pattern, SearchOption searchOption)
        {
            return Directory.GetFiles(path, "*" + pattern, searchOption).
                Select(fn => new FileInfo(fn)).
                OrderBy(f => Regex.Replace(f.Name, @"\d+", n => n.Value.PadLeft(4, '0'))).
                Select(f => f.FullName).
                ToList(); 
        }

        #endregion File List


        [StructLayout(LayoutKind.Sequential)]
        private struct RM_UNIQUE_PROCESS
        {
            public int dwProcessId;
            public System.Runtime.InteropServices.ComTypes.FILETIME ProcessStartTime;
        }

        private const int RmRebootReasonNone = 0;
        private const int CCH_RM_MAX_APP_NAME = 255;
        private const int CCH_RM_MAX_SVC_NAME = 63;

        private enum RM_APP_TYPE
        {
            RmUnknownApp = 0,
            RmMainWindow = 1,
            RmOtherWindow = 2,
            RmService = 3,
            RmExplorer = 4,
            RmConsole = 5,
            RmCritical = 1000
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        private struct RM_PROCESS_INFO
        {
            public RM_UNIQUE_PROCESS Process;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_APP_NAME + 1)]
            public string strAppName;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_SVC_NAME + 1)]
            public string strServiceShortName;

            public RM_APP_TYPE ApplicationType;
            public uint AppStatus;
            public uint TSSessionId;
            [MarshalAs(UnmanagedType.Bool)]
            public bool bRestartable;
        }

        [DllImport("rstrtmgr.dll", CharSet = CharSet.Unicode)]
        private static extern int RmRegisterResources(uint pSessionHandle,
                                              UInt32 nFiles,
                                              string[] rgsFilenames,
                                              UInt32 nApplications,
                                              [In] RM_UNIQUE_PROCESS[] rgApplications,
                                              UInt32 nServices,
                                              string[] rgsServiceNames);

        [DllImport("rstrtmgr.dll", CharSet = CharSet.Auto)]
        private static extern int RmStartSession(out uint pSessionHandle, int dwSessionFlags, string strSessionKey);

        [DllImport("rstrtmgr.dll")]
        private static extern int RmEndSession(uint pSessionHandle);

        [DllImport("rstrtmgr.dll")]
        private static extern int RmGetList(uint dwSessionHandle,
                                    out uint pnProcInfoNeeded,
                                    ref uint pnProcInfo,
                                    [In, Out] RM_PROCESS_INFO[] rgAffectedApps,
                                    ref uint lpdwRebootReasons);

        /// <summary>
        /// Find out what process(es) have a lock on the specified file.
        /// </summary>
        /// <param name="path">Path of the file.</param>
        /// <returns>Processes locking the file</returns>
        /// <remarks>See also:
        /// http://msdn.microsoft.com/en-us/library/windows/desktop/aa373661(v=vs.85).aspx
        /// http://wyupdate.googlecode.com/svn-history/r401/trunk/frmFilesInUse.cs (no copyright in code at time of viewing)
        /// 
        /// </remarks>
        public static List<Process> WhoIsLocking(string path)
        {
            uint handle;
            string key = Guid.NewGuid().ToString();
            List<Process> processes = new List<Process>();

            int res = RmStartSession(out handle, 0, key);
            if (res != 0) throw new Exception("Could not begin restart session.  Unable to determine file locker.");

            try
            {
                const int ERROR_MORE_DATA = 234;
                uint pnProcInfoNeeded = 0,
                     pnProcInfo = 0,
                     lpdwRebootReasons = RmRebootReasonNone;

                string[] resources = new string[] { path }; // Just checking on one resource.

                res = RmRegisterResources(handle, (uint)resources.Length, resources, 0, null, 0, null);

                if (res != 0) throw new Exception("Could not register resource.");

                //Note: there's a race condition here -- the first call to RmGetList() returns
                //      the total number of process. However, when we call RmGetList() again to get
                //      the actual processes this number may have increased.
                res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, null, ref lpdwRebootReasons);

                if (res == ERROR_MORE_DATA)
                {
                    // Create an array to store the process results
                    RM_PROCESS_INFO[] processInfo = new RM_PROCESS_INFO[pnProcInfoNeeded];
                    pnProcInfo = pnProcInfoNeeded;

                    // Get the list
                    res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, processInfo, ref lpdwRebootReasons);
                    if (res == 0)
                    {
                        processes = new List<Process>((int)pnProcInfo);

                        // Enumerate all of the results and add them to the 
                        // list to be returned
                        for (int i = 0; i < pnProcInfo; i++)
                        {
                            try
                            {
                                processes.Add(Process.GetProcessById(processInfo[i].Process.dwProcessId));
                            }
                            // catch the error -- in case the process is no longer running
                            catch (ArgumentException) { }
                        }
                    }
                    else throw new Exception("Could not list processes locking resource.");
                }
                else if (res != 0) throw new Exception("Could not list processes locking resource. Failed to get size of result.");
            }
            finally
            {
                RmEndSession(handle);
            }

            return processes;
        }
    }
}