update

FCS.Lib.Utility.csproj

@@ -53,12 +53,14 @@
   <ItemGroup>
     <Compile Include="ExtensionsEx.cs" />
     <Compile Include="Generators.cs" />
+    <Compile Include="GuidGenerator.cs" />
+    <Compile Include="GuidVersion.cs" />
     <Compile Include="IRepository.cs" />
     <Compile Include="IAsyncReadonlyRepo.cs" />
     <Compile Include="IRepositoryEx.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="VatFormatValidator.cs" />
-    <Compile Include="Mogrifiers.cs" />
+    <Compile Include="Mogrify.cs" />
     <Compile Include="QueryHelper.cs" />
     <Compile Include="StringOptions.cs" />
     <Compile Include="Squid.cs" />

FCS.Lib.Utility.csproj.user

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <ProjectView>ProjectFiles</ProjectView>
+    <ProjectView>ShowAllFiles</ProjectView>
   </PropertyGroup>
 </Project>

GuidGenerator.cs

@@ -0,0 +1,157 @@
+using System;
+using System.Text;
+
+namespace FCS.Lib.Utility
+{
+    /// <summary>
+    /// Used for generating UUID based on RFC 4122.
+    /// </summary>
+    /// <seealso href="http://www.ietf.org/rfc/rfc4122.txt">RFC 4122 - A Universally Unique IDentifier (UUID) URN Namespace</seealso>
+    public static class GuidGenerator
+    {
+        // number of bytes in guid
+        public const int ByteArraySize = 16;
+
+        // multiplex variant info
+        public const int VariantByte = 8;
+        public const int VariantByteMask = 0x3f;
+        public const int VariantByteShift = 0x80;
+
+        // multiplex version info
+        public const int VersionByte = 7;
+        public const int VersionByteMask = 0x0f;
+        public const int VersionByteShift = 4;
+
+        // indexes within the uuid array for certain boundaries
+        private const byte TimestampByte = 0;
+        private const byte GuidClockSequenceByte = 8;
+        private const byte NodeByte = 10;
+
+        // offset to move from 1/1/0001, which is 0-time for .NET, to gregorian 0-time of 10/15/1582
+        private static readonly DateTimeOffset GregorianCalendarStart = new(1582, 10, 15, 0, 0, 0, TimeSpan.Zero);
+
+        // random clock sequence and node
+        public static byte[] DefaultClockSequence { get; set; }
+        public static byte[] DefaultNode { get; set; }
+
+        static GuidGenerator()
+        {
+            DefaultClockSequence = new byte[2];
+            DefaultNode = new byte[6];
+
+            var random = new Random();
+            random.NextBytes(DefaultClockSequence);
+            random.NextBytes(DefaultNode);
+        }
+
+        public static void SetDefaultNode(string nodeName)
+        {
+            var x = nodeName.GetHashCode();
+            var node = $"{x:X}";
+            DefaultNode = Encoding.UTF8.GetBytes(node.ToCharArray(), 0, 6);
+        }
+        public static GuidVersion GetVersion(this Guid guid)
+        {
+            var bytes = guid.ToByteArray();
+            return (GuidVersion)((bytes[VersionByte] & 0xFF) >> VersionByteShift);
+        }
+
+        public static DateTimeOffset GetDateTimeOffset(Guid guid)
+        {
+            var bytes = guid.ToByteArray();
+
+            // reverse the version
+            bytes[VersionByte] &= VersionByteMask;
+            bytes[VersionByte] |= (byte)GuidVersion.TimeBased >> VersionByteShift;
+
+            var timestampBytes = new byte[8];
+            Array.Copy(bytes, TimestampByte, timestampBytes, 0, 8);
+
+            var timestamp = BitConverter.ToInt64(timestampBytes, 0);
+            var ticks = timestamp + GregorianCalendarStart.Ticks;
+
+            return new DateTimeOffset(ticks, TimeSpan.Zero);
+        }
+
+        public static DateTime GetDateTime(Guid guid)
+        {
+            return GetDateTimeOffset(guid).DateTime;
+        }
+
+        public static DateTime GetLocalDateTime(Guid guid)
+        {
+            return GetDateTimeOffset(guid).LocalDateTime;
+        }
+
+        public static DateTime GetUtcDateTime(Guid guid)
+        {
+            return GetDateTimeOffset(guid).UtcDateTime;
+        }
+
+        public static Guid GenerateTimeBasedGuid()
+        {
+            return GenerateTimeBasedGuid(DateTimeOffset.UtcNow, DefaultClockSequence, DefaultNode);
+        }
+
+        public static Guid GenerateTimeBasedGuid(string nodeName)
+        {
+            var x = nodeName.GetHashCode();
+            var node = $"{x:X}";
+            var defaultNode = Encoding.UTF8.GetBytes(node.ToCharArray(), 0, 6);
+            return GenerateTimeBasedGuid(DateTimeOffset.UtcNow, DefaultClockSequence, defaultNode);
+        }
+
+        public static Guid GenerateTimeBasedGuid(DateTime dateTime)
+        {
+            return GenerateTimeBasedGuid(dateTime, DefaultClockSequence, DefaultNode);
+        }
+
+        public static Guid GenerateTimeBasedGuid(DateTimeOffset dateTime)
+        {
+            return GenerateTimeBasedGuid(dateTime, DefaultClockSequence, DefaultNode);
+        }
+
+        public static Guid GenerateTimeBasedGuid(DateTime dateTime, byte[] clockSequence, byte[] node)
+        {
+            return GenerateTimeBasedGuid(new DateTimeOffset(dateTime), clockSequence, node);
+        }
+
+        public static Guid GenerateTimeBasedGuid(DateTimeOffset dateTime, byte[] clockSequence, byte[] node)
+        {
+            if (clockSequence == null)
+                throw new ArgumentNullException(nameof(clockSequence));
+
+            if (node == null)
+                throw new ArgumentNullException(nameof(node));
+
+            if (clockSequence.Length != 2)
+                throw new ArgumentOutOfRangeException(nameof(clockSequence), "The clockSequence must be 2 bytes.");
+
+            if (node.Length != 6)
+                throw new ArgumentOutOfRangeException(nameof(node), "The node must be 6 bytes.");
+
+            var ticks = (dateTime - GregorianCalendarStart).Ticks;
+            var guid = new byte[ByteArraySize];
+            var timestamp = BitConverter.GetBytes(ticks);
+
+            // copy node
+            Array.Copy(node, 0, guid, NodeByte, Math.Min(6, node.Length));
+
+            // copy clock sequence
+            Array.Copy(clockSequence, 0, guid, GuidClockSequenceByte, Math.Min(2, clockSequence.Length));
+
+            // copy timestamp
+            Array.Copy(timestamp, 0, guid, TimestampByte, Math.Min(8, timestamp.Length));
+
+            // set the variant
+            guid[VariantByte] &= VariantByteMask;
+            guid[VariantByte] |= VariantByteShift;
+
+            // set the version
+            guid[VersionByte] &= VersionByteMask;
+            guid[VersionByte] |= (byte)GuidVersion.TimeBased << VersionByteShift;
+
+            return new Guid(guid);
+        }
+    }
+}

GuidVersion.cs

@@ -0,0 +1,11 @@
+namespace FCS.Lib.Utility
+{
+    // guid version types
+    public enum GuidVersion
+    {
+        TimeBased = 0x01,
+        Reserved = 0x02,
+        NameBased = 0x03,
+        Random = 0x04
+    }
+}

Mogrify.cs

@@ -6,7 +6,7 @@
 // Last Modified By : Frede H.
 // Last Modified On : 02-24-2022
 // ***********************************************************************
-// <copyright file="Mogrifiers.cs" company="FCS">
+// <copyright file="Mogrify.cs" company="FCS">
 //    Copyright (C) 2022 FCS Frede's Computer Services.
 //    This program is free software: you can redistribute it and/or modify
 //    it under the terms of the Affero GNU General Public License as
@@ -35,8 +35,18 @@ using System.Text.RegularExpressions;
 
 namespace FCS.Lib.Utility
 {
-    public static class Mogrifiers
+    public static class Mogrify
     {
+        public static int MonthFromTimestamp(long timeStamp)
+        {
+            return TimeStampToDateTime(timeStamp).Month;
+        }
+
+        public static bool TimestampInMonth(long timestamp, int month)
+        {
+            return TimeStampToDateTime(timestamp).Month == month;
+        }
+
         public static Dictionary<string,long> DateToTimestampRange(DateTime dateTime)
         {
             var dt1 = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day,0,0,0);