[WIP|Draft|Spike] First try using Pidgin Parser lib for WKT1Parser.

src/ProjNet/ProjNET.csproj

@@ -36,4 +36,8 @@ Proj.NET performs point-to-point coordinate conversions between geodetic coordin
 		<ResolvedMatchingContract Include="$(NugetPackageRoot)projnet\2.0.0\lib\netstandard2.0\ProjNET.dll" />
 	</ItemGroup>
 
+	<ItemGroup> 
+	  <PackageReference Include="Pidgin" Version="2.5.0" />
+	</ItemGroup>
+
 </Project>

src/ProjNet/Wkt/Utils.cs

@@ -0,0 +1,26 @@
+using System;
+
+namespace ProjNet.Wkt
+{
+    /// <summary>
+    /// Helper functions for WKT Parser(s).
+    /// </summary>
+    public class Utils
+    {
+        internal static double CalcAsFractionOf(uint i, uint f)
+        {
+            // Convert f to string to count the digits
+            string fstr = f.ToString();
+            int fractionDigits = fstr.Length;
+
+            double d = i;
+
+            // Calculate the fractional part from f based on the number of fractional digits
+            double divisor = Math.Pow(10, fractionDigits);
+            double fractionPart = f / divisor;
+
+            // Sum i and the fractional part
+            return d + fractionPart;
+        }
+    }
+}

src/ProjNet/Wkt/v1/DateTimeBuilder.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Globalization;
+using Pidgin;
+
+namespace ProjNet.Wkt.v1
+{
+    internal sealed class DateTimeBuilder
+    {
+        internal int? Year { get; set; }
+        internal int? Month { get; set; }
+        internal int? Day { get; set; }
+
+        internal uint? OrdinalDay { get; set; }
+
+        internal int? Hour { get; set; }
+        internal int? Minutes { get; set; }
+        internal int? Seconds { get; set; }
+        internal int? Milliseconds { get; set; }
+
+        internal TimeSpan? LocalOffset { get; set; }
+
+        internal DateTimeKind Kind { get; set; } = DateTimeKind.Unspecified;
+
+
+        public DateTimeBuilder SetYear(int y)
+        {
+            Year = y;
+            return this;
+        }
+        public DateTimeBuilder SetMonth(int m)
+        {
+            Month = m;
+            return this;
+        }
+        public DateTimeBuilder SetDay(int d)
+        {
+            Day = d;
+            return this;
+        }
+
+        public DateTimeBuilder SetHour(int h)
+        {
+            Hour = h;
+            return this;
+        }
+        public DateTimeBuilder SetMinutes(int m)
+        {
+            Minutes = m;
+            return this;
+        }
+        public DateTimeBuilder SetSeconds(int s)
+        {
+            Seconds = s;
+            return this;
+        }
+        public DateTimeBuilder SetMilliseconds(int ms)
+        {
+            Milliseconds = ms;
+            return this;
+        }
+
+        public DateTimeBuilder SetOrdinalDay(Maybe<uint> od)
+        {
+            OrdinalDay = od.HasValue ? od.GetValueOrDefault() : OrdinalDay;
+            return this;
+        }
+
+
+        public DateTimeBuilder SetKind(DateTimeKind k)
+        {
+            Kind = k;
+            return this;
+        }
+
+        public DateTimeBuilder SetLocalOffset(TimeSpan lo)
+        {
+            if (lo == TimeSpan.Zero)
+            {
+                Kind = DateTimeKind.Utc;
+            }
+            else
+            {
+                LocalOffset = lo;
+                Kind = DateTimeKind.Local;
+            }
+
+            return this;
+        }
+
+        public DateTimeBuilder Merge(DateTimeBuilder other)
+        {
+            Day = Day ?? other.Day;
+            Month = Month ?? other.Month;
+            Year = Year ?? other.Year;
+
+            Hour = Hour ?? other.Hour;
+            Minutes = Minutes ?? other.Minutes;
+            Seconds = Seconds ?? other.Seconds;
+            Milliseconds = Milliseconds ?? other.Milliseconds;
+
+            OrdinalDay = OrdinalDay ?? other.OrdinalDay;
+            Kind = Kind == DateTimeKind.Unspecified ? other.Kind : Kind;
+            LocalOffset = LocalOffset ?? other.LocalOffset;
+
+            return this;
+        }
+
+        public DateTimeOffset ToDateTimeOffset()
+        {
+            var dt = new DateTime(Year.GetValueOrDefault(), Month.GetValueOrDefault(), Day.GetValueOrDefault(),
+                Hour.GetValueOrDefault(), Minutes.GetValueOrDefault(), Seconds.GetValueOrDefault(),
+                Milliseconds.GetValueOrDefault(),
+                new GregorianCalendar(),
+                Kind);
+
+            return new DateTimeOffset(dt, LocalOffset.GetValueOrDefault());
+        }
+    }
+}

src/ProjNet/Wkt/v1/tree/AreaDescription.cs

@@ -0,0 +1,34 @@
+using System.Globalization;
+using System.Text;
+
+namespace ProjNet.Wkt.v1.tree
+{
+    /// <summary>
+    /// Area description is an optional attribute which describes a geographic area over which a CRS or coordinate operation is applicable.
+    /// </summary>
+    /// <remarks>
+    /// See 7.3.3.2 Area description in specification document.
+    /// </remarks>
+    public class AreaDescription : Extent
+    {
+        /// <summary>
+        /// The Text Description.
+        /// </summary>
+        public string Description { get; set; }
+
+        /// <summary>
+        /// AreaDescriptionParser to WKT.
+        /// </summary>
+        /// <returns></returns>
+        public override string ToWKT()
+        {
+            var sb = new StringBuilder();
+
+            sb.Append("AREA[\"");
+            sb.Append(Description);
+            sb.Append("\"]");
+
+            return sb.ToString();
+        }
+    }
+}

src/ProjNet/Wkt/v1/tree/AuthorityCitation.cs

@@ -0,0 +1,28 @@
+using System.Text;
+
+namespace ProjNet.Wkt.v1.tree
+{
+    /// <summary>
+    /// AuthorityCitation a simple wkt helper class containing a (sub) Attribute.
+    /// </summary>
+    public class AuthorityCitation: IWktAttribute
+    {
+        private string Citation { get; set; }
+
+        public AuthorityCitation(string citation)
+        {
+            Citation = citation;
+        }
+
+        public string ToWKT()
+        {
+            var sb = new StringBuilder();
+
+            sb.Append($@"CITATION[""");
+            sb.Append(Citation);
+            sb.Append($@"""]");
+
+            return sb.ToString();
+        }
+    }
+}

src/ProjNet/Wkt/v1/tree/BBox.cs

@@ -0,0 +1,56 @@
+using System.Globalization;
+using System.Text;
+
+namespace ProjNet.Wkt.v1.tree
+{
+    /// <summary>
+    /// BoundingBox is an optional WKT attribute.
+    /// </summary>
+    /// <remarks>
+    /// See 7.3.3.3 Geographic bounding box in specification document.
+    /// </remarks>
+    public class BBox : Extent
+    {
+        /// <summary>
+        /// The lower left latitude (Ymin)
+        /// </summary>
+        public double LowerLeftLatitude { get; set; }
+
+        /// <summary>
+        /// The lower left longitude (Xmin)
+        /// </summary>
+        public double LowerLeftLongitude { get; set; }
+
+        /// <summary>
+        /// The upper right latitude (Ymax)
+        /// </summary>
+        public double UpperRightLatitude { get; set; }
+
+        /// <summary>
+        /// The upper right longitude (Xmax)
+        /// </summary>
+        public double UpperRightLongitude { get; set; }
+
+
+        /// <summary>
+        /// BBox to WKT.
+        /// </summary>
+        /// <returns></returns>
+        public override string ToWKT()
+        {
+            var sb = new StringBuilder();
+
+            sb.Append("BBOX[");
+            sb.Append(LowerLeftLatitude.ToString(CultureInfo.InvariantCulture));
+            sb.Append(",");
+            sb.Append(LowerLeftLongitude.ToString(CultureInfo.InvariantCulture));
+            sb.Append(",");
+            sb.Append(UpperRightLatitude.ToString(CultureInfo.InvariantCulture));
+            sb.Append(",");
+            sb.Append(UpperRightLongitude.ToString(CultureInfo.InvariantCulture));
+            sb.Append("]");
+
+            return sb.ToString();
+        }
+    }
+}

src/ProjNet/Wkt/v1/tree/Extent.cs

@@ -0,0 +1,8 @@
+namespace ProjNet.Wkt.v1.tree
+{
+    public abstract class Extent : IWktAttribute
+    {
+        public abstract string ToWKT();
+
+    }
+}

src/ProjNet/Wkt/v1/tree/IWktAttribute.cs

@@ -0,0 +1,10 @@
+namespace ProjNet.Wkt.v1.tree
+{
+    /// <summary>
+    /// Interface for specifying WKT Attributes.
+    /// </summary>
+    public interface IWktAttribute
+    {
+        string ToWKT();
+    }
+}

src/ProjNet/Wkt/v1/tree/Identifier.cs

@@ -0,0 +1,89 @@
+
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace ProjNet.Wkt.v1.tree
+{
+    /// <summary>
+    /// Identifier is an optional attribute which references an external
+    /// description of the object and which may be applied to a coordinate reference system, a coordinate
+    /// operation or a boundCRS. It may also be utilised for components of these objects although this
+    /// is not recommended except for coordinate operation methods (including map projections)
+    /// and parameters. Multiple identifiers may be given for any object.
+    ///
+    /// When an identifier is given for a coordinate reference system, coordinate operation or boundCRS,
+    /// it applies to the whole object including all of its components.
+    ///
+    /// Should any attributes or values given in the cited identifier be in conflict with attributes
+    /// or values given explicitly in the WKT description, the WKT values shall prevail.
+    /// </summary>
+    /// <remarks>
+    /// See 7.3.4 Identifier in specification document.
+    /// </remarks>
+    public class Identifier : IWktAttribute
+    {
+        /// <summary>
+        /// AuthorityName
+        /// </summary>
+        public string AuthorityName { get; set; }
+
+        /// <summary>
+        /// AuthorityUniqueIdentifier
+        /// </summary>
+        public object AuthorityUniqueIdentifier { get; set; }
+
+        /// <summary>
+        /// Version (Optional)
+        /// </summary>
+        public object Version { get; set; }
+
+        /// <summary>
+        /// AuthorityCitation (Optional)
+        /// </summary>
+        public  AuthorityCitation AuthorityCitation { get; set; }
+
+        /// <summary>
+        /// Id Uri (Optional)
+        /// </summary>
+        /// <returns></returns>
+        public Uri IdUri { get; set; }
+
+
+        public string ToWKT()
+        {
+            var sb = new StringBuilder();
+
+            sb.Append("ID[");
+
+            sb.Append($@"""{AuthorityName}""");
+            sb.Append($@"""{AuthorityUniqueIdentifier}""");
+
+            if (Version != null)
+            {
+                if (Version is double d)
+                {
+                    sb.Append(d.ToString(CultureInfo.InvariantCulture));
+                }
+                else if (Version is string vs)
+                {
+                    sb.Append($@"""{vs}""");
+                }
+            }
+
+            if (AuthorityCitation != null)
+            {
+                sb.Append(AuthorityCitation.ToWKT());
+            }
+
+            if (IdUri != null)
+            {
+                sb.Append(IdUri.ToWKT());
+            }
+
+            sb.Append("]");
+
+            return sb.ToString();
+        }
+    }
+}