Expose DSID product specification subfields (PRSP, PSDN, PRED, PROF)

src/EncDotNet.S57/S57DataSetIdentification.cs

@@ -29,7 +29,7 @@ public sealed record S57DataSetIdentification
     /// <summary>Gets the edition date (STED).</summary>
     public string S57EditionNumber { get; init; } = string.Empty;
 
-    /// <summary>Gets the producing agency code (PRSP).</summary>
+    /// <summary>Gets the producing agency code (AGEN).</summary>
     public int ProducingAgency { get; init; }
 
     /// <summary>Gets the data structure (DSTR).</summary>
@@ -43,4 +43,27 @@ public sealed record S57DataSetIdentification
 
     /// <summary>Gets the comment (COMT).</summary>
     public string Comment { get; init; } = string.Empty;
+
+    /// <summary>Gets the product specification code (PRSP).</summary>
+    /// <remarks>
+    /// S-57 Edition 3.1, Part 3 §7.3.1.1 enumerates 1 = ENC (Electronic Navigational Chart) and
+    /// 2 = ODD (IHO Object Catalogue Data Dictionary). Inland ENC producers declare 10.
+    /// When the data set uses the ASCII lexical form, the mnemonics <c>ENC</c> and <c>ODD</c> are
+    /// mapped to 1 and 2. The value is 0 when the subfield is absent.
+    /// </remarks>
+    public int ProductSpecification { get; init; }
+
+    /// <summary>Gets the product specification description (PSDN).</summary>
+    public string ProductSpecificationDescription { get; init; } = string.Empty;
+
+    /// <summary>Gets the product specification edition number (PRED), for example "2.0".</summary>
+    public string ProductSpecificationEdition { get; init; } = string.Empty;
+
+    /// <summary>Gets the application profile identification code (PROF).</summary>
+    /// <remarks>
+    /// S-57 Edition 3.1, Part 3 §7.3.1.1 enumerates 1 = EN (ENC new), 2 = ER (ENC revision) and
+    /// 3 = DD (IHO data dictionary). When the data set uses the ASCII lexical form, those mnemonics
+    /// are mapped to their numeric codes. The value is 0 when the subfield is absent.
+    /// </remarks>
+    public int ApplicationProfile { get; init; }
 }

src/EncDotNet.S57/S57DocumentReader.cs

@@ -1,5 +1,6 @@
 using System.Buffers.Binary;
 using System.Collections.Immutable;
+using System.Globalization;
 using EncDotNet.Iso8211;
 using Microsoft.Extensions.Logging;
 
@@ -186,6 +187,8 @@ private static S57DataSetIdentification ParseDataSetIdentification(Iso8211Record
         string dsnm, edtn, updn, uadt, isdt, sted;
         ushort agen = 0;
         string comt = "";
+        int prsp = 0, prof = 0;
+        string psdn = "", pred = "";
 
         var fieldDef = ddr?.GetFieldDefinition(S57FieldTags.DSID)
             ?? throw new InvalidOperationException("DDR is required but not available. DSID field definition not found.");
@@ -204,6 +207,24 @@ private static S57DataSetIdentification ParseDataSetIdentification(Iso8211Record
         isdt = reader.GetSubfield<string>(S57SubfieldNames.ISDT);
         sted = reader.GetSubfield<string>(S57SubfieldNames.STED);
 
+        // PRSP and PROF are b11 in the binary form but mnemonics (A(3) / A(2)) in the ASCII form,
+        // so read them as strings (binary values convert to their decimal text) and map to codes.
+        if (reader.TryGetSubfield<string>(S57SubfieldNames.PRSP, out var prspValue))
+        {
+            prsp = ParseCodedSubfield(prspValue, ProductSpecificationMnemonics);
+        }
+        if (reader.TryGetSubfield<string>(S57SubfieldNames.PSDN, out var psdnValue))
+        {
+            psdn = psdnValue;
+        }
+        if (reader.TryGetSubfield<string>(S57SubfieldNames.PRED, out var predValue))
+        {
+            pred = predValue;
+        }
+        if (reader.TryGetSubfield<string>(S57SubfieldNames.PROF, out var profValue))
+        {
+            prof = ParseCodedSubfield(profValue, ApplicationProfileMnemonics);
+        }
         if (reader.TryGetSubfield<ushort>(S57SubfieldNames.AGEN, out var agenValue))
         {
             agen = agenValue;
@@ -240,10 +261,35 @@ private static S57DataSetIdentification ParseDataSetIdentification(Iso8211Record
             DataStructure = dstr,
             AttfLexicalLevel = aall,
             NatfLexicalLevel = nall,
-            Comment = comt
+            Comment = comt,
+            ProductSpecification = prsp,
+            ProductSpecificationDescription = psdn,
+            ProductSpecificationEdition = pred,
+            ApplicationProfile = prof
         };
     }
 
+    private static readonly string[] ProductSpecificationMnemonics = ["ENC", "ODD"];
+
+    private static readonly string[] ApplicationProfileMnemonics = ["EN", "ER", "DD"];
+
+    /// <summary>
+    /// Converts a coded DSID subfield value to its numeric code. Accepts either the decimal text of
+    /// a binary value or an ASCII mnemonic (whose 1-based position in <paramref name="mnemonics"/>
+    /// is its code). Returns 0 for empty or unrecognized values.
+    /// </summary>
+    private static int ParseCodedSubfield(string value, string[] mnemonics)
+    {
+        var trimmed = value.Trim();
+        if (int.TryParse(trimmed, NumberStyles.Integer, CultureInfo.InvariantCulture, out var code))
+        {
+            return code;
+        }
+
+        var index = Array.IndexOf(mnemonics, trimmed.ToUpperInvariant());
+        return index >= 0 ? index + 1 : 0;
+    }
+
     /// <summary>
     /// Parses a Data Set Parameters record.
     /// </summary>

tests/EndDotNet.UnitTests/S57DocumentReaderTests.cs

@@ -48,7 +48,7 @@ private static byte[] CreateS57Document(params byte[][] dataRecords)
     /// <summary>
     /// Creates an S-57 Data Descriptive Record (DDR) with all required field definitions.
     /// </summary>
-    private static byte[] CreateS57Ddr()
+    private static byte[] CreateS57Ddr(string? dsidDescriptors = null, string? dsidFormats = null)
     {
         // Build all field definitions for DDR
         var fields = new List<(string tag, byte[] data)>();
@@ -60,8 +60,8 @@ private static byte[] CreateS57Ddr()
         // Format: RCNM(b11), RCID(b14), EXPP(b11), INTU(b11), DSNM(A), EDTN(A), UPDN(A), UADT(A), ISDT(A), STED(A), PRSP(b11), PSDN(A), PRED(A), PROF(b11), AGEN(b12), COMT(A)
         fields.Add(("DSID", CreateDdrFieldData(
             "DSID",
-            "RCNM!RCID!EXPP!INTU!DSNM!EDTN!UPDN!UADT!ISDT!STED!PRSP!PSDN!PRED!PROF!AGEN!COMT",
-            "(b11,b14,b11,b11,A,A,A,A,A,A,b11,A,A,b11,b12,A)")));
+            dsidDescriptors ?? "RCNM!RCID!EXPP!INTU!DSNM!EDTN!UPDN!UADT!ISDT!STED!PRSP!PSDN!PRED!PROF!AGEN!COMT",
+            dsidFormats ?? "(b11,b14,b11,b11,A,A,A,A,A,A,b11,A,A,b11,b12,A)")));
 
         // DSSI - Data Set Structure Information Field
         // Format: DSTR(b11), AALL(b11), NALL(b11), NOMR(b14), NOCR(b14), NOGR(b14), NOLR(b14), NOIN(b14), NOCN(b14), NOED(b14), NOFA(b14)
@@ -290,7 +290,11 @@ private static byte[] CreateDsidRecord(
         string uadt = "20250101",
         string isdt = "20250101",
         string sted = "03.1",
-        ushort agen = 540)
+        ushort agen = 540,
+        byte prsp = 1,
+        string psdn = "",
+        string pred = "",
+        byte prof = 1)
     {
         // Build DSID field data
         using var ms = new MemoryStream();
@@ -306,10 +310,10 @@ private static byte[] CreateDsidRecord(
         WriteString(writer, uadt);    // UADT
         WriteString(writer, isdt);    // ISDT
         WriteString(writer, sted);    // STED
-        writer.Write((byte)1);        // PRSP
-        WriteString(writer, "");      // PSDN
-        WriteString(writer, "");      // PRED
-        writer.Write((byte)1);        // PROF
+        writer.Write(prsp);           // PRSP
+        WriteString(writer, psdn);    // PSDN
+        WriteString(writer, pred);    // PRED
+        writer.Write(prof);           // PROF
         writer.Write(agen);           // AGEN
         WriteString(writer, "");      // COMT
         writer.Write((byte)0x1E);     // Field terminator
@@ -739,6 +743,106 @@ public void Read_DocumentWithDsid_ParsesDataSetIdentification()
         Assert.Equal(540, document.DataSetIdentification.ProducingAgency);
     }
 
+    [Theory]
+    [InlineData(1, "", "2.0", 1)]
+    [InlineData(10, "Inland ENC", "2.4", 2)]
+    public void Read_DocumentWithDsid_ParsesProductSpecification(byte prsp, string psdn, string pred, byte prof)
+    {
+        // Arrange
+        var dsidRecord = CreateDsidRecord(prsp: prsp, psdn: psdn, pred: pred, prof: prof);
+        var data = CreateS57Document(dsidRecord);
+
+        // Act
+        var document = S57DocumentReader.Read(data);
+
+        // Assert
+        Assert.NotNull(document.DataSetIdentification);
+        Assert.Equal(prsp, document.DataSetIdentification.ProductSpecification);
+        Assert.Equal(psdn, document.DataSetIdentification.ProductSpecificationDescription);
+        Assert.Equal(pred, document.DataSetIdentification.ProductSpecificationEdition);
+        Assert.Equal(prof, document.DataSetIdentification.ApplicationProfile);
+        Assert.Equal(540, document.DataSetIdentification.ProducingAgency);
+    }
+
+    [Theory]
+    [InlineData("ENC", "EN", 1, 1)]
+    [InlineData("ODD", "DD", 2, 3)]
+    [InlineData("10", "ER", 10, 2)]
+    public void Read_DocumentWithAsciiDsid_MapsProductSpecificationMnemonics(string prsp, string prof, int expectedPrsp, int expectedProf)
+    {
+        // Arrange: PRSP and PROF use their ASCII (A) form instead of b11
+        var ddr = CreateS57Ddr(dsidFormats: "(b11,b14,b11,b11,A,A,A,A,A,A,A,A,A,A,b12,A)");
+
+        using var ms = new MemoryStream();
+        using var writer = new BinaryWriter(ms);
+        writer.Write((byte)10);       // RCNM
+        writer.Write(1u);             // RCID
+        writer.Write((byte)1);        // EXPP
+        writer.Write((byte)5);        // INTU
+        WriteString(writer, "TEST");  // DSNM
+        WriteString(writer, "1");     // EDTN
+        WriteString(writer, "0");     // UPDN
+        WriteString(writer, "");      // UADT
+        WriteString(writer, "");      // ISDT
+        WriteString(writer, "03.1");  // STED
+        WriteString(writer, prsp);    // PRSP
+        WriteString(writer, "");      // PSDN
+        WriteString(writer, "2.4");   // PRED
+        WriteString(writer, prof);    // PROF
+        writer.Write((ushort)540);    // AGEN
+        WriteString(writer, "");      // COMT
+        writer.Write((byte)0x1E);     // Field terminator
+
+        var data = ddr.Concat(CreateDataRecord("DSID", ms.ToArray())).ToArray();
+
+        // Act
+        var document = S57DocumentReader.Read(data);
+
+        // Assert
+        Assert.NotNull(document.DataSetIdentification);
+        Assert.Equal(expectedPrsp, document.DataSetIdentification.ProductSpecification);
+        Assert.Equal("2.4", document.DataSetIdentification.ProductSpecificationEdition);
+        Assert.Equal(expectedProf, document.DataSetIdentification.ApplicationProfile);
+    }
+
+    [Fact]
+    public void Read_DocumentWithDsidWithoutProductSpecification_DefaultsToEmpty()
+    {
+        // Arrange: DSID definition omits PRSP, PSDN, PRED and PROF
+        var ddr = CreateS57Ddr(
+            dsidDescriptors: "RCNM!RCID!EXPP!INTU!DSNM!EDTN!UPDN!UADT!ISDT!STED!AGEN!COMT",
+            dsidFormats: "(b11,b14,b11,b11,A,A,A,A,A,A,b12,A)");
+
+        using var ms = new MemoryStream();
+        using var writer = new BinaryWriter(ms);
+        writer.Write((byte)10);       // RCNM
+        writer.Write(1u);             // RCID
+        writer.Write((byte)1);        // EXPP
+        writer.Write((byte)5);        // INTU
+        WriteString(writer, "TEST");  // DSNM
+        WriteString(writer, "1");     // EDTN
+        WriteString(writer, "0");     // UPDN
+        WriteString(writer, "");      // UADT
+        WriteString(writer, "");      // ISDT
+        WriteString(writer, "03.1");  // STED
+        writer.Write((ushort)540);    // AGEN
+        WriteString(writer, "");      // COMT
+        writer.Write((byte)0x1E);     // Field terminator
+
+        var data = ddr.Concat(CreateDataRecord("DSID", ms.ToArray())).ToArray();
+
+        // Act
+        var document = S57DocumentReader.Read(data);
+
+        // Assert
+        Assert.NotNull(document.DataSetIdentification);
+        Assert.Equal(0, document.DataSetIdentification.ProductSpecification);
+        Assert.Equal(string.Empty, document.DataSetIdentification.ProductSpecificationDescription);
+        Assert.Equal(string.Empty, document.DataSetIdentification.ProductSpecificationEdition);
+        Assert.Equal(0, document.DataSetIdentification.ApplicationProfile);
+        Assert.Equal(540, document.DataSetIdentification.ProducingAgency);
+    }
+
     [Fact]
     public void Read_DocumentWithDspm_ParsesDataSetParameters()
     {