Add versification table implementation

src/SIL.Machine/Corpora/FileParatextProjectSettingsParser.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Linq;
+using SIL.Scripture;
 
 namespace SIL.Machine.Corpora
 {
@@ -10,6 +11,7 @@ public class FileParatextProjectSettingsParser : ParatextProjectSettingsParserBa
         public FileParatextProjectSettingsParser(string projectDir)
         {
             _projectDir = projectDir;
+            Versification.Table.Implementation = new FileVersificationTable(projectDir);
         }
 
         protected override UsfmStylesheet CreateStylesheet(string fileName)

src/SIL.Machine/Corpora/FileVersificationTable.cs

@@ -0,0 +1,26 @@
+using System.IO;
+
+namespace SIL.Machine.Corpora
+{
+    public class FileVersificationTable : VersificationTableBase
+    {
+        private readonly string _projectDir;
+
+        public FileVersificationTable(string projectDir)
+        {
+            _projectDir = projectDir;
+        }
+
+        protected override string ProjectName => Path.GetFileName(_projectDir);
+
+        protected override bool FileExists(string fileName)
+        {
+            return File.Exists(Path.Combine(_projectDir, fileName));
+        }
+
+        protected override Stream OpenFile(string fileName)
+        {
+            return File.OpenRead(Path.Combine(_projectDir, fileName));
+        }
+    }
+}

src/SIL.Machine/Corpora/ParatextProjectSettingsParserBase.cs

@@ -40,22 +40,7 @@ public ParatextProjectSettings Parse()
             {
                 var guid = (string)settingsDoc.Root.Element("Guid");
                 string versName = ((ScrVersType)scrVersType).ToString() + "-" + guid;
-                if (Versification.Table.Implementation.Exists(versName))
-                {
-                    versification = new ScrVers(versName);
-                }
-                else
-                {
-                    using (var reader = new StreamReader(Open("custom.vrs")))
-                    {
-                        versification = Versification.Table.Implementation.Load(
-                            reader,
-                            "custom.vrs",
-                            versification,
-                            versName
-                        );
-                    }
-                }
+                versification = new ScrVers(versName);
             }
 
             var stylesheetFileName = (string)settingsDoc.Root.Element("StyleSheet") ?? "usfm.sty";

src/SIL.Machine/Corpora/VersificationTableBase.cs

@@ -0,0 +1,61 @@
+using System;
+using System.IO;
+using SIL.Scripture;
+
+namespace SIL.Machine.Corpora
+{
+    public abstract class VersificationTableBase : Versification.Table
+    {
+        protected abstract string ProjectName { get; }
+
+        protected override Versification Get(string versName)
+        {
+            if (!Exists(versName))
+            {
+                LoadVersification(ref versName);
+            }
+
+            return base.Get(versName);
+        }
+
+        public override bool VersificationFileExists(string versName)
+        {
+            string[] parts = versName.Split(new[] { '-' }, 2);
+            if (parts.Length == 1)
+                return base.VersificationFileExists(versName); // Not a custom versification
+            return FileExists("custom.vrs");
+        }
+
+        private void LoadVersification(ref string versName)
+        {
+            string[] parts = versName.Split(new[] { '-' }, 2);
+            if (parts.Length > 1)
+            {
+                bool isValidVersType = Enum.TryParse(parts[0], out ScrVersType versType);
+                if (!isValidVersType || versType == ScrVersType.Unknown)
+                    versType = ScrVersType.English;
+
+                ScrVers baseVers = new ScrVers(versType);
+                if (!FileExists("custom.vrs"))
+                {
+                    versName = parts[0];
+                }
+                else
+                {
+                    using (Stream stream = OpenFile("custom.vrs"))
+                    {
+                        Load(
+                            new StreamReader(stream),
+                            ProjectName != null ? Path.Combine(ProjectName, "custom.vrs") : null,
+                            baseVers,
+                            versName
+                        );
+                    }
+                }
+            }
+        }
+
+        protected abstract bool FileExists(string fileName);
+        protected abstract Stream OpenFile(string fileName);
+    }
+}

src/SIL.Machine/Corpora/ZipParatextProjectSettingsParser.cs

@@ -1,6 +1,7 @@
 using System.IO;
 using System.IO.Compression;
 using System.Linq;
+using SIL.Scripture;
 
 namespace SIL.Machine.Corpora
 {
@@ -11,6 +12,7 @@ public class ZipParatextProjectSettingsParser : ZipParatextProjectSettingsParser
         public ZipParatextProjectSettingsParser(ZipArchive archive)
         {
             _archive = archive;
+            Versification.Table.Implementation = new ZipVersificationTable(archive);
         }
 
         protected override bool Exists(string fileName)

src/SIL.Machine/Corpora/ZipVersificationTable.cs

@@ -0,0 +1,30 @@
+using System.IO;
+using System.IO.Compression;
+
+namespace SIL.Machine.Corpora
+{
+    public class ZipVersificationTable : VersificationTableBase
+    {
+        private readonly ZipArchive _archive;
+
+        public ZipVersificationTable(ZipArchive archive)
+        {
+            _archive = archive;
+        }
+
+        protected override string ProjectName => null;
+
+        protected override bool FileExists(string fileName)
+        {
+            return _archive.GetEntry(fileName) != null;
+        }
+
+        protected override Stream OpenFile(string fileName)
+        {
+            ZipArchiveEntry entry = _archive.GetEntry(fileName);
+            if (entry == null)
+                return null;
+            return entry.Open();
+        }
+    }
+}