feat: improve DXF export and cross-platform file handling

- PepSettings: add DrawingsDirectory property for DXF endpoint config
- DrawingDxfExporter: support subprogram calls, skip non-cut linear moves,
  remove spurious radians-to-degrees conversion on arc angles, set AC1018 DXF version
- DrawingReader: handle .loop-info/.cadsnapshot entries gracefully, derive
  DrawingInfo from loop names when .info entry is absent, use FileShare.Read
- DrawingInfoReader: use TryParse instead of Parse for material number
- Drawing: make GetLoopName public (used by DrawingDxfExporter)
- ZipHelper: use FileShare.Read to allow concurrent readers on Windows/Linux
- NestFilterData: skip status filter when value is "All"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PepApi.Core/Configuration/PepSettings.cs

@@ -4,4 +4,5 @@ public class PepSettings
 {
     public string NestDirectory { get; set; } = string.Empty;
     public string MaterialsFile { get; set; } = string.Empty;
+    public string DrawingsDirectory { get; set; } = string.Empty;
 }

PepApi.Core/Models/NestFilterData.cs

@@ -77,7 +77,7 @@ namespace PepApi.Core.Models
                 nests = nests.Where(n => n.DateCreated <= this.EndDate);
             }
 
-            if (this.Status != null)
+            if (this.Status != null && !this.Status.Equals("All", StringComparison.OrdinalIgnoreCase))
             {
                 var x = this.Status.ToUpper();
                 nests = nests.Where(n => n.Status.ToUpper() == x);

PepLib.Core/IO/DrawingDxfExporter.cs

@@ -1,4 +1,4 @@
-using ACadSharp;
+using ACadSharp;
 using ACadSharp.IO;
 using ACadSharp.Tables;
 using CSMath;
@@ -17,13 +17,43 @@ public static class DrawingDxfExporter
     public static Stream Export(Drawing drawing)
     {
         var doc = new CadDocument();
+        doc.Header.Version = ACadVersion.AC1018;
+
+        // Collect loop IDs that are called as subprograms so we skip drawing them as top-level
+        var subprogramIds = new HashSet<int>();
+        foreach (var loop in drawing.Loops)
+        {
+            foreach (var code in loop)
+            {
+                if (code.CodeType() == CodeType.SubProgramCall)
+                    subprogramIds.Add(((SubProgramCall)code).LoopId);
+            }
+        }
 
         foreach (var loop in drawing.Loops)
         {
+            var loopNumber = GetLoopNumber(loop.Name);
+            if (subprogramIds.Contains(loopNumber))
+                continue; // drawn inline at SubProgramCall positions
+
             var layer = new Layer(loop.Name);
             doc.Layers.Add(layer);
 
-            var pos = new Vector();
+            DrawLoop(doc, drawing, loop, layer, new Vector());
+        }
+
+        var buffer = new MemoryStream();
+        using (var writer = new DxfWriter(buffer, doc, false))
+        {
+            writer.Write();
+        }
+
+        return new MemoryStream(buffer.ToArray());
+    }
+
+    private static Vector DrawLoop(CadDocument doc, Drawing drawing, Loop loop, Layer layer, Vector startPos)
+    {
+        var pos = startPos;
 
         foreach (var code in loop)
         {
@@ -35,6 +65,8 @@ public static class DrawingDxfExporter
 
                 case CodeType.LinearMove:
                     var lm = (LinearMove)code;
+                    if (lm.Type == EntityType.Cut)
+                    {
                         var lineEnd = Advance(pos, lm.EndPoint, loop.Mode);
                         doc.Entities.Add(new AcadLine
                         {
@@ -43,6 +75,11 @@ public static class DrawingDxfExporter
                             Layer = layer
                         });
                         pos = lineEnd;
+                    }
+                    else
+                    {
+                        pos = Advance(pos, lm.EndPoint, loop.Mode);
+                    }
                     break;
 
                 case CodeType.CircularMove:
@@ -58,11 +95,9 @@ public static class DrawingDxfExporter
                     var endAngle = Math.Atan2(arcEnd.Y - arcCenter.Y, arcEnd.X - arcCenter.X);
 
                     if (cm.Rotation == RotationType.CW)
-                        {
                         (startAngle, endAngle) = (endAngle, startAngle);
-                        }
 
-                        if (Math.Abs(startAngle - endAngle) < 1e-10) // full circle
+                    if (Math.Abs(startAngle - endAngle) < 1e-10)
                     {
                         doc.Entities.Add(new AcadCircle
                         {
@@ -77,26 +112,33 @@ public static class DrawingDxfExporter
                         {
                             Center = ToXYZ(arcCenter),
                             Radius = radius,
-                                StartAngle = startAngle * (180.0 / Math.PI),
+                            StartAngle = startAngle,
-                                EndAngle = endAngle * (180.0 / Math.PI),
+                            EndAngle = endAngle,
                             Layer = layer
                         });
                     }
 
                     pos = arcEnd;
                     break;
-                }
+
+                case CodeType.SubProgramCall:
+                    var call = (SubProgramCall)code;
+                    var subLoop = drawing.Loops.FirstOrDefault(l => l.Name == drawing.GetLoopName(call.LoopId));
+                    if (subLoop != null)
+                        DrawLoop(doc, drawing, subLoop, layer, pos);
+                    // pos unchanged — subprograms are closed shapes that return to start
+                    break;
             }
         }
 
-        var buffer = new MemoryStream();
+        return pos;
-        using (var writer = new DxfWriter(buffer, doc, false))
+    }
+
+    private static int GetLoopNumber(string loopName)
     {
-            writer.Write();
+        var idx = loopName.LastIndexOf(".loop-", StringComparison.OrdinalIgnoreCase);
-        }
+        if (idx < 0) return -1;
-
+        return int.TryParse(loopName.Substring(idx + 6), out var n) ? n : -1;
-        var stream = new MemoryStream(buffer.ToArray());
-        return stream;
     }
 
     private static Vector Advance(Vector current, Vector offset, ProgrammingMode mode) =>
@@ -104,4 +146,3 @@ public static class DrawingDxfExporter
 
     private static XYZ ToXYZ(Vector v) => new XYZ(v.X, v.Y, 0);
 }
-

PepLib.Core/IO/DrawingInfoReader.cs

@@ -34,7 +34,8 @@ namespace PepLib.IO
 
             stream.Seek(0x9, SeekOrigin.Current);
 
-            Info.MaterialNumber = int.Parse(ReadString(0x40, ref stream));
+            int.TryParse(ReadString(0x40, ref stream), out var materialNumber);
+            Info.MaterialNumber = materialNumber;
             Info.MaterialGrade = ReadString(0x10, ref stream);
             Info.ProgrammedBy = ReadString(0x40, ref stream);
             Info.CreatedBy = ReadString(0x40, ref stream);

PepLib.Core/IO/DrawingReader.cs

@@ -1,5 +1,4 @@
 using PepLib.Models;
-using System.Diagnostics;
 using System.IO.Compression;
 using System.Text.RegularExpressions;
 
@@ -38,6 +37,11 @@ namespace PepLib.IO
                             LoadInfo(memstream);
                             memstream.Close();
                             continue;
+
+                        case ".loop-info":
+                        case ".cadsnapshot":
+                            memstream.Close();
+                            continue;
                     }
 
                     if (Regex.IsMatch(extension, "loop-\\d\\d\\d"))
@@ -47,6 +51,9 @@ namespace PepLib.IO
                 }
             }
 
+            if (Drawing.Info == null)
+                Drawing.Info = DeriveInfoFromLoops();
+
             Drawing.ResolveLoops();
         }
 
@@ -62,7 +69,7 @@ namespace PepLib.IO
 
             try
             {
-                stream = new FileStream(nestFile, FileMode.Open);
+                stream = new FileStream(nestFile, FileMode.Open, FileAccess.Read, FileShare.Read);
                 Read(stream);
             }
             finally
@@ -73,16 +80,23 @@ namespace PepLib.IO
         }
 
         private void LoadInfo(Stream stream)
-        {
-            try
         {
             Drawing.Info = DrawingInfo.Load(stream);
         }
-            catch (Exception exception)
+
+        private DrawingInfo DeriveInfoFromLoops()
         {
-                Debug.WriteLine(exception.Message);
+            var info = new DrawingInfo();
-                Debug.WriteLine(exception.StackTrace);
+
+            if (Drawing.Loops.Count > 0)
+            {
+                // Loop names follow the pattern "{DrawingName}.loop-XXX"
+                var loopName = Drawing.Loops[0].Name;
+                var suffix = loopName.LastIndexOf(".loop-", StringComparison.OrdinalIgnoreCase);
+                info.Name = suffix >= 0 ? loopName.Substring(0, suffix) : loopName;
             }
+
+            return info;
         }
 
         private Loop ReadLoop(string name, Stream stream)

PepLib.Core/Models/Drawing.cs

@@ -76,7 +76,7 @@ namespace PepLib.Models
             return null;
         }
 
-        private string GetLoopName(int loopId)
+        public string GetLoopName(int loopId)
         {
             return string.Format("{0}.loop-{1}", Info.Name, loopId.ToString().PadLeft(3, '0'));
         }

PepLib.Core/Utilities/ZipHelper.cs

@@ -18,7 +18,7 @@ namespace PepLib.Utilities
             var nameList = new List<string>();
             var streamList = new List<Stream>();
 
-            using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read))
+            using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.Read))
             using (var zip = new ZipArchive(fileStream, ZipArchiveMode.Read))
             {
                 foreach (var entry in zip.Entries)
@@ -52,7 +52,7 @@ namespace PepLib.Utilities
         /// <returns></returns>
         public static bool ExtractByExtension(string file, string extension, out string name, out Stream stream)
         {
-            using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read))
+            using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.Read))
             using (var zip = new ZipArchive(fileStream, ZipArchiveMode.Read))
             {
                 foreach (var entry in zip.Entries)