feat: add BomAnalyzer — groups BOM items by material+thickness and matches DXFs

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

OpenNest.IO/Bom/BomAnalyzer.cs

@@ -0,0 +1,100 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace OpenNest.IO.Bom
+{
+    public class BomAnalysis
+    {
+        public List<MaterialGroup> Groups { get; set; } = new List<MaterialGroup>();
+        public List<BomItem> Skipped { get; set; } = new List<BomItem>();
+        public List<BomItem> Unmatched { get; set; } = new List<BomItem>();
+    }
+
+    public class MaterialGroup
+    {
+        public string Material { get; set; }
+        public double Thickness { get; set; }
+        public List<MatchedPart> Parts { get; set; } = new List<MatchedPart>();
+    }
+
+    public class MatchedPart
+    {
+        public BomItem Item { get; set; }
+        public string DxfPath { get; set; }
+    }
+
+    public static class BomAnalyzer
+    {
+        public static BomAnalysis Analyze(List<BomItem> items, string dxfFolder)
+        {
+            var result = new BomAnalysis();
+
+            // Build a case-insensitive lookup of DXF files in the folder (if it exists)
+            var folderExists = Directory.Exists(dxfFolder);
+            var dxfFiles = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+
+            if (folderExists)
+            {
+                foreach (var file in Directory.GetFiles(dxfFolder, "*.dxf"))
+                {
+                    var nameWithoutExt = Path.GetFileNameWithoutExtension(file);
+                    dxfFiles[nameWithoutExt] = file;
+                }
+            }
+
+            // Partition items into: skipped, unmatched, or matched (grouped)
+            var matched = new List<MatchedPart>();
+
+            foreach (var item in items)
+            {
+                if (string.IsNullOrWhiteSpace(item.FileName) || !item.Thickness.HasValue)
+                {
+                    result.Skipped.Add(item);
+                    continue;
+                }
+
+                var lookupName = item.FileName;
+
+                // Strip .dxf extension if the BOM includes it
+                if (lookupName.EndsWith(".dxf", StringComparison.OrdinalIgnoreCase))
+                    lookupName = Path.GetFileNameWithoutExtension(lookupName);
+
+                if (!folderExists)
+                {
+                    // No folder to search — group items without a DXF path
+                    matched.Add(new MatchedPart { Item = item, DxfPath = null });
+                }
+                else if (dxfFiles.TryGetValue(lookupName, out var dxfPath))
+                {
+                    matched.Add(new MatchedPart { Item = item, DxfPath = dxfPath });
+                }
+                else
+                {
+                    result.Unmatched.Add(item);
+                }
+            }
+
+            // Group matched parts by material + thickness
+            var groups = matched
+                .GroupBy(p => new
+                {
+                    Material = (p.Item.Material ?? "").ToUpperInvariant(),
+                    Thickness = p.Item.Thickness.Value
+                })
+                .Select(g => new MaterialGroup
+                {
+                    Material = g.First().Item.Material ?? "",
+                    Thickness = g.Key.Thickness,
+                    Parts = g.ToList()
+                })
+                .OrderBy(g => g.Material)
+                .ThenBy(g => g.Thickness)
+                .ToList();
+
+            result.Groups = groups;
+            return result;
+        }
+    }
+}