feat: switch BOM export to a formatted xlsx template instead of generated sheets

Copy a pre-built "BOM Template.xlsx" (with headers/formatting) and write into
it rather than deleting/recreating worksheets from scratch, so output keeps
consistent styling. Cut Templates sheet no longer stores a File Name column;
the DXF filename is now derived from the stored revision, simplifying the
existing-templates map and removing redundant state.

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

.gitignore

@@ -1,6 +1,9 @@
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 
+# Stray Windows redirect artifact
+/nul
+
 # User-specific files
 *.suo
 *.user

ExportDXF/ExportDXF.csproj

@@ -37,6 +37,9 @@
     <Content Include="Templates\Blank.drwdot">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Content>
+    <Content Include="Templates\BOM Template.xlsx">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
   </ItemGroup>
 
 

ExportDXF/Services/DxfExportService.cs

@@ -130,7 +130,7 @@ namespace ExportDXF.Services
             ExportContext context,
             string tempDir,
             string outputFolder,
-            Dictionary<string, (string ContentHash, int Revision, string FileName)> existingTemplates,
+            Dictionary<string, (string ContentHash, int Revision)> existingTemplates,
             List<BomItem> bomItems)
         {
             LogProgress(context, "Active document is a Part");
@@ -159,7 +159,7 @@ namespace ExportDXF.Services
             ExportContext context,
             string tempDir,
             string outputFolder,
-            Dictionary<string, (string ContentHash, int Revision, string FileName)> existingTemplates,
+            Dictionary<string, (string ContentHash, int Revision)> existingTemplates,
             List<BomItem> bomItems)
         {
             LogProgress(context, "Active document is an Assembly");
@@ -200,7 +200,7 @@ namespace ExportDXF.Services
             ExportContext context,
             string tempDir,
             string outputFolder,
-            Dictionary<string, (string ContentHash, int Revision, string FileName)> existingTemplates,
+            Dictionary<string, (string ContentHash, int Revision)> existingTemplates,
             List<BomItem> bomItems)
         {
             LogProgress(context, "Active document is a Drawing");
@@ -294,7 +294,7 @@ namespace ExportDXF.Services
             string tempDir,
             string outputFolder,
             ExportContext context,
-            Dictionary<string, (string ContentHash, int Revision, string FileName)> existingTemplates,
+            Dictionary<string, (string ContentHash, int Revision)> existingTemplates,
             List<BomItem> bomItems)
         {
             int successCount = 0;
@@ -362,7 +362,7 @@ namespace ExportDXF.Services
             Item item,
             ExportContext context,
             string outputFolder,
-            Dictionary<string, (string ContentHash, int Revision, string FileName)> existingTemplates,
+            Dictionary<string, (string ContentHash, int Revision)> existingTemplates,
             BomItem bomItem)
         {
             var baseName = FilenameTemplateParser.Evaluate(context.FilenameTemplate, item);
@@ -377,15 +377,15 @@ namespace ExportDXF.Services
                 if (existing.ContentHash == contentHash)
                 {
                     // Unchanged — skip file write, keep existing
-                    dxfFileName = existing.FileName;
                     revision = existing.Revision;
+                    dxfFileName = GetRevisionFileName(baseName, revision);
 
                     LogProgress(context, $"Unchanged: {dxfFileName}", LogLevel.Info, item.PartName);
                     _logFileService.LogInfo($"Unchanged: {dxfFileName}");
 
                     bomItem.CutTemplate = new CutTemplate
                     {
-                        DxfFilePath = dxfFileName,
+                        DxfFilePath = Path.GetFileNameWithoutExtension(dxfFileName),
                         ContentHash = contentHash,
                         Revision = revision,
                         Thickness = item.Thickness > 0 ? item.Thickness : (double?)null,
@@ -402,7 +402,7 @@ namespace ExportDXF.Services
                     dxfFileName = GetRevisionFileName(baseName, revision);
 
                     LogProgress(context, $"Updated: {dxfFileName} (Rev{revision})", LogLevel.Info, item.PartName);
-                    _logFileService.LogInfo($"Updated: {dxfFileName} (was {existing.FileName})");
+                    _logFileService.LogInfo($"Updated: {dxfFileName}");
                 }
             }
             else

ExportDXF/Services/ExcelExportService.cs

@@ -1,6 +1,8 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using ClosedXML.Excel;
 using ExportDXF.Models;
 
@@ -8,14 +10,18 @@ namespace ExportDXF.Services
 {
     public class ExcelExportService
     {
+        private static readonly string TemplatePath = Path.Combine(
+            Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
+            "Templates",
+            "BOM Template.xlsx");
         /// <summary>
         /// Reads existing Cut Templates from an xlsx file to compare content hashes.
         /// Returns empty dictionary if file doesn't exist or has no Cut Templates sheet.
-        /// Key = Item #, Value = (ContentHash, Revision, FileName)
+        /// Key = Item #, Value = (ContentHash, Revision)
         /// </summary>
-        public Dictionary<string, (string ContentHash, int Revision, string FileName)> ReadExistingCutTemplates(string xlsxPath)
+        public Dictionary<string, (string ContentHash, int Revision)> ReadExistingCutTemplates(string xlsxPath)
         {
-            var result = new Dictionary<string, (string, int, string)>();
+            var result = new Dictionary<string, (string, int)>();
 
             if (!File.Exists(xlsxPath))
                 return result;
@@ -49,12 +55,9 @@ namespace ExportDXF.Services
                     var revision = headers.ContainsKey("Revision")
                         ? ws.Cell(row, headers["Revision"]).GetValue<int>()
                         : 1;
-                    var fileName = headers.ContainsKey("File Name")
-                        ? ws.Cell(row, headers["File Name"]).GetString()
-                        : "";
 
                     if (!string.IsNullOrEmpty(itemNo))
-                        result[itemNo] = (hash, revision, fileName);
+                        result[itemNo] = (hash, revision);
                 }
             }
 
@@ -71,9 +74,12 @@ namespace ExportDXF.Services
             List<Dictionary<string, string>> rawBomTable,
             List<BomItem> bomItems)
         {
-            using (var workbook = File.Exists(xlsxPath)
+            if (!File.Exists(TemplatePath))
-                ? new XLWorkbook(xlsxPath)
+                throw new FileNotFoundException("Excel template not found.", TemplatePath);
-                : new XLWorkbook())
+
+            File.Copy(TemplatePath, xlsxPath, overwrite: true);
+
+            using (var workbook = new XLWorkbook(xlsxPath))
             {
                 WriteBomSheet(workbook, rawBomTable);
                 WriteCutTemplatesSheet(workbook, bomItems);
@@ -86,10 +92,9 @@ namespace ExportDXF.Services
             if (rawBomTable == null || rawBomTable.Count == 0)
                 return;
 
-            if (workbook.TryGetWorksheet("BOM", out _))
+            var sheet = GetOrCreateSheet(workbook, "BOM");
-                workbook.Worksheets.Delete("BOM");
+            sheet.Clear();
 
-            var sheet = workbook.Worksheets.Add("BOM");
             var columns = rawBomTable[0].Keys.ToList();
 
             for (int col = 0; col < columns.Count; col++)
@@ -110,30 +115,34 @@ namespace ExportDXF.Services
 
         private void WriteCutTemplatesSheet(XLWorkbook workbook, List<BomItem> bomItems)
         {
-            if (workbook.TryGetWorksheet("Cut Templates", out _))
+            var sheet = GetOrCreateSheet(workbook, "Cut Templates");
-                workbook.Worksheets.Delete("Cut Templates");
 
-            var sheet = workbook.Worksheets.Add("Cut Templates");
+            // Clear data rows only (preserve template headers/formatting in row 1)
-
+            var lastRow = sheet.LastRowUsed()?.RowNumber() ?? 1;
-            var headers = new[] { "Item #", "File Name", "Revision", "Thickness", "K-Factor", "Bend Radius", "Content Hash" };
+            if (lastRow > 1)
-            for (int col = 0; col < headers.Length; col++)
+                sheet.Range(2, 1, lastRow, sheet.LastColumnUsed()?.ColumnNumber() ?? 1).Clear();
-                sheet.Cell(1, col + 1).Value = headers[col];
 
             int row = 2;
             foreach (var item in bomItems.Where(b => b.CutTemplate != null).OrderBy(b => b.ItemNo))
             {
                 var ct = item.CutTemplate;
                 sheet.Cell(row, 1).Value = item.ItemNo;
-                sheet.Cell(row, 2).Value = ct.DxfFilePath;
+                sheet.Cell(row, 2).Value = ct.Revision;
-                sheet.Cell(row, 3).Value = ct.Revision;
+                sheet.Cell(row, 3).Value = ct.Thickness ?? 0;
-                sheet.Cell(row, 4).Value = ct.Thickness ?? 0;
+                sheet.Cell(row, 4).Value = ct.KFactor ?? 0;
-                sheet.Cell(row, 5).Value = ct.KFactor ?? 0;
+                sheet.Cell(row, 5).Value = ct.DefaultBendRadius ?? 0;
-                sheet.Cell(row, 6).Value = ct.DefaultBendRadius ?? 0;
+                sheet.Cell(row, 6).Value = ct.ContentHash ?? "";
-                sheet.Cell(row, 7).Value = ct.ContentHash ?? "";
                 row++;
             }
 
             sheet.Columns().AdjustToContents();
         }
+
+        private IXLWorksheet GetOrCreateSheet(XLWorkbook workbook, string name)
+        {
+            if (workbook.TryGetWorksheet(name, out var sheet))
+                return sheet;
+            return workbook.Worksheets.Add(name);
+        }
     }
 }