feat(engine): share stock construction across nesting callers

OpenNest.Engine.Tests/Jobs/NestStockBuilderTests.cs

@@ -0,0 +1,68 @@
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Tests.Jobs;
+
+public class NestStockBuilderTests
+{
+    private static Plate Template() => new(new Size(48, 96))
+    {
+        Quantity = 7,
+        PartSpacing = 0.25,
+        EdgeSpacing = new Spacing(1, 2, 3, 4),
+        Quadrant = 3,
+    };
+
+    [Fact]
+    public void TemplateWithoutOptionsUsesUnlimitedStockAndSnapshotsSettings()
+    {
+        var template = Template();
+        var stock = Assert.Single(NestStockBuilder.FromTemplate(template, null));
+        Assert.Equal("plate", stock.Id);
+        Assert.Null(stock.Quantity);
+        Assert.Equal(template.Size, stock.Size);
+        Assert.Equal(template.PartSpacing, stock.PartSpacing);
+        Assert.Equal(template.EdgeSpacing, stock.EdgeSpacing);
+        Assert.Equal(template.Quadrant, stock.Quadrant);
+        template.Size = new Size(60, 120);
+        template.EdgeSpacing = default;
+        Assert.Equal(new Size(48, 96), stock.Size);
+        Assert.Equal(new Spacing(1, 2, 3, 4), stock.EdgeSpacing);
+    }
+
+    [Fact]
+    public void OptionsHaveStableDistinctIdsAndCopyTemplateSettings()
+    {
+        var template = Template();
+        var options = new[]
+        {
+            new PlateOption { Width = 60, Length = 120 },
+            new PlateOption { Width = 72, Length = 144 },
+        };
+        var stock = NestStockBuilder.FromTemplate(template, options, quantityPerOption: 2);
+        Assert.Equal(new[] { "option-0", "option-1" }, stock.Select(s => s.Id));
+        Assert.Equal(new[] { new Size(60, 120), new Size(72, 144) }, stock.Select(s => s.Size));
+        Assert.All(stock, s =>
+        {
+            Assert.Equal(2, s.Quantity);
+            Assert.Equal(template.EdgeSpacing, s.EdgeSpacing);
+            Assert.Equal(template.PartSpacing, s.PartSpacing);
+            Assert.Equal(template.Quadrant, s.Quadrant);
+        });
+        Assert.Equal(new Size(48, 96), template.Size);
+    }
+
+    [Fact]
+    public void SinglePlateOffersExactlyOneSheetNotPlateRepeatQuantity()
+    {
+        var stock = Assert.Single(NestStockBuilder.SinglePlate(Template()));
+        Assert.Equal(1, stock.Quantity);
+    }
+
+    [Fact]
+    public void MissingTemplateIsRejected()
+    {
+        Assert.Throws<ArgumentNullException>(() => NestStockBuilder.FromTemplate(null, null));
+        Assert.Throws<ArgumentNullException>(() => NestStockBuilder.SinglePlate(null));
+    }
+}

OpenNest.Engine/Jobs/NestStockBuilder.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using OpenNest.Engine.Jobs.Adapters;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Jobs;
+
+/// <summary>Shared stock snapshots for whole-job front ends. Plate repeat count is not inventory.</summary>
+public static class NestStockBuilder
+{
+    public static IReadOnlyList<NestPlateStock> FromTemplate(
+        Plate template,
+        IReadOnlyList<PlateOption> options,
+        int? quantityPerOption = null
+    )
+    {
+        ArgumentNullException.ThrowIfNull(template);
+        if (options == null || options.Count == 0)
+            return new[] { DrawingJobMapper.FromPlate("plate", template, quantityPerOption) };
+
+        var stock = new List<NestPlateStock>(options.Count);
+        for (var i = 0; i < options.Count; i++)
+        {
+            var option = options[i];
+            ArgumentNullException.ThrowIfNull(option);
+            stock.Add(new NestPlateStock(
+                $"option-{i}",
+                new Size(option.Width, option.Length),
+                quantityPerOption,
+                template.PartSpacing,
+                template.EdgeSpacing,
+                template.Quadrant
+            ));
+        }
+        return stock.AsReadOnly();
+    }
+
+    /// <summary>Single-sheet callers may not silently create additional sheets.</summary>
+    public static IReadOnlyList<NestPlateStock> SinglePlate(Plate plate) =>
+        FromTemplate(plate, null, quantityPerOption: 1);
+}