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feat: replace XML nest file format with JSON (v2)

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Replace three separate XML metadata files (info, drawing-info,
plate-info) and per-plate G-code placement files with a single
nest.json inside the ZIP archive. Programs remain as G-code text
under a programs/ folder.

This eliminates ~400 lines of hand-written XML read/write code
and fragile ID-based dictionary linking. Now uses System.Text.Json
with DTO records for clean serialization. Also adds Priority and
Constraints fields to drawing serialization (previously omitted).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
AJ Isaacs
2026-03-12 18:44:43 -04:00
parent ad50751250
commit c2534ef08b
5 changed files with 1268 additions and 659 deletions
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docs/superpowers/plans/2026-03-12-nest-file-format-v2.md Normal file
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# Nest File Format v2 Implementation Plan
> **For agentic workers:** REQUIRED: Use superpowers:subagent-driven-development (if subagents available) or superpowers:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
**Goal:** Replace the XML+G-code nest file format with a single `nest.json` metadata file plus `programs/` folder inside the ZIP archive.
**Architecture:** Add a `NestFormat` static class containing DTO records and shared JSON options. Rewrite `NestWriter` to serialize DTOs to JSON and write programs under `programs/`. Rewrite `NestReader` to deserialize JSON and read programs from `programs/`. Public API unchanged.
**Tech Stack:** `System.Text.Json` (built into .NET 8, no new packages needed)
**Spec:** `docs/superpowers/specs/2026-03-12-nest-file-format-v2-design.md`
---
## File Structure
| Action | File | Responsibility |
|--------|------|----------------|
| Create | `OpenNest.IO/NestFormat.cs` | DTO records for JSON serialization + shared `JsonSerializerOptions` |
| Rewrite | `OpenNest.IO/NestWriter.cs` | Serialize nest to JSON + write programs to `programs/` folder |
| Rewrite | `OpenNest.IO/NestReader.cs` | Deserialize JSON + read programs from `programs/` folder |
No other files change. `ProgramReader.cs`, `DxfImporter.cs`, `DxfExporter.cs`, `Extensions.cs`, all domain model classes, and all caller sites remain untouched.
---
## Chunk 1: DTO Records and JSON Options
### Task 1: Create NestFormat.cs with DTO records
**Files:**
- Create: `OpenNest.IO/NestFormat.cs`
These DTOs are the JSON shape — flat records that map 1:1 with the spec's JSON schema. They live in `OpenNest.IO` because they're serialization concerns, not domain model.
- [ ] **Step 1: Create `NestFormat.cs`**
```csharp
using System.Text.Json;
namespace OpenNest.IO
{
public static class NestFormat
{
public static readonly JsonSerializerOptions JsonOptions = new()
{
PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
WriteIndented = true
};
public record NestDto
{
public int Version { get; init; } = 2;
public string Name { get; init; } = "";
public string Units { get; init; } = "Inches";
public string Customer { get; init; } = "";
public string DateCreated { get; init; } = "";
public string DateLastModified { get; init; } = "";
public string Notes { get; init; } = "";
public PlateDefaultsDto PlateDefaults { get; init; } = new();
public List<DrawingDto> Drawings { get; init; } = new();
public List<PlateDto> Plates { get; init; } = new();
}
public record PlateDefaultsDto
{
public SizeDto Size { get; init; } = new();
public double Thickness { get; init; }
public int Quadrant { get; init; } = 1;
public double PartSpacing { get; init; }
public MaterialDto Material { get; init; } = new();
public SpacingDto EdgeSpacing { get; init; } = new();
}
public record DrawingDto
{
public int Id { get; init; }
public string Name { get; init; } = "";
public string Customer { get; init; } = "";
public ColorDto Color { get; init; } = new();
public QuantityDto Quantity { get; init; } = new();
public int Priority { get; init; }
public ConstraintsDto Constraints { get; init; } = new();
public MaterialDto Material { get; init; } = new();
public SourceDto Source { get; init; } = new();
}
public record PlateDto
{
public int Id { get; init; }
public SizeDto Size { get; init; } = new();
public double Thickness { get; init; }
public int Quadrant { get; init; } = 1;
public int Quantity { get; init; } = 1;
public double PartSpacing { get; init; }
public MaterialDto Material { get; init; } = new();
public SpacingDto EdgeSpacing { get; init; } = new();
public List<PartDto> Parts { get; init; } = new();
}
public record PartDto
{
public int DrawingId { get; init; }
public double X { get; init; }
public double Y { get; init; }
public double Rotation { get; init; }
}
public record SizeDto
{
public double Width { get; init; }
public double Height { get; init; }
}
public record MaterialDto
{
public string Name { get; init; } = "";
public string Grade { get; init; } = "";
public double Density { get; init; }
}
public record SpacingDto
{
public double Left { get; init; }
public double Top { get; init; }
public double Right { get; init; }
public double Bottom { get; init; }
}
public record ColorDto
{
public int A { get; init; } = 255;
public int R { get; init; }
public int G { get; init; }
public int B { get; init; }
}
public record QuantityDto
{
public int Required { get; init; }
}
public record ConstraintsDto
{
public double StepAngle { get; init; }
public double StartAngle { get; init; }
public double EndAngle { get; init; }
public bool Allow180Equivalent { get; init; }
}
public record SourceDto
{
public string Path { get; init; } = "";
public OffsetDto Offset { get; init; } = new();
}
public record OffsetDto
{
public double X { get; init; }
public double Y { get; init; }
}
}
}
```
- [ ] **Step 2: Build to verify DTOs compile**
Run: `dotnet build OpenNest.IO/OpenNest.IO.csproj`
Expected: Build succeeded.
- [ ] **Step 3: Commit**
```bash
git add OpenNest.IO/NestFormat.cs
git commit -m "feat: add NestFormat DTOs for JSON nest file format v2"
```
---
## Chunk 2: Rewrite NestWriter
### Task 2: Rewrite NestWriter to use JSON serialization
**Files:**
- Rewrite: `OpenNest.IO/NestWriter.cs`
The writer keeps the same public API: `NestWriter(Nest nest)` constructor and `bool Write(string file)`. Internally it builds a `NestDto` from the domain model, serializes it to `nest.json`, and writes each drawing's program to `programs/program-N`.
The G-code writing methods (`WriteDrawing`, `GetCodeString`, `GetLayerString`) are preserved exactly — they write program G-code to streams, which is unchanged. The `WritePlate` method and all XML methods (`AddNestInfo`, `AddPlateInfo`, `AddDrawingInfo`) are removed.
- [ ] **Step 1: Rewrite `NestWriter.cs`**
Replace the entire file. Key changes:
- Remove `using System.Xml`
- Add `using System.Text.Json`
- Remove `AddNestInfo()`, `AddPlateInfo()`, `AddDrawingInfo()`, `AddPlates()`, `WritePlate()` methods
- Add `BuildNestDto()` method that maps domain model → DTOs
- `Write()` now serializes `NestDto` to `nest.json` and writes programs to `programs/program-N`
- Keep `WriteDrawing()`, `GetCodeString()`, `GetLayerString()` exactly as-is
```csharp
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Text.Json;
using OpenNest.CNC;
using OpenNest.Math;
using static OpenNest.IO.NestFormat;
namespace OpenNest.IO
{
public sealed class NestWriter
{
private const int OutputPrecision = 10;
private const string CoordinateFormat = "0.##########";
private readonly Nest nest;
private Dictionary<int, Drawing> drawingDict;
public NestWriter(Nest nest)
{
this.drawingDict = new Dictionary<int, Drawing>();
this.nest = nest;
}
public bool Write(string file)
{
nest.DateLastModified = DateTime.Now;
SetDrawingIds();
using var fileStream = new FileStream(file, FileMode.Create);
using var zipArchive = new ZipArchive(fileStream, ZipArchiveMode.Create);
WriteNestJson(zipArchive);
WritePrograms(zipArchive);
return true;
}
private void SetDrawingIds()
{
var id = 1;
foreach (var drawing in nest.Drawings)
{
drawingDict.Add(id, drawing);
id++;
}
}
private void WriteNestJson(ZipArchive zipArchive)
{
var dto = BuildNestDto();
var json = JsonSerializer.Serialize(dto, JsonOptions);
var entry = zipArchive.CreateEntry("nest.json");
using var stream = entry.Open();
using var writer = new StreamWriter(stream, Encoding.UTF8);
writer.Write(json);
}
private NestDto BuildNestDto()
{
return new NestDto
{
Version = 2,
Name = nest.Name ?? "",
Units = nest.Units.ToString(),
Customer = nest.Customer ?? "",
DateCreated = nest.DateCreated.ToString("o"),
DateLastModified = nest.DateLastModified.ToString("o"),
Notes = nest.Notes ?? "",
PlateDefaults = BuildPlateDefaultsDto(),
Drawings = BuildDrawingDtos(),
Plates = BuildPlateDtos()
};
}
private PlateDefaultsDto BuildPlateDefaultsDto()
{
var pd = nest.PlateDefaults;
return new PlateDefaultsDto
{
Size = new SizeDto { Width = pd.Size.Width, Height = pd.Size.Height },
Thickness = pd.Thickness,
Quadrant = pd.Quadrant,
PartSpacing = pd.PartSpacing,
Material = new MaterialDto
{
Name = pd.Material.Name ?? "",
Grade = pd.Material.Grade ?? "",
Density = pd.Material.Density
},
EdgeSpacing = new SpacingDto
{
Left = pd.EdgeSpacing.Left,
Top = pd.EdgeSpacing.Top,
Right = pd.EdgeSpacing.Right,
Bottom = pd.EdgeSpacing.Bottom
}
};
}
private List<DrawingDto> BuildDrawingDtos()
{
var list = new List<DrawingDto>();
foreach (var kvp in drawingDict.OrderBy(k => k.Key))
{
var d = kvp.Value;
list.Add(new DrawingDto
{
Id = kvp.Key,
Name = d.Name ?? "",
Customer = d.Customer ?? "",
Color = new ColorDto { A = d.Color.A, R = d.Color.R, G = d.Color.G, B = d.Color.B },
Quantity = new QuantityDto { Required = d.Quantity.Required },
Priority = d.Priority,
Constraints = new ConstraintsDto
{
StepAngle = d.Constraints.StepAngle,
StartAngle = d.Constraints.StartAngle,
EndAngle = d.Constraints.EndAngle,
Allow180Equivalent = d.Constraints.Allow180Equivalent
},
Material = new MaterialDto
{
Name = d.Material.Name ?? "",
Grade = d.Material.Grade ?? "",
Density = d.Material.Density
},
Source = new SourceDto
{
Path = d.Source.Path ?? "",
Offset = new OffsetDto { X = d.Source.Offset.X, Y = d.Source.Offset.Y }
}
});
}
return list;
}
private List<PlateDto> BuildPlateDtos()
{
var list = new List<PlateDto>();
for (var i = 0; i < nest.Plates.Count; i++)
{
var plate = nest.Plates[i];
var parts = new List<PartDto>();
foreach (var part in plate.Parts)
{
var match = drawingDict.Where(dwg => dwg.Value == part.BaseDrawing).FirstOrDefault();
parts.Add(new PartDto
{
DrawingId = match.Key,
X = part.Location.X,
Y = part.Location.Y,
Rotation = part.Rotation
});
}
list.Add(new PlateDto
{
Id = i + 1,
Size = new SizeDto { Width = plate.Size.Width, Height = plate.Size.Height },
Thickness = plate.Thickness,
Quadrant = plate.Quadrant,
Quantity = plate.Quantity,
PartSpacing = plate.PartSpacing,
Material = new MaterialDto
{
Name = plate.Material.Name ?? "",
Grade = plate.Material.Grade ?? "",
Density = plate.Material.Density
},
EdgeSpacing = new SpacingDto
{
Left = plate.EdgeSpacing.Left,
Top = plate.EdgeSpacing.Top,
Right = plate.EdgeSpacing.Right,
Bottom = plate.EdgeSpacing.Bottom
},
Parts = parts
});
}
return list;
}
private void WritePrograms(ZipArchive zipArchive)
{
foreach (var kvp in drawingDict.OrderBy(k => k.Key))
{
var name = $"programs/program-{kvp.Key}";
var stream = new MemoryStream();
WriteDrawing(stream, kvp.Value);
var entry = zipArchive.CreateEntry(name);
using var entryStream = entry.Open();
stream.CopyTo(entryStream);
}
}
private void WriteDrawing(Stream stream, Drawing drawing)
{
var program = drawing.Program;
var writer = new StreamWriter(stream);
writer.AutoFlush = true;
writer.WriteLine(program.Mode == Mode.Absolute ? "G90" : "G91");
for (var i = 0; i < drawing.Program.Length; ++i)
{
var code = drawing.Program[i];
writer.WriteLine(GetCodeString(code));
}
stream.Position = 0;
}
private string GetCodeString(ICode code)
{
switch (code.Type)
{
case CodeType.ArcMove:
{
var sb = new StringBuilder();
var arcMove = (ArcMove)code;
var x = System.Math.Round(arcMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat);
var y = System.Math.Round(arcMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat);
var i = System.Math.Round(arcMove.CenterPoint.X, OutputPrecision).ToString(CoordinateFormat);
var j = System.Math.Round(arcMove.CenterPoint.Y, OutputPrecision).ToString(CoordinateFormat);
if (arcMove.Rotation == RotationType.CW)
sb.Append(string.Format("G02X{0}Y{1}I{2}J{3}", x, y, i, j));
else
sb.Append(string.Format("G03X{0}Y{1}I{2}J{3}", x, y, i, j));
if (arcMove.Layer != LayerType.Cut)
sb.Append(GetLayerString(arcMove.Layer));
return sb.ToString();
}
case CodeType.Comment:
{
var comment = (Comment)code;
return ":" + comment.Value;
}
case CodeType.LinearMove:
{
var sb = new StringBuilder();
var linearMove = (LinearMove)code;
sb.Append(string.Format("G01X{0}Y{1}",
System.Math.Round(linearMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat),
System.Math.Round(linearMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat)));
if (linearMove.Layer != LayerType.Cut)
sb.Append(GetLayerString(linearMove.Layer));
return sb.ToString();
}
case CodeType.RapidMove:
{
var rapidMove = (RapidMove)code;
return string.Format("G00X{0}Y{1}",
System.Math.Round(rapidMove.EndPoint.X, OutputPrecision).ToString(CoordinateFormat),
System.Math.Round(rapidMove.EndPoint.Y, OutputPrecision).ToString(CoordinateFormat));
}
case CodeType.SetFeedrate:
{
var setFeedrate = (Feedrate)code;
return "F" + setFeedrate.Value;
}
case CodeType.SetKerf:
{
var setKerf = (Kerf)code;
switch (setKerf.Value)
{
case KerfType.None: return "G40";
case KerfType.Left: return "G41";
case KerfType.Right: return "G42";
}
break;
}
case CodeType.SubProgramCall:
{
var subProgramCall = (SubProgramCall)code;
break;
}
}
return string.Empty;
}
private string GetLayerString(LayerType layer)
{
switch (layer)
{
case LayerType.Display:
return ":DISPLAY";
case LayerType.Leadin:
return ":LEADIN";
case LayerType.Leadout:
return ":LEADOUT";
case LayerType.Scribe:
return ":SCRIBE";
default:
return string.Empty;
}
}
}
}
```
- [ ] **Step 2: Build to verify NestWriter compiles**
Run: `dotnet build OpenNest.sln`
Expected: Build succeeded.
- [ ] **Step 3: Commit**
```bash
git add OpenNest.IO/NestWriter.cs
git commit -m "feat: rewrite NestWriter to use JSON format v2"
```
---
## Chunk 3: Rewrite NestReader
### Task 3: Rewrite NestReader to use JSON deserialization
**Files:**
- Rewrite: `OpenNest.IO/NestReader.cs`
The reader keeps the same public API: `NestReader(string file)`, `NestReader(Stream stream)`, and `Nest Read()`. Internally it reads `nest.json`, deserializes to `NestDto`, reads programs from `programs/program-N`, and assembles the domain model.
All XML parsing, plate G-code parsing, dictionary-linking (`LinkProgramsToDrawings`, `LinkPartsToPlates`), and the helper enums/methods are removed.
- [ ] **Step 1: Rewrite `NestReader.cs`**
Replace the entire file:
```csharp
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text.Json;
using OpenNest.CNC;
using OpenNest.Geometry;
using static OpenNest.IO.NestFormat;
namespace OpenNest.IO
{
public sealed class NestReader
{
private readonly Stream stream;
private readonly ZipArchive zipArchive;
public NestReader(string file)
{
stream = new FileStream(file, FileMode.Open, FileAccess.Read);
zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
}
public NestReader(Stream stream)
{
this.stream = stream;
zipArchive = new ZipArchive(stream, ZipArchiveMode.Read);
}
public Nest Read()
{
var nestJson = ReadEntry("nest.json");
var dto = JsonSerializer.Deserialize<NestDto>(nestJson, JsonOptions);
var programs = ReadPrograms(dto.Drawings.Count);
var drawingMap = BuildDrawings(dto, programs);
var nest = BuildNest(dto, drawingMap);
zipArchive.Dispose();
stream.Close();
return nest;
}
private string ReadEntry(string name)
{
var entry = zipArchive.GetEntry(name)
?? throw new InvalidDataException($"Nest file is missing required entry '{name}'.");
using var entryStream = entry.Open();
using var reader = new StreamReader(entryStream);
return reader.ReadToEnd();
}
private Dictionary<int, Program> ReadPrograms(int count)
{
var programs = new Dictionary<int, Program>();
for (var i = 1; i <= count; i++)
{
var entry = zipArchive.GetEntry($"programs/program-{i}");
if (entry == null) continue;
using var entryStream = entry.Open();
var memStream = new MemoryStream();
entryStream.CopyTo(memStream);
memStream.Position = 0;
var reader = new ProgramReader(memStream);
programs[i] = reader.Read();
}
return programs;
}
private Dictionary<int, Drawing> BuildDrawings(NestDto dto, Dictionary<int, Program> programs)
{
var map = new Dictionary<int, Drawing>();
foreach (var d in dto.Drawings)
{
var drawing = new Drawing(d.Name);
drawing.Customer = d.Customer;
drawing.Color = Color.FromArgb(d.Color.A, d.Color.R, d.Color.G, d.Color.B);
drawing.Quantity.Required = d.Quantity.Required;
drawing.Priority = d.Priority;
drawing.Constraints.StepAngle = d.Constraints.StepAngle;
drawing.Constraints.StartAngle = d.Constraints.StartAngle;
drawing.Constraints.EndAngle = d.Constraints.EndAngle;
drawing.Constraints.Allow180Equivalent = d.Constraints.Allow180Equivalent;
drawing.Material = new Material(d.Material.Name, d.Material.Grade, d.Material.Density);
drawing.Source.Path = d.Source.Path;
drawing.Source.Offset = new Vector(d.Source.Offset.X, d.Source.Offset.Y);
if (programs.TryGetValue(d.Id, out var pgm))
drawing.Program = pgm;
map[d.Id] = drawing;
}
return map;
}
private Nest BuildNest(NestDto dto, Dictionary<int, Drawing> drawingMap)
{
var nest = new Nest();
nest.Name = dto.Name;
Units units;
if (Enum.TryParse(dto.Units, true, out units))
nest.Units = units;
nest.Customer = dto.Customer;
nest.DateCreated = DateTime.Parse(dto.DateCreated);
nest.DateLastModified = DateTime.Parse(dto.DateLastModified);
nest.Notes = dto.Notes;
// Plate defaults
var pd = dto.PlateDefaults;
nest.PlateDefaults.Size = new Size(pd.Size.Width, pd.Size.Height);
nest.PlateDefaults.Thickness = pd.Thickness;
nest.PlateDefaults.Quadrant = pd.Quadrant;
nest.PlateDefaults.PartSpacing = pd.PartSpacing;
nest.PlateDefaults.Material = new Material(pd.Material.Name, pd.Material.Grade, pd.Material.Density);
nest.PlateDefaults.EdgeSpacing = new Spacing(pd.EdgeSpacing.Left, pd.EdgeSpacing.Bottom, pd.EdgeSpacing.Right, pd.EdgeSpacing.Top);
// Drawings
foreach (var d in drawingMap.OrderBy(k => k.Key))
nest.Drawings.Add(d.Value);
// Plates
foreach (var p in dto.Plates.OrderBy(p => p.Id))
{
var plate = new Plate();
plate.Size = new Size(p.Size.Width, p.Size.Height);
plate.Thickness = p.Thickness;
plate.Quadrant = p.Quadrant;
plate.Quantity = p.Quantity;
plate.PartSpacing = p.PartSpacing;
plate.Material = new Material(p.Material.Name, p.Material.Grade, p.Material.Density);
plate.EdgeSpacing = new Spacing(p.EdgeSpacing.Left, p.EdgeSpacing.Bottom, p.EdgeSpacing.Right, p.EdgeSpacing.Top);
foreach (var partDto in p.Parts)
{
if (!drawingMap.TryGetValue(partDto.DrawingId, out var dwg))
continue;
var part = new Part(dwg);
part.Rotate(partDto.Rotation);
part.Offset(new Vector(partDto.X, partDto.Y));
plate.Parts.Add(part);
}
nest.Plates.Add(plate);
}
return nest;
}
}
}
```
- [ ] **Step 2: Build to verify NestReader compiles**
Run: `dotnet build OpenNest.sln`
Expected: Build succeeded.
- [ ] **Step 3: Commit**
```bash
git add OpenNest.IO/NestReader.cs
git commit -m "feat: rewrite NestReader to use JSON format v2"
```
---
## Chunk 4: Smoke Test
### Task 4: Manual smoke test via OpenNest.Console
**Files:** None modified — this is a verification step.
Use the `OpenNest.Console` project (or the MCP server) to verify round-trip: create a nest, save it, reload it, confirm data is intact.
- [ ] **Step 1: Build the full solution**
Run: `dotnet build OpenNest.sln`
Expected: Build succeeded with no errors.
- [ ] **Step 2: Round-trip test via MCP tools**
Use the OpenNest MCP tools to:
1. Create a drawing (e.g. a rectangle via `create_drawing`)
2. Create a plate via `create_plate`
3. Fill the plate via `fill_plate`
4. Save the nest via the console app or verify `get_plate_info` shows parts
5. If a nest file exists on disk, load it with `load_nest` and verify `get_plate_info` returns the same data
- [ ] **Step 3: Inspect the ZIP contents**
Unzip a saved nest file and verify:
- `nest.json` exists with correct structure
- `programs/program-1` (etc.) exist with G-code content
- No `info`, `drawing-info`, `plate-info`, or `plate-NNN` files exist
- [ ] **Step 4: Commit any fixes**
If any issues were found and fixed, commit them:
```bash
git add -u
git commit -m "fix: address issues found during nest format v2 smoke test"
```

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# Nest File Format v2 Design
## Problem
The current nest file format stores metadata across three separate XML files (`info`, `drawing-info`, `plate-info`) plus per-plate G-code files for part placements inside a ZIP archive. This results in ~400 lines of hand-written XML read/write code, fragile dictionary-linking to reconnect drawings/plates by ID after parsing, and the overhead of running the full G-code parser just to extract part positions.
## Design
### File Structure
The nest file remains a ZIP archive. Contents:
```
nest.json
programs/
program-1
program-2
...
```
- **`nest.json`** — single JSON file containing all metadata and part placements.
- **`programs/program-N`** — G-code text for each drawing's CNC program (1-indexed, no zero-padding). Previously stored at the archive root as `program-NNN` (zero-padded). Parsed by `ProgramReader`, written by existing G-code serialization logic. Format unchanged.
Plate G-code files (`plate-NNN`) are removed. Part placements are stored inline in `nest.json`.
### JSON Schema
```json
{
"version": 2,
"name": "string",
"units": "Inches | Millimeters",
"customer": "string",
"dateCreated": "2026-03-12T10:30:00",
"dateLastModified": "2026-03-12T14:00:00",
"notes": "string (plain JSON, no URI-escaping)",
"plateDefaults": {
"size": { "width": 0.0, "height": 0.0 },
"thickness": 0.0,
"quadrant": 1,
"partSpacing": 0.0,
"material": { "name": "string", "grade": "string", "density": 0.0 },
"edgeSpacing": { "left": 0.0, "top": 0.0, "right": 0.0, "bottom": 0.0 }
},
"drawings": [
{
"id": 1,
"name": "string",
"customer": "string",
"color": { "a": 255, "r": 0, "g": 0, "b": 0 },
"quantity": { "required": 0 },
"priority": 0,
"constraints": {
"stepAngle": 0.0,
"startAngle": 0.0,
"endAngle": 0.0,
"allow180Equivalent": false
},
"material": { "name": "string", "grade": "string", "density": 0.0 },
"source": {
"path": "string",
"offset": { "x": 0.0, "y": 0.0 }
}
}
],
"plates": [
{
"id": 1,
"size": { "width": 0.0, "height": 0.0 },
"thickness": 0.0,
"quadrant": 1,
"quantity": 1,
"partSpacing": 0.0,
"material": { "name": "string", "grade": "string", "density": 0.0 },
"edgeSpacing": { "left": 0.0, "top": 0.0, "right": 0.0, "bottom": 0.0 },
"parts": [
{ "drawingId": 1, "x": 0.0, "y": 0.0, "rotation": 0.0 }
]
}
]
}
```
Key details:
- **Version**: `"version": 2` at the top level for future format migration.
- Drawing `id` values are 1-indexed, matching `programs/program-N` filenames.
- Part `rotation` is stored in **radians** (matches internal domain model, no conversion needed).
- Part `drawingId` references the drawing's `id` in the `drawings` array.
- **Dates**: local time, serialized via `DateTime.ToString("o")` (ISO 8601 round-trip format with timezone offset).
- **Notes**: stored as plain JSON strings. The v1 URI-escaping (`Uri.EscapeDataString`) is not needed since JSON handles special characters natively.
- `quantity.required` is the only quantity persisted; `nested` is computed at load time from part placements.
- **Units**: enum values match the domain model: `Inches` or `Millimeters`.
- **Size**: uses `width`/`height` matching the `OpenNest.Geometry.Size` struct.
- **Drawing.Priority** and **Drawing.Constraints** (stepAngle, startAngle, endAngle, allow180Equivalent) are now persisted (v1 omitted these).
- **Empty collections**: `drawings` and `plates` arrays are always present (may be empty `[]`). The `programs/` folder is empty when there are no drawings.
### Serialization Approach
Use `System.Text.Json` with small DTO (Data Transfer Object) classes for serialization. The DTOs map between the domain model and the JSON structure, keeping serialization concerns out of the domain classes.
### What Changes
| File | Change |
|------|--------|
| `NestWriter.cs` | Replace all XML writing and plate G-code writing with JSON serialization. Programs written to `programs/` folder. |
| `NestReader.cs` | Replace all XML parsing, plate G-code parsing, and dictionary-linking with JSON deserialization. Programs read from `programs/` folder. |
### What Stays the Same
| File | Reason |
|------|--------|
| `ProgramReader.cs` | G-code parsing for CNC programs is unchanged. |
| `NestWriter` G-code writing (`WriteDrawing`, `GetCodeString`) | G-code serialization for programs is unchanged. |
| `DxfImporter.cs`, `DxfExporter.cs`, `Extensions.cs` | Unrelated to nest file format. |
| Domain model classes | No changes needed. |
### Public API
The public API is unchanged:
- `NestReader(string file)` and `NestReader(Stream stream)` constructors preserved.
- `NestReader.Read()` returns `Nest`.
- `NestWriter(Nest nest)` constructor preserved.
- `NestWriter.Write(string file)` returns `bool`.
### Callers (no changes needed)
- `MainForm.cs:329` — `new NestReader(path)`
- `MainForm.cs:363` — `new NestReader(dlg.FileName)`
- `EditNestForm.cs:212` — `new NestWriter(Nest)`
- `EditNestForm.cs:223` — `new NestWriter(nst)`
- `Document.cs:27` — `new NestWriter(Nest)`
- `OpenNest.Console/Program.cs:94` — `new NestReader(nestFile)`
- `OpenNest.Console/Program.cs:190` — `new NestWriter(nest)`
- `OpenNest.Mcp/InputTools.cs:30` — `new NestReader(path)`