ModernUO/Projects/UOContent/Engines/Spawners/BaseSpawner.Dto.cs
Kamron Batman d8a64f3316
refactor(spawners): replace DynamicJson with typed SpawnerDto records (#2505)
## Summary

Removes the dated `DynamicJson` JSON helper and migrates spawner JSON (de)serialization to a polymorphic `record SpawnerDto` hierarchy. `DynamicJson` was the last remaining consumer (regions moved off it in #1400).

The key correctness improvement: **System.Text.Json deserializes plain DTO records, never a live `Item`.** Previously, deserializing directly into an `Item` meant STJ constructed world-registered objects *before* the data was validated — a malformed/hand-edited spawn file could leave orphaned spawner Items in the world save. Now a parse failure is GC-only; `dto.ToSpawner()` constructs the spawner only from a fully-validated DTO and self-cleans on failure.

## What changed

- **New:** `SpawnerDto` (abstract) + `SpawnerDataDto` / `RegionSpawnerDto` / `ProximitySpawnerDto`, each marked with a reusable `[JsonDiscoverableType]` opt-in attribute. Auto-discovered at the `Configure` phase — no manual registration list (avoids the regions `Register<T>()` footgun), open to custom spawner subtypes.
- **Symmetric mapping:** `BaseSpawner.ToDto()` (export) ⇄ `SpawnerDto.ToSpawner()` (import). `ToSpawner()` deletes-and-rethrows on any failure, so the importer can never orphan an Item.
- **`SpawnerJsonSerializer`** wires `$type` polymorphism on the `SpawnerDto` root with loud collision/constructibility validation.
- **Import/export commands** rewired to the typed DTO path (reflection `FindTypeByName`/`CreateInstance` removed).
- **Data migration:** the 109 `Distribution/Data/Spawns/**` files moved from `"type"`→`"$type"` and legacy `homeRange`→`spawnBounds`. The runtime still *reads* legacy `homeRange` for external files. The `homeRange→spawnBounds` formula is proven equivalent to the runtime conversion (`BoundsEquivalenceTests`, hr=0/1/3/7).
- **Deleted:** `Projects/Server/Json/DynamicJson.cs`.

Sparse export output matches the legacy `ToJson` (nullable DTO properties + `WhenWritingNull`). Binary world-save serialization is untouched.

## Tests

- DTO round-trip per spawner type; sparse-default omission; legacy `homeRange` read; export/import file round-trip.
- `Import_MalformedFile_LeaksNoWorldItems` — proves a mid-array parse failure constructs zero world Items.
- `AllSpawnFilesLoadTests` — every migrated spawn file deserializes and builds.
- Duplicate-discriminator validation.
- UOContent.Tests 485/485, Server.Tests 710/710, build clean.

## Follow-up (not in this PR)

`Rectangle3DConverter.Write` (in `Projects/Server/`) omits `z1/z2` when `Start.Z == -128`, so a future server-side export of a `homeRange`-style spawner round-trips depth 256→255. Pre-existing and out of scope here (Server change); the migrated data reads correctly. Worth a separate small converter PR.
2026-06-25 23:24:45 -07:00

117 lines
4.3 KiB
C#

/*************************************************************************
* ModernUO *
* Copyright 2019-2026 - ModernUO Development Team *
* Email: hi@modernuo.com *
* File: BaseSpawner.Dto.cs *
* *
* This program is free software: you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation, either version 3 of the License, or *
* (at your option) any later version. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
*************************************************************************/
using System;
namespace Server.Engines.Spawners;
public abstract partial class BaseSpawner
{
/// <summary>Applies the common DTO fields to this freshly-created spawner (import path).</summary>
internal void ApplyDto(SpawnerDto dto)
{
_guid = dto.Guid == Guid.Empty ? Guid.NewGuid() : dto.Guid;
if (!string.IsNullOrEmpty(dto.Name))
{
Name = dto.Name;
}
// Compact homeRange -> spawnBounds (Map not available yet; use the DTO location).
if (dto.HomeRange >= 0)
{
SpawnBounds = BoundsFromHomeRange(dto.Location, dto.HomeRange);
}
InitSpawn(dto.Count, dto.MinDelay, dto.MaxDelay, dto.Team, SpawnBounds);
_walkingRange = dto.WalkingRange;
_spawnLocationIsHome = dto.SpawnLocationIsHome;
_spawnPositionMode = dto.SpawnPositionMode;
_maxSpawnAttempts = dto.MaxSpawnAttempts;
if (dto.Entries != null)
{
for (var i = 0; i < dto.Entries.Count; i++)
{
var entry = dto.Entries[i];
AddEntry(entry.SpawnedName, entry.SpawnedProbability, entry.SpawnedMaxCount, false, entry.Properties, entry.Parameters);
}
}
}
/// <summary>The square spawn bounds a homeRange radius represents (centered on the location).</summary>
private protected static Rectangle3D BoundsFromHomeRange(Point3D location, int homeRange)
{
int z;
int depth;
if (homeRange == 0)
{
z = location.Z;
depth = 0;
}
else
{
z = -128;
depth = 256;
}
return new Rectangle3D(
location.X - homeRange,
location.Y - homeRange,
z,
homeRange * 2 + 1,
homeRange * 2 + 1,
depth
);
}
private protected string DtoName
{
get
{
var name = Name;
return string.IsNullOrEmpty(name) || name == DefaultName ? null : name;
}
}
// ToDto helpers for values whose export form differs from the public property. (Guid/MinDelay/
// MaxDelay/Team/SpawnLocationIsHome match their property and are referenced directly in ToDto.)
// Raw field; the public WalkingRange is computed (falls back to HomeRange).
private protected int DtoWalkingRange => _walkingRange;
// Abandoned is a transient runtime state, not persisted -> map to Automatic (omitted).
private protected SpawnPositionMode DtoSpawnPositionMode =>
_spawnPositionMode == SpawnPositionMode.Abandoned ? SpawnPositionMode.Automatic : _spawnPositionMode;
// Runtime treats 0 as DefaultMaxSpawnAttempts -> map the default to 0 (omitted).
private protected int DtoMaxSpawnAttempts => _maxSpawnAttempts == DefaultMaxSpawnAttempts ? 0 : _maxSpawnAttempts;
// The radius if SpawnBounds is exactly what it reconstructs (lossless square); otherwise -1.
private protected int DtoHomeRange
{
get
{
if (SpawnBounds == default || !IsHomeRangeStyle)
{
return -1;
}
var homeRange = HomeRange;
return SpawnBounds == BoundsFromHomeRange(Location, homeRange) ? homeRange : -1;
}
}
}