fix: Fixes region priority and resolution. (#1254)

- [X] Fixes world location JSON deserializer.
- [X] Fixes region resolver and priorities.
- [X] Removes DynamicJson from regions.
- [X] Adds missing region music.

Projects/Server/Regions/RegionJsonSerializer.cs

@@ -0,0 +1,148 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2022 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: RegionJsonSerializer.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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
+using Server.Json;
+using Server.Logging;
+using Server.Utilities;
+
+namespace Server;
+
+public static class RegionJsonSerializer
+{
+    private static readonly ILogger logger = LogFactory.GetLogger(typeof(RegionJsonSerializer));
+
+    // Note: This is filled during the `Configure` phase by RegisterRegionForSerialization,
+    // so it is not available to a JsonConverter which might be used during earlier phases.
+    private static Dictionary<Type, Type> _regionToDtoLookup = new() { { typeof(Region), typeof(RegionJsonDto) } };
+    private static JsonDerivedType[] _derivedTypes = { new(typeof(RegionJsonDto), nameof(Region)) };
+
+    private static JsonSerializerOptions _options = new(JsonConfig.DefaultOptions)
+    {
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingDefault,
+        TypeInfoResolver = new DefaultJsonTypeInfoResolver
+        {
+            Modifiers =
+            {
+                static typeInfo =>
+                {
+                    if (typeInfo.Type != typeof(RegionJsonDto))
+                    {
+                        return;
+                    }
+
+                    typeInfo.PolymorphismOptions = new JsonPolymorphismOptions();
+                    for (var i = 0; i < _derivedTypes.Length; i++)
+                    {
+                        typeInfo.PolymorphismOptions.DerivedTypes.Add(_derivedTypes[i]);
+                    }
+                },
+            }
+        }
+    };
+
+    public static void RegisterRegionForSerialization<TDto, TRegion>()
+        where TDto : RegionJsonDto, new() where TRegion : Region
+    {
+        for (var i = 0; i < _derivedTypes.Length; i++)
+        {
+            if (_derivedTypes[i].DerivedType == typeof(TDto))
+            {
+                throw new Exception(
+                    $"Type '{typeof(TDto)}' has already been registered for serialization with the region loader."
+                );
+            }
+        }
+
+        Array.Resize(ref _derivedTypes, _derivedTypes.Length + 1);
+        _derivedTypes[^1] = new JsonDerivedType(typeof(TDto), typeof(TRegion).Name);
+        _regionToDtoLookup[typeof(TRegion)] = typeof(TDto);
+    }
+
+    internal static void LoadRegions()
+    {
+        var path = Path.Join(Core.BaseDirectory, "Data/regions.json");
+
+        logger.Information("Loading regions");
+
+        var stopwatch = Stopwatch.StartNew();
+
+        var regions = JsonConfig.Deserialize<List<RegionJsonDto>>(path, _options);
+        if (regions == null)
+        {
+            throw new JsonException($"Failed to deserialize {path}.");
+        }
+
+        foreach (var dto in regions)
+        {
+            var region = dto.ToRegion();
+            region.Register();
+        }
+
+        stopwatch.Stop();
+
+        logger.Information(
+            "Loading regions {Status} ({Count} regions) ({Duration:F2} seconds)",
+            "done",
+            regions.Count,
+            stopwatch.Elapsed.TotalSeconds
+        );
+    }
+
+    // Note: This is not thread safe. To make `SerializeRegions` threadsafe, use `[ThreadStatic]` or just create the lists
+    // in the function and take the GC hit.
+    private static List<RegionJsonDto> _regionJsonDtos;
+
+    public static void SerializeRegions(string path, IEnumerable<Region> regions)
+    {
+        _regionJsonDtos ??= new List<RegionJsonDto>();
+        foreach (var region in regions)
+        {
+            if (_regionToDtoLookup.TryGetValue(region.GetType(), out var dtoType))
+            {
+                var dto = dtoType.CreateInstance<RegionJsonDto>();
+                dto.FromRegion(region);
+                _regionJsonDtos.Add(dto);
+            }
+        }
+
+        JsonConfig.Serialize(path, _regionJsonDtos, _options);
+        _regionJsonDtos.Clear();
+    }
+
+    public static string SerializeRegions(IEnumerable<Region> regions)
+    {
+        _regionJsonDtos ??= new List<RegionJsonDto>();
+        foreach (var region in regions)
+        {
+            if (_regionToDtoLookup.TryGetValue(region.GetType(), out var dtoType))
+            {
+                var dto = dtoType.CreateInstance<RegionJsonDto>();
+                dto.FromRegion(region);
+                _regionJsonDtos.Add(dto);
+            }
+        }
+
+        var output = JsonConfig.Serialize(_regionJsonDtos, _options);
+        _regionJsonDtos.Clear();
+        return output;
+    }
+}