// SPDX-FileCopyrightText: 2025 Erin Catto

// SPDX-FileCopyrightText: 2025 Ikpil Choi(ikpil@naver.com)

// SPDX-License-Identifier: MIT

using System;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

using Box2D.NET.Samples.Primitives;

using Serilog;

using static Box2D.NET.B2Types;

namespace Box2D.NET.Samples.Samples;

public class SampleFactory

{

private static readonly ILogger Logger = Log.ForContext<SampleFactory>();

public static readonly SampleFactory Shared = new SampleFactory();

private readonly List<SampleEntry> _sampleEntries;

public int SampleCount => _sampleEntries.Count;

private SampleFactory()

{

_sampleEntries = new List<SampleEntry>();

}

public int RegisterSample(string category, string name, Func<SampleContext, Sample> fcn)

{

int index = _sampleEntries.Count;

var entry = new SampleEntry(category, name, fcn, null);

_sampleEntries.Add(entry);

return index;

}

public int RegisterSampleWithCapacity(string category, string name, Func<SampleContext, Sample> fcn, Func<B2Capacity> capacityFcn)

{

int index = _sampleEntries.Count;

var entry = new SampleEntry(category, name, fcn, capacityFcn);

_sampleEntries.Add(entry);

return index;

}

public Sample Create(int index, SampleContext context)

{

var entry = GetInternal(index);

context.capacity = entry.CapacityFcn != null ? entry.CapacityFcn.Invoke() : b2DefaultWorldDef().capacity;

var sample = entry.CreateFcn.Invoke(context);

return sample;

}

public string GetCategory(int index)

{

var entry = GetInternal(index);

return entry.Category;

}

public string GetName(int index)

{

var entry = GetInternal(index);

return entry.Name;

}

private SampleEntry GetInternal(int index)

{

var sample = _sampleEntries[index];

return sample;

}

private static int CompareSamples(SampleEntry sa, SampleEntry sb)

{

int result = string.Compare(sa.Category, sb.Category, StringComparison.InvariantCultureIgnoreCase);

if (result == 0)

{

result = string.Compare(sa.Name, sb.Name, StringComparison.InvariantCultureIgnoreCase);

}

return result;

}

public void LoadSamples()

{

Assembly assembly = Assembly.GetExecutingAssembly();

var sampleTypes = assembly.GetTypes()

.Where(t => t.IsSubclassOf(typeof(Sample)) && !t.IsAbstract)

.ToList();

int index = 0;

foreach (var type in sampleTypes)

{

// Attributes = {MethodAttributes} Private | Static | HideBySig | SpecialName | RTSpecialName

// BindingFlags = {BindingFlags} Static | NonPublic

var method = type.GetConstructors(BindingFlags.Static | BindingFlags.NonPublic);

if (0 >= method.Length)

{

Logger.Information($"can not load sample - {type.Name}");

continue;

}

method[0].Invoke(null, null);

var title = GetTitle(index);

Logger.Information($"loaded sample - {title}");

++index;

}

}

public void SortSamples()

{

_sampleEntries.Sort(CompareSamples);

}

public string GetTitle(int index)

{

var entry = GetInternal(index);

return entry.Title;

}

}