using System.Reflection;
using AcDream.App.World;
using AcDream.Runtime.Entities;

namespace AcDream.App.Tests.World;

public sealed class RuntimeEntityOwnershipTests
{
    [Fact]
    public void LiveEntityRuntime_ComposesCanonicalRuntimeDirectory()
    {
        FieldInfo directory = typeof(LiveEntityRuntime).GetField(
            "_directory",
            BindingFlags.Instance | BindingFlags.NonPublic)
            ?? throw new InvalidOperationException("Missing canonical entity directory.");
        FieldInfo sidecars = typeof(LiveEntityRuntime).GetField(
            "_activeRecords",
            BindingFlags.Instance | BindingFlags.NonPublic)
            ?? throw new InvalidOperationException("Missing App projection sidecar store.");

        Assert.Equal(typeof(RuntimeEntityDirectory), directory.FieldType);
        Assert.Equal(typeof(RuntimeEntityRecord), sidecars.FieldType.GetGenericArguments()[0]);
        Assert.Equal(typeof(LiveEntityRecord), sidecars.FieldType.GetGenericArguments()[1]);
    }

    [Fact]
    public void AppCompatibilityLookup_IsNotASecondGuidDictionary()
    {
        FieldInfo compatibilityView = typeof(LiveEntityRuntime).GetField(
            "_recordsByGuid",
            BindingFlags.Instance | BindingFlags.NonPublic)
            ?? throw new InvalidOperationException("Missing migration compatibility view.");

        Assert.False(compatibilityView.FieldType.IsGenericType);
        Assert.DoesNotContain(
            compatibilityView.FieldType.GetInterfaces(),
            type => type.IsGenericType
                && type.GetGenericTypeDefinition() == typeof(IDictionary<,>));
    }

    [Fact]
    public void CanonicalRuntimeRecord_HasNoProjectionOrBackendSurface()
    {
        string[] forbiddenPropertyNames =
        [
            "WorldEntity",
            "AnimationRuntime",
            "RemoteMotionRuntime",
            "ProjectileRuntime",
            "EffectProfile",
            "ResourcesRegistered",
            "IsSpatiallyProjected",
            "IsSpatiallyVisible",
        ];
        PropertyInfo[] properties = typeof(RuntimeEntityRecord).GetProperties(
            BindingFlags.Instance | BindingFlags.Public);

        Assert.DoesNotContain(
            properties,
            property => forbiddenPropertyNames.Contains(
                property.Name,
                StringComparer.Ordinal));
        Assert.DoesNotContain(
            properties,
            property => IsPresentationType(property.PropertyType));
    }

    private static bool IsPresentationType(Type type)
    {
        string? ns = type.Namespace;
        return ns?.StartsWith("AcDream.App", StringComparison.Ordinal) == true
            || ns?.StartsWith("AcDream.UI", StringComparison.Ordinal) == true
            || ns?.StartsWith("Silk.NET", StringComparison.Ordinal) == true
            || ns?.StartsWith("ImGuiNET", StringComparison.Ordinal) == true;
    }
}