using System;
using System.Diagnostics;
using System.IO;
using System.Net.Security;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Loader;
using GlitchyEngine.Core;
using GlitchyEngine.Math;

namespace GlitchyEngine;

/// <summary>
/// All methods in here are glued to the ScriptGlue.bf in the engine.
/// </summary>
internal static class ScriptGlue
{
#region Entity
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Entity_AddComponent(UUID entityId, Type componentType);

    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern bool Entity_HasComponent(UUID entityId, Type componentType);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Entity_RemoveComponent(UUID entityId, Type componentType);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Entity_FindEntityWithName(string name, out UUID uuid);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern object Entity_GetScriptInstance(UUID entityId);
    
#endregion Entity

#region TransformComponent

    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Transform_GetTranslation(UUID entityId, out float3 translation);

    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Transform_SetTranslation(UUID entityId, in float3 translation);

#endregion TransformComponent

#region RigidBody2D
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void RigidBody2D_ApplyForce(UUID entityId, in float2 force, float2 point, bool wakeUp);

    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void RigidBody2D_ApplyForceToCenter(UUID entityId, in float2 force, bool wakeUp);

#endregion RigidBody2D

#region Physics2D
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Physics2D_GetGravity(out float2 gravity);

    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern void Physics2D_SetGravity(in float2 gravity);

#endregion Physics2D

#region Math
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern float modf_float(float x, out float integerPart);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern float2 modf_float2(float2 x, out float2 integerPart);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern float3 modf_float3(float3 x, out float3 integerPart);
    
    [MethodImpl(MethodImplOptions.InternalCall)]
    internal static extern float4 modf_float4(float4 x, out float4 integerPart);

#endregion
    
    private static AssemblyLoadContext? _scriptAssemblyContext;

    private static Assembly? _appAssembly;

    [UnmanagedCallersOnly]
    public static unsafe void LoadScriptAssembly(byte* assemblyData, long assemblyLength, byte* pdbData, long pdbLength)
    {
        using UnmanagedMemoryStream assemblyStream = new(assemblyData, assemblyLength);

        using UnmanagedMemoryStream? pdbStream = (pdbData != null) ? new UnmanagedMemoryStream(pdbData, pdbLength) : null;

        LoadAssembly(assemblyStream, pdbStream);
    }

    private static void LoadAssembly(Stream assemblyStream, Stream? pdbStream)//(string path)
    {
        try
        {
            _scriptAssemblyContext ??= new AssemblyLoadContext("ScriptContext", true);
            
            _appAssembly = _scriptAssemblyContext.LoadFromStream(assemblyStream, pdbStream);
            
            Debug.Assert(_appAssembly != null);
            
            // Test the loaded assembly
            _appAssembly.GetType("Sandbox.TestClass")?.GetMethod("InternalTest")?.Invoke(null, null);
        }
        catch (Exception e)
        {
            Console.WriteLine($"Fehler: {e}");
        }
    }
    
    [UnmanagedCallersOnly]
    public static void UnloadAssemblies()
    {
        UnloadContext();
    }

    private static void UnloadContext()
    {
        _scriptAssemblyContext?.Unload();
        _scriptAssemblyContext = null;
    }
}