using System;
using System.IO;
using System.Runtime.InteropServices;

public static class SystemLibrary
{
#if UNITY_STANDALONE_WIN || UNITY_GAMECORE
    [DllImport("kernel32", EntryPoint = "LoadLibrary", SetLastError = true, CharSet = CharSet.Unicode)]
    private static extern IntPtr LoadLibraryNative(string lpFileName);

    [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool SetDllDirectory(string lpPathName);

    public static IntPtr LoadLibrary(string lpFileName)
    {
        string lpPathName = Path.GetDirectoryName(lpFileName);
        lpFileName = Path.GetFileName(lpFileName);
        SetDllDirectory(lpPathName.Replace('/', '\\'));
        return LoadLibraryNative(lpFileName);
    }

    [DllImport("kernel32", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool FreeLibrary(IntPtr hModule);

    [DllImport("kernel32")]
    public static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);
#elif UNITY_PS4 || UNITY_PS5
    [DllImport("SceKernelShim.prx", EntryPoint = "LoadLibrary")]
    private static extern Int32 LoadLibraryNative(string filename);
    
    public static IntPtr LoadLibrary(string filename)
    {
        Int32 moduleHandle = LoadLibraryNative(filename);
        if (moduleHandle <= 0)
        {
            UnityEngine.Debug.LogError($"Error loading PRX module '{filename}', error code = 0x{moduleHandle:X}");
            return IntPtr.Zero;
        }

        return new IntPtr(moduleHandle);
    }

    [DllImport("SceKernelShim.prx", EntryPoint = "FreeLibrary")]
    private static extern bool FreeLibraryNative(Int32 moduleHandle);
    
    public static bool FreeLibrary(IntPtr hModule)
    {
        return FreeLibraryNative(hModule.ToInt32());
    }

    [DllImport("SceKernelShim.prx")]
    public static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);
#endif
}