using System.Runtime.InteropServices;

namespace Robovoice.Tts.LibPiper;

internal static class NativeDependencyLoader
{
    private static int _loaded;

    public static void EnsureLoaded()
    {
        if (Interlocked.CompareExchange(ref _loaded, 1, 0) != 0)
            return;

        string baseDir = AppContext.BaseDirectory;
        string nativeDir = Path.Combine(baseDir, "runtimes", "win-x64", "native");

        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && Directory.Exists(nativeDir))
        {
            if (!SetDllDirectory(nativeDir))
                throw new InvalidOperationException(
                    $"SetDllDirectory failed for: {nativeDir}");
        }
    }

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