using System.Runtime.InteropServices;

internal static class Nova64Core
{
    private const string LibName = "nova64_core";

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void DisplayFlushDelegate(IntPtr buffer, ushort width, ushort height);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void AudioOutputDelegate(IntPtr samples, uint count);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public delegate int SdReadFileDelegate(uint slotIdx, string filePath, IntPtr destinationBuffer, uint destinationLength);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public delegate int SdGetFileSizeDelegate(uint slotIdx, string filePath);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void CartridgeStatusDelegate(uint slotIdx, bool isInserted);

    [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public delegate void LogMessageDelegate([MarshalAs(UnmanagedType.LPStr)] string message);

    [StructLayout(LayoutKind.Sequential)]
    public struct Nova64IoInterface
    {
        public IntPtr display_flush;
        public IntPtr audio_output;
        public IntPtr sd_read_file;
        public IntPtr sd_get_file_size;
        public IntPtr cartridge_status;
        public IntPtr log_message;
    }

    [DllImport(LibName, CallingConvention = CallingConvention.Cdecl)]
    public static extern bool nova64_init(IntPtr io_interface);

    [DllImport(LibName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int nova64_main();

    [DllImport(LibName, CallingConvention = CallingConvention.Cdecl)]
    public static extern bool nova64_shutdown();

    [DllImport(LibName, CallingConvention = CallingConvention.Cdecl)]
    public static extern uint nova64_get_version();
}