using System.Runtime.InteropServices;

namespace RobotNet10.RobotApp.SickScanXdApi;

/// <summary>
/// P/Invoke declarations for sick_scan_xd C API
/// </summary>
public static class SickScanApiNative
{
    private const string LibraryName = "sick_scan_xd_shared_lib"; // libsick_scan_xd_shared_lib.so
    
    // Structs matching C API (exact field names with snake_case)
    
    [StructLayout(LayoutKind.Sequential)]
    public struct SickScanHeader
    {
        public uint seq;
        public uint timestamp_sec;
        public uint timestamp_nsec;
        
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]
        public byte[] frame_id;
    }
    
    [StructLayout(LayoutKind.Sequential)]
    public struct SickScanUint8Array
    {
        public ulong capacity;
        public ulong size;
        public IntPtr buffer;  // uint8_t*
    }
    
    [StructLayout(LayoutKind.Sequential)]
    public struct SickScanPointFieldMsg
    {
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]
        public byte[] name;
        public uint offset;
        public byte datatype;
        public uint count;
    }
    
    [StructLayout(LayoutKind.Sequential)]
    public struct SickScanPointFieldArray
    {
        public ulong capacity;
        public ulong size;
        public IntPtr buffer;  // SickScanPointFieldMsg*
    }
    
    [StructLayout(LayoutKind.Sequential)]
    public struct SickScanPointCloudMsg
    {
        public SickScanHeader header;
        public uint height;
        public uint width;
        public SickScanPointFieldArray fields;
        public byte is_bigendian;
        public uint point_step;
        public uint row_step;
        public SickScanUint8Array data;
        public byte is_dense;
        public int num_echos;
        public int segment_idx;
        
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]
        public byte[] topic;
    }
    
    // API Functions
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern IntPtr SickScanApiCreate(int argc, IntPtr argv);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiRelease(IntPtr apiHandle);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiInitByCli(
        IntPtr apiHandle,
        int argc,
        IntPtr argv);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiInitByLaunchfile(
        IntPtr apiHandle,
        IntPtr launchfileArgs);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiClose(IntPtr apiHandle);
    
    // Callback registration
    public delegate void PointCloudMsgCallback(IntPtr apiHandle, ref SickScanPointCloudMsg msg);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiRegisterPolarPointCloudMsg(
        IntPtr apiHandle,
        PointCloudMsgCallback callback);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiDeregisterPolarPointCloudMsg(
        IntPtr apiHandle,
        PointCloudMsgCallback callback);
    
    // Polling function
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiWaitNextPolarPointCloudMsg(
        IntPtr apiHandle,
        ref SickScanPointCloudMsg msg,
        double timeoutSec);
    
    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl)]
    public static extern int SickScanApiFreePointCloudMsg(
        IntPtr apiHandle,
        ref SickScanPointCloudMsg msg);
    
    // Error codes
    public const int SICK_SCAN_API_SUCCESS = 0;
    public const int SICK_SCAN_API_ERROR = 1;
    public const int SICK_SCAN_API_NOT_LOADED = 2;
    public const int SICK_SCAN_API_NOT_INITIALIZED = 3;
    public const int SICK_SCAN_API_NOT_IMPLEMENTED = 4;
    public const int SICK_SCAN_API_TIMEOUT = 5;
}