using System.Runtime.InteropServices;

namespace EC.Helper.CameraSDK;

public class HiKSDK : ICameraSDK
{
    #region Attr

    private int LoginId { get; set; } = -1;

    #endregion Attr

    public HiKSDK(CameraInfo cameraInfo) : base(cameraInfo)
    {
    }

    #region Base Method

    public override bool Init()
    {
        bool ret = ConnectSuccess();
        if (ret) return true;

        HiKOriSDK.NET_DVR_DEVICEINFO_V30 deviceInfo = new();
        LoginId = HiKOriSDK.NET_DVR_Login_V30(CameraInfo.Ip, CameraInfo.Port, CameraInfo.UserName, CameraInfo.Password, ref deviceInfo);
        ret = ConnectSuccess();

        return ret;
    }

    public override bool Destory()
    {
        bool ret = ConnectSuccess();
        if (!ret) return true;

        ret = HiKOriSDK.NET_DVR_Logout(LoginId);
        if (ret) LoginId = -1;

        return ret;
    }

    public override bool ConnectSuccess()
    {
        return LoginId >= 0;
    }

    public override void BuildException()
    {
        uint errCode = HiKOriSDK.NET_DVR_GetLastError();
        if (errCode == 0) return;
        throw CameraException.New(CameraType.HiK, (int)errCode);
    }

    #endregion Base Method

    #region Main Method

    private static class GPIParams
    {
        public static int Size { get; private set; }
        public static Type Type { get; private set; }

        static GPIParams()
        {
            HiKOriSDK.NET_DVR_PTZPOS ptzPos = new();
            Size = Marshal.SizeOf(ptzPos);
            Type = ptzPos.GetType();
        }
    }

    public override PtzInfo GetPtzInfo()
    {
        bool ret = ConnectSuccess();
        if (!ret) return PtzInfo.Default;

        HiKOriSDK.NET_DVR_PTZPOS entity = new();
        int dwSize = GPIParams.Size;
        uint dwReturned = 0;
        IntPtr ptrBuf = Marshal.AllocHGlobal(dwSize);
        Marshal.StructureToPtr(entity, ptrBuf, true);
        try
        {
            ret = HiKOriSDK.NET_DVR_GetDVRConfig(LoginId, HiKOriSDK.NET_DVR_GET_PTZPOS, 0, ptrBuf, (uint)dwSize, ref dwReturned);
            if (!ret) { BuildException(); return PtzInfo.Default; }
            object? objBuf = Marshal.PtrToStructure(ptrBuf, GPIParams.Type);
            if (objBuf == null) return PtzInfo.Default;
            entity = (HiKOriSDK.NET_DVR_PTZPOS)objBuf;
            return PtzInfo.New(entity.wPanPos, entity.wTiltPos, entity.wZoomPos);
        }
        finally
        {
            Marshal.FreeHGlobal(ptrBuf);
        }
    }

    public override bool TryGetPtzInfo(out PtzInfo ptzInfo)
    {
        bool ret = ConnectSuccess();
        if (!ret) { ptzInfo = PtzInfo.Default; return false; }

        HiKOriSDK.NET_DVR_PTZPOS entity = new();
        int dwSize = GPIParams.Size;
        uint dwReturned = 0;
        IntPtr ptrBuf = Marshal.AllocHGlobal(dwSize);
        Marshal.StructureToPtr(entity, ptrBuf, true);
        try
        {
            ret = HiKOriSDK.NET_DVR_GetDVRConfig(LoginId, HiKOriSDK.NET_DVR_GET_PTZPOS, 0, ptrBuf, (uint)dwSize, ref dwReturned);
            if (!ret) { BuildException(); ptzInfo = PtzInfo.Default; return false; }
            object? objBuf = Marshal.PtrToStructure(ptrBuf, GPIParams.Type);
            if (objBuf == null) { ptzInfo = PtzInfo.Default; return false; }
            entity = (HiKOriSDK.NET_DVR_PTZPOS)objBuf;
            ptzInfo = PtzInfo.New(entity.wPanPos, entity.wTiltPos, entity.wZoomPos);
            return true;
        }
        finally
        {
            Marshal.FreeHGlobal(ptrBuf);
        }
    }

    #endregion Main Method
}