using System.Runtime.InteropServices;

namespace EC.Helper.CameraSDK;

public class DaHuaSDK : ICameraSDK
{
    #region Attr

    private IntPtr LoginId { get; set; } = IntPtr.Zero;

    #endregion Attr

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

    #region Base Method

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

        DaHuaOriSDK.NET_IN_LOGIN_WITH_HIGHLEVEL_SECURITY stuInParam = new();
        stuInParam.dwSize = (uint)Marshal.SizeOf(stuInParam);
        stuInParam.szIP = CameraInfo.Ip;
        stuInParam.nPort = CameraInfo.Port;
        stuInParam.szUserName = CameraInfo.UserName;
        stuInParam.szPassword = CameraInfo.Password;
        stuInParam.emSpecCap = DaHuaOriSDK.EM_LOGIN_SPAC_CAP_TYPE.TCP;
        stuInParam.pCapParam = IntPtr.Zero;
        DaHuaOriSDK.NET_OUT_LOGIN_WITH_HIGHLEVEL_SECURITY stuOutParam = new();
        stuOutParam.dwSize = (uint)Marshal.SizeOf(stuOutParam);
        LoginId = DaHuaOriSDK.CLIENT_LoginWithHighLevelSecurity(ref stuInParam, ref stuOutParam);
        ret = ConnectSuccess();
        if (ret) DaHuaOriSDK.CLIENT_SetAutoReconnect(delegate (IntPtr lLoginID, IntPtr pchDVRIP, int nDVRPort, IntPtr dwUser)
        {
            LoginId = lLoginID;
        }, IntPtr.Zero);

        return ret;
    }

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

        ret = DaHuaOriSDK.CLIENT_Logout(LoginId);
        if (ret) LoginId = IntPtr.Zero;

        return ret;
    }

    public override bool ConnectSuccess()
    {
        return LoginId != IntPtr.Zero;
    }

    public override void BuildException()
    {
        uint errCode = (uint)DaHuaOriSDK.CLIENT_GetLastError();
        if (errCode == 0) return;
        errCode -= 0x80000000;
        throw CameraException.New(CameraManufactor.DaHua, (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()
        {
            DaHuaOriSDK.DH_PTZ_LOCATION_INFO info = new();
            Size = Marshal.SizeOf(info);
            Type = info.GetType();
        }
    }

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

        DaHuaOriSDK.DH_PTZ_LOCATION_INFO entity = new();
        int nBufLen = GPIParams.Size;
        int pRetLen = 0;
        IntPtr ptrBuf = Marshal.AllocHGlobal(GPIParams.Size);
        Marshal.StructureToPtr(entity, ptrBuf, true);
        try
        {
            ret = DaHuaOriSDK.CLIENT_QueryDevState(LoginId, (int)DaHuaOriSDK.EM_DEVICE_STATE.PTZ_LOCATION, ptrBuf, nBufLen, ref pRetLen, 3000);
            if (!ret) { BuildException(); return PtzInfo.Default; }
            object? objBuf = Marshal.PtrToStructure(ptrBuf, GPIParams.Type);
            if (objBuf == null) return PtzInfo.Default;
            entity = (DaHuaOriSDK.DH_PTZ_LOCATION_INFO)objBuf;
            return PtzInfo.New(entity.nPTZPan, entity.nPTZTilt, entity.nPTZZoom);
        }
        finally
        {
            Marshal.FreeHGlobal(ptrBuf);
        }
    }

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

        DaHuaOriSDK.DH_PTZ_LOCATION_INFO entity = new();
        int nBufLen = GPIParams.Size;
        int pRetLen = 0;
        IntPtr ptrBuf = Marshal.AllocHGlobal(GPIParams.Size);
        Marshal.StructureToPtr(entity, ptrBuf, true);
        try
        {
            ret = DaHuaOriSDK.CLIENT_QueryDevState(LoginId, (int)DaHuaOriSDK.EM_DEVICE_STATE.PTZ_LOCATION, ptrBuf, nBufLen, ref pRetLen, 3000);
            if (!ret) { BuildException(); ptzInfo = PtzInfo.Default; return false; }
            object? objBuf = Marshal.PtrToStructure(ptrBuf, GPIParams.Type);
            if (objBuf == null) { ptzInfo = PtzInfo.Default; return false; }
            entity = (DaHuaOriSDK.DH_PTZ_LOCATION_INFO)objBuf;
            ptzInfo = PtzInfo.New(entity.nPTZPan, entity.nPTZTilt, entity.nPTZZoom);
            return true;
        }
        finally
        {
            Marshal.FreeHGlobal(ptrBuf);
        }
    }

    #endregion Main Method
}