%%
%% %CopyrightBegin%
%%
%% SPDX-License-Identifier: Apache-2.0
%%
%% Copyright Ericsson AB 2011-2025. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
-module(observer_port_wx).
-moduledoc false.

-export([start_link/3]).

%% wx_object callbacks
-export([init/1, handle_info/2, terminate/2, code_change/3, handle_call/3,
	 handle_event/2, handle_sync_event/3, handle_cast/2]).

-behaviour(wx_object).
-include_lib("wx/include/wx.hrl").
-include("observer_defs.hrl").

-define(GRID, 300).
-define(ID_REFRESH, 301).
-define(ID_REFRESH_INTERVAL, 302).
-define(ID_PORT_INFO, 303).
-define(ID_PORT_INFO_SELECTED, 304).
-define(ID_TRACE_PORTS, 305).
-define(ID_TRACE_NAMES, 306).
-define(ID_TRACE_NEW, 307).
-define(ID_TRACE_ALL, 308).
-define(ID_CLOSE_PORT, 309).

-define(TRACE_PORTS_STR, "Trace selected ports").
-define(TRACE_NAMES_STR, "Trace selected ports, "
	"if a process have a registered name "
	"processes with same name will be traced on all nodes").

-record(port,
	{id,
	 connected,
	 name,
	 controls,
	 slot,
	 id_str,
	 links,
	 monitors,
	 monitored_by,
         parallelism,
         locking,
         queue_size,
         memory,
         inet}).

-record(opt, {sort_key=2,
	      sort_incr=true,
              odd_bg
	     }).

-record(state,
	{
	  parent,
	  grid,
	  panel,
	  node={node(),true},
	  opt=#opt{},
	  right_clicked_port,
	  ports,
	  timer,
	  open_wins=[]
	}).

start_link(Notebook,  Parent, Config) ->
    wx_object:start_link(?MODULE, [Notebook, Parent, Config], []).

init([Notebook, Parent, Config]) ->
    Panel = wxPanel:new(Notebook),
    Sizer = wxBoxSizer:new(?wxVERTICAL),
    Style = ?wxLC_REPORT bor ?wxLC_HRULES,
    Grid = wxListCtrl:new(Panel, [{winid, ?GRID}, {style, Style}]),
    wxSizer:add(Sizer, Grid, [{flag, ?wxEXPAND bor ?wxALL},
			      {proportion, 1}, {border, 5}]),
    wxWindow:setSizer(Panel, Sizer),
    Li = wxListItem:new(),
    AddListEntry = fun({Name, Align, DefSize}, Col) ->
			   wxListItem:setText(Li, Name),
			   wxListItem:setAlign(Li, Align),
			   wxListCtrl:insertColumn(Grid, Col, Li),
			   wxListCtrl:setColumnWidth(Grid, Col, DefSize),
			   Col + 1
		   end,
    Scale = observer_wx:get_scale(),
    ListItems = [{"Id", ?wxLIST_FORMAT_LEFT,  Scale*150},
		 {"Connected", ?wxLIST_FORMAT_LEFT, Scale*150},
		 {"Name", ?wxLIST_FORMAT_LEFT, Scale*150},
		 {"Controls", ?wxLIST_FORMAT_LEFT, Scale*200},
		 {"Slot", ?wxLIST_FORMAT_RIGHT, Scale*50}],
    lists:foldl(AddListEntry, 0, ListItems),
    wxListItem:destroy(Li),

    wxListCtrl:connect(Grid, command_list_item_right_click),
    wxListCtrl:connect(Grid, command_list_item_activated),
    wxListCtrl:connect(Grid, command_list_col_click),
    wxListCtrl:connect(Grid, size, [{skip, true}]),

    wxWindow:setFocus(Grid),
    Even = wxSystemSettings:getColour(?wxSYS_COLOUR_LISTBOX),
    Odd = observer_lib:mix(Even, wxSystemSettings:getColour(?wxSYS_COLOUR_HIGHLIGHT), 0.8),
    Opt = #opt{odd_bg=Odd},
    {Panel, #state{grid=Grid, parent=Parent, panel=Panel, timer=Config, opt=Opt}}.

handle_event(#wx{id=?ID_REFRESH},
	     State = #state{node=Node, grid=Grid, opt=Opt}) ->
    Ports0 = get_ports(Node),
    Ports = update_grid(Grid, sel(State), Opt, Ports0),
    {noreply, State#state{ports=Ports}};

handle_event(#wx{obj=Obj, event=#wxClose{}}, #state{open_wins=Opened} = State) ->
    NewOpened =
	case lists:keytake(Obj,2,Opened) of
	    false -> Opened;
	    {value,_,Rest} -> Rest
	end,
    {noreply, State#state{open_wins=NewOpened}};

handle_event(#wx{event=#wxList{type=command_list_col_click, col=Col}},
	     State = #state{node=Node, grid=Grid,
			    opt=Opt0=#opt{sort_key=Key, sort_incr=Bool}}) ->
    Opt = case Col+2 of
	      Key -> Opt0#opt{sort_incr=not Bool};
	      NewKey -> Opt0#opt{sort_key=NewKey}
	  end,
    Ports0 = get_ports(Node),
    Ports = update_grid(Grid, sel(State), Opt, Ports0),
    wxWindow:setFocus(Grid),
    {noreply, State#state{opt=Opt, ports=Ports}};

handle_event(#wx{event=#wxSize{size={W,_}}},  State=#state{grid=Grid}) ->
    observer_lib:set_listctrl_col_size(Grid, W),
    {noreply, State};

handle_event(#wx{event = #wxList{type      = command_list_item_activated,
                                 itemIndex = Index}},
	     State = #state{grid      = Grid,
                            ports     = Ports,
                            open_wins = Opened}) ->
    if
        length(Ports) >= (Index+1) ->
            Port      = lists:nth(Index+1, Ports),
            NewOpened = display_port_info(Grid, Port, Opened),
            {noreply, State#state{open_wins=NewOpened}};
        true -> % Race - should we do somthing here?
            {noreply, State}
    end;

handle_event(#wx{event=#wxList{type=command_list_item_right_click,
			       itemIndex=Index}},
	     State=#state{panel=Panel, ports=Ports}) ->
    case Index of
	-1 ->
	    {noreply, State};
	_ ->
	    Port = lists:nth(Index+1, Ports),
	    Menu = wxMenu:new(),
	    wxMenu:append(Menu, ?ID_PORT_INFO,
			  "Port info for " ++ erlang:port_to_list(Port#port.id)),
	    wxMenu:append(Menu, ?ID_TRACE_PORTS,
			  "Trace selected ports",
			  [{help, ?TRACE_PORTS_STR}]),
	    wxMenu:append(Menu, ?ID_TRACE_NAMES,
			  "Trace selected ports by name (all nodes)",
			  [{help, ?TRACE_NAMES_STR}]),
	    wxMenu:append(Menu, ?ID_CLOSE_PORT,
			  "Close " ++ erlang:port_to_list(Port#port.id)),
	    wxWindow:popupMenu(Panel, Menu),
	    wxMenu:destroy(Menu),
	    {noreply, State#state{right_clicked_port=Port}}
    end;

handle_event(#wx{id=?ID_PORT_INFO},
	     State = #state{grid=Grid, right_clicked_port=Port,
			    open_wins=Opened}) ->
    case Port of
	undefined ->
	    {noreply, State};
	_ ->
	    NewOpened = display_port_info(Grid, Port, Opened),
	    {noreply, State#state{right_clicked_port=undefined,
				  open_wins=NewOpened}}
    end;

handle_event(#wx{id=?ID_PORT_INFO_SELECTED},
	     State = #state{grid=Grid, ports=Ports, open_wins=Opened}) ->
    case get_selected_items(Grid,Ports) of
	[] ->
	    observer_wx:create_txt_dialog(State#state.panel, "No selected ports",
					  "Port Info", ?wxICON_EXCLAMATION),
	    {noreply, State};
	Selected ->
	    NewOpened = lists:foldl(fun(P,O) -> display_port_info(Grid, P, O) end,
				    Opened, Selected),
	    {noreply, State#state{open_wins = NewOpened}}
    end;

handle_event(#wx{id=?ID_CLOSE_PORT}, State = #state{right_clicked_port=Port}) ->
    case Port of
	undefined ->
	    {noreply, State};
	_ ->
	    erlang:port_close(Port#port.id),
	    {noreply, State#state{right_clicked_port=undefined}}
	end;

handle_event(#wx{id=?ID_TRACE_PORTS}, #state{grid=Grid, ports=Ports}=State)  ->
    case get_selected_items(Grid, Ports) of
	[] ->
	    observer_wx:create_txt_dialog(State#state.panel, "No selected ports",
					  "Tracer", ?wxICON_EXCLAMATION);
	Selected ->
	    SelectedIds = [Port#port.id || Port <- Selected],
	    observer_trace_wx:add_ports(SelectedIds)
    end,
    {noreply,  State};

handle_event(#wx{id=?ID_TRACE_NAMES}, #state{grid=Grid, ports=Ports}=State)  ->
    case get_selected_items(Grid, Ports) of
	[] ->
	    observer_wx:create_txt_dialog(State#state.panel, "No selected ports",
					  "Tracer", ?wxICON_EXCLAMATION);
	Selected ->
	    IdsOrRegs =
		[case Port#port.name of
		     [] -> Port#port.id;
		     Name -> Name
		 end || Port <- Selected],
	    observer_trace_wx:add_ports(IdsOrRegs)
    end,
    {noreply,  State};

handle_event(#wx{id=?ID_TRACE_NEW, event=#wxCommand{type=command_menu_selected}}, State) ->
    observer_trace_wx:add_ports([new_ports]),
    {noreply,  State};

handle_event(#wx{id=?ID_REFRESH_INTERVAL},
	     State = #state{grid=Grid, timer=Timer0}) ->
    Timer = observer_lib:interval_dialog(Grid, Timer0, 10, 5*60),
    {noreply, State#state{timer=Timer}};

handle_event(#wx{obj=MoreEntry,event=#wxMouse{type=left_down},userData={more,More}}, State) ->
    observer_lib:add_scroll_entries(MoreEntry,More),
    {noreply, State};

handle_event(#wx{event=#wxMouse{type=left_down}, userData=TargetPid}, State) ->
    observer ! {open_link, TargetPid},
    {noreply, State};

handle_event(#wx{obj=Obj, event=#wxMouse{type=enter_window}}, State) ->
    wxTextCtrl:setForegroundColour(Obj,{0,0,100,255}),
    {noreply, State};

handle_event(#wx{obj=Obj, event=#wxMouse{type=leave_window}}, State) ->
    wxTextCtrl:setForegroundColour(Obj,?wxBLUE),
    {noreply, State};

handle_event(Event, _State) ->
    error({unhandled_event, Event}).

handle_sync_event(_Event, _Obj, _State) ->
    ok.

handle_call(get_config, _, #state{timer=Timer}=State) ->
    {reply, observer_lib:timer_config(Timer), State};

handle_call(Event, From, _State) ->
    error({unhandled_call, Event, From}).

handle_cast(Event, _State) ->
    error({unhandled_cast, Event}).

handle_info({portinfo_open, PortIdStr},
	    State = #state{node={ActiveNodeName,ActiveAvailable}, grid=Grid,
                           opt=Opt, open_wins=Opened}) ->
    NodeName = node(list_to_port(PortIdStr)),
    Available =
        case NodeName of
            ActiveNodeName ->
                ActiveAvailable;
            _ ->
                portinfo_available(NodeName)
        end,
    if Available ->
            Ports0 = get_ports({NodeName,Available}),
            Port = lists:keyfind(PortIdStr, #port.id_str, Ports0),
            NewOpened =
                case Port of
                    false ->
                        self() ! {error,"No such port: " ++ PortIdStr},
                        Opened;
                    _ ->
                        display_port_info(Grid, Port, Opened)
                end,
            Ports =
                case NodeName of
                    ActiveNodeName ->
                        update_grid(Grid, sel(State), Opt, Ports0);
                    _ ->
                        State#state.ports
                end,
            {noreply, State#state{ports=Ports, open_wins=NewOpened}};
       true ->
            popup_unavailable_info(NodeName),
            {noreply, State}
    end;

handle_info(refresh_interval, State = #state{node=Node, grid=Grid, opt=Opt,
                                             ports=OldPorts}) ->
    case get_ports(Node) of
        OldPorts ->
            %% no change
            {noreply, State};
        Ports0 ->
            Ports = update_grid(Grid, sel(State), Opt, Ports0),
            {noreply, State#state{ports=Ports}}
    end;

handle_info({active, NodeName}, State = #state{parent=Parent, grid=Grid, opt=Opt,
                                               timer=Timer0}) ->
    Available = portinfo_available(NodeName),
    Available orelse popup_unavailable_info(NodeName),
    Ports0 = get_ports({NodeName,Available}),
    Ports = update_grid(Grid, sel(State), Opt, Ports0),
    wxWindow:setFocus(Grid),
    create_menus(Parent),
    Timer = observer_lib:start_timer(Timer0, 10),
    {noreply, State#state{node={NodeName,Available}, ports=Ports, timer=Timer}};

handle_info(not_active, State = #state{timer = Timer0}) ->
    Timer = observer_lib:stop_timer(Timer0),
    {noreply, State#state{timer=Timer}};

handle_info({info, {port_info_not_available,NodeName}},
            State = #state{panel=Panel}) ->
    Str = io_lib:format("Can not fetch port info from ~p.~n"
                        "Too old OTP version.",[NodeName]),
    observer_lib:display_info_dialog(Panel, Str),
    {noreply, State};

handle_info({error, Error}, #state{panel=Panel} = State) ->
    Str = io_lib:format("ERROR: ~ts~n",[Error]),
    observer_lib:display_info_dialog(Panel, Str),
    {noreply, State};

handle_info(_Event, State) ->
    {noreply, State}.

terminate(_Event, _State) ->
    ok.

code_change(_, _, State) ->
    State.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

create_menus(Parent) ->
    MenuEntries =
	[{"View",
	  [#create_menu{id = ?ID_PORT_INFO_SELECTED,
			text = "Port info for selected ports\tCtrl+I"},
	   separator,
	   #create_menu{id = ?ID_REFRESH, text = "Refresh\tCtrl+R"},
	   #create_menu{id = ?ID_REFRESH_INTERVAL, text = "Refresh Interval..."}
	  ]},
	 {"Trace",
	  [#create_menu{id=?ID_TRACE_PORTS, text="Trace selected ports"},
	   #create_menu{id=?ID_TRACE_NAMES, text="Trace selected ports by name (all nodes)"},
	   #create_menu{id=?ID_TRACE_NEW, text="Trace new ports"}
	  ]}
	],
    observer_wx:create_menus(Parent, MenuEntries).

get_ports({_NodeName,false}) ->
    [];
get_ports({NodeName,true}) ->
    case get_ports2(NodeName) of
	Error = {error, _} ->
	    self() ! Error,
	    [];
	Res ->
	    Res
    end.
get_ports2(NodeName) ->
    case rpc:call(NodeName, observer_backend, get_port_list, []) of
	{badrpc, Error} ->
	    {error, Error};
	Error = {error, _} ->
	    Error;
	Result ->
	    [list_to_portrec(Port) || Port <- Result]
    end.

list_to_portrec(PL) ->
    %% PortInfo:
    %% {registered_name, RegisteredName :: atom()} |
    %% {id, Index :: integer() >= 0} |
    %% {connected, Pid :: pid()} |
    %% {links, Pids :: [pid()]} |
    %% {name, String :: string()} |
    %% {input, Bytes :: integer() >= 0} |
    %% {output, Bytes :: integer() >= 0} |
    %% {os_pid, OsPid :: integer() >= 0 | undefined},
    PortId = proplists:get_value(port_id, PL),
    #port{id = PortId,
	  id_str = erlang:port_to_list(PortId),
	  slot = proplists:get_value(id, PL),
	  connected = proplists:get_value(connected, PL),
	  links = proplists:get_value(links, PL, []),
	  name = proplists:get_value(registered_name, PL, []),
	  monitors = proplists:get_value(monitors, PL, []),
	  monitored_by = proplists:get_value(monitored_by, PL, []),
	  controls = proplists:get_value(name, PL),
          parallelism = proplists:get_value(parallelism, PL),
          locking = proplists:get_value(locking, PL),
          queue_size = proplists:get_value(queue_size, PL, 0),
          memory = proplists:get_value(memory, PL, 0),
          inet = proplists:get_value(inet, PL, [])}.

portrec_to_list(#port{id = Id,
		      slot = Slot,
		      connected = Connected,
		      links = Links,
		      name = Name,
		      monitors = Monitors,
                      monitored_by = MonitoredBy,
		      controls = Controls,
                      parallelism = Parallelism,
                      locking = Locking,
                      queue_size = QueueSize,
                      memory = Memory,
                      inet = Inet}) ->
    [{id,Id},
     {slot,Slot},
     {connected,Connected},
     {links,Links},
     {name,Name},
     {monitors,Monitors},
     {monitored_by,MonitoredBy},
     {controls,Controls},
     {parallelism,Parallelism},
     {locking,Locking},
     {queue_size,QueueSize},
     {memory,Memory} |
     Inet].

display_port_info(Parent, PortRec, Opened) ->
    PortIdStr = PortRec#port.id_str,
    case lists:keyfind(PortIdStr,1,Opened) of
	false ->
	    Frame = do_display_port_info(Parent, PortRec),
	    [{PortIdStr,Frame}|Opened];
	{_,Win} ->
	    wxFrame:raise(Win),
	    Opened
    end.

do_display_port_info(Parent0, PortRec) ->
    Parent = observer_lib:get_wx_parent(Parent0),
    Title = "Port Info: " ++ PortRec#port.id_str,
    Scale = observer_wx:get_scale(),
    Frame = wxMiniFrame:new(Parent, ?wxID_ANY, Title,
			    [{style, ?wxSYSTEM_MENU bor ?wxCAPTION
				  bor ?wxCLOSE_BOX bor ?wxRESIZE_BORDER},
                             {size,{Scale * 600, Scale * 400}}]),
    ScrolledWin = wxScrolledWindow:new(Frame,[{style,?wxHSCROLL bor ?wxVSCROLL}]),
    wxScrolledWindow:enableScrolling(ScrolledWin,true,true),
    wxScrolledWindow:setScrollbars(ScrolledWin,20,20,0,0),
    Sizer = wxBoxSizer:new(?wxVERTICAL),
    wxWindow:setSizer(ScrolledWin,Sizer),
    Port = portrec_to_list(PortRec),
    Fields0 = port_info_fields(Port),
    _UpFields = observer_lib:display_info(ScrolledWin, Sizer, Fields0),
    wxFrame:center(Frame),
    wxFrame:connect(Frame, close_window, [{skip, true}]),
    wxFrame:show(Frame),
    Frame.



port_info_fields(Port0) ->
    {InetStruct,Port} = inet_extra_fields(Port0),
    Struct =
	[{"Overview",
	  [{"Registered Name",  name},
	   {"Connected",        {click,connected}},
	   {"Slot",             slot},
	   {"Controls",         controls},
           {"Parallelism",      parallelism},
           {"Locking",          locking},
           {"Queue Size",       {bytes,queue_size}},
           {"Memory",           {bytes,memory}}]},
	 {scroll_boxes,
	  [{"Links",1,{click,links}},
	   {"Monitors",1,{click,filter_monitor_info()}},
	   {"Monitored by",1,{click,monitored_by}}]} | InetStruct],
    observer_lib:fill_info(Struct, Port).

inet_extra_fields(Port) ->
    Statistics = proplists:get_value(statistics,Port,[]),
    Options = proplists:get_value(options,Port,[]),
    Struct =
        case proplists:get_value(controls,Port) of
            Inet when Inet=="tcp_inet"; Inet=="udp_inet"; Inet=="sctp_inet" ->
                [{"Inet",
                  [{"Local Address",      {inet,local_address}},
                   {"Local Port Number",  local_port},
                   {"Remote Address",     {inet,remote_address}},
                   {"Remote Port Number", remote_port}]},
                 {"Statistics",
                  [stat_name_and_unit(Key) || {Key,_} <- Statistics]},
                 {"Options",
                  [{atom_to_list(Key),Key} || {Key,_} <- Options]}];
            _ ->
                []
        end,
    Port1 = lists:keydelete(statistics,1,Port),
    Port2 = lists:keydelete(options,1,Port1),
    {Struct,Port2 ++ Statistics ++ Options}.

stat_name_and_unit(recv_avg) ->
    {"Average package size received", {bytes,recv_avg}};
stat_name_and_unit(recv_cnt) ->
    {"Number of packets received", recv_cnt};
stat_name_and_unit(recv_dvi) ->
    {"Average packet size deviation received", {bytes,recv_dvi}};
stat_name_and_unit(recv_max) ->
    {"Largest packet received", {bytes,recv_max}};
stat_name_and_unit(recv_oct) ->
    {"Total received", {bytes,recv_oct}};
stat_name_and_unit(send_avg) ->
    {"Average packet size sent", {bytes, send_avg}};
stat_name_and_unit(send_cnt) ->
    {"Number of packets sent", send_cnt};
stat_name_and_unit(send_max) ->
    {"Largest packet sent", {bytes, send_max}};
stat_name_and_unit(send_oct) ->
    {"Total sent", {bytes, send_oct}};
stat_name_and_unit(send_pend) ->
    {"Data waiting to be sent from driver", {bytes,send_pend}};
stat_name_and_unit(Key) ->
    {atom_to_list(Key), Key}.

filter_monitor_info() ->
    fun(Data) ->
	    Ms = proplists:get_value(monitors, Data),
	    [Pid || {process, Pid} <- Ms]
    end.

update_grid(Grid, Sel, Opt, Ports) ->
    wx:batch(fun() -> update_grid2(Grid, Sel, Opt, Ports) end).
update_grid2(Grid, Sel, #opt{sort_key=Sort,sort_incr=Dir, odd_bg=BG}, Ports) ->
    wxListCtrl:deleteAllItems(Grid),
    Update =
	fun(#port{id = Id,
		  slot = Slot,
		  connected = Connected,
		  name = Name,
		  controls = Ctrl},
	    Row) ->
		_Item = wxListCtrl:insertItem(Grid, Row, ""),
		if (Row rem 2) =:= 1 ->
			wxListCtrl:setItemBackgroundColour(Grid, Row, BG);
		   true -> ignore
		end,

		lists:foreach(fun({Col, Val}) ->
				      wxListCtrl:setItem(Grid, Row, Col,
							 observer_lib:to_str(Val))
			      end,
			      [{0,Id},{1,Connected},{2,Name},{3,Ctrl},{4,Slot}]),
                case lists:member(Id, Sel) of
                    true ->
                        wxListCtrl:setItemState(Grid, Row, 16#FFFF, ?wxLIST_STATE_SELECTED);
                    false ->
                        wxListCtrl:setItemState(Grid, Row, 0, ?wxLIST_STATE_SELECTED)
                end,
		Row + 1
	end,
    PortInfo = case Dir of
		   false -> lists:reverse(lists:keysort(Sort, Ports));
		   true -> lists:keysort(Sort, Ports)
	       end,
    lists:foldl(Update, 0, PortInfo),
    PortInfo.

sel(#state{grid=Grid, ports=Ports}) ->
    [Id || #port{id=Id} <- get_selected_items(Grid, Ports)].

get_selected_items(Grid, Data) ->
    get_indecies(get_selected_items(Grid, -1, []), Data).
get_selected_items(Grid, Index, ItemAcc) ->
    Item = wxListCtrl:getNextItem(Grid, Index, [{geometry, ?wxLIST_NEXT_ALL},
						{state, ?wxLIST_STATE_SELECTED}]),
    case Item of
	-1 ->
	    lists:reverse(ItemAcc);
	_ ->
	    get_selected_items(Grid, Item, [Item | ItemAcc])
    end.

get_indecies(Items, Data) ->
    get_indecies(Items, 0, Data).
get_indecies([I|Rest], I, [H|T]) ->
    [H|get_indecies(Rest, I+1, T)];
get_indecies(Rest = [_|_], I, [_|T]) ->
    get_indecies(Rest, I+1, T);
get_indecies(_, _, _) ->
    [].

portinfo_available(NodeName) ->
    _ = rpc:call(NodeName, code, ensure_loaded, [observer_backend]),
    case rpc:call(NodeName, erlang, function_exported,
                  [observer_backend, get_port_list, 0]) of
        true  -> true;
        false -> false
    end.

popup_unavailable_info(NodeName) ->
    self() ! {info, {port_info_not_available, NodeName}},
    ok.
