/**
  * @file jupyter.yap4py
  *
  * @brief JUpyter support.
  */

:- yap_flag(gc_trace,verbose).

  % :- module( jupyter,
  %            [jupyter_query/3,
  %            errors/2,
  %            ready/2,
  %           completion/2,
  %         ]
%%            ).
:- use_module(library(hacks)).

:-	 use_module(library(lists)).
:-	 use_module(library(maplist)).

:-	 use_module(library(python)).
:-	 use_module(library(yapi)).
:-	 use_module(library(complete)).

:- python_import(sys).

jupyter_query(Caller, Cell, Line ) :-
	jupyter_cell(Caller, Cell, Line).

jupyter_cell(_Caller, Cell, _Line) :-
	jupyter_consult(Cell),	%stack_dump,
	fail.
jupyter_cell( _Caller, _, '' ) :- !.
jupyter_cell( _Caller, _, Line ) :-
	blank( Line ),
	!.
jupyter_cell( Caller, _, Line ) :-
	Self := Caller.query,
    catch(
	python_query(Self,Line),
	E=error(A,B),
	 system_error(A,B)
    ).

restreams(call) :-
    streams(true).
restreams(fail) :-
    streams(false).
restreams(answer).
restreams(exit) :-
    streams(false).
restreams(!).
restreams(external_exception(_)).
restreams(exception).

jupyter_consult(Text) :-
	blank( Text ),
	!.
jupyter_consult(Cell) :-
%	Name = 'Inp',
%	stream_property(Stream, file_name(Name) ),
%	setup_call_cleanup(
    catch(
	(
	    Options = [],
	    open_mem_read_stream( Cell, Stream),
	    load_files(user:'jupyter cell',[stream(Stream)| Options])
	),
	E=error(A,B),
	(close(Stream), system_error(A,B))
    ),
    fail.
jupyter_consult(_Cell).

blank(Text) :-
    atom(Text),
    !,
	atom_codes(Text, L),
	maplist( code_type(space), L).
blank(Text) :-
    string(Text),
    !,
    string_codes(Text, L),
    maplist( code_type(space), L).

streams(false) :-
    close(user_input),
    close(user_output),
    close(user_error).
streams(true) :-
    open('/python/input', read, Input, [alias(user_input),bom(false),script(false)]),
    open('/python/sys.stdout', append, Output, [alias(user_output)]),
    open('/python/sys.stderr', append, Error, [alias(user_error)]).

ready(_Self, Line ) :-
            blank( Line ),
            !.
ready(Self, Line ) :-
    errors( Self, Line ),
    \+ syntax_error(_,_).

errors( Self, Text ) :-
       	setup_call_cleanup(
       			   open_events( Self, Text, Stream),
       			   goals(Self, Stream),
       			   close_events( Self )
       	 	   ).

clauses(_Self, Stream) :-
    repeat,
    read_clause(Stream, Cl, [term_position(_Pos), syntax_errors(fail)] ),
%	command( Self, Cl ),
    Cl == end_of_file,
    !.

goals(_Self, Stream) :-
    repeat,
    read_term(Stream, Cl, [term_position(_Pos), syntax_errors(fail)] ),
%	command( Self, Cl ),
    Cl == end_of_file,
    !.

command(_, end_of_file) :- !.

command( _Self, ( :- op(Prio,Assoc,Name) ) ) :-
	addop(Prio,Assoc,Name).

command( _Self, ( :- module(Name, Exports) )) :-
	retract( active_module( M0 ) ),
	atom_concat( '__m0_', Name, M ),
	assert( active_module(M) ),
	assert( undo( active_module(M0) ) ),
	maplist( addop2(M), Exports).


addop(Prio,Assoc,Name) :-
	(
	current_op(OPrio, SimilarAssoc, Name),
	op(Prio, Assoc, Name),
	matched_op(Assoc, SimilarAssoc)
	->
		assertz( undo(op( OPrio, Assoc, Name ) ) )
		;
		assertz( undo(op( 0, Assoc, Name ) ) )
		).

addop2(M, op(Prio, Assoc, Name)) :-
	addop( Prio, Assoc, M:Name ).

matched_op(A, B) :-
	optype( A, T),
	optype( B, T).

optype(fx,pre).
optype(fy,pre).
optype(xfx,in).
optype(xfy,in).
optype(yfx,in).
optype(yfy,in).
optype(xf,pos).
optype(yf,pos).

:- dynamic user:portray_message/2.
:-  multifile user:portray_message/2.

:- dynamic syntax_error/4, undo/1.

user:portray_message(_Severity, error(syntax_error(Cause),info(between(_,LN,_), _FileName, CharPos, Details))) :-
	nb_getval(jupyter_cell, on),
        assert( syntax_error(Cause,LN,CharPos,Details) ).
user:portray_message(_Severity, error(style_check(_),_) ) :-
	nb_getval(jupyter_cell, on).

open_events(Self, Text, Stream) :-
	Self.errors := [],
	nb_setval( jupyter, on),
    open_mem_read_stream( Text, Stream ).

:- initialization( nb_setval( jupyter, off ) ).

close_events( _Self ) :-
	nb_setval( jupyter, off ),
	retract( undo(G) ),
	call(G),
	fail.
close_events( Self ) :-
	retract( syntax_error( C, L, N, A )),
    Self.errors := [t(C,L,N,A)] + Self.errors,
    fail.
close_events( _ ).


:- if(  current_prolog_flag(apple, true) ).

:- putenv( 'LC_ALL', 'en_us:UTF-8').

plot_inline :-
	X := self.inline_plotting,
	nb_setval(inline, X ),
	X = true,
	!,
	:= (
	   import( matplotlib ),
	   matplotlib.use( `nbagg` )
	   ).

:- endif.

%:- ( start_low_level_trace ).