/*  $Id$

    Part of SWI-Prolog

    Author:        Jan Wielemaker
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi-prolog.org
    Copyright (C): 1985-2002, University of Amsterdam

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    As a special exception, if you link this library with other files,
    compiled with a Free Software compiler, to produce an executable, this
    library does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/

:- module(emacs_interface,
	  [ '$editor_load_code'/2
	  , find_predicate1/2
	  , emacs_consult/1
	  , emacs_dabbrev_atom/1
	  , emacs_complete_atom/1
	  , emacs_previous_command/0
	  , emacs_next_command/0
	  , call_emacs/1
	  , call_emacs/2
	  , running_under_emacs_interface/0
	  ]).


		/********************************
		*              UTIL		*
		********************************/

running_under_emacs_interface :-
	emacs_tmp_file(_).

emacs_tmp_file(File) :-
	current_prolog_flag(argv, Argv),
	has_tmp_file(Argv, File).

has_tmp_file(['+C', Raw|_], File) :- !,
	atom_concat('Emacs:', File, Raw).
has_tmp_file([_|T], File) :-
	has_tmp_file(T, File).


		/********************************
		*            SETUP		*
		********************************/

:- (   running_under_emacs_interface
   ->  '$set_prompt'('a%m%l%! ?- ')
   ;   true
   ).


		/********************************
		*           CONSULT		*
		********************************/

%	'$editor_load_code'(+Kind, +File)
%	Load code from EMACS.  `Kind' is {procedure,region,buffer}.
%	`File' is the name of the file from which the code comes.  It
%	is an absolute filename.
%
%	To be implemented.  There is a start for portions of a file
%	(region, procedure), but this is hard:  What is the starting
%	line of the region (for error-messages).  There is also a
%	problem with path-names: `File' is emacs notion of the absolute
%	filename.  SWI-Prologs notion may be different due to symbolic
%	links.  Finally: the region might be the entire file, in which
%	case we need to know about the module info ...`
%
%	(MA)
%	For the time being:
%	"buffer" loads the entire file associated with the buffer.
%	"predicate" and "region" load the tmp-file. Yes, module info is
%	scrambled...



'$editor_load_code'(buffer, File) :- !,
	consult(File).
'$editor_load_code'(_Kind, _File) :-
	emacs_tmp_file(TmpFile),
	consult(TmpFile).

		/********************************
		*    TELL EMACS ABOUT ERRORS	*
		********************************/

%	Redefine [] to clear the compilation-buffer first

:- (   running_under_emacs_interface
   ->  user:redefine_system_predicate([_|_]),
       user:redefine_system_predicate(make),
       user:(module_transparent '.'/2),
       user:assert(([H|T] :- emacs_consult([H|T]))),
       user:assert((make :- emacs_interface:emacs_make)),
       user:assert(exception(A,B,C) :- emacs_interface:exception(A,B,C))
   ;   true
   ).


:- dynamic
	compilation_base_dir/1.

:- module_transparent
	emacs_consult/1.

emacs_consult(Files) :-
	emacs_start_compilation,
	consult(Files),
	emacs_finish_compilation.


emacs_make :-
	emacs_start_compilation,
	system:make,
	emacs_finish_compilation.


exception(warning, warning(Path, Line, Message), _) :-
	emacs_warning_file(Path, File),
	call_emacs('(prolog-compilation-warning "~w" "~d" "~w")',
		   [File, Line, Message]),
	fail.					  % give normal message too


emacs_start_compilation :-
	absolute_file_name('', Pwd),
	asserta(compilation_base_dir(Pwd)),
	call_emacs('(prolog-compilation-start "~w")', [Pwd]).


emacs_finish_compilation :-
	retractall(emacs_compilation_base_dir(_)),
	call_emacs('(prolog-compilation-finish)').


emacs_warning_file(user, _) :- !,
	fail.					  % donot give warnings here
emacs_warning_file(Path, File) :-
	compilation_base_dir(Cwd),
	atom_concat(Cwd, File, Path), !.
emacs_warning_file(Path, Path).



		/********************************
		*         FIND PREDICATE	*
		********************************/

%%	find_predicate1(Name, Arity)
%

find_predicate1(Name, Arity) :-
	find_predicate(Name, Arity, Preds),
	(   Preds == []
	->  call_emacs('(@find "undefined" "nodebug")')
	;   forall(member(Head, Preds),
		   ( source_file(Head, File1)
		   , remove_double_slashes(File1, File)
		   , call_emacs('(@fd-in "\"~w\" ~w ~w")', [Name, Arity, File])
		   ))
	->  call_emacs('(@find "ok" "nodebug")')
	;   call_emacs('(@find "none" "nodebug")')
	).

remove_double_slashes(Atom, Atom1) :-
	name(Atom, L),
	remove_double_slashes_list(L, L1),
	name(Atom1, L1).

remove_double_slashes_list([], []).
remove_double_slashes_list([0'/, 0'/|T], L) :- !,
	remove_double_slashes_list([0'/|T], L).
remove_double_slashes_list([H|T], [H|T1]) :-
	remove_double_slashes_list(T, T1).


find_predicate(Name, Arity, Preds) :-
	(   integer(Arity)
	->  functor(Head, Name, Arity)
	;   true
	),
	findall(Pred, find_predicate_(Head, Pred), Preds).

find_predicate_(Head, Module:Head) :-
	current_predicate(_, Module:Head),
	\+ predicate_property(Module:Head, imported_from(_)).


		/********************************
		*          ATOM DABREV		*
		********************************/

emacs_dabbrev_atom(Sofar) :-
	'$complete_atom'(Sofar, Extended, Unique), !,
	map_unique_to_lisp(Unique, LispBool),
	call_emacs('(prolog-complete-atom-with "~s" ~w)',
		   [Extended, LispBool]).
emacs_dabbrev_atom(Sofar) :-
	call_emacs('(prolog-completion-error-message (concat "No completions for: " "~s"))', [Sofar]).

map_unique_to_lisp(unique, t).
map_unique_to_lisp(not_unique, nil).


		/********************************
		*         ATOM COMPLETION	*
		********************************/

emacs_complete_atom(Sofar) :-
	'$atom_completions'(Sofar, List), List \== [], !,
	call_emacs('(prolog-completions-start-collect)'),
	emacs_transfer_completions(List, 1),
	call_emacs('(prolog-completions-run "~s")', [Sofar]).
emacs_complete_atom(Sofar) :-
	call_emacs('(prolog-completion-error-message (concat "No completions for: " "~s"))', [Sofar]).

emacs_transfer_completions([], _).
emacs_transfer_completions([Atom|T], N) :-
	call_emacs('(prolog-transfer-completion "~w" ~d)', [Atom, N]),
	NN is N + 1,
	emacs_transfer_completions(T, NN).


		/********************************
		*             HISTORY		*
		********************************/

emacs_insert_command(Nr) :-
	recorded('$history_list', Nr/Command), !,
	flag(emacs_shown_command, _, Nr),
	call_emacs('(prolog-insert-history-command "~w")', Command).
emacs_insert_command(_) :-
	call_emacs('(prolog-completion-error-message "No more commands")').

emacs_previous_command :-
	flag('$last_event', Last, Last),
	(   flag(emacs_last_command, Last, Last)
	->  flag(emacs_shown_command, Shown, Shown),
	    This is Shown - 1,
	    emacs_insert_command(This)
	;   flag(emacs_last_command, _, Last),
	    emacs_insert_command(Last)
	).


emacs_next_command :-
	flag('$last_event', Last, Last),
	(   flag(emacs_last_command, Last, Last)
	->  flag(emacs_shown_command, Shown, Shown),
	    This is Shown + 1,
	    emacs_insert_command(This)
	;   flag(emacs_last_command, _, Last),
	    emacs_insert_command(Last)
	).


		/********************************
		*           CALL EMACS		*
		********************************/

call_emacs(Fmt) :-
	call_emacs(Fmt, []).
call_emacs(Fmt, Args) :-
	atomic_list_concat(['', Fmt, ''], F1),
	format(F1, Args),
	flush_output.

