/*  $Id$

    Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        J.Wielemaker@vu.nl
    WWW:           http://www.swi-prolog.org/projects/xpce/
    Copyright (C): 1985-2011, University of Amsterdam
			      VU University 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  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(pce_require,
	  [ pce_require/1		% file
	  , pce_require/3		% file x directive x message
	  ]).
:- use_module(library(pce)).
:- require([ absolute_file_name/3
	   , append/3
	   , forall/2
	   , ignore/1
	   , is_list/1
	   , member/2
	   , pce_error/1
	   , sformat/3
	   ]).

/** <module> XPCE sanity check and cross-referencer

This module is part of infrastructure to port XPCE between SWI, SICStus
and Quintus.

@tbd	This should be (re-)based on library(prolog_xref).
*/

target_prolog(common).			% Common between QP 3.2 and SICStus 3

:- dynamic
	called/1,			% called head
	defined/1,			% defined head
	output_to/2,			% output is emacs buffer
	current_require_declaration/1.	% Current declaration

		 /*******************************
		 *	     BUILT-INS		*
		 *******************************/

:- use_module(library('xref/common')).	% Common built-in's

system_predicate(require(_)).
system_predicate(discontiguous(_)).
system_predicate(Head) :-
	built_in(Head).


		/********************************
		*            TOPLEVEL		*
		********************************/

%%	pce_require(+File) is det.
%
%	Compute the require/1 directive for  File   and  print it to the
%	current output.

pce_require(File) :-
	clean,
	collect(File),
	report.

%%	pce_require(+File, -Directive, -Message) is det.
%
%	Compute the :- require/1 directive by cross-referencing File.

pce_require(File, Directive, Message) :-
	new(D, string),
	new(M, string),
	asserta(output_to(D, M), Clause),
	pce_require(File),
	erase(Clause),
	get(D, value, Directive),
	get(M, value, Message).


clean :-
	retractall(called(_)),
	retractall(defined(_)),
	retractall(current_require_declaration(_)).


collect(File) :-
	find_source_file(File, Source),
	seeing(Old), see(Source),
	repeat,
	    catch(read(Term), E,
		  (   print_message(error, E),
		      fail
		  )),
	    req_expand(Term, T),
	    (   T == end_of_file
	    ->  !, seen, see(Old)
	    ;   process(T),
		fail
	    ).


		 /*******************************
		 *	     EXPANSION		*
		 *******************************/

%%	req_expand(+Term, -Expanded)
%
%	Do the term-expansion.  We have to pass require as we need it
%	for validation.  Otherwise we do term-expansion, handling all
%	of the XPCE class compiler as normal Prolog afterwards.

req_expand((:- require(X)), (:- require(X))) :- !.
req_expand(Term, _) :-
	requires_library(Term, Lib),
	ensure_loaded(user:Lib),
	fail.
req_expand(Term, T) :-
	expand_term(Term, Expanded),
	(   is_list(Expanded)
	->  member(T, Expanded)
	;   T = Expanded
	).


%%	requires_library(+Term, -Library)
%
%	known expansion hooks.  Should be more dynamic!

requires_library((:- emacs_begin_mode(_,_,_,_,_)), library(emacs_extend)).
requires_library((:- draw_begin_shape(_,_,_,_)), library(pcedraw)).


		 /*******************************
		 *	     PROCESS		*
		 *******************************/

process((:- Directive)) :- !,
	process_directive(Directive), !.
process((Head :- Body)) :- !,
	assert_defined(Head),
	process_body(Body).
process('$source_location'(_File, _Line):Clause) :- !,
	process(Clause).
process(Head) :-
	assert_defined(Head).

		/********************************
		 *           DIRECTIVES		*
		 ********************************/

process_directive(List) :-
	is_list(List), !,
	process_directive(consult(List)).
process_directive(use_module(_Module, Import)) :-
	assert_import(Import).
process_directive(require(Import)) :-		 % Include if report only
	assert_current_require_declaration(Import).
process_directive(use_module(Modules)) :-
	process_use_module(Modules).
process_directive(consult(Modules)) :-
	process_use_module(Modules).
process_directive(ensure_loaded(Modules)) :-
	process_use_module(Modules).
process_directive(dynamic(Dynamic)) :-
	assert_dynamic(Dynamic).

process_directive(op(P, A, N)) :-
	op(P, A, N).			% should be local ...
process_directive(pce_expansion:push_compile_operators) :-
	pce_expansion:push_compile_operators.
process_directive(pce_expansion:pop_compile_operators) :-
	pce_expansion:pop_compile_operators.
process_directive(Goal) :-
	process_body(Goal).


	      /********************************
	      *             BODY		*
	      ********************************/

meta_goal((A, B),		[A, B]).
meta_goal((A; B),		[A, B]).
meta_goal((A| B),		[A, B]).
meta_goal((A -> B),		[A, B]).
meta_goal(findall(_V, G, _L),	[G]).
meta_goal(setof(_V, G, _L),	[G]).
meta_goal(bagof(_V, G, _L),	[G]).
meta_goal(forall(A, B),		[A, B]).
meta_goal(maplist(G, _),	[G+1]).
meta_goal(maplist(G, _, _),	[G+2]).
meta_goal(maplist(G, _, _, _),	[G+3]).
meta_goal(checklist(G, _L),	[G+1]).
meta_goal(call(G),		[G]).
meta_goal(call(G, _A1),		[G+1]).
meta_goal(call(G, _A1, _A2),	[G+2]).
meta_goal(not(G),		[G]).
meta_goal(\+(G),		[G]).
meta_goal(ignore(G),		[G]).
meta_goal(once(G),		[G]).
meta_goal(initialization(G),	[G]).

meta_goal(ifmaintainer(G),	[G]).	% used in manual

process_body(Goal) :-
	meta_goal(Goal, Metas), !,
	assert_called(Goal),
	process_called_list(Metas).
process_body(Goal) :-
	assert_called(Goal),
	ignore(check_goal(Goal)).

process_called_list([]).
process_called_list([H|T]) :-
	process_meta(H),
	process_called_list(T).

process_meta(A+N) :- !,
	nonvar(A),
	\+ A = _:_,
	A =.. List,
	length(Rest, N),
	append(List, Rest, NList),
	Term =.. NList,
	process_body(Term).
process_meta(G) :-
	process_body(G).


		/********************************
		*           CHECKING		*
		********************************/

check_goal(Goal) :-
	send_list_goal(Goal),
	output_compatibility('Send/[2,3] used with list argument').

send_list_goal(Goal) :-
	(   Goal = send(A, B)
	;   Goal = send(A, B, C)
	),
	member(X, [A,B,C]),
	nonvar(X),
	X = [_|_], !.


		/********************************
		*       INCLUDED MODULES	*
		********************************/

process_use_module(_Module:_Files) :- !. % loaded in another module
process_use_module([]) :- !.
process_use_module([H|T]) :- !,
	process_use_module(H),
	process_use_module(T).
process_use_module(library(pce)) :- !,	% bit special
	file_public_list(library(pce), Public),
	forall(member(Name/Arity, Public),
	       (   functor(Term, Name, Arity),
		   \+ system_predicate(Term),
		   \+ Term = pce_error(_) % hack!?
	       ->  assert_defined(Term)
	       ;   true
	       )).
process_use_module(File) :-
	(   file_public_list(File, Public)
	->  assert_import(Public)
	;   true
	).

file_public_list(File, Public) :-
	find_source_file(File, Source),
	seeing(Old), see(Source),
	read(ModuleDecl),
	seen, see(Old),
	ModuleDecl = (:- module(_, Public)).


		/********************************
		*       PHASE 1 ASSERTIONS	*
		********************************/

assert_called(Var) :-
	var(Var), !.
assert_called(Goal) :-
	called(Goal), !.
assert_called(Goal) :-
	functor(Goal, Name, Arity),
	functor(Term, Name, Arity),
	asserta(called(Term)).

assert_defined(_Module:_Head) :- !.	% defining in another module.  Bah!
assert_defined(Goal) :-
	defined(Goal), !.
assert_defined(Goal) :-
	functor(Goal, Name, Arity),
	functor(Term, Name, Arity),
	check_system_predicate(Term),
	asserta(defined(Term)).

assert_import([]) :- !.
assert_import([H|T]) :-
	assert_import(H),
	assert_import(T).
assert_import(Name/Arity) :-
	functor(Term, Name, Arity),
	assert_defined(Term).

assert_dynamic((A, B)) :- !,
	assert_dynamic(A),
	assert_dynamic(B).
assert_dynamic(Name/Arity) :-
	functor(Term, Name, Arity),
	assert_defined(Term).


assert_current_require_declaration([]).
assert_current_require_declaration([Name/Arity|Rest]) :-
	functor(Head, Name, Arity),
	assert(current_require_declaration(Head)),
	assert_current_require_declaration(Rest).

check_system_predicate(Head) :-
	system_predicate(Head), !,
	functor(Head, Name, Arity),
	target_prolog(Prolog),
	source_warning('Redefined ~w system predicate: ~w/~d',
		       [Prolog, Name, Arity]).
pce_ifhostproperty(prolog(swi),
(check_system_predicate(Head) :-
	predicate_property(system:Head, system_predicate), !,
	functor(Head, Name, Arity),
	Prolog = 'SWI-Prolog',
	source_warning('Redefined ~w system predicate: ~w/~d',
		       [Prolog, Name, Arity]))).
check_system_predicate(_).

		/********************************
		*             REPORT		*
		********************************/

undefined(Head) :-
	defined(Head), !, fail.
undefined(Head) :-
	system_predicate(Head), !, fail.
undefined(_).

report :-
	findall(Head, (called(Head), undefined(Head)), U0),
	sort(U0, Undefined),		% remove duplicates
	(   forall(member(U, Undefined), current_require_declaration(U)),
	    forall(current_require_declaration(U), member(U, Undefined))
	->  message(':- require/1: up-to-date')
	;   output(':- require([ '),
	    report_undefined(Undefined),
	    output(']).~n')
	).


report_undefined([]).
report_undefined([L]) :- !,
	functor(L, Name, Arity),
	report_name_arity(Name, Arity),
	output('~n	   ', []).
report_undefined([H|T]) :-
	functor(H, Name, Arity),
	report_name_arity(Name, Arity),
	output(',~n	     ', []),
	report_undefined(T).

report_name_arity(Name, Arity) :-
	current_op(P, _, Name),
	P >= 1000, !,
	output('(~q)/~d', [Name, Arity]).
report_name_arity(Name, Arity) :-
	output('~q', [Name/Arity]).


		/********************************
		*            UTILITIES		*
		********************************/

%%	find_source_file(+Spec, -File)
%
%	Find named source file.

find_source_file(Spec, File) :-
	do_find_source_file(Spec, File), !.
find_source_file(Spec, _) :-
	source_warning('Cannot file from ~w', [Spec]),
	fail.

do_find_source_file(Spec, File) :-
	absolute_file_name(Spec, File,
			   [ file_type(prolog),
			     access(read),
			     file_errors(fail)
			   ]), !.


		/********************************
		*            OUTPUT		*
		********************************/

to_string(Prolog, string(Prolog)) :-
	is_list(Prolog), !.
to_string(Atomic, Atomic).

output(Fmt) :-
	output(Fmt, []).
output(Fmt, Args) :-
	output_to(D, _), D \== @nil, !,
	sformat(Buf, Fmt, Args),
	to_string(Buf, String),
	send(D, append, String).
output(Fmt, Args) :-
	format(Fmt, Args).


message(Fmt) :-
	message(Fmt, []).
message(Fmt, Args) :-
	output_to(_, Msg), Msg \== @nil, !,
	sformat(Buf, Fmt, Args),
	to_string(Buf, String),
	send(Msg, append, String).
message(Fmt, Args) :-
	format(user_error, Fmt, Args),
	format(user_error, '~n', []).


output_compatibility(Fmt) :-
	output_compatibility(Fmt, []).
output_compatibility(Fmt, Args) :-
	source_warning(Fmt, Args).

source_warning(Fmt, Args) :-
	pce_error(preformatted(Fmt, Args)).
