:- yap_flag( double_quotes, string ).

:- yap_flag( write_strings, on ).

:- style_check( all ).

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

:- initialization(main).

:- dynamic owner/5.

main :-
	unix( argv( [] ) ), !,
	maplist( owner, ['.'] ),
	open( 'exports.yap', write, Es ),
	dump( Es ),
	close( Es ).
main :-
	unix( argv(Args) ),
	maplist( owner, Args ),
	open( 'exports.yap', write, Es ),
	dump( Es ),
	close( Es ).

owner( D ) :-
	file_property( D, type( P ) ),
	owner( D, P ).

owner( P, directory ) :-
	directory_files( P , L),
	member( F, L ),
	F \= '.',
	F \= '..',
	F \= '.git',
	F \= 'pltotex.pl',
	atom_concat( [P, '/', F], FF),
	owner( FF ),
	fail.
owner( File, regular ) :-
	scan( File ),
	fail.
owner( _, _).


scan( OF ) :-
	file_base_name( OF, B ),
	( sub_atom( B, Len, _, 0, '.yap' )
	->
	  true
	;
	  sub_atom( B, Len, _, 0, '.pl' )
	->
	  true
	;
	  sub_atom( B, Len, _, 0, '.P' )
	->
	  true
	;
	  sub_atom( B, Len, _, 0, '.prolog' )
	->
	  true
	;
	  sub_atom( B, Len, _, 0,  '.bp' )
	->
	  true
	),
	sub_atom( B, 0, Len, _,  Base ),
	open( OF, read, Fs ),
	repeat,
	(
	   catch( read( Fs, ( :- Cmd ) ), _, fail )
	->
	   Cmd = module( Mod, Exports ),
	   maplist( declare(Mod, Base, OF), Exports)
	;
	   !, close( Fs ), fail
	).

declare(Mod,  Base, File, N/A) :-
	absolute_file_name( File, OF, []),
	( owner( OOF, Base, Mod, N, _A), OOF \= OF 
	->
	  format( user_error, 'conflict: ~a in ~a and ~a~n',[N, OF, OOF])
	;
	  true
	),
	assert( owner( OF, Base, Mod, N, A) ).
declare(_Mod, _B,  _File, op(_,_,_)).

dump( S ) :-
	owner( OF, Base, Mod, N, A),
	format( S , ':- file( ~q, ~q, ~q, ~a, ~d ).~n',[ OF, Base, Mod, N, A ]),
	fail.
dump( _ ).