/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-2014	 *
*									 *
*************************************************************************/

%% @file absf.yap
%% @author L.Damas, V.S.Costa

%% @{

/** @defgroup absolute_file_name File Name Resolution

   @ingroup builtins

  Support for file name resolution through absolute_file_name/3 and
  friends. These utility built-ins describe a list of directories that
  are used by load_files/2 to search. They include pre-compiled paths
  plus user-defined directories, directories based on environment
  variables and registry information to search for files.

  **/
:- system_module( absolute_file_name, [absolute_file_name/2,
        absolute_file_name/3,
        add_to_path/1,
        add_to_path/2,
        path/1,
        remove_from_path/1], ['$full_filename'/3,
        '$system_library_directories'/2]).

:- use_system_module( '$_boot', ['$system_catch'/4]).

:- use_system_module( '$_errors', ['$do_error'/2]).

:- use_system_module( '$_lists', [member/2]).

:- multifile user:library_directory/1.

:- dynamic user:library_directory/1.
%% user:library_directory( ?Dir )
%  Specifies the set of directories where
% one can find Prolog libraries.
%
% 1. honor YAPSHAREDIR
user:library_directory( Dir ) :-
        getenv( 'YAPSHAREDIR', Dir0),
        absolute_file_name( Dir0, [file_type(directory), expand(true),file_errors(fail)], Dir ).
%% 2. honor user-library
user:library_directory( Dir ) :-
        absolute_file_name( '~/share/Yap', [file_type(directory), expand(true),file_errors(fail)], Dir ).
%% 3. honor current directory
user:library_directory( Dir ) :-
        absolute_file_name( '.', [file_type(directory), expand(true),file_errors(fail)], Dir ).
%% 4. honor default location.
user:library_directory( Dir ) :-
	system_library( Dir ).

/**
  @pred user:commons_directory(? _Directory_:atom) is nondet, dynamic

  State the location of the Commons Prolog Initiative.

  This directory is initialized as a rule that calls the system predicate
  library_directories/2.
*/

:- multifile user:commons_directory/1.

:- dynamic user:commons_directory/1.


user:commons_directory( Path ):-
    system_commons( Path ).

/**
  @pred user:foreign_directory(? _Directory_:atom) is nondet, dynamic

  State the location of the Foreign Prolog Initiative.

  This directory is initialized as a rule that calls the system predicate
  library_directories/2.
*/

:- multifile user:foreign_directory/1.

:- dynamic user:foreign_directory/1.

user:foreign_directory( Path ):-
    system_foreign( Path ).

/**
  @pred user:prolog_file_type(?Suffix:atom, ?Handler:atom) is nondet, dynamic

  This multifile/dynamic predicate relates a file extension _Suffix_
  to a language or file type _Handler_. By
  default, it supports the extensions yap, pl, and prolog for prolog files and
  uses one of dll, so, or dylib for shared objects. Initial definition is:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~prolog
  prolog_file_type(yap, prolog).
  prolog_file_type(pl, prolog).
  prolog_file_type(prolog, prolog).
  prolog_file_type(qly, prolog).
  prolog_file_type(qly, qly).
  prolog_file_type(A, prolog) :-
    current_prolog_flag(associate, A),
    A \== prolog,
    A \==pl,
    A \== yap.
  prolog_file_type(A, executable) :-
    current_prolog_flag(shared_object_extension, A).
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

*/

:- multifile user:prolog_file_type/2.

:- dynamic user:prolog_file_type/2.

user:prolog_file_type(yap, prolog).
user:prolog_file_type(pl, prolog).
user:prolog_file_type(prolog, prolog).
user:prolog_file_type(A, prolog) :-
	current_prolog_flag(associate, A),
	A \== prolog,
	A \== pl,
	A \== yap.
user:prolog_file_type(qly, qly).
user:prolog_file_type(A, executable) :-
	current_prolog_flag(shared_object_extension, A).


/**
  @pred user:file_search_path(+Name:atom, -Directory:atom) is nondet

  Allows writing file names as compound terms. The  _Name_ and
  _DIRECTORY_ must be atoms. The predicate may generate multiple
  solutions. The predicate is originally defined as follows:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~prolog
file_search_path(library, Dir) :-
  library_directory(Dir).
file_search_path(commons, Dir) :-
  commons_directory(Dir).
file_search_path(swi, Home) :-
  current_prolog_flag(home, Home).
file_search_path(yap, Home) :-
        current_prolog_flag(home, Home).
file_search_path,(system, Dir) :-
  prolog_flag(host_type, Dir).
file_search_path(foreign, Dir) :-
  foreign_directory(Dir).
file_search_path(path, C) :-
    (   getenv('PATH', A),
        (   current_prolog_flag(windows, true)
          ->  atomic_list_concat(B, ;, A)
        ;   atomic_list_concat(B, :, A)
        ),
        lists:member(C, B)
    ).

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  Thus, `compile(library(A))` will search for a file using
  library_directory/1 to obtain the prefix,
  whereas 'compile(system(A))` would look at the `host_type` flag.

@}

*/

:- multifile user:file_search_path/2.

:- dynamic user:file_search_path/2.

user:file_search_path(library, Dir) :-
	user:library_directory(Dir).
user:file_search_path(commons, Dir) :-
	user:commons_directory(Dir).
user:file_search_path(swi, Home) :-
	current_prolog_flag(home, Home).
user:file_search_path(yap, Home) :-
    current_prolog_flag(home, Home).
user:file_search_path(system, Dir) :-
	prolog_flag(host_type, Dir).
user:file_search_path(foreign, Dir) :-
    working_directory(Dir,Dir).
user:file_search_path(foreign, yap('lib/Yap')).
user:file_search_path(path, C) :-
    (   getenv('PATH', A),
	(   current_prolog_flag(windows, true)
	->  atomic_list_concat(B, ;, A)
	;   atomic_list_concat(B, :, A)
	),
	lists:member(C, B)
    ).

%%@}

absolute_file_name(File,TrueFileName,Opts) :-
    ( var(TrueFileName) ->
	  true ;
      atom(TrueFileName), TrueFileName \= []
    ), !,
    absolute_file_name(File,Opts,TrueFileName).
absolute_file_name(File,Opts,TrueFileName) :-
    '$absolute_file_name'(File,Opts,TrueFileName,absolute_file_name(File,Opts,TrueFileName)).

/**
  @pred absolute_file_name(+Name:atom,+Path:atom) is nondet

  Converts the given file specification into an absolute path, using default options. See absolute_file_name/3 for details on the options.
*/
absolute_file_name(V,Out) :- var(V), !,	% absolute_file_name needs commenting.
	'$do_error'(instantiation_error, absolute_file_name(V, Out)).
absolute_file_name(user,user) :- !.
absolute_file_name(File0,File) :-
	'$absolute_file_name'(File0,[access(none),file_type(txt),file_errors(fail),solutions(first)],File,absolute_file_name(File0,File)).

'$full_filename'(F0, F, G) :-
	'$absolute_file_name'(F0,[access(read),
                              file_type(prolog),
                              file_errors(fail),
                              solutions(first),
                              expand(true)],F,G).

'$absolute_file_name'(File, _Opts, _TrueFileName, G) :- var(File), !,
	'$do_error'(instantiation_error, G).
'$absolute_file_name'(File,LOpts,TrueFileName, G) :-
	current_prolog_flag(open_expands_filename, OldF),
	current_prolog_flag( fileerrors, PreviousFileErrors ),
	current_prolog_flag( verbose_file_search, PreviousVerbose ),
	abs_file_parameters(LOpts,Opts),
	get_abs_file_parameter( verbose_file_search, Opts, Verbose ),
	get_abs_file_parameter( expand, Opts, Expand ),
	set_prolog_flag( verbose_file_search,  Verbose ),
	get_abs_file_parameter( file_errors, Opts, FErrors ),
	(  FErrors == fail ->
	  set_prolog_flag( fileerrors, false )
	;
	  set_prolog_flag( fileerrors, true )
	),
	set_prolog_flag(file_name_variables, Expand),
	'$absf_trace'('search for ~w with options ~w', [File, LOpts] ),
	'$find_in_path'(File, Opts,TrueFileName,G),
	(
	  get_abs_file_parameter( solutions, Opts, first )
	 ->
	 '$absf_trace'('found solution ~a', [TrueFileName] ),
%	 	stop_lowxb(  _level_trace,
	 set_prolog_flag( fileerrors, PreviousFileErrors ),
	 set_prolog_flag( open_expands_filename, OldF),
	 set_prolog_flag( verbose_file_search, PreviousVerbose ),
	 '$absf_trace'('first solution only', [] ),
	 !
	 ;
	 (
	  '$absf_trace'('found solution ~a', [TrueFileName] ),
%	 	stop_low_level_trace,
	  set_prolog_flag( fileerrors, PreviousFileErrors ),
	  set_prolog_flag( file_name_variables, OldF),
	  set_prolog_flag( verbose_file_search, PreviousVerbose )
	;
	  set_prolog_flag( verbose_file_search, Verbose ),
	  get_abs_file_parameter( file_errors, Opts, FErrors ),
	  set_prolog_flag(file_name_variables, Expand),
	  fail
	 )
	;
				% no solution
%	 	stop_low_level_trace,
	 set_prolog_flag( fileerrors, PreviousFileErrors ),
	 set_prolog_flag( verbose_file_search, PreviousVerbose ),
	 set_prolog_flag(file_name_variables, OldF),
	 get_abs_file_parameter( file_errors, Opts, error ),
	 '$do_error'(existence_error(file,File),G)
	).

% This sequence must be followed:
% user and user_input are special;
% library(F) must check library_directories
% T(F) must check file_search_path
% all must try search in path
'$find_in_path'(user,_,user_input, _) :- !.
'$find_in_path'(user_input,_,user_input, _) :- !.
'$find_in_path'(S, Opts, NewFile, Call) :-
	S =.. [Name,File0],
	'$cat_file_name'(File0,File), !,
	'$absf_trace'('~w(~w) to ~w', [Name, File0, File] ),
	'$dir_separator'(D),
	atom_codes(A,[D]),
	'$extend_path_directory'(Name, A, File, Opts, NewFile, Call).
'$find_in_path'(File0,Opts,NewFile,_) :-
	'$cat_file_name'(File0,File), !,
	'$add_path'(File, PFile),
	'$get_abs_file'(PFile,Opts,AbsFile),
    '$absf_trace'('~w to ~w', [PFile, NewFile] ),
	'$search_in_path'(AbsFile,Opts,NewFile).
'$find_in_path'(File,_,_,Call) :-
	'$do_error'(domain_error(source_sink,File),Call).

% allow paths in File Name
'$cat_file_name'(File0,File) :-
	atom(File0), !,
	File = File0.
'$cat_file_name'(Atoms, File) :-
	'$to_list_of_atoms'(Atoms, List, []),
	atom_concat(List, File).

'$to_list_of_atoms'(V, _, _) :- var(V), !, fail.
'$to_list_of_atoms'(Atom, [Atom|L], L) :- atom(Atom), !.
'$to_list_of_atoms'(Atoms, L1, LF) :-
	Atoms =.. [A,As,Bs],
	atom_codes(A,[D]),
	'$dir_separator'(D),
	'$to_list_of_atoms'(As, L1, [A|L2]),
	'$to_list_of_atoms'(Bs, L2, LF).

'$get_abs_file'(File,Opts, ExpFile) :-
	'$control_for_expansion'(Opts, Expand),
	get_abs_file_parameter( relative_to, Opts, RelTo ),
	prolog_expanded_file_system_path( File, Expand, RelTo, ExpFile ),
	'$absf_trace'('Traditional expansion: ~w', [ExpFile] ).


'$control_for_expansion'(Opts, true) :-
	get_abs_file_parameter( expand, Opts, true ),
	!.
'$control_for_expansion'(_Opts, Flag) :-
	current_prolog_flag( open_expands_filename, Flag ).


'$search_in_path'(File,Opts,F) :-
	get_abs_file_parameter( extensions, Opts, Extensions ),
	'$absf_trace'('check extensions ~w?', [Extensions] ),
	'$add_extensions'(Extensions, File, F0),
	'$glob'( F0, Opts, FG),
	get_abs_file_parameter( file_type, Opts, Type ),
	get_abs_file_parameter( access, Opts, Access ),
	'$check_file'(FG,Type, Access, F),
	'$absf_trace'(' ~a  ok!', [Access]).
'$search_in_path'(File,Opts,F) :-
	get_abs_file_parameter( file_type, Opts, Type ),
	'$absf_trace'('check type ~w', [Type] ),
	'$add_type_extensions'(Type,File, F0),
	get_abs_file_parameter( access, Opts, Access ),
	'$glob'( F0, Opts, FG),
	'$check_file'(FG, Type, Access, F),
	'$absf_trace'('   ~w   ok!', [Access]).

'$glob'( File1, Opts, ExpFile) :-
	'$control_for_expansion'(Opts, Expand),
	get_abs_file_parameter( glob, Opts, Glob ),
	(Glob \== ''
	->
	'$dir_separator'(D),
	atom_codes(DA,[D]),
	 atom_concat( [File1, DA, Glob], File2 ),
	 expand_file_name(File2, ExpFiles),
     '$enumerate_glob'(File1, ExpFiles, ExpFile)
	;
	 Expand == true
	->
	 expand_file_name(File1, ExpFiles),
     '$enumerate_glob'(File1, ExpFiles, ExpFile)
	 ;
	 File1 = ExpFile
	),
	'$absf_trace'(' With globbing (glob=~q;expand=~a): ~w', [Glob,Expand,ExpFile] ).


'$enumerate_glob'(File1, [ExpFile], ExpFile) :-
    !.
'$enumerate_glob'(File1, ExpFiles, ExpFile) :-
    lists:member(ExpFile, ExpFiles),
    file_base_name( ExpFile, Base ),
    Base \= '.',
    Base \='..'.


% always verify if a directory
'$check_file'(F, directory, _, F) :-
	!,
	exists_directory(F).
'$check_file'(F, _Type, none, F) :- !.
'$check_file'(F0, _Type, Access, F0) :-
	access_file(F0, Access),
	\+ exists_directory(F0). % if it has a type cannot be a directory..

'$add_extensions'([Ext|_], File,F) :-
	'$absf_trace'(' extension ~w', [Ext] ),
	'$mk_sure_true_ext'(Ext,NExt),
	atom_concat([File,NExt],F).
'$add_extensions'([_|Extensions],File,F) :-
	'$add_extensions'(Extensions,File,F).

'$mk_sure_true_ext'(Ext,NExt) :-
	atom_codes(Ext,[C|L]),
	C \= 0'.,
	!,
	atom_codes(NExt,[0'.,C|L]).
'$mk_sure_true_ext'(Ext,Ext).

'$add_type_extensions'(Type,File,F) :-
	( Type == source -> NType = prolog ; NType = Type ),
	user:prolog_file_type(Ext, NType),
	atom_concat([File,'.',Ext],F),
	'$absf_trace'('      extension ~w?', [F] ).
'$add_type_extensions'(_,File,File) :-
	'$absf_trace'('  wo  extension ~w?', [File] ).

'$add_path'(File, File) :-
	is_absolute_file_name(File), !.
'$add_path'(File, File) :-
	working_directory(Dir, Dir),
	'$dir_separator'( D ),
	atom_codes( DSep, [D] ),
	atomic_concat([Dir, DSep,File],PFile),
	'$absf_trace'(' try . or ~a: ~a', [Dir,PFile] ).
'$add_path'(File, PFile) :-
	recorded('$path',Path,_),
	atom_concat([Path,File],PFile),
	'$absf_trace'(' try ~a from path-data base: ~a', [Path, PFile] ).

'$system_library_directories'(library, Dir) :-
	user:library_directory( Dir ).
%	'$split_by_sep'(0, 0, Dirs, Dir).
'$system_library_directories'(foreign, Dir) :-
	foreign_directory( Dir ).
% compatibility with old versions
% search the current directory first.
'$system_library_directories'(commons, Dir) :-
	commons_directory( Dir ).

'$split_by_sep'(Start, Next, Dirs, Dir) :-
    current_prolog_flag(windows, true),
    '$split_by_sep'(Start, Next, Dirs, ';', Dir), !.
'$split_by_sep'(Start, Next, Dirs, Dir) :-
    '$split_by_sep'(Start, Next, Dirs, ':', Dir).

'$split_by_sep'(Start, Next, Dirs, Sep, Dir) :-
    sub_atom(Dirs, Next, 1, _, Let), !,
    '$continue_split_by_sep'(Let, Start, Next, Dirs, Sep, Dir).
'$split_by_sep'(Start, Next, Dirs, _Sep, Dir) :-
    Next > Start,
    Len is Next-Start,
    sub_atom(Dirs, Start, Len, _, Dir).


% closed a directory
'$continue_split_by_sep'(Sep, Start, Next, Dirs, Sep, Dir) :-
    Sz is Next-Start,
    Sz > 0,
    sub_atom(Dirs, Start, Sz, _, Dir).
% next dir
'$continue_split_by_sep'(Sep , _Start, Next, Dirs, Sep, Dir) :- !,
    N1 is Next+1,
    '$split_by_sep'(N1, N1, Dirs, Dir).
% same dir
'$continue_split_by_sep'(_Let, Start, Next, Dirs, Sep, Dir) :-
    N1 is Next+1,
    '$split_by_sep'(Start, N1, Dirs, Sep, Dir).


'$extend_path_directory'(_Name, _D, File, _Opts, File, _Call) :-
	is_absolute_file_name(File), !.
'$extend_path_directory'(Name, D, File, Opts, NewFile, Call) :-
	user:file_search_path(Name, IDirs),
	'$absf_trace'('file_search_path  ~a is ~w', [Name, IDirs] ),
	ground(IDirs),
	(
	 '$extend_path_directory'(IDirs, D, File, Opts, NewFile, Call)
	;
         atom(IDirs) ->
	 '$split_by_sep'(0, 0, IDirs, Dir)
	;
	   Dir = IDirs
	),
	'$extend_pathd'(Dir, D, File, Opts, NewFile, Call).

'$extend_pathd'(Dir, A, File, Opts, NewFile, Goal) :-
	atom(Dir), !,
	'$add_file_to_dir'(Dir,A,File,NFile),
	'$absf_trace'(' try  ~a', [NFile] ),
	'$find_in_path'(NFile, Opts, NewFile, Goal), !.
'$extend_pathd'(Name, A, File, Opts, OFile, Goal) :-
	nonvar(Name),
	Name =.. [N,P0],
	'$add_file_to_dir'(P0,A,File,NFile),
	NewName =.. [N,NFile],
	'$absf_trace'(' try  ~q', [NewName] ),
	'$find_in_path'(NewName, Opts, OFile, Goal).

'$add_file_to_dir'(P0,A,Atoms,NFile) :-
	atom_concat([P0,A,Atoms],NFile).

'$absf_trace'(Msg, Args ) :-
	current_prolog_flag( verbose_file_search, true ),
	!,
	print_message( informational, absolute_file_path( Msg, Args ) ).
'$absf_trace'(_Msg, _Args ).

/** @pred prolog_file_name( +File, -PrologFileaNme)

Unify _PrologFileName_ with the Prolog file associated to _File_.

*/
prolog_file_name(File, PrologFileName) :-
	var(File), !,
	'$do_error'(instantiation_error, prolog_file_name(File, PrologFileName)).
prolog_file_name(user, Out) :- !, Out = user.
prolog_file_name(File, PrologFileName) :-
	atom(File), !,
	system:true_file_name(File, PrologFileName).
prolog_file_name(File, PrologFileName) :-
	'$do_error'(type_error(atom,File), prolog_file_name(File, PrologFileName)).

/**
  @pred path(-Directories:list) is det,deprecated

 YAP specific procedure that returns a list of user-defined directories
 in the library search-path.We suggest using user:file_search_path/2 for
 compatibility with other Prologs.
*/
path(Path) :-
	findall(X,'$in_path'(X),Path).

'$in_path'(X) :-
	recorded('$path',Path,_),
	atom_codes(Path,S),
	( S = ""  -> X = '.' ;
	  atom_codes(X,S) ).

/**
  @pred add_to_path(+Directory:atom) is det,deprecated

  YAP-specific predicate to include directory in library search path.
  We suggest using user:file_search_path/2 for
  compatibility with other Prologs.
*/
add_to_path(New) :-
	add_to_path(New,last).

/**
  @pred add_to_path(+Directory:atom, +Position:atom) is det,deprecated

  YAP-specific predicate to include directory in front or back of
  library search path. We suggest using user:file_search_path/2 for
  compatibility with other Prologs and more extensive functionality.
*/
add_to_path(New,Pos) :-
	atom(New), !,
	'$check_path'(New,Str),
	atom_codes(Path,Str),
	'$add_to_path'(Path,Pos).

'$add_to_path'(New,_) :-
	recorded('$path',New,R),
	erase(R),
	fail.
'$add_to_path'(New,last) :-
	!,
	recordz('$path',New,_).
'$add_to_path'(New,first) :-
	recorda('$path',New,_).

/**  @pred   remove_from_path(+Directory:atom) is det,deprecated

*/
remove_from_path(New) :- '$check_path'(New,Path),
			recorded('$path',Path,R), erase(R).

'$check_path'(At,SAt) :- atom(At), !, atom_codes(At,S), '$check_path'(S,SAt).
'$check_path'([],[]).
'$check_path'([Ch],[Ch]) :- '$dir_separator'(Ch), !.
'$check_path'([Ch],[Ch,A]) :- !, integer(Ch), '$dir_separator'(A).
'$check_path'([N|S],[N|SN]) :- integer(N), '$check_path'(S,SN).