/*  $Id$

    Part of XPCE
    Designed and implemented by Anjo Anjewierden and Jan Wielemaker
    E-mail: jan@swi.psy.uva.nl

    Copyright (C) 1993 University of Amsterdam. All rights reserved.
*/

:- module(pce_cpp_header,
	  [ generate_cpp_class_header_file/0
	  ]).
:- use_module(library(pce)).
:- require([ append/1
	   , apply/2
	   , between/3
	   , concat/3
	   , concat_atom/2
	   , forall/2
	   , ignore/1
	   , is_list/1
	   , memberchk/2
	   , nth1/3
	   , once/1
	   ]).

itf_max_arg(9).

m4_file(M4) :-
	get(string('%s/include/pce-cpp.m4', @pce?home), value, M4).
cpp_header_dir(Dir) :-
	get(string('%s/include/pce', @pce?home), value, Dir).

generate_cpp_class_header_file :-
	m4_file(M4), telling(Old), tell(M4),
	output('divert(-1)\n'),
	m4('Global'),
	m4('Object'),
	m4('Chain'),
	m4('Class'),
	tell(Old),

	new(X, chain),
	send(@classes, for_all, if(@arg2?creator == built_in,
				   message(X, append, @arg1))),
	send(X, delete, class),
	ignore(send(X, delete, call)),	% just make sure
	send(X, delete, object),
	send(X, delete, variable),
	send(X, delete, chain),
	send(X, delete, pce),
	send(X, delete, string),
	send(X, sort),
	send(X, for_all, message(@prolog, cpp_class, @arg1)),

	m4_file(M4), telling(Old), tell(M4),
	output('divert(0)\n'),
	told, tell(Old).

cpp_class(ClassName) :-
	cpp_header_dir(Dir),
	cpp_class_name(ClassName, CppName),
	concat_atom([Dir, /, CppName, '.h'], File),
	telling(Old), tell(File),
	xpce_file_header(CppName),
	generate_class_def(ClassName),
	generate_as(ClassName),
	xpce_file_footer(CppName),
	told, tell(Old).


xpce_file_header(ClassName) :-
	output('/*  $Id$\n\n'),
	output('    Part of XPCE\n'),
	output('    Designed and implemented by Anjo Anjewierden and Jan Wielemaker\n'),
	output('    E-mail: jan@swi.psy.uva.nl\n\n'),
	output('    Copyright (C) 1993 University of Amsterdam. All rights reserved.\n*/\n\n'),
	output('#ifndef _PCE_%s_H\n', ClassName?upcase),
	output('#define _PCE_%s_H\n\n', ClassName?upcase).

xpce_file_footer(ClassName) :-
	output('#endif /*!_PCE_%s_H*/\n', ClassName?upcase).
	

generate_as(ClassName) :-
	get(@pce, convert, ClassName, class, Class),
	get(Class, name, Name),
	once(cpp_class_name(Name, CppName)),
	output('inline Pce%s\nAs%s(PceArg a)\n', [CppName, CppName]),
	output('{ return *((Pce%s*) &a);\n}\n\n', CppName).


generate_class_def(ClassName) :-
	get(@pce, convert, ClassName, class, Class),
	get(Class, send_method, initialise, InitMethod),
	get(Class, name, Name),
	once(cpp_class_name(Name, CppName)),
	output('extern Any Class%s;\n', CppName),
	output('class Pce%s :public PceObject\n{\npublic:\n', CppName),
	get(InitMethod, types, Types),
	argument_range(Types, Low, High),
	forall(between(Low, High, Arity),
	       constructor(InitMethod, CppName, Arity)),
	output('};\n\n').

m4(CppName) :-
	output('define(`Pce%s'', `ifelse($#, 1, ``$0(PceArg($1))'''', $#, 0, ``$0'''', ``$0($*)'''')'')\n', CppName).

constructor(_, CppName, 1) :-
	m4_file(File),
	(   telling(Old), append(File),
	    m4(CppName),
	    tell(Old)
	->  fail
	).
constructor(InitMethod, CppName, N) :-
	arg_names(InitMethod, 1, N, [], ArgNames),
	output('  Pce%s(', CppName),
	forall(between(1, N, Arg),
	       constructor_iarg(ArgNames, Arg)),
	output(') :\n    PceObject(Class%s', CppName),
	forall(between(1, N, Arg),
	       constructor_oarg(ArgNames, Arg)),
	output(')\n  {\n  }\n').

arg_names(_, I, N, _, []) :-
	I =:= N + 1, !.
arg_names(InitMethod, I, N, D, [TheName|R]) :-
	get(InitMethod, argument_type, I, Type),
	get(Type, argument_name, Name),
	cpp_arg_name(Name, ArgName),
	unique_name(ArgName, D, TheName),
	NI is I + 1,
	arg_names(InitMethod, NI, N, [TheName|D], R).

cpp_arg_name(@nil, a).			% unnamed xpce argument
cpp_arg_name(return, ret).		% avoid C-keywords
cpp_arg_name(class, cl).
cpp_arg_name(int, i).
cpp_arg_name(char, chr).
cpp_arg_name(then, thn).
cpp_arg_name(else, els).
cpp_arg_name(default, def).
cpp_arg_name(X, X).			% ok-to-use name

unique_name(Name, D, Name) :-
	\+ memberchk(Name, D), !.
unique_name(Name, D, Unique) :-
	between(2, 100, N),
	concat(Name, N, Unique),
	\+ memberchk(Unique, D).

constructor_iarg(ArgNames, Arg) :-
	(   Arg \== 1
	->  output(', ')
	;   true
	),
	nth1(Arg, ArgNames, Name),
	output('PceArg %s', Name).

constructor_oarg(ArgNames, Arg) :-
	nth1(Arg, ArgNames, Name),
	output(', %s', Name).
	    
argument_range(Types, Low, High) :-
	get(Types, size, Size),
	(   Size == 0
	->  Low = 0,
	    High = 0
	;   get(Types, element, Size, Last),
	    (   get(Last, vector, @on)
	    ->	VLow is Size - 1,
		itf_max_arg(High)
	    ;	VLow is Size,
		High = Size
	    ),
	    (	between(1, VLow, DLow),
		get(Types, element, DLow, Type),
		get(Type, check, @default, _)
	    ->  Low is DLow - 1
	    ;	Low is VLow
	    )
	).

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

output(Fmt) :-
	output(Fmt, []).
output(Fmt, Atom) :-
	\+ is_list(Atom), !,
	output(Fmt, [Atom]).
output(Fmt, Args) :-
	apply(send(@pce, format, Fmt), Args).

cpp_class_name(*,	'Times').
cpp_class_name(-,	'Minus').
cpp_class_name(+, 	'Plus').
cpp_class_name(/,	'Divide').
cpp_class_name(:=,	'Binding').
cpp_class_name(<,	'Less').
cpp_class_name(=,	'Equation').
cpp_class_name(=<,	'LessEqual').
cpp_class_name(==,	'Equal').
cpp_class_name(>,	'Greater').
cpp_class_name(>=,	'GreaterEqual').
cpp_class_name(?,	'Obtain').
cpp_class_name(\==,	'NonEqual').
cpp_class_name(Name, CppName) :-
	get(Name, capitalise, CppName).
