/* File:      libwwwconfig.P -- loader for the libwww foreign module
** Author(s): kifer
** Contact:   xsb-contact@cs.sunysb.edu
** 
** Copyright (C) The Research Foundation of SUNY, 1999
** 
** XSB is free software; you can redistribute it and/or modify it under the
** terms of the GNU Library General Public License as published by the Free
** Software Foundation; either version 2 of the License, or (at your option)
** any later version.
** 
** XSB 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 Library General Public License for
** more details.
** 
** You should have received a copy of the GNU Library General Public License
** along with XSB; if not, write to the Free Software Foundation,
** Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** $Id: libwwwconfig.P,v 1.22 2002/03/15 09:19:49 kifer Exp $
** 
*/


:- compiler_options([xpp_on]).
#include "extensions_xsb.h"


:- import slash/1, str_cat/3, machine_file_exists/1 from machine.
:- import fmt_write_string/3, file_time/2 from file_io.
:- import search_module/6 from consult.
:- import libwww_info/2 from libwww_init.
:- import compile_so/3, runtime_loader_flag/3 from foreign.
:- import path_sysop/3, path_sysop/2 from file_io.

%% Construct the file cc/xsb_libwww.H on the fly
make_libwwwH(CC, CC_opts, LoaderFlags) :-
    slash(Slash),
    xsb_configuration(configuration, XSBconfiguration),
    package_configuration(dir(libwww), LibwwwDir),
    fmt_write_string(LD_directives_file,
		     '%s%scc%slibwww_request%s',
		     f(LibwwwDir, Slash, Slash,XSB_HDR_EXTENSION_ATOM)),
    telling(OldTell),
    tell(LD_directives_file),
    writeln('%% This file is generated on-the-fly by libwwwconfig.P'),
    writeln('%% Do not edit--any changes will be written over.'),
    write('%% XSB config:            '), writeln(XSBconfiguration),
    write('%% XSB CC:                '), writeln(CC),
    write('%% Libwww compiler flags: '), writeln(CC_opts),
    writeln(':- import slash/1 from machine.'),
    writeln(':- export do_libwww_request___/1.'),
    fmt_write(':- ldoption('' %s'').', arg(LoaderFlags)), nl,
    told,
    tell(OldTell).
    

:-  package_configuration(dir(libwww), LibwwwDir),
    slash(Slash),
    Basename = libwww_request,
    Basename_xml = libwww_parse_xml,
    Basename_rdf = libwww_parse_rdf,
    Basename_html = libwww_parse_html,
    fmt_write_string(Module, '%s%scc%s%s', f(LibwwwDir,Slash,Slash,Basename)),
    fmt_write_string(Module_xml,
		     '%s%scc%s%s', f(LibwwwDir,Slash,Slash,Basename_xml)),
    fmt_write_string(Module_rdf,
		     '%s%scc%s%s', f(LibwwwDir,Slash,Slash,Basename_rdf)),
    fmt_write_string(Module_html,
		     '%s%scc%s%s', f(LibwwwDir,Slash,Slash,Basename_html)),
    (  %% avoid recompilation: check if xsb_libwww object file exists and 
       %% is newer than xsb_libwww.c.
       search_module(Basename,Dir,_Mod,_Ext,_Base,ModuleO),
       str_cat(Module, '.c', ModuleSourceFile),
       str_cat(Module, XSB_HDR_EXTENSION_ATOM, ModuleH),
       machine_file_exists(ModuleH),
       file_time(ModuleO, time(CT1,CT2)),
       file_time(ModuleSourceFile, time(ST1,ST2)),
       time(ST1,ST2) @< time(CT1,CT2)
    %% module compiled and is current, so just load
    -> [Basename]

    %% If Module isn't compiled or is old --- recompile
    ;   xsb_configuration(compiler, CC),
	libwww_info(ldflags, LoaderFlags0),
	libwww_info(ccflags, CC_opts),
	libwww_info(libdir, LibwwwLibdir),
	xsb_configuration(config_libdir, ConfigLibdir),

	runtime_loader_flag(CC, LibwwwLibdir, RunpathFlag),
	%% Add something like -Wl,-rpath,<libdir> to the loader flags
	fmt_write_string(LoaderFlags1, '%s %s', arg(RunpathFlag,LoaderFlags0)),

	%% Compile the _util.c file into a shared object
	compile_so(Module_xml, [cc(CC), cc_opts(CC_opts)], LoaderFlags1),
	compile_so(Module_rdf, [cc(CC), cc_opts(CC_opts)], LoaderFlags1),
	compile_so(Module_html, [cc(CC), cc_opts(CC_opts)], LoaderFlags1),
	%% Move Module_util to the arch-dependent library
	fmt_write_string(LibMod_xml,
			 '%s%s%s.so', a(ConfigLibdir,Slash,Basename_xml)),
	fmt_write_string(LibMod_rdf,
			 '%s%s%s.so', a(ConfigLibdir,Slash,Basename_rdf)),
	fmt_write_string(LibMod_html,
			 '%s%s%s.so', a(ConfigLibdir,Slash,Basename_html)),
	str_cat(Module_xml, '.so', SharedLib_xml),
	str_cat(Module_rdf, '.so', SharedLib_rdf),
	str_cat(Module_html, '.so', SharedLib_html),
	force_rename(SharedLib_xml,LibMod_xml),
	force_rename(SharedLib_rdf,LibMod_rdf),
	force_rename(SharedLib_html,LibMod_html),
	%% Make options for the main foreign module (libwww_request.c)
	fmt_write_string(LoaderFlags2, '%s %s %s %s',
			 a(LoaderFlags1,LibMod_xml,LibMod_rdf,LibMod_html)),
	make_libwwwH(CC, CC_opts, LoaderFlags2),
	str_cat(Module, XSB_OBJ_EXTENSION_ATOM, Objfile),
	consult(Module, [cc(CC), cc_opts(CC_opts)]),
	fmt_write_string(LibObjFile,
			 '%s%s%s%s',
			 args(ConfigLibdir,Slash,Basename,XSB_OBJ_EXTENSION_ATOM)),
	force_rename(Objfile, LibObjFile),
	str_cat(Module, '.so', SharedLib),
	fmt_write_string(LibMod, '%s%s%s.so', a(ConfigLibdir,Slash,Basename)),
	force_rename(SharedLib,LibMod)
     ).

%% Windows semantics for renaming is such that the op fails, 
%% if the target exists
force_rename(Orig,Target) :-
	(path_sysop(unlink,Target), !; true),
	path_sysop(rename,Orig,Target).