dnl Copyright (C) 2009 Nick Bowler
dnl Copying and distribution of this file, with or without modification,
dnl are permitted in any medium without royalty provided the copyright
dnl notice and this notice are preserved.  This file is offered as-is,
dnl without any warranty.

AC_DEFUN([_LIBMODPLUG_TEST], [dnl
AC_CACHE_CHECK([whether libmodplug works],
	[libmodplug_cv_works],
	[AC_LINK_IFELSE([AC_LANG_PROGRAM([dnl
#include <modplug.h>
], [dnl
unsigned char buf@<:@128@:>@ = {0};
ModPlugFile *f = ModPlug_Load(buf, sizeof buf);
ModPlug_Unload(f);
])], [libmodplug_cv_works=yes], [libmodplug_cv_works=no])])
])

dnl CHECK_LIBMODPLUG([action-if-ok], [action-if-fail])
AC_DEFUN([CHECK_LIBMODPLUG],
[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
AC_ARG_VAR([LIBMODPLUG_CFLAGS], [C compiler flags for libmodplug])dnl
AC_ARG_VAR([LIBMODPLUG_LIBS],   [linker flags for libmodplug])dnl

if test x"$PKG_CONFIG" != x; then
	AC_MSG_CHECKING([pkg-config database for libmodplug])
	_PKG_CONFIG([libmodplug_cflags], [cflags], [libmodplug])
	_PKG_CONFIG([libmodplug_libs],   [libs],   [libmodplug])
	if test x$pkg_failed = xyes; then
		errors=`$PKG_CONFIG --errors-to-stdout --print-errors libmodplug`
		echo "$errors" >&AS_MESSAGE_LOG_FD
		AC_MSG_RESULT([no])
	else
		if test x"$LIBMODPLUG_CFLAGS" = x; then
			LIBMODPLUG_CFLAGS=$pkg_cv_libmodplug_cflags
		fi
		if test x"$LIBMODPLUG_LIBS" = x; then
			LIBMODPLUG_LIBS=$pkg_cv_libmodplug_libs
		fi

		AC_MSG_RESULT([yes])
	fi
fi

if test x"$LIBMODPLUG_CFLAGS" = x; then
	LIBMODPLUG_CFLAGS="-I$includedir/libmodplug"
fi

if test x"$LIBMODPLUG_LIBS" = x; then
	LIBMODPLUG_LIBS=-lmodplug
fi

AC_LANG_PUSH([C])
old_cflags=$CFLAGS
old_libs=$LIBS
CFLAGS="$LIBMODPLUG_CFLAGS $CFLAGS"
LIBS="$LIBMODPLUG_LIBS $LIBS"

_LIBMODPLUG_TEST

CFLAGS=$old_cflags
LIBS=$old_libs
AC_LANG_POP([C])

if test x"$libmodplug_cv_works" = x"yes"; then
	AC_SUBST([LIBMODPLUG_CFLAGS])
	AC_SUBST([LIBMODPLUG_LIBS])
	ifelse([$1], [], [true], [$1])
else
	ifelse([$2], [], [AC_MSG_FAILURE([dnl
libmodplug is required.  The latest version can be
obtained from http://modplug-xmms.sourceforge.net/.

If libmodplug is installed but was not found by this configure script,
consider adjusting LIBMODPLUG_CFLAGS and/or LIBMODPLUG_LIBS as necessary.

If pkg-config is installed, it may help to adjust PKG_CONFIG_PATH
if libmodplug is installed in a non-standard prefix.
])], [$2])
fi
])