# Helper function to setup variables for a package.
# $1 -> the package name. Used in configure.ac and also as a prefix
#	for the variables ($1_DIR, $1_INCLUDE, $1_LIB) in makeopts
# $3 ->	option name, used in --with-$3 or --without-$3 when calling configure.
# $2 and $4 are just text describing the package (short and long form)

# AST_EXT_LIB_SETUP([package], [short description], [configure option name], [long description])

AC_DEFUN([AST_EXT_LIB_SETUP],
[
    $1_DESCRIP="$2"
    $1_OPTION="$3"
    AC_ARG_WITH([$3], AC_HELP_STRING([--with-$3=PATH],[use $2 files in PATH $4]),
    [
	case ${withval} in
	n|no)
	USE_$1=no
	;;
	y|ye|yes)
	ac_mandatory_list="${ac_mandatory_list} $1"
	;;
	*)
	$1_DIR="${withval}"
	ac_mandatory_list="${ac_mandatory_list} $1"
	;;
	esac
    ])
    PBX_$1=0
    AH_TEMPLATE(m4_bpatsubst([[HAVE_$1]], [(.*)]), [Define to 1 if you have the $2 library.])
    AC_SUBST([$1_LIB])
    AC_SUBST([$1_INCLUDE])
    AC_SUBST([$1_DIR])
    AC_SUBST([PBX_$1])
])

# Check for existence of a given package ($1), either looking up a function
# in a library, or, if no function is supplied, only check for the
# existence of the header files.

# AST_EXT_LIB_CHECK([package], [library], [function], [header],
#	 [extra libs], [extra cflags], [version])
AC_DEFUN([AST_EXT_LIB_CHECK],
[
if test "x${PBX_$1}" != "x1" -a "${USE_$1}" != "no"; then
   pbxlibdir=""
   # if --with-$1=DIR has been specified, use it.
   if test "x${$1_DIR}" != "x"; then
      if test -d ${$1_DIR}/lib; then
      	 pbxlibdir="-L${$1_DIR}/lib"
      else
      	 pbxlibdir="-L${$1_DIR}"
      fi
   fi
   pbxfuncname="$3"
   if test "x${pbxfuncname}" = "x" ; then   # empty lib, assume only headers
      AST_$1_FOUND=yes
   else
      AC_CHECK_LIB([$2], [${pbxfuncname}], [AST_$1_FOUND=yes], [AST_$1_FOUND=no], ${pbxlibdir} $5)
   fi

   # now check for the header.
   if test "${AST_$1_FOUND}" = "yes"; then
      $1_LIB="${pbxlibdir} -l$2 $5"
      # if --with-$1=DIR has been specified, use it.
      if test "x${$1_DIR}" != "x"; then
	 $1_INCLUDE="-I${$1_DIR}/include"
      fi
      $1_INCLUDE="${$1_INCLUDE} $6"
      if test "x$4" = "x" ; then	# no header, assume found
         $1_HEADER_FOUND="1"
      else				# check for the header
         saved_cppflags="${CPPFLAGS}"
         CPPFLAGS="${CPPFLAGS} ${$1_INCLUDE}"
         AC_CHECK_HEADER([$4], [$1_HEADER_FOUND=1], [$1_HEADER_FOUND=0])
         CPPFLAGS="${saved_cppflags}"
      fi
      if test "x${$1_HEADER_FOUND}" = "x0" ; then
         $1_LIB=""
         $1_INCLUDE=""
      else
         if test "x${pbxfuncname}" = "x" ; then		# only checking headers -> no library
	    $1_LIB=""
	 fi
         PBX_$1=1
         if test "x${$1_OPTION}" = "x"; then
            dnl Ensure that we have an autoheader, when AST_EXT_LIB_SETUP was
            dnl not called.  Note that we cannot use shell substitution in the
            dnl description, because the shell is never invoked when rendering
            dnl the autoheader.  Only m4 substitutions will expand correctly.
            AC_DEFINE_UNQUOTED([HAVE_$1], 1, [Define to 1 to indicate $1 functionality.])
            AC_DEFINE_UNQUOTED([HAVE_$1_VERSION], [$7], [Define to indicate the $1 library version])
         else
            cat >>confdefs.h <<_ACEOF
[@%:@define] HAVE_$1 1
[@%:@define] HAVE_$1_VERSION $7
_ACEOF
         fi
      fi
   fi
fi
])