# RS needs GMP 4.2 or newer, this script will fail if an old version is
# detected

find_package( GMP )
find_package( MPFI )

if( MPFI_FOUND )

  include( ${MPFI_USE_FILE} )
  include( CGAL_VersionUtils )

  find_path(RS_INCLUDE_DIR
            NAMES rs_exports.h
            PATHS ENV RS_INC_DIR
            DOC "The directory containing the RS include files"
           )

  find_path(RS3_INCLUDE_DIR
            NAMES rs3_fncts.h
            PATHS ENV RS_INC_DIR
            DOC "The directory containing the RS3 include files"
           )

  find_library(RS_LIBRARIES
               NAMES rsexport_rs
               PATHS ENV RS_LIB_DIR
               DOC "Path to the RS library"
              )

  find_library(RS3_LIBRARIES
               NAMES rs3
               PATHS ENV RS_LIB_DIR
               DOC "Path to the RS3 library"
              )

  if ( NOT CGAL_GMP_VERSION ) 
    set ( CGAL_GMP_VERSION ${GMP_VERSION} )
  endif()

  IS_VERSION_LESS("${CGAL_GMP_VERSION}" "4.2.0" _IS_GMP_VERSION_TO_LOW)

  if(_IS_GMP_VERSION_TO_LOW)

    message( STATUS
      "RS needs GMP>=4.2. Your GMP version is ${CGAL_GMP_VERSION}." )

  else(_IS_GMP_VERSION_TO_LOW)

    if( RS_INCLUDE_DIR AND RS_LIBRARIES )
      set(RS_FOUND TRUE)
    endif( RS_INCLUDE_DIR AND RS_LIBRARIES )

    if( RS3_INCLUDE_DIR AND RS3_LIBRARIES )
      set(RS3_FOUND TRUE)
    endif( RS3_INCLUDE_DIR AND RS3_LIBRARIES )

    if( RS_LIBRARIES )
      get_filename_component(RS_LIBRARIES_DIR ${RS_LIBRARIES} PATH CACHE )
    endif( RS_LIBRARIES )

    if( NOT RS_INCLUDE_DIR OR NOT RS_LIBRARIES_DIR )
      include( RSConfig OPTIONAL )
    endif( NOT RS_INCLUDE_DIR OR NOT RS_LIBRARIES_DIR )

    include(FindPackageHandleStandardArgs)

    find_package_handle_standard_args( RS
                                       "DEFAULT_MSG"
                                       RS_LIBRARIES
                                       RS_INCLUDE_DIR )

  endif(_IS_GMP_VERSION_TO_LOW)

else( MPFI_FOUND )

  message( STATUS "RS requires MPFI" )
  set( RS_FOUND FALSE )

endif( MPFI_FOUND )

if(RS_FOUND)
  set(RS_USE_FILE "CGAL_UseRS")
endif(RS_FOUND)