#shamelessly borrowed from FreeCAD project: https://github.com/FreeCAD/FreeCAD/blob/master/cMake/FindOpenCasCade.cmake
# Try to find OCE / OCC
# Once done this will define
#
# OCC_FOUND          - system has OCC - OpenCASCADE
# OCC_INCLUDE_DIR    - where the OCC include directory can be found
# OCC_LIBRARY_DIR    - where the OCC library directory can be found
# OCC_LIBRARIES      - Link this to use OCC
# OCC_OCAF_LIBRARIES - Link this to use OCC OCAF framework

# First try to find OpenCASCADE Community Edition
if(NOT DEFINED OCE_DIR)
  # Check for OSX needs to come first because UNIX evaluates to true on OSX
  if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
    if(DEFINED MACPORTS_PREFIX)
      find_package(OCE QUIET HINTS ${MACPORTS_PREFIX}/Library/Frameworks)
    elseif(DEFINED HOMEBREW_PREFIX)
      find_package(OCE QUIET HINTS ${HOMEBREW_PREFIX}/Cellar/opencascade/*)
    endif()
  elseif(UNIX)
    set(OCE_DIR "/usr/local/share/cmake/")
  elseif(WIN32)
    set(OCE_DIR "c:/OCE-0.4.0/share/cmake")
  endif()
endif()

if(${ELMER_USE_OCC_VARIANT} MATCHES "Community Edition")
  find_package(OCE QUIET)
endif()

if(OCE_FOUND)
  message(STATUS "-- OpenCASCADE Community Edition has been found.")
  # Disable this define. For more details see bug #0001872
  #add_definitions (-DHAVE_CONFIG_H)
  set(OCC_INCLUDE_DIR ${OCE_INCLUDE_DIRS})
  #set(OCC_LIBRARY_DIR ${OCE_LIBRARY_DIR})
else(OCE_FOUND) #look for OpenCASCADE
  # we first try to find opencascade directly:
  if(NOT OCCT_CMAKE_FALLBACK)
    find_package(OpenCASCADE CONFIG QUIET)
  endif(NOT OCCT_CMAKE_FALLBACK)
  if(OpenCASCADE_FOUND)
    set(OCC_FOUND ${OpenCASCADE_FOUND})
    set(OCC_INCLUDE_DIR ${OpenCASCADE_INCLUDE_DIR})
    set(OCC_LIBRARY_DIR ${OpenCASCADE_LIBRARY_DIR})
    set(OCC_LIBRARIES ${OpenCASCADE_LIBRARIES})
    set(OCC_OCAF_LIBRARIES TKCAF TKXCAF)
  else(OpenCASCADE_FOUND)
    if(WIN32)
      if(CYGWIN OR MINGW)
      FIND_PATH(OCC_INCLUDE_DIR Standard_Version.hxx
          /usr/include/opencascade
          /usr/local/include/opencascade
          /opt/opencascade/include
          /opt/opencascade/inc
        )
        FIND_LIBRARY(OCC_LIBRARY TKernel
          /usr/lib
          /usr/local/lib
          /opt/opencascade/lib
        )
      else(CYGWIN OR MINGW)
      FIND_PATH(OCC_INCLUDE_DIR Standard_Version.hxx
          "[HKEY_LOCAL_MACHINE\\SOFTWARE\\SIM\\OCC\\2;Installation Path]/include"
        )
        FIND_LIBRARY(OCC_LIBRARY TKernel
          "[HKEY_LOCAL_MACHINE\\SOFTWARE\\SIM\\OCC\\2;Installation Path]/lib"
        )
      endif(CYGWIN OR MINGW)
    else(WIN32)
      FIND_PATH(OCC_INCLUDE_DIR Standard_Version.hxx
        /usr/include/occt
        /usr/include/opencascade
        /usr/local/include/opencascade
        /opt/opencascade/include
        /opt/opencascade/inc
      )
      FIND_LIBRARY(OCC_LIBRARY TKernel
        /usr/lib
        /usr/local/lib
        /opt/opencascade/lib
      )
    endif(WIN32)
    if(OCC_LIBRARY)
      GET_FILENAME_COMPONENT(OCC_LIBRARY_DIR ${OCC_LIBRARY} PATH)
      IF(NOT OCC_INCLUDE_DIR)
        FIND_PATH(OCC_INCLUDE_DIR Standard_Version.hxx
          ${OCC_LIBRARY_DIR}/../inc
        )
      ENDIF()
    endif(OCC_LIBRARY)
  endif(OpenCASCADE_FOUND)
endif(OCE_FOUND)

if(OCC_INCLUDE_DIR)
  file(STRINGS ${OCC_INCLUDE_DIR}/Standard_Version.hxx OCC_MAJOR
    REGEX "#define OCC_VERSION_MAJOR.*"
  )
  string(REGEX MATCH "[0-9]+" OCC_MAJOR ${OCC_MAJOR})
  file(STRINGS ${OCC_INCLUDE_DIR}/Standard_Version.hxx OCC_MINOR
    REGEX "#define OCC_VERSION_MINOR.*"
  )
  string(REGEX MATCH "[0-9]+" OCC_MINOR ${OCC_MINOR})
  file(STRINGS ${OCC_INCLUDE_DIR}/Standard_Version.hxx OCC_MAINT
    REGEX "#define OCC_VERSION_MAINTENANCE.*"
  )
  string(REGEX MATCH "[0-9]+" OCC_MAINT ${OCC_MAINT})

  set(OCC_VERSION_STRING "${OCC_MAJOR}.${OCC_MINOR}.${OCC_MAINT}")
endif(OCC_INCLUDE_DIR)

# handle the QUIETLY and REQUIRED arguments and set OCC_FOUND to TRUE if
# all listed variables are TRUE
include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(OCC REQUIRED_VARS OCC_INCLUDE_DIR VERSION_VAR OCC_VERSION_STRING)

if(OCC_FOUND)
  set(OCC_LIBRARIES
    TKFillet
    TKMesh
    TKernel
    TKG2d
    TKG3d
    TKMath
    TKIGES
    TKSTL
    TKShHealing
    TKXSBase
    TKBin
    TKBool
    TKBO
    TKCDF
    TKBRep
    TKTopAlgo
    TKGeomAlgo
    TKGeomBase
    TKOffset
    TKPrim
    TKSTEP
    TKSTEPBase
    TKSTEPAttr
    TKHLR
    TKFeat
  )
  set(OCC_OCAF_LIBRARIES
    TKCAF
    TKXCAF
    TKLCAF
    TKXDESTEP
    TKXDEIGES
    TKMeshVS
  )
  if(OCC_VERSION_STRING VERSION_LESS 6.7.3)
    list(APPEND OCC_OCAF_LIBRARIES TKAdvTools)
  endif(OCC_VERSION_STRING VERSION_LESS 6.7.3)
  message(STATUS "-- Found OCE/OpenCASCADE version: ${OCC_VERSION_STRING}")
  message(STATUS "-- OCE/OpenCASCADE include directory: ${OCC_INCLUDE_DIR}")
  message(STATUS "-- OCE/OpenCASCADE shared libraries directory: ${OCC_LIBRARY_DIR}")
else(OCC_FOUND)
  #message(SEND_ERROR "Neither OpenCASCADE Community Edition nor OpenCasCade were found: will not build CAD modules!")
endif(OCC_FOUND)