# -*- mode: cmake -*-
#
# METIS Find Module for MSTK
# Shamelessly stolen from Amanzi open source code https://software.lanl.gov/ascem/trac
#
# Usage:
#    Control the search through METIS_DIR or setting environment variable
#    METIS_ROOT to the METIS installation prefix.
#
#    This module does not search default paths!
#
#    Following variables are set:
#    METIS_FOUND            (BOOL)       Flag indicating if METIS was found
#    METIS_INCLUDE_DIR      (PATH)       Path to the METIS include file
#    METIS_INCLUDE_DIRS     (LIST)       List of all required include files
#    METIS_LIBRARY_DIR      (PATH)       Path to the METIS library
#    METIS_LIBRARY          (FILE)       METIS library
#    METIS_LIBRARIES        (LIST)       List of all required METIS libraries
#
# #############################################################################
# Standard CMake modules see CMAKE_ROOT/Modules
include(FindPackageHandleStandardArgs)
# Amanzi CMake functions see <root>/tools/cmake for source
#     include(PrintVariable)
if ( METIS_LIBRARIES AND METIS_INCLUDE_DIRS )
# Do nothing. Variables are set. No need to search again
else(METIS_LIBRARIES AND METIS_INCLUDE_DIRS)
# Cache variables
if(METIS_DIR)
    set(METIS_DIR "${METIS_DIR}" CACHE PATH "Path to search for METIS include and library files")
    endif()
if(METIS_INCLUDE_DIR)
    set(METIS_INCLUDE_DIR "${METIS_INCLUDE_DIR}" CACHE PATH "Path to search for METIS include files")
    endif()
if(METIS_LIBRARY_DIR)
    set(METIS_LIBRARY_DIR "${METIS_LIBRARY_DIR}" CACHE PATH "Path to search for METIS library files")
endif()

# Search for include files
# Search order preference:
#  (1) METIS_INCLUDE_DIR - check existence of path AND if the include files exist
#  (2) METIS_DIR/<include>
#  (3) Default CMake paths See cmake --html-help=out.html file for more information.
#
    set(metis_inc_names "metis.h")
if (METIS_INCLUDE_DIR)
    if (EXISTS "${METIS_INCLUDE_DIR}")
    find_path(metis_test_include_path
            NAMES ${metis_inc_names}
            HINTS ${METIS_INCLUDE_DIR}
            NO_DEFAULT_PATH)
if(NOT metis_test_include_path)
    message(SEND_ERROR "Can not locate ${metis_inc_names} in ${METIS_INCLUDE_DIR}")
endif()
    set(METIS_INCLUDE_DIR "${metis_test_include_path}")
else()
    message(SEND_ERROR "METIS_INCLUDE_DIR=${METIS_INCLUDE_DIR} does not exist")
    set(METIS_INCLUDE_DIR "METIS_INCLUDE_DIR-NOTFOUND")
    endif()
else() 
# Metis sometimes puts the include files in a subdir called Lib
    set(metis_inc_suffixes "include" "Lib")
if(METIS_DIR)
    if (EXISTS "${METIS_DIR}" )
    find_path(METIS_INCLUDE_DIR
            NAMES ${metis_inc_names}
            HINTS ${METIS_DIR}
            PATH_SUFFIXES ${metis_inc_suffixes}
            NO_DEFAULT_PATH)
else()
    message(SEND_ERROR "METIS_DIR=${METIS_DIR} does not exist")
    set(METIS_INCLUDE_DIR "METIS_INCLUDE_DIR-NOTFOUND")
    endif()   
else()
    find_path(METIS_INCLUDE_DIR
            NAMES ${metis_inc_names}
            PATH_SUFFIXES ${metis_inc_suffixes})
    endif()
    endif()
if ( NOT METIS_INCLUDE_DIR )
    message(SEND_ERROR "Can not locate METIS include directory")
endif()
# Search for libraries
# Search order preference:
#  (1) METIS_LIBRARY_DIR - check existence of path AND if the library file exists
#  (2) METIS_DIR/<lib,Lib>
#  (3) Default CMake paths See cmake --html-help=out.html file for more information.
#
    set(metis_lib_names "metis5" "metis")
if (METIS_LIBRARY_DIR)
    if (EXISTS "${METIS_LIBRARY_DIR}")
    find_library(METIS_LIBRARY
            NAMES ${metis_lib_names}
            HINTS ${METIS_LIBRARY_DIR}
            NO_DEFAULT_PATH)
else()
    message(SEND_ERROR "METIS_LIBRARY_DIR=${METIS_LIBRARY_DIR} does not exist")
    set(METIS_LIBRARY "METIS_LIBRARY-NOTFOUND")
    endif()
else() 
    list(APPEND metis_lib_suffixes "lib" "Lib")
if(METIS_DIR)
    if (EXISTS "${METIS_DIR}" )
    find_library(METIS_LIBRARY
            NAMES ${metis_lib_names}
            HINTS ${METIS_DIR}
            PATH_SUFFIXES ${metis_lib_suffixes}
            NO_DEFAULT_PATH)
else()
    message(SEND_ERROR "METIS_DIR=${METIS_DIR} does not exist")
    set(METISLIBRARY "METIS_LIBRARY-NOTFOUND")
    endif()   
else()
    find_library(METIS_LIBRARY
            NAMES ${metis_lib_names}
            PATH_SUFFIXES ${metis_lib_suffixes})
    endif()
    endif()
if ( NOT METIS_LIBRARY )
    message(SEND_ERROR "Can not locate METIS library")
endif()   

# Define prerequisite packages
set(METIS_INCLUDE_DIRS ${METIS_INCLUDE_DIR})
set(METIS_LIBRARIES    ${METIS_LIBRARY})

endif(METIS_LIBRARIES AND METIS_INCLUDE_DIRS )   
# Send useful message if everything is found
    find_package_handle_standard_args(METIS DEFAULT_MSG
            METIS_LIBRARIES
            METIS_INCLUDE_DIRS)
# find_package_handle_standard_args should set METIS_FOUND but it does not!
    if ( METIS_LIBRARIES AND METIS_INCLUDE_DIRS)
    set(METIS_FOUND TRUE)
    else()
    set(METIS_FOUND FALSE)
endif()
# Define the version
mark_as_advanced(
        METIS_INCLUDE_DIR
        METIS_INCLUDE_DIRS
        METIS_LIBRARY
        METIS_LIBRARIES
        METIS_LIBRARY_DIR
        )