#
# Cython
#

# This finds the "cython" executable in your PATH, and then in some standard
# paths:
FIND_FILE(CYTHON_BIN cython /usr/bin /usr/local/bin)
SET(CYTHON_FLAGS --cplus --fast-fail)

SET(Cython_FOUND FALSE)
IF (CYTHON_BIN)
    # Try to run Cython, to make sure it works:
    execute_process(
        COMMAND ${CYTHON_BIN} ${CYTHON_FLAGS} ${CMAKE_MODULE_PATH}/cython_test.pyx
        RESULT_VARIABLE CYTHON_RESULT
        OUTPUT_QUIET
        ERROR_QUIET
        )
    if (CYTHON_RESULT EQUAL 0)
        # Only if cython exits with the return code 0, we know that all is ok:
        SET(Cython_FOUND TRUE)
        SET(Cython_Compilation_Failed FALSE)
    else (CYTHON_RESULT EQUAL 0)
        SET(Cython_Compilation_Failed TRUE)
    endif (CYTHON_RESULT EQUAL 0)
ENDIF (CYTHON_BIN)


IF (Cython_FOUND)
        IF (NOT Cython_FIND_QUIETLY)
                MESSAGE(STATUS "Found CYTHON: ${CYTHON_BIN}")
        ENDIF (NOT Cython_FIND_QUIETLY)
ELSE (Cython_FOUND)
        IF (Cython_FIND_REQUIRED)
        if(Cython_Compilation_Failed)
            MESSAGE(STATUS "Found CYTHON: ${CYTHON_BIN}")
        else(Cython_Compilation_Failed)
            MESSAGE(FATAL_ERROR "Could not find Cython. Please install Cython.")
        endif(Cython_Compilation_Failed)
        ENDIF (Cython_FIND_REQUIRED)
ENDIF (Cython_FOUND)


# This allows to link Cython files
# Examples:
# 1) to compile assembly.pyx to assembly.so:
#   CYTHON_ADD_MODULE(assembly)
# 2) to compile assembly.pyx and something.cpp to assembly.so:
#   CYTHON_ADD_MODULE(assembly something.cpp)

# Cythonizes the .pyx files into .cpp file (but doesn't compile it)
macro(CYTHON_ADD_MODULE_PYX name)
  set(depends ${name}.pyx)
  if(CYTHON_INCLUDE_DIRECTORIES)
    foreach(dir ${CYTHON_INCLUDE_DIRECTORIES})
      file(GLOB pxd_srcs ${CYTHON_INCLUDE_DIRECTORIES}/*.pxd)
      list(APPEND depends ${pxd_srcs})
    endforeach()
  elseif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.pxd)
    list(APPEND depends ${CMAKE_CURRENT_SOURCE_DIR}/${name}.pxd)
    set(CYTHON_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR})
  endif()
  # Allow the user to specify dependencies as optional arguments
  list(APPEND depends ${ARGN})
  add_custom_command(
    OUTPUT ${name}.cpp
    COMMAND ${CYTHON_BIN}
    ARGS ${CYTHON_FLAGS} -I ${CYTHON_INCLUDE_DIRECTORIES} -o ${name}.cpp ${CMAKE_CURRENT_SOURCE_DIR}/${name}.pyx
    DEPENDS ${depends}
    COMMENT "Cythonizing ${name}.pyx")
endmacro(CYTHON_ADD_MODULE_PYX)

# Cythonizes and compiles a .pyx file
macro(CYTHON_ADD_MODULE name pyx)
  CYTHON_ADD_MODULE_PYX(${pyx})
  add_library(${name} MODULE ${pyx}.cpp)
  target_include_directories(${name} PRIVATE ${PYTHON_INCLUDE_PATH})
  target_link_libraries(${name} ${PYTHON_LIBRARIES})
  set_target_properties(${name} PROPERTIES
    PREFIX "${PYTHON_MODULE_PREFIX}"
    OUTPUT_NAME ${pyx})
endmacro(CYTHON_ADD_MODULE)