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# Perform Python installation discovery early and in one place, for consistency.
#
# Note: If necessary, the Python location can be hinted with Python3_ROOT_DIR
# For additional parameters affecting Python installation discovery, see
# https://cmake.org/cmake/help/latest/module/FindPython3.html#hints
if(FIND_PACKAGE_MESSAGE_DETAILS_Python3)
    # Keep quiet on subsequent runs of cmake
    set(Python3_FIND_QUIETLY ON)
    set(PythonInterp_FIND_QUIETLY ON)
endif()
# Older CMake versions might not search for Python newer than 3.7.
set(Python_ADDITIONAL_VERSIONS 3.8)
# We advocate using Python venvs to manage package availability, so by default
# we want to preferentially discover user-space software.
set(Python3_FIND_REGISTRY LAST)
# Make package discovery consistent with Unix behavior and our documented
# suggestions for installing dependencies.
set(CMAKE_FIND_FRAMEWORK LAST)
if(GMX_PYTHON_PACKAGE)
    find_package(Python3 3.6 COMPONENTS Interpreter Development)
    if (NOT Python3_FOUND OR NOT Python3_Development_FOUND)
        message(FATAL_ERROR "Could not locate Python development requirements. \
                Provide appropriate CMake hints or set GMX_PYTHON_PACKAGE=OFF")
    endif ()
else()
    find_package(Python3 3.6 COMPONENTS Interpreter)
endif()
# Other components, such as pybind and googletest, may expect the
# PYTHON_EXECUTABLE variable from pre-3.12 FindPythonInterp.cmake.
if (Python3_Interpreter_FOUND)
    set(PYTHON_EXECUTABLE ${Python3_EXECUTABLE} CACHE FILEPATH "Location hint for Python interpreter.")
endif ()
# We've already generated all of the output we need, even though other subcomponents
# may call find_package(PythonInterp) later on.
set(Python3_FIND_QUIETLY ON)
set(PythonInterp_FIND_QUIETLY ON)