"""

Tool to run Cython files (.pyx) into .c and .cpp.

TODO:

 - Add support for dynamically selecting in-process Cython

   through CYTHONINPROCESS variable.

 - Have a CYTHONCPP option which turns on C++ in flags and

   changes output extension at the same time

VARIABLES:

 - CYTHON - The path to the "cython" command line tool.

 - CYTHONFLAGS - Flags to pass to the "cython" command line tool.

AUTHORS:

 - David Cournapeau

 - Dag Sverre Seljebotn

"""

import SCons

from SCons.Builder import Builder

from SCons.Action import Action

#def cython_action(target, source, env):

#    print target, source, env

#    from Cython.Compiler.Main import compile as cython_compile

#    res = cython_compile(str(source[0]))

cythonAction = Action("$CYTHONCOM")

def create_builder(env):

    try:

        cython = env['BUILDERS']['Cython']

    except KeyError:

        cython = SCons.Builder.Builder(

                  action = cythonAction,

                  emitter = {},

                  suffix = cython_suffix_emitter,

                  single_source = 1)

        env['BUILDERS']['Cython'] = cython

    return cython

def cython_suffix_emitter(env, source):

    return "$CYTHONCFILESUFFIX"

def generate(env):

    env["CYTHON"] = "cython"

    env["CYTHONCOM"] = "$CYTHON $CYTHONFLAGS -o $TARGET $SOURCE"

    env["CYTHONCFILESUFFIX"] = ".c"

    c_file, cxx_file = SCons.Tool.createCFileBuilders(env)

    c_file.suffix['.pyx'] = cython_suffix_emitter

    c_file.add_action('.pyx', cythonAction)

    c_file.suffix['.py'] = cython_suffix_emitter

    c_file.add_action('.py', cythonAction)

    create_builder(env)

def exists(env):

    try:

#        import Cython

        return True

    except ImportError:

        return False