require.py

from __future__ import absolute_import, print_function, unicode_literals

from functools import wraps

from wolframclient.utils.api import pip


def installed_modules():
    return {i.key: i.version for i in pip.get_installed_distributions()}


def missing_requirements(*modules):

    distributions = installed_modules()

    for module in modules:
        version = None
        if isinstance(module, (tuple, list)):
            module, version = module

        if not module in distributions or version and not distributions[module] == version:
            yield version and "%s==%s" % (module, version) or module


def require_module(*modules):

    commands = list(missing_requirements(*modules))

    if commands:

        print("Update in progress: pip install %s --user" % " ".join(commands))

        if pip.running_under_virtualenv():
            pip.main(["install"] + commands)
        else:
            pip.main(["install", "--user"] + commands)


def require(*modules):
    def outer(func):
        @wraps(func)
        def inner(*args, **kw):
            require_module(*modules)
            return func(*args, **kw)

        return inner

    return outer