#------------------------------------------------------------------------------#
# Filename:    importer.py                                                     #
# Created:     06/20/2015                                                      #
# Author:      Boštjan Mejak                                                   #
# E-mail:      bostjan.xperia@gmail.com                                        #
# License:     GPLv3                                                           #
#------------------------------------------------------------------------------#

"""
The importer module exposes a function named tryToImport() which takes two
keyword arguments, module and namespace. The module argument must be passed with
a module name as a string, and the namespace argument must always be passed with
globals() as a value.

If the import fails for any reason, an error message box is shown to the user.
"""

import importlib


def tryToImport(module, namespace):
    """
    Show a message box if a user-given module can't be imported.

    The function tryToImport() takes two arguments, module and namespace. When
    calling this function, the module argument must be passed as a string and
    the namespace argument must be passed with globals() as a value.
    """

    try:
        moduleObject = importlib.import_module(module)
        namespace[module] = moduleObject

    except ImportError as module:
        import ctypes
        import sys

        PARENT = None
        MESSAGE = u"{importedModule} is missing.".format(importedModule=module.name)
        CAPTION = u"Application Error"
        STYLE = 0 | 16  # An error message box with an OK button

        ctypes.windll.user32.MessageBoxW(PARENT,
                                         MESSAGE,
                                         CAPTION,
                                         STYLE)

        sys.exit("Not all library dependencies were met.")