import inspect
import sys


def sysarg_to_string(argv):
    """
    Transform a list of strings into a single string
    Add quotes if needed
    :return:
    """
    if argv is None or not argv:
        return ""

    result = ""
    first = True
    for s in argv:
        if not first:
            result += " "

        result += '"' + s + '"' if " " in s else s
        first = False

    if result[0] in ('"', "'"):
        result = result[1:-1]  # strip quotes
    return result


def get_class(qname):
    """
    Loads a class from its full qualified name
    :param qname:
    :return:
    """
    parts = qname.split('.')
    module = ".".join(parts[:-1])
    m = __import__(module)
    for comp in parts[1:]:
        m = getattr(m, comp)
    return m

def get_module(qname):
    """
    Loads a module from its full qualified name
    :param qname:
    :return:
    """
    parts = qname.split('.')
    m = __import__(qname)
    for comp in parts[1:]:
        m = getattr(m, comp)
    return m


def new_object(kls, *args, **kwargs):
    """
    New instance of an object
    :param kls:
    :param args:
    :param kwargs:
    :return:
    """
    obj_type = get_class(kls)
    return obj_type(*args, **kwargs)


def get_full_qualified_name(obj):
    """
    Returns the full qualified name of a class (including its module name )
    :param obj:
    :return:
    """
    module = obj.__class__.__module__
    if module is None or module == str.__class__.__module__:
        return obj.__class__.__name__  # Avoid reporting __builtin__
    else:
        return module + '.' + obj.__class__.__name__


def get_classes(module_name):
    mod = get_module(module_name)
    for name in dir(mod):
        obj = getattr(mod, name)
        if inspect.isclass(obj):
            yield obj


def remove_from_list(lst, to_remove):
    """
    Removes elements from a list if they exist
    :param lst:
    :param to_remove:
    :return:
    """
    for item in to_remove:
        if item in lst:
            lst.remove(item)

    return lst