mrDoctorWho/vk4xmpp

# coding: utf-8
# This file is a part of VK4XMPP transport
# © simpleApps, 2015.

"""
Manages python modules as xmpppy handlers
"""

__author__ = "mrDoctorWho <mrdoctorwho@gmail.com>"
__version__ = "1.1"

import os
from writer import *
from __main__ import Component, TransportFeatures, UserFeatures


def proxy(func):
    def wrapper(type, *args):
        if type:
            for (handler, typ, ns, makefirst) in args:
                if isinstance(ns, list):
                    while ns:
                        func(type, handler, typ, ns.pop(), makefirst=makefirst)
                else:
                    func(type, handler, typ, ns, makefirst=makefirst)
    return wrapper


@proxy
def register(*args, **kwargs):
    Component.RegisterHandler(*args, **kwargs)


@proxy
def unregister(*args, **kwargs):
    Component.UnregisterHandler(*args)


def addFeatures(features, list=TransportFeatures):
    for feature in features:
        list.add(feature)


def removeFeatures(features, list=TransportFeatures):
    for feature in features:
        if feature in list:
            list.remove(feature)


class ModuleManager(object):

    """
    A complete module manager.
    You can easy load, reload and unload any module using it.
    Modules are different from extensions:
    While extensions works in main globals() and have their callbacks,
    modules works in their own globals() and they're not affect to the core.
    Unfortunately, most of modules are not protected from harm
        so they may have affect on the connection
    """

    loaded = set([])

    @staticmethod
    def getFeatures(module):
        return getattr(module, "MOD_FEATURES_USER", [])

    @classmethod
    def __register(cls, module):
        register(module.MOD_TYPE, *module.MOD_HANDLERS)
        addFeatures(module.MOD_FEATURES)
        addFeatures(cls.getFeatures(module), UserFeatures)
        cls.loaded.add(module.__name__)

    @classmethod
    def __unregister(cls, module):
        unregister(module.MOD_TYPE, *module.MOD_HANDLERS)
        removeFeatures(module.MOD_FEATURES)
        removeFeatures(cls.getFeatures(module), UserFeatures)
        cls.loaded.remove(module.__name__)

    @classmethod
    def list(cls):
        modules = []
        for file in os.listdir("modules"):
            name, ext = os.path.splitext(file)
            if ext == ".py":
                modules.append(name)
        return modules

    @classmethod
    def __load(cls, name, reload_=False):
        try:
            if reload_:
                module = sys.modules[name]
                cls.__unregister(module)
                module = reload(module)
            else:
                module = __import__(name, globals(), locals())
        except Exception:
            crashLog("modulemanager.load")
            module = None
        return module

    @classmethod
    def load(cls, list=[]):
        result = []
        errors = []
        for name in list:
            loaded = name in cls.loaded
            module = cls.__load(name, loaded)
            if not module:
                errors.append(name)
                continue

            result.append(name)
            cls.__register(module)
        return (result, errors)

    @classmethod
    def unload(cls, list=[]):
        result = []
        for name in list:
            if name in sys.modules:
                cls.__unregister(sys.modules[name])
                del sys.modules[name]
                result.append(name)
        return result