from importlib import import_module

from django.utils import timezone

from misago.conf import settings
from misago.core import forms

from misago.threads.models import Prefix


START = 0
REPLY = 1
EDIT = 2


class EditorFormset(object):
    """
    This is gigantozaurus that handles entire posting process

    * It stores context in which we are acting
    * It inits forms for posting view
    *
    """
    def __init__(self, **kwargs):
        self.errors = []

        self._forms_list = []
        self._forms_dict = {}

        self.kwargs = kwargs
        self.__dict__.update(kwargs)

        self.datetime = timezone.now()

        self.middlewares = []
        self._load_middlewares()

    @property
    def start_form(self):
        return self.mode == START

    @property
    def reply_form(self):
        return self.mode == REPLY

    @property
    def edit_form(self):
        return self.mode == EDIT

    def _load_middlewares(self):
        kwargs = self.kwargs.copy()
        kwargs['datetime'] = self.datetime

        for middleware in settings.MISAGO_POSTING_MIDDLEWARE:
            module_name = '.'.join(middleware.split('.')[:-1])
            class_name = middleware.split('.')[-1]

            middleware_module = import_module(module_name)
            middleware_class = getattr(middleware_module, class_name)

            middleware_obj = middleware_class(prefix=middleware, **kwargs)
            self.middlewares.append((middleware, middleware_obj))

    def get_forms_list(self):
        """return list of forms belonging to formset"""
        if not self._forms_list:
            self._build_forms_cache()
        return self._forms_list

    def get_forms_dict(self):
        """return list of forms belonging to formset"""
        if not self._forms_dict:
            self._build_forms_cache()
        return self._forms_dict

    def _build_forms_cache(self):
        for middleware, obj in self.middlewares:
            form = obj.make_form()
            if form:
                self._forms_dict[middleware] = form
                self._forms_list.append(form)

    def get_main_forms(self):
        """return list of main forms"""
        main_forms = []
        for form in self.get_forms_list():
            try:
                if form.is_main and form.legend:
                    main_forms.append(form)
            except AttributeError:
                pass
        return main_forms

    def get_supporting_forms(self):
        """return list of supporting forms"""
        supporting_forms = []
        for form in self.get_forms_list():
            try:
                if form.is_supporting and form.legend:
                    supporting_forms.append(form)
            except AttributeError:
                pass
        return supporting_forms

    def is_valid(self):
        """validate all forms"""
        all_forms_valid = True
        for form in self.get_forms_list():
            if not form.is_valid():
                all_forms_valid = False
        return all_forms_valid

    def save(self):
        """change state"""
        forms_dict = self.get_forms_dict()
        for middleware, obj in self.middlewares:
            obj.pre_save(forms_dict.get(middleware))
        for middleware, obj in self.middlewares:
            obj.save(forms_dict.get(middleware))
        for middleware, obj in self.middlewares:
            obj.post_save(forms_dict.get(middleware))

    def update(self):
        """handle POST that shouldn't result in state change"""
        forms_dict = self.get_forms_dict()
        for middleware, obj in self.middlewares:
            obj.pre_save(forms_dict.get(middleware))


class EditorFormsetMiddleware(object):
    """
    Abstract middleware classes
    """
    def __init__(self, **kwargs):
        self.kwargs = kwargs
        self.__dict__.update(kwargs)

    def make_form(self):
        pass

    def pre_save(self, form):
        pass

    def save(self, form):
        pass

    def post_save(self, form):
        pass