from django import forms
from django.core.urlresolvers import reverse
from django.forms import ValidationError
from django.shortcuts import redirect
from django.template import RequestContext
from django.utils.translation import ugettext as _
from misago.acl.exceptions import ACLError403, ACLError404
from misago.apps.errors import error403, error404
from misago.forms import Form, FormFields
from misago.models import Forum, Thread, Post
from misago.readstrackers import ForumsTracker

class ThreadsListBaseView(object):
    def _fetch_forum(self):
        self.fetch_forum()
        self.proxy = Forum.objects.parents_aware_forum(self.forum)
        self.request.acl.forums.allow_forum_view(self.forum)
        if self.forum.level:
            self.parents = Forum.objects.forum_parents(self.forum.pk)
        if self.forum.lft + 1 != self.forum.rght:
            self.forum.subforums = Forum.objects.treelist(self.request.acl.forums, self.forum, tracker=ForumsTracker(self.request.user))

    def threads_actions(self):
        pass

    def make_form(self):
        self.form = None
        list_choices = self.threads_actions();
        if (not self.request.user.is_authenticated()
            or not list_choices):
            return

        form_fields = {}
        form_fields['list_action'] = forms.ChoiceField(choices=list_choices)
        list_choices = []
        for item in self.threads:
            if item.forum_id == self.forum.pk:
                list_choices.append((item.pk, None))
        if not list_choices:
            return

        form_fields['list_items'] = forms.MultipleChoiceField(choices=list_choices, widget=forms.CheckboxSelectMultiple)
        self.form = type('ThreadsViewForm', (Form,), form_fields)

    def handle_form(self):
        if self.request.method == 'POST':
            self.form = self.form(self.request.POST, request=self.request)
            if self.form.is_valid():
                checked_items = []
                posts = []
                for thread in self.threads:
                    if str(thread.pk) in self.form.cleaned_data['list_items'] and thread.forum_id == self.forum.pk:
                        posts.append(thread.start_post_id)
                        if thread.start_post_id != thread.last_post_id:
                            posts.append(thread.last_post_id)
                        checked_items.append(thread.pk)
                if checked_items:
                    if posts:
                        for post in Post.objects.filter(id__in=posts).prefetch_related('user'):
                            for thread in self.threads:
                                if thread.start_post_id == post.pk:
                                    thread.start_post = post
                                if thread.last_post_id == post.pk:
                                    thread.last_post = post
                                if thread.start_post_id == post.pk or thread.last_post_id == post.pk:
                                    break
                    form_action = getattr(self, 'action_' + self.form.cleaned_data['list_action'])
                    try:
                        response = form_action(checked_items)
                        if response:
                            return response
                        return redirect(self.request.path)
                    except forms.ValidationError as e:
                        self.message = Message(e.messages[0], 'error')
                else:
                    self.message = Message(_("You have to select at least one thread."), 'error')
            else:
                if 'list_action' in self.form.errors:
                    self.message = Message(_("Action requested is incorrect."), 'error')
                else:
                    self.message = Message(form.non_field_errors()[0], 'error')
        else:
            self.form = self.form(request=self.request)

    def __new__(cls, request, **kwargs):
        obj = super(ThreadsListBaseView, cls).__new__(cls)
        return obj(request, **kwargs)

    def __call__(self, request, **kwargs):
        self.request = request
        self.kwargs = kwargs
        self.pagination = {}
        self.parents = []
        self.threads = []
        self.message = request.messages.get_message('threads')
        try:
            self._fetch_forum()
            self.fetch_threads()
            self.form = None
            self.make_form()
            if self.form:
                response = self.handle_form()
                if response:
                    return response
        except Forum.DoesNotExist:
            return error404(request)
        except ACLError403 as e:
            return error403(request, unicode(e))
        except ACLError404 as e:
            return error404(request, unicode(e))

        # Merge proxy into forum
        self.forum.closed = self.proxy.closed

        return request.theme.render_to_response(('%s/list.html' % self.templates_prefix),
                                                {
                                                 'message': self.message,
                                                 'forum': self.forum,
                                                 'parents': self.parents,
                                                 'count': self.count,
                                                 'list_form': FormFields(self.form).fields if self.form else None,
                                                 'threads': self.threads,
                                                 'pagination': self.pagination,
                                                 },
                                                context_instance=RequestContext(request));