from django.http import HttpResponse

from openslides.config.api import config
from openslides.projector.api import get_active_slide
from openslides.utils.tornado_webserver import ProjectorSocketHandler
from openslides.utils.views import (AjaxView, CreateView, DeleteView, RedirectView, ListView,
                                    UpdateView)

from .forms import MediafileManagerForm, MediafileNormalUserForm
from .models import Mediafile


class MediafileListView(ListView):
    """
    View to see a table of all uploaded files.
    """
    model = Mediafile

    def check_permission(self, request, *args, **kwargs):
        return (request.user.has_perm('mediafile.can_see') or
                request.user.has_perm('mediafile.can_upload') or
                request.user.has_perm('mediafile.can_manage'))

    def get_context_data(self, *args, **kwargs):
        context = super(MediafileListView, self).get_context_data(*args, **kwargs)
        for mediafile in context['mediafile_list']:
            if self.request.user.has_perm('mediafile.can_manage'):
                mediafile.with_action_buttons = True
            elif self.request.user.has_perm('mediafile.can_upload') and self.request.user == mediafile.uploader:
                mediafile.with_action_buttons = True
            else:
                mediafile.with_action_buttons = False
        return context


class MediafileViewMixin(object):
    """
    Mixin for create and update views for mediafiles.

    A manager can set the uploader manually, else the request user is set as uploader.
    """
    model = Mediafile
    success_url_name = 'mediafile_list'
    url_name_args = []

    def get_form(self, form_class):
        form_kwargs = self.get_form_kwargs()
        if not self.request.user.has_perm('mediafile.can_manage'):
            return MediafileNormalUserForm(**form_kwargs)
        else:
            return MediafileManagerForm(**form_kwargs)

    def manipulate_object(self, *args, **kwargs):
        """
        Method to handle the uploader. If a user has manager permissions,
        he has to set the uploader in the given form field. Then this
        method only calls super. Else it sets the requesting user as uploader.
        """
        if not self.request.user.has_perm('mediafile.can_manage'):
            self.object.uploader = self.request.user
        return super(MediafileViewMixin, self).manipulate_object(*args, **kwargs)


class MediafileCreateView(MediafileViewMixin, CreateView):
    """
    View to upload a new file.
    """
    required_permission = 'mediafile.can_upload'

    def get_form_kwargs(self, *args, **kwargs):
        form_kwargs = super(MediafileCreateView, self).get_form_kwargs(*args, **kwargs)
        if self.request.method == 'GET':
            form_kwargs['initial'].update({'uploader': self.request.user})
        return form_kwargs


class MediafileUpdateView(MediafileViewMixin, UpdateView):
    """
    View to edit the entry of an uploaded file.
    """
    def check_permission(self, request, *args, **kwargs):
        return (request.user.has_perm('mediafile.can_manage') or
                (request.user.has_perm('mediafile.can_upload') and
                 self.get_object().uploader == self.request.user))

    def get_form_kwargs(self, *args, **kwargs):
        form_kwargs = super(MediafileUpdateView, self).get_form_kwargs(*args, **kwargs)
        form_kwargs['initial'].update({'uploader': self.get_object().uploader.pk})
        return form_kwargs


class MediafileDeleteView(DeleteView):
    """
    View to delete the entry of an uploaded file and the file itself.
    """
    model = Mediafile
    success_url_name = 'mediafile_list'

    def check_permission(self, request, *args, **kwargs):
        return (request.user.has_perm('mediafile.can_manage') or
                (request.user.has_perm('mediafile.can_upload') and self.get_object().uploader == self.request.user))

    def on_clicked_yes(self, *args, **kwargs):
        """Deletes the file in the filesystem, if user clicks "Yes"."""
        self.get_object().mediafile.delete()
        return super(MediafileDeleteView, self).on_clicked_yes(*args, **kwargs)


class PdfNavBaseView(AjaxView):
    """
    BaseView for the Pdf Ajax Navigation.
    """

    def get_ajax_context(self, *args, **kwargs):
        return {'current_page': self.active_slide['page_num']}

    def load_other_page(self, active_slide):
        """
        Tell connected clients to load an other pdf page.
        """
        config['projector_active_slide'] = active_slide
        ProjectorSocketHandler.send_updates(
            {'calls': {'load_pdf_page': active_slide['page_num']}})


class PdfNextView(PdfNavBaseView):
    """
    Activate the next Page of a pdf and return the number of the current page.
    """

    def get(self, request, *args, **kwargs):
        """
        Increment the page number by 1.

        If the page number is set in the active slide, we are the value is
        incremented by 1. Otherwise, it is the first page and it is set to 2.
        """
        self.active_slide = get_active_slide()
        if self.active_slide['callback'] == 'mediafile':
            if 'page_num' not in self.active_slide:
                self.active_slide['page_num'] = 2
            else:
                self.active_slide['page_num'] += 1
            self.load_other_page(self.active_slide)
            response = super(PdfNextView, self).get(self, request, *args, **kwargs)
        else:
            # no Mediafile is active and the JavaScript should not do anything.
            response = HttpResponse()
        return response


class PdfPreviousView(PdfNavBaseView):
    """
    Activate the previous Page of a pdf and return the number of the current page.
    """

    def get(self, request, *args, **kwargs):
        """
        Decrement the page number by 1.

        If the page number is set and it is greater than 1, it is decremented
        by 1. Otherwise, it is the first page and nothing happens.
        """
        self.active_slide = get_active_slide()
        response = None
        if self.active_slide['callback'] == 'mediafile':
            if 'page_num' in self.active_slide and self.active_slide['page_num'] > 1:
                self.active_slide['page_num'] -= 1
                self.load_other_page(self.active_slide)
                response = super(PdfPreviousView, self).get(self, request, *args, **kwargs)
        if not response:
            response = HttpResponse()
        return response


class PdfGoToPageView(PdfNavBaseView):
    """
    Activate the page set in the textfield.
    """

    def get(self, request, *args, **kwargs):
        target_page = int(request.GET.get('page_num'))
        self.active_slide = get_active_slide()
        if target_page:
            self.active_slide['page_num'] = target_page
            self.load_other_page(self.active_slide)
            response = super(PdfGoToPageView, self).get(self, request, *args, **kwargs)
        else:
            response = HttpResponse()
        return response


class PdfToggleFullscreenView(RedirectView):
    """
    Toggle fullscreen mode for pdf presentations.
    """
    allow_ajax = True
    url_name = 'core_dashboard'

    def get_ajax_context(self, *args, **kwargs):
        config['pdf_fullscreen'] = not config['pdf_fullscreen']
        active_slide = get_active_slide()
        if active_slide['callback'] == 'mediafile':
            ProjectorSocketHandler.send_updates(
                {'calls': {'toggle_fullscreen': config['pdf_fullscreen']}})
        return {'fullscreen': config['pdf_fullscreen']}