# Copyright (C) 2021 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

import os
import zipfile
from io import BytesIO

from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.mail import mail_managers
from django.http import HttpResponse
from django.urls import reverse_lazy
from django.views.generic.detail import DetailView
from django.views.generic.edit import FormView
from photologue.models import Gallery
from photologue.views import GalleryArchiveIndexView, GalleryYearArchiveView
from taggit.models import Tag

from .forms import UploadForm


class TagDetail(LoginRequiredMixin, DetailView):
    model = Tag

    def get_context_data(self, **kwargs):
        """
        Insert the single object into the context dict.
        """
        current_tag = self.get_object().slug
        context = super().get_context_data(**kwargs)
        context['galleries'] = Gallery.objects.on_site().is_public() \
            .filter(extended__tags__slug=current_tag) \
            .order_by('-extended__date_start')
        return context


class CustomGalleryArchiveIndexView(GalleryArchiveIndexView):
    """
    Override to use event date
    """
    date_field = 'extended__date_start'
    uses_datetime_field = False  # Fix related object access


class CustomGalleryYearArchiveView(GalleryYearArchiveView):
    """
    Override to use event date
    """
    date_field = 'extended__date_start'
    uses_datetime_field = False  # Fix related object access


class CustomGalleryDetailView(DetailView):
    """
    Custom gallery detail view to filter on photo owner
    """
    queryset = Gallery.objects.on_site().is_public()

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)

        # Query with extended and owner to reduce database lag
        context['photos'] = self.object.public().select_related('extended__owner')

        # List owners
        context['owners'] = []
        for photo in context['photos']:
            if hasattr(photo, 'extended') and photo.extended.owner not in context['owners']:
                context['owners'].append(photo.extended.owner)

        # Filter on owner
        if 'owner' in self.kwargs:
            context['photos'] = context['photos'].filter(extended__owner__id=self.kwargs['owner'])

        return context


class GalleryDownload(LoginRequiredMixin, DetailView):
    model = Gallery

    def get(self, request, *args, **kwargs):
        """
        Download a zip file of the gallery on GET request.
        """
        # Create zip file with pictures
        gallery = self.get_object()
        byte_data = BytesIO()
        zip_file = zipfile.ZipFile(byte_data, "w")
        for photo in gallery.public():
            filename = os.path.basename(os.path.normpath(photo.image.path))
            zip_file.write(photo.image.path, filename)
        zip_file.close()

        # Return zip file
        response = HttpResponse(byte_data.getvalue(), content_type='application/x-zip-compressed')
        response['Content-Disposition'] = f"attachment; filename={gallery.slug}.zip"
        return response


class GalleryUpload(FormView):
    """
    Form to upload new photos in a gallery
    """
    form_class = UploadForm
    template_name = "photologue/upload.html"
    success_url = reverse_lazy("gallery-upload")

    def form_valid(self, form):
        # Upload photos
        # We take files from the request to support multiple upload
        files = self.request.FILES.getlist('file_field')
        form.save(self.request.user, files)

        # Notify user then managers
        messages.success(self.request, "Photos has been successfully uploaded.")
        gallery_title = form.cleaned_data['gallery'] or form.cleaned_data.get('new_gallery_title', '')
        photos = ", ".join(f.name for f in files)
        mail_managers(
            subject="New photos upload",
            message=f"{self.request.user.username} has uploaded in `{gallery_title}`: {photos}",
        )

        return super().form_valid(form)