import datetime
import os
import time

from django.contrib.auth.decorators import login_required, permission_required
from django.http import FileResponse
from django.shortcuts import render, redirect
from django.utils import timezone

from .models import Menu
from .settings import BASE_DIR
from .forms import MenuUploadForm
from aleksis.core.util import messages
from django.utils.translation import gettext_lazy as _


@login_required
@permission_required("mensa.add_menu")
def upload(request):
    if request.method == 'POST':
        form = MenuUploadForm(request.POST, request.FILES)
        if form.is_valid():
            form.save()

            messages.success(request, _("The menu was uploaded successfully."))
            return redirect('menu_index')
    else:
        form = MenuUploadForm()
    return render(request, 'mensa/upload.html', {
        'form': form
    })


@login_required
@permission_required("mensa.add_menu")
def delete(request, id):
    Menu.objects.get(id=id).delete()

    messages.success(request, _("The menu was deleted successfully."))
    return redirect("menu_index")


@login_required
@permission_required("menu.add_menu")
def index(request):
    menus = Menu.objects.all().order_by("calendar_week", "year")
    return render(request, 'mensa/index.html', {"menus": menus})


def return_pdf(filename):
    """Read and response a PDF file"""

    file = open(filename, "rb")
    return FileResponse(file, content_type="application/pdf")


def return_default_pdf():
    """Response the default PDF"""

    return return_pdf(os.path.join(BASE_DIR, "default.pdf"))


def show_current(request):
    # Get current date with year and calendar week
    current_date = timezone.datetime.now()
    year, calendar_week = current_date.isocalendar()[:2]

    # Calculate the number of days to next friday
    days_to_add = 5 - current_date.isoweekday()
    if days_to_add < 0:
        days_to_add = days_to_add + 7

    if days_to_add == 6 or days_to_add == 7:
        calendar_week += 1

    # Create datetime with next friday and time 14:10
    friday = current_date + datetime.timedelta(days=days_to_add)
    friday_14_10 = timezone.datetime(friday.year, friday.month, friday.day, 14, 10)

    # Check whether to show the plan of the next week or the current week
    if current_date > friday_14_10:
        calendar_week += 1

    # Look for matching PDF in DB
    try:
        obj = Menu.objects.get(year=year, calendar_week=calendar_week)
        return return_pdf(os.path.join(settings.MEDIA_ROOT, str(obj.pdf)))

    # Or show the default PDF
    except Menu.DoesNotExist:
        return return_default_pdf()