#  Episodes.Community - Community-Driven TV Show Episode Link Sharing Site
#  Copyright (C) 2017  Evert "Diamond" Prants <evert@lunasqu.ee>, Taizo "Tsa6" Simpson <taizo@tsa6.net>
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Affero General Public License as
#  published by the Free Software Foundation, either version 3 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Affero General Public License for more details.
#
#  You should have received a copy of the GNU Affero General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.

from django.shortcuts import render
from django.views import View
from django.views.generic.base import TemplateView
from django.contrib.auth import login as auth_login, authenticate
from django.conf import settings
from django.http import HttpResponse
from django.http import HttpResponseRedirect
from django.db.models import Max, F
from django.contrib.auth.views import logout
import requests
import hashlib
import json
from .models import User
from .models import Show
from .models import Submission
from .models import DiscussionBoard

# Redirect url should point to this view
class LoginRedirect(View):
    def get(self, req):
        
        # Check request has correct arguments
        request_valid = 'state' in req.GET and 'code' in req.GET
        if not request_valid:
            r = HttpResponse('<h1>Error</h1><p>There was an error in your request.  Please <a href=/login>try again</a></p>')
            r.status = 400
            return r

        # Check state
        userstate = generateState(req)
        if userstate == req.GET['state']:
            code = req.GET['code']

            user = authenticate(code=code)

            if user is not None and user.is_active:
                auth_login(req, user)

                return HttpResponseRedirect('/')

            return HttpResponse('<h1>Error</h1><br><p>It looks like something went wrong while trying to authenticate you. Please try again later.</p>', status=500)
        
        return HttpResponse('<h1>Unmatching state tokens</h1><br><p>It looks like the request to login wasn\'t started by you.  Try going back to the home page and logging in again.</p>', status=400)

class Login(View):
    def get(self, req):
        url = '%sauthorize?response_type=code&client_id=%s&redirect_uri=%s&scope=email privilege&state=%s'%(settings.AUTH_TOKEN_ENDPOINT,settings.AUTH_CLIENT_ID,settings.AUTH_REDIRECT_URL, generateState(req))
        response = HttpResponse("Redirecting you to the IcyNet auth page...")
        response.status_code = 302
        response['Location'] = url
        return response

def LogoutView(request):
    logout(request)
    return HttpResponseRedirect('/')

def generateState(request):
    request.session.save()

    m = hashlib.sha256()
    m.update(bytearray(request.session.session_key, 'utf-8'))
    m.update(bytearray(settings.SECRET_KEY, 'utf-8'))
    return m.hexdigest()

class LandingPage(TemplateView):

    template_name = "landing_page.html"

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data()
        ctx['recent'] = Show.objects.annotate(recency=Max('episodes__airdate')).order_by('-recency')[:8]
        ctx['stats'] = {
            'shows': Show.objects.count(),
            'episodes': Submission.objects.count(),
            'boards': DiscussionBoard.objects.count()
        }
        return ctx

class Shows(TemplateView):
    template_name = "shows.html"

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data()
        ctx['shows'] = Show.objects.all()
        return ctx