import xml.etree.ElementTree as ET

import json

from django.utils import timezone
from django.utils.timezone import datetime, timedelta
from django.shortcuts import render, redirect
from django.db.models import Q
from django.utils.html import mark_safe
from django.conf import settings
from django.http import HttpResponse, Http404

from . import models
from . import tasks
from ..signalbot.rpc import send_reaction
from .utils import render_to_json
from ..utils import default_context

TS_FORMAT = "%Y-%m-%dT%H:%M:%S"


def get_now():
    return timezone.make_aware(datetime.now(), timezone.get_default_timezone())


def get_monday(date):
    d = date.strftime('%Y-W%W-1')
    return datetime.strptime(d, "%Y-W%W-%w").strftime('%Y-%m-%d')


def format_week(week):
    a = datetime.strptime(week, '%Y-%m-%d')
    b = (a + timedelta(days=6))
    fmt = '%b %d'
    a = a.strftime(fmt)
    b = b.strftime(fmt)
    extra = models.Week.objects.filter(monday=week).first()
    if extra:
        extra = ': ' + extra.title
    else:
        extra = ''
    return '%s - %s%s' % (a, b, extra)


def get_weeks(archive):
    weeks = sorted(set(archive.values_list('year', 'week')))
    weeks = [datetime.strptime('%s-W%s-1' % w, "%Y-W%W-%w").strftime('%Y-%m-%d') for w in weeks]
    weeks = [{
        'date': week,
        'year': week.split('-')[0],
        'title': format_week(week)
    } for week in weeks]
    return weeks


def index(request):
    context = default_context(request)
    now = request.GET.get("now")
    if request.user.is_staff and now:
        now = datetime.strptime(now, TS_FORMAT)
        now = timezone.make_aware(now, timezone.get_default_timezone())
    elif request.user.is_staff:
        now = get_now()
    else:
        now = None
    week, archive = models.Item.public(now)
    context['items'] = week
    if archive.exists():
        context['archive'] = '/_%s/' % get_monday(get_now() - timedelta(days=7))
    if now:
        context['now'] = now
        context['previous_week'] = (now - timedelta(days=7)).strftime(TS_FORMAT)
        context['next_week'] = (now + timedelta(days=7)).strftime(TS_FORMAT)
    return render(request, 'index.html', context)


def archive(request, year=None, month=None, day=None, week=None):
    context = default_context(request)
    _, archive = models.Item.public()
    if year and month and day:
        date = datetime.strptime('%s-%s-%s' % (year, month, day), '%Y-%m-%d')
        week = int(date.strftime('%W'))
        year = int(year)
        archive_week = archive.filter(year=year, week=week).order_by('published')
        context['weeks'] = get_weeks(archive)
        context['this_week'] = date.strftime('%Y-%m-%d')
        context['this_year'] = date.strftime('%Y')
        extra = models.Week.objects.filter(monday=context['this_week']).first()
        if extra:
            context['week_title'] = extra.title
    elif week:
        week = int(week)
        year = int(year)
        week = datetime.strptime('%s-W%s-1' % (year, week), "%Y-W%W-%w").strftime('%Y-%m-%d')
        return redirect('/_%s/' % week)
    elif year:
        week = datetime.strptime('%s-W1-1' % year, "%Y-W%W-%w").strftime('%Y-%m-%d')
        return redirect('/_%s/' % week)
    context['items'] = archive_week
    return render(request, 'archive.html', context)


def item(request, id):
    context = default_context(request)
    item = models.Item.objects.get(id=id)
    if not request.user.is_staff and (
        not item.published or item.published >= get_now()
    ):
        raise Http404
    context['item'] = item
    context['url'] = request.build_absolute_uri(item.get_absolute_url())
    qs = item.comments.order_by('created')
    if not request.user.is_staff:
        q = ~Q(published=None)
        if request.user.is_authenticated:
            q |= Q(user=request.user)
        if request.session and request.session.session_key:
            q |= Q(session_key=request.session.session_key)
        qs = qs.filter(q)
    comments = []
    for comment in qs:
        comments.append(comment.json())
    context['comments'] = mark_safe(json.dumps(comments, ensure_ascii=False))
    context['comments'] = json.dumps(comments, ensure_ascii=False)

    user = {}
    if request.user.is_staff:
        user['is_moderator'] = True
    if request.user.is_authenticated:
        user['username'] = request.user.username

    context['user'] = mark_safe(json.dumps(user))
    request.session['item'] = id
    qs = models.Item.objects.exclude(published=None).exclude(id=item.id)
    if not request.user.is_staff:
        now = get_now()
        qs = qs.filter(published__lt=now)
    previous_item = qs.exclude(published__gt=item.published).order_by('-published').first()
    next_item = qs.exclude(published__lt=item.published).order_by('published').first()
    if next_item:
        context['next'] = next_item.get_absolute_url()
    if previous_item:
        context['previous'] = previous_item.get_absolute_url()

    return render(request, 'item.html', context)


def comment(request):
    response = {}
    data = json.loads(request.body)
    comment = models.Comment()
    comment.item = models.Item.objects.get(id=data['item'])
    if request.user.is_authenticated:
        comment.user = request.user
        if comment.user.has_perm('app.item.can_post_comment'):
            comment.published = get_now()
    else:
        comment.name = data['name']
        comment.email = data['email']
        comment.session_key = request.session.session_key
    comment.text = data['text']
    comment.save()
    link = request.build_absolute_uri(comment.item.get_absolute_url())
    tasks.notify_moderators.delay(comment.id, link)
    response = comment.json()
    return render_to_json(response)


def publish_comment(request):
    response = {}
    data = json.loads(request.body)
    if request.user.is_staff:
        comment = models.Comment.objects.get(id=data['comment'])
        comment.published = get_now()
        comment.save()
        if comment.data.get("moderator_ts"):
            account = settings.SIGNAL_ACCOUNT
            group = settings.SIGNAL_MODERATORS_GROUP
            send_reaction(
                account, comment.data["moderator_ts"], "🎉", group=group
            )
            link = request.build_absolute_uri(comment.item.get_absolute_url())
            msg = '%s commented on <b>%s</b> at <a href="%s">%s</a>' % (
                comment.name, comment.item.title, link, link
            )
            tasks.notify_telegram.delay(msg)
        response['status'] = 'ok'
    else:
        response['error'] = 'permission denied'
    return render_to_json(response)


def atom_xml(request):
    feed = ET.Element("feed")
    feed.attrib['xmlns'] = 'http://www.w3.org/2005/Atom'
    feed.attrib['xmlns:media'] = 'http://search.yahoo.com/mrss/'
    feed.attrib['xml:lang'] = 'en'
    title = ET.SubElement(feed, "title")
    title.text = settings.SITENAME
    title.attrib['type'] = 'text'
    link = ET.SubElement(feed, "link")
    link.attrib['rel'] = 'self'
    link.attrib['type'] = 'application/atom+xml'
    atom_link = request.build_absolute_uri('/atom.xml')
    link.attrib['href'] = atom_link
    el = ET.SubElement(feed, 'id')
    el.text = atom_link

    week, archive = models.Item.public()
    for item in week:
        page_link = request.build_absolute_uri(item.get_absolute_url())

        entry = ET.Element("entry")
        title = ET.SubElement(entry, "title")
        title.text = item.title
        link = ET.SubElement(entry, "link")
        link.attrib['rel'] = 'alternate'
        link.attrib['href'] = page_link
        updated = ET.SubElement(entry, "updated")
        updated.text = item.modified.strftime("%Y-%m-%dT%H:%M:%SZ")
        published = ET.SubElement(entry, "published")
        published.text = item.created.strftime("%Y-%m-%dT%H:%M:%SZ")
        el = ET.SubElement(entry, "id")
        el.text = page_link
        print(item.data)
        if 'title' in item.data and 'thumbnail' in item.data:
            html = f'''
                <p>
                    {item.data['title']}
                </p>
                <img src={ item.data['thumbnail'] }>
        '''.strip()
        content = ET.SubElement(entry, "content")
        content.attrib['type'] = 'html'
        content.text = html
        feed.append(entry)
    return HttpResponse(
        '<?xml version="1.0" encoding="utf-8" ?>\n' + ET.tostring(feed).decode(),
        'application/atom+xml'
    )