import time
from datetime import datetime, timedelta
import uuid
from urllib import parse

from django.views.generic import View
from django.http import HttpResponse, JsonResponse
from django.http.request import validate_host, split_domain_port
from django.conf import settings
from django.utils.decorators import method_decorator
from django.views.decorators.cache import never_cache

from pingcap_sso.user_behavior_track import report_event
from pingcap_sso.utils.requests import get_client_agent, get_client_ip
from pingcap_sso.user_behavior_track.models import TrackEvent


class EventView(View):

    TRACK_ID_COOKIE_NAME = '_track_id'
    TRACK_USER_OPENID_COOKIE_NAME = 'uid'
    TRACK_EVENTS = {
        'pageview': '访问了页面',
        'event': '触发自定义事件'
    }

    def dispatch(self, request, *args, **kwargs):
        origin = request.META.get('HTTP_ORIGIN')
        host = None
        if origin:
            host = parse.urlparse(origin).hostname
        else:
            host = request.get_host()

        # host is not exist in header if user visit page at file:///index.html
        if not host:
            return JsonResponse({'detail': 'invalid host'}, status=400)

        if not validate_host(
                split_domain_port(host)[0],
                settings.TRUSTED_HOSTS):
            return JsonResponse({'detail': 'invalid host'}, status=400)

        track_id = request.COOKIES.get(self.TRACK_ID_COOKIE_NAME) or self._generate_tack_id()

        uid = None
        cookie_uid = request.COOKIES.get(self.TRACK_USER_OPENID_COOKIE_NAME)
        query_uid = request.GET.get('uid')

        if request.user.is_authenticated:
            uid = request.user.openid
        elif cookie_uid:
            uid = cookie_uid
        else:
            uid = query_uid

        response = super(EventView, self).dispatch(
            request, host, track_id, uid, *args, **kwargs)
        response.set_cookie(
            self.TRACK_ID_COOKIE_NAME,
            track_id,
            expires=datetime.utcnow() + timedelta(days=730),
            domain=settings.SESSION_COOKIE_DOMAIN
        )
        return response

    @method_decorator(never_cache)
    def get(self, request, host, track_id, uid, *args, **kwargs):
        data = request.GET
        dl = data.get('dl')  # document.location.href
        dr = data.get('dr')  # document.referrer
        dt = data.get('dt')  # document.title
        ts = data.get('ts')  # 客户端时间戳
        ul = data.get('ul')  # navigator.language
        sr = data.get('sr')  # 屏幕宽度
        version = data.get('v')  # 事件版本号
        event = data.get('e')  # 事件类型

        if not dl:
            return JsonResponse({'detail': 'invalid payload'}, status=400)

        if event not in self.TRACK_EVENTS:
            return JsonResponse({'detail': 'invalid events'}, status=400)

        _url_parse = parse.urlparse(dl)
        pure_url = '{}://{}{}'.format(_url_parse.scheme, _url_parse.netloc, _url_parse.path)
        utm = dict(parse.parse_qsl(_url_parse.query))
        utm_source = utm.get('utm_source')
        utm_medium = utm.get('utm_medium')
        utm_campaign = utm.get('utm_campaign')

        event_desc = self.TRACK_EVENTS[event]

        if event == 'pageview':
            if host == 'docs.pingcap.com':
                event_desc = '浏览了文档'
            elif host == 'forms.pingcap.com':
                event_desc = '打开了表单'

        description = '{event} [{title}]({url})'.format(
            event=event_desc, title=dt, url=dl)

        event_type = 'site.{}.{}'.format(
            host.replace('.', '#'),
            event
        )

        event_body = {
            'dl': dl,
            'dr': dr,
            'ts': ts,
            'ul': ul,
            'dt': dt,
            'sr': sr,
            'e': event,
            'v': version,
            'pure_url': pure_url
        }

        report_event(
            openid=uid,
            event_type=event_type,
            event_body=event_body,
            track_id=track_id,
            user_agent=get_client_agent(request),
            ip=get_client_ip(request),
            pure_url=pure_url[:255],
            utm_source=utm_source[:64] if utm_source else None,
            utm_medium=utm_medium[:64] if utm_medium else None,
            utm_campaign=utm_campaign[:64] if utm_campaign else None,
            description=description,
            source=TrackEvent.SOURCE_BROWSER
        )

        return HttpResponse()

    def _generate_tack_id(self):
        return '{}.{}'.format(uuid.uuid1(), int(time.time()))