from datetime import datetime, timedelta
import re

from django.utils.deprecation import MiddlewareMixin
from django.conf import settings
from .models import User


class ReferrerMiddleware(MiddlewareMixin):
    def process_request(self, request):
        if "ref" in request.GET:
            id = request.GET["ref"]
        elif "referrer" in request.COOKIES:
            id = request.COOKIES["referrer"]
        else:
            return

        try:
            id = int(id.strip())
        except (ValueError, TypeError):
            return

        try:
            u = User.objects.get(id=id)
        except User.DoesNotExist:
            return

        request.session["referrer"] = u.id

    def process_response(self, request, response):
        id = request.session.get("referrer")
        if not id:
            return response

        max_age = 365 * 24 * 60 * 60
        expires = datetime.utcnow() + timedelta(seconds=max_age)
        expires = expires.strftime("%a, %d-%b-%Y %H:%M:%S GMT")
        response.set_cookie(
            "referrer",
            id,
            max_age=max_age,
            expires=expires,
            domain=settings.SESSION_COOKIE_DOMAIN,
            secure=settings.SESSION_COOKIE_SECURE or None,
        )
        return response


class CampaignMiddleware(MiddlewareMixin):
    GET_FIELDS = ["pk_campaign", "utm_campaign", "utm_medium", "utm_source"]

    def _get_name(self, request):
        for f in self.GET_FIELDS:
            if f in request.GET and request.GET[f]:
                return request.GET[f]
        if "campaign" in request.COOKIES:
            return request.COOKIES["campaign"]
        return None

    def process_request(self, request):
        name = self._get_name(request)
        if not name:
            return

        name = name.strip()

        if len(name) >= 64 or not re.match("^[a-zA-Z0-9_.:-]+$", name):
            return

        request.session["campaign"] = name

    def process_response(self, request, response):
        name = request.session.get("campaign")
        if not name:
            return response

        max_age = 365 * 24 * 60 * 60
        expires = datetime.utcnow() + timedelta(seconds=max_age)
        expires = expires.strftime("%a, %d-%b-%Y %H:%M:%S GMT")
        response.set_cookie(
            "campaign",
            name,
            max_age=max_age,
            expires=expires,
            domain=settings.SESSION_COOKIE_DOMAIN,
            secure=settings.SESSION_COOKIE_SECURE or None,
        )
        return response