from django.contrib import auth
from django.core.exceptions import MultipleObjectsReturned
from django.utils.translation import ugettext as _

from utils.api import APIView, validate_serializer
from utils.captcha import Captcha
from utils.otp_auth import OtpAuth
from ..decorators import login_required
from ..models import User, UserProfile
from ..serializers import (UserLoginSerializer, UserRegisterSerializer,
                           UserChangePasswordSerializer)


class UserLoginAPI(APIView):
    @validate_serializer(UserLoginSerializer)
    def post(self, request):
        """
        User login api
        """
        data = request.data
        user = auth.authenticate(username=data["username"], password=data["password"])
        # None is returned if username or password is wrong
        if user:
            if not user.two_factor_auth:
                auth.login(request, user)
                return self.success(_("Succeeded"))

            # `tfa_code` not in post data
            if user.two_factor_auth and "tfa_code" not in data:
                return self.success("tfa_required")

            if OtpAuth(user.tfa_token).valid_totp(data["tfa_code"]):
                auth.login(request, user)
                return self.success(_("Succeeded"))
            else:
                return self.error(_("Invalid two factor verification code"))
        else:
            return self.error(_("Invalid username or password"))

    # todo remove this, only for debug use
    def get(self, request):
        auth.login(request, auth.authenticate(username=request.GET["username"], password=request.GET["password"]))
        return self.success({})


class UserRegisterAPI(APIView):
    @validate_serializer(UserRegisterSerializer)
    def post(self, request):
        """
        User register api
        """
        data = request.data
        captcha = Captcha(request)
        if not captcha.check(data["captcha"]):
            return self.error(_("Invalid captcha"))
        try:
            User.objects.get(username=data["username"])
            return self.error(_("Username already exists"))
        except User.DoesNotExist:
            pass
        try:
            User.objects.get(email=data["email"])
            return self.error(_("Email already exists"))
        # Some old data has duplicate email
        except MultipleObjectsReturned:
            return self.error(_("Email already exists"))
        except User.DoesNotExist:
            user = User.objects.create(username=data["username"], email=data["email"])
            user.set_password(data["password"])
            user.save()
            UserProfile.objects.create(user=user)
            return self.success(_("Succeeded"))


class UserChangePasswordAPI(APIView):
    @validate_serializer(UserChangePasswordSerializer)
    @login_required
    def post(self, request):
        """
        User change password api
        """
        data = request.data
        captcha = Captcha(request)
        if not captcha.check(data["captcha"]):
            return self.error(_("Invalid captcha"))
        username = request.user.username
        user = auth.authenticate(username=username, password=data["old_password"])
        if user:
            user.set_password(data["new_password"])
            user.save()
            return self.success(_("Succeeded"))
        else:
            return self.error(_("Invalid old password"))