from django.contrib.auth import login, logout
from django.conf import settings

from rest_framework import status
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.generics import GenericAPIView
from rest_framework.permissions import IsAuthenticated, AllowAny
from rest_framework.authentication import SessionAuthentication, \
    TokenAuthentication
from rest_framework.authtoken.models import Token
from rest_framework.generics import RetrieveUpdateAPIView

from .app_settings import (TokenSerializer, UserDetailsSerializer,
    LoginSerializer, PasswordResetSerializer, PasswordResetConfirmSerializer,
    PasswordChangeSerializer)


class LoggedInRESTAPIView(APIView):
    authentication_classes = ((SessionAuthentication, TokenAuthentication))
    permission_classes = ((IsAuthenticated,))


class LoggedOutRESTAPIView(APIView):
    permission_classes = ((AllowAny,))


class Login(LoggedOutRESTAPIView, GenericAPIView):

    """
    Check the credentials and return the REST Token
    if the credentials are valid and authenticated.
    Calls Django Auth login method to register User ID
    in Django session framework

    Accept the following POST parameters: username, password
    Return the REST Framework Token Object's key.
    """

    serializer_class = LoginSerializer
    token_model = Token
    response_serializer = TokenSerializer

    def get_serializer(self):
        return self.serializer_class(data=self.request.DATA,
            context={'request': self.request, 'view': self})

    def login(self):
        self.user = self.serializer.object['user']
        self.token, created = self.token_model.objects.get_or_create(
            user=self.user)
        if getattr(settings, 'REST_SESSION_LOGIN', True):
            login(self.request, self.user)

    def get_response(self):
        return Response(self.response_serializer(self.token).data,
            status=status.HTTP_200_OK)

    def get_error_response(self):
        return Response(self.serializer.errors,
            status=status.HTTP_400_BAD_REQUEST)

    def post(self, request, *args, **kwargs):
        self.serializer = self.get_serializer()
        if not self.serializer.is_valid():
            return self.get_error_response()
        self.login()
        return self.get_response()


class Logout(LoggedInRESTAPIView):

    """
    Calls Django logout method and delete the Token object
    assigned to the current User object.

    Accepts/Returns nothing.
    """

    def post(self, request):
        try:
            request.user.auth_token.delete()
        except:
            pass

        logout(request)

        return Response({"success": "Successfully logged out."},
                        status=status.HTTP_200_OK)


class UserDetails(LoggedInRESTAPIView, RetrieveUpdateAPIView):

    """
    Returns User's details in JSON format.

    Accepts the following GET parameters: token
    Accepts the following POST parameters:
        Required: token
        Optional: email, first_name, last_name and UserProfile fields
    Returns the updated UserProfile and/or User object.
    """
    serializer_class = UserDetailsSerializer

    def get_object(self):
        return self.request.user


class PasswordReset(LoggedOutRESTAPIView, GenericAPIView):

    """
    Calls Django Auth PasswordResetForm save method.

    Accepts the following POST parameters: email
    Returns the success/fail message.
    """

    serializer_class = PasswordResetSerializer

    def post(self, request, *args, **kwargs):
        # Create a serializer with request.DATA
        serializer = self.get_serializer(data=request.DATA)

        if not serializer.is_valid():
            return Response(serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)
        serializer.save()
        # Return the success message with OK HTTP status
        return Response({"success": "Password reset e-mail has been sent."},
                         status=status.HTTP_200_OK)


class PasswordResetConfirm(LoggedOutRESTAPIView, GenericAPIView):

    """
    Password reset e-mail link is confirmed, therefore this resets the user's password.

    Accepts the following POST parameters: new_password1, new_password2
    Accepts the following Django URL arguments: token, uid
    Returns the success/fail message.
    """

    serializer_class = PasswordResetConfirmSerializer

    def post(self, request):
        serializer = self.get_serializer(data=request.DATA)
        if not serializer.is_valid():
            return Response(serializer.errors,
                status=status.HTTP_400_BAD_REQUEST)
        serializer.save()
        return Response({"success": "Password has been reset with the new password."})


class PasswordChange(LoggedInRESTAPIView, GenericAPIView):

    """
    Calls Django Auth SetPasswordForm save method.

    Accepts the following POST parameters: new_password1, new_password2
    Returns the success/fail message.
    """

    serializer_class = PasswordChangeSerializer

    def post(self, request):
        serializer = self.get_serializer(data=request.DATA)
        if not serializer.is_valid():
            return Response(serializer.errors,
                status=status.HTTP_400_BAD_REQUEST)
        serializer.save()
        return Response({"success": "New password has been saved."})