SMART-31 created serializer for user login

.gitignore

@@ -1,3 +1,4 @@
 .idea/
 *.iml
 .idea
+*__pycache__/

rest-app/smartpicasso/app/user/serializers.py

@@ -1,11 +1,17 @@
 """
 @author p.dolata
 """
+from django.contrib.auth import authenticate
+from django.contrib.auth.models import update_last_login
 from rest_framework import serializers
+from rest_framework_jwt.settings import api_settings
 
 from smartpicasso.app.user.models import User
 from smartpicasso.app.user_profile.models import UserProfile
 
+JWT_PAYLOAD_HANDLER = api_settings.JWT_PAYLOAD_HANDLER
+JWT_ENCODE_HANDLER = api_settings.JWT_ENCODE_HANDLER
+
 
 class UserSerializer(serializers.ModelSerializer):
     """
@@ -38,3 +44,27 @@ class UserRegistrationSerializer(serializers.ModelSerializer):
             phone_number=profile_data['phone_number'],
         )
         return user
+
+
+class UserLoginSerializer(serializers.Serializer):
+    """
+    Class to manage serializing user during singing in
+    """
+    email = serializers.CharField(max_length=255)
+    password = serializers.CharField(max_length=128, write_only=True)
+    token = serializers.CharField(max_length=255, read_only=True)
+
+    def validate(self, data):
+        email = data.get('email', None)
+        password = data.get('password', None)
+        user = authenticate(email=email, password=password)
+        if user is None:
+            raise serializers.ValidationError('An user with provided email and password is not found')
+        try:
+            payload = JWT_PAYLOAD_HANDLER(user)
+            jwt_token = JWT_ENCODE_HANDLER(payload)
+            update_last_login(None, user)
+        except User.DoesNotExist:
+            raise serializers.ValidationError('User with given email and password does not exist')
+
+        return {'email': user.email, 'token': jwt_token}