Updated ReaderCollection to be able to display other helpful informat…

…ion around multiple readers

chalicelib/model.py

@@ -64,10 +64,23 @@ class ReaderCollection(CamelCaseAttributesMixin):
     Will be most commonly used in responses
     """
 
-    def __init__(self, readers: Sequence[Reader]):
+    def __init__(self, readers: Sequence[Reader], user_id: str = None):
+        self.flagged_by_any = any(reader.flagged for reader in readers)
+        self.read_by_any = len(readers) > 0
         self.count = len(readers)
         self.reader_list = readers
 
+        # If a user id is provided we can calculate some quick things around
+        # if that user has flagged or read any messages in the collection.
+        # The properties use 'you' because the assumption is made that whoever makes this request
+        # will have their ID passed in most of the time.
+        if user_id is not None:
+            self.read_by_you = any(reader.user_id == user_id for reader in readers)
+            self.flagged_by_you = any(reader.user_id == user_id and reader.flagged for reader in readers)
+        else:
+            self.read_by_you = None
+            self.flagged_by_you = None
+
 
 class ContactMessage(Document):
     """

tests/test_model.py

@@ -2,7 +2,7 @@
 
 import pytest
 
-from chalicelib.model import Reason, Sender, Reader, ContactMessage
+from chalicelib.model import Reason, Sender, Reader, ContactMessage, ReaderCollection
 
 
 @pytest.fixture
@@ -92,3 +92,45 @@ def test_contact_message_is_correctly_serialized(contact_message: ContactMessage
         'timeUpdated': '2001-09-09T01:46:40',
         'timeCreated': '2001-09-09T01:46:40'
     }
+
+
+def test_reader_collection_fields_are_calculated_correctly_without_user_id(reader: Reader):
+    readers = [reader]
+    collection = ReaderCollection(readers)
+
+    assert collection.__dict__ == {
+        'count': 1,
+        'read_by_any': True,
+        'flagged_by_any': True,
+        'read_by_you': None,
+        'flagged_by_you': None,
+        'reader_list': readers
+    }
+
+
+def test_reader_collection_fields_are_calculated_correctly_with_known_id(reader: Reader):
+    readers = [reader]
+    collection = ReaderCollection(readers, '123')
+
+    assert collection.__dict__ == {
+        'count': 1,
+        'read_by_any': True,
+        'flagged_by_any': True,
+        'read_by_you': True,
+        'flagged_by_you': True,
+        'reader_list': readers
+    }
+
+
+def test_reader_collection_fields_are_calculated_correctly_with_unknown_id(reader: Reader):
+    readers = [reader]
+    collection = ReaderCollection(readers, 'unknown id')
+
+    assert collection.__dict__ == {
+        'count': 1,
+        'read_by_any': True,
+        'flagged_by_any': True,
+        'read_by_you': False,
+        'flagged_by_you': False,
+        'reader_list': readers
+    }