realm: Use enums for accessing setting values.

This commit updates code, majorly in tests, to use
setting values from enums instead of directly using
the constants defined in Realm.

We still have those constants defined Realm as they
are used in a couple of places where the same code
is used for different settings. These will be
handled later.

zerver/models/realms.py

@@ -262,47 +262,17 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
     POLICY_NOBODY = 6
     POLICY_OWNERS_ONLY = 7
 
-    COMMON_POLICY_TYPES = [
-        POLICY_MEMBERS_ONLY,
-        POLICY_ADMINS_ONLY,
-        POLICY_FULL_MEMBERS_ONLY,
-        POLICY_MODERATORS_ONLY,
-    ]
+    COMMON_POLICY_TYPES = [field.value for field in CommonPolicyEnum]
 
-    COMMON_MESSAGE_POLICY_TYPES = [
-        POLICY_MEMBERS_ONLY,
-        POLICY_ADMINS_ONLY,
-        POLICY_FULL_MEMBERS_ONLY,
-        POLICY_MODERATORS_ONLY,
-        POLICY_EVERYONE,
-    ]
+    COMMON_MESSAGE_POLICY_TYPES = [field.value for field in CommonMessagePolicyEnum]
 
-    INVITE_TO_REALM_POLICY_TYPES = [
-        POLICY_MEMBERS_ONLY,
-        POLICY_ADMINS_ONLY,
-        POLICY_FULL_MEMBERS_ONLY,
-        POLICY_MODERATORS_ONLY,
-        POLICY_NOBODY,
-    ]
+    INVITE_TO_REALM_POLICY_TYPES = [field.value for field in InviteToRealmPolicyEnum]
 
-    # We don't allow granting roles less than Moderator access to
-    # create web-public streams, since it's a sensitive feature that
-    # can be used to send spam.
     CREATE_WEB_PUBLIC_STREAM_POLICY_TYPES = [
-        POLICY_ADMINS_ONLY,
-        POLICY_MODERATORS_ONLY,
-        POLICY_OWNERS_ONLY,
-        POLICY_NOBODY,
+        field.value for field in CreateWebPublicStreamPolicyEnum
     ]
 
-    EDIT_TOPIC_POLICY_TYPES = [
-        POLICY_MEMBERS_ONLY,
-        POLICY_ADMINS_ONLY,
-        POLICY_FULL_MEMBERS_ONLY,
-        POLICY_MODERATORS_ONLY,
-        POLICY_EVERYONE,
-        POLICY_NOBODY,
-    ]
+    EDIT_TOPIC_POLICY_TYPES = [field.value for field in EditTopicPolicyEnum]
 
     MOVE_MESSAGES_BETWEEN_STREAMS_POLICY_TYPES = INVITE_TO_REALM_POLICY_TYPES
 
@@ -317,21 +287,33 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
     )
 
     # Who in the organization is allowed to add custom emojis.
-    add_custom_emoji_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
+    add_custom_emoji_policy = models.PositiveSmallIntegerField(
+        default=CommonPolicyEnum.MEMBERS_ONLY
+    )
 
     # Who in the organization is allowed to create streams.
-    create_public_stream_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
-    create_private_stream_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
-    create_web_public_stream_policy = models.PositiveSmallIntegerField(default=POLICY_OWNERS_ONLY)
+    create_public_stream_policy = models.PositiveSmallIntegerField(
+        default=CommonPolicyEnum.MEMBERS_ONLY
+    )
+    create_private_stream_policy = models.PositiveSmallIntegerField(
+        default=CommonPolicyEnum.MEMBERS_ONLY
+    )
+    create_web_public_stream_policy = models.PositiveSmallIntegerField(
+        default=CreateWebPublicStreamPolicyEnum.OWNERS_ONLY
+    )
 
     # Who in the organization is allowed to delete messages they themselves sent.
-    delete_own_message_policy = models.PositiveSmallIntegerField(default=POLICY_EVERYONE)
+    delete_own_message_policy = models.PositiveSmallIntegerField(
+        default=CommonMessagePolicyEnum.EVERYONE
+    )
 
     # Who in the organization is allowed to edit topics of any message.
-    edit_topic_policy = models.PositiveSmallIntegerField(default=POLICY_EVERYONE)
+    edit_topic_policy = models.PositiveSmallIntegerField(default=EditTopicPolicyEnum.EVERYONE)
 
     # Who in the organization is allowed to invite other users to organization.
-    invite_to_realm_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
+    invite_to_realm_policy = models.PositiveSmallIntegerField(
+        default=InviteToRealmPolicyEnum.MEMBERS_ONLY
+    )
 
     # UserGroup whose members are allowed to create invite link.
     create_multiuse_invite_group = models.ForeignKey(
@@ -347,45 +329,29 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
     )
 
     # Who in the organization is allowed to invite other users to streams.
-    invite_to_stream_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
+    invite_to_stream_policy = models.PositiveSmallIntegerField(
+        default=CommonPolicyEnum.MEMBERS_ONLY
+    )
 
     # Who in the organization is allowed to move messages between streams.
     move_messages_between_streams_policy = models.PositiveSmallIntegerField(
         default=POLICY_MEMBERS_ONLY
     )
 
-    user_group_edit_policy = models.PositiveSmallIntegerField(default=POLICY_MEMBERS_ONLY)
+    user_group_edit_policy = models.PositiveSmallIntegerField(default=CommonPolicyEnum.MEMBERS_ONLY)
 
-    PRIVATE_MESSAGE_POLICY_UNLIMITED = 1
-    PRIVATE_MESSAGE_POLICY_DISABLED = 2
     private_message_policy = models.PositiveSmallIntegerField(
-        default=PRIVATE_MESSAGE_POLICY_UNLIMITED
+        default=PrivateMessagePolicyEnum.UNLIMITED
     )
-    PRIVATE_MESSAGE_POLICY_TYPES = [
-        PRIVATE_MESSAGE_POLICY_UNLIMITED,
-        PRIVATE_MESSAGE_POLICY_DISABLED,
-    ]
+    PRIVATE_MESSAGE_POLICY_TYPES = [field.value for field in PrivateMessagePolicyEnum]
 
     # Global policy for who is allowed to use wildcard mentions in
     # streams with a large number of subscribers.  Anyone can use
     # wildcard mentions in small streams regardless of this setting.
-    WILDCARD_MENTION_POLICY_EVERYONE = 1
-    WILDCARD_MENTION_POLICY_MEMBERS = 2
-    WILDCARD_MENTION_POLICY_FULL_MEMBERS = 3
-    WILDCARD_MENTION_POLICY_ADMINS = 5
-    WILDCARD_MENTION_POLICY_NOBODY = 6
-    WILDCARD_MENTION_POLICY_MODERATORS = 7
     wildcard_mention_policy = models.PositiveSmallIntegerField(
-        default=WILDCARD_MENTION_POLICY_ADMINS,
+        default=WildcardMentionPolicyEnum.ADMINS,
     )
-    WILDCARD_MENTION_POLICY_TYPES = [
-        WILDCARD_MENTION_POLICY_EVERYONE,
-        WILDCARD_MENTION_POLICY_MEMBERS,
-        WILDCARD_MENTION_POLICY_FULL_MEMBERS,
-        WILDCARD_MENTION_POLICY_ADMINS,
-        WILDCARD_MENTION_POLICY_NOBODY,
-        WILDCARD_MENTION_POLICY_MODERATORS,
-    ]
+    WILDCARD_MENTION_POLICY_TYPES = [field.value for field in WildcardMentionPolicyEnum]
 
     # Threshold in days for new users to create streams, and potentially take
     # some other actions.
@@ -581,17 +547,8 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
     }
     plan_type = models.PositiveSmallIntegerField(default=PLAN_TYPE_SELF_HOSTED)
 
-    # This value is also being used in web/src/settings_bots.bot_creation_policy_values.
-    # On updating it here, update it there as well.
-    BOT_CREATION_EVERYONE = 1
-    BOT_CREATION_LIMIT_GENERIC_BOTS = 2
-    BOT_CREATION_ADMINS_ONLY = 3
-    bot_creation_policy = models.PositiveSmallIntegerField(default=BOT_CREATION_EVERYONE)
-    BOT_CREATION_POLICY_TYPES = [
-        BOT_CREATION_EVERYONE,
-        BOT_CREATION_LIMIT_GENERIC_BOTS,
-        BOT_CREATION_ADMINS_ONLY,
-    ]
+    bot_creation_policy = models.PositiveSmallIntegerField(default=BotCreationPolicyEnum.EVERYONE)
+    BOT_CREATION_POLICY_TYPES = [field.value for field in BotCreationPolicyEnum]
 
     UPLOAD_QUOTA_LIMITED = 5
     UPLOAD_QUOTA_STANDARD_FREE = 50