[V3 Config] Record custom group information using cog_add event (#2550)

* Do things differently

* Uncomment critical lines

* Reduce, reuse, recycle

* Check groups on all new config objects after a cog loads

* I don't know why this is failing now or why we need the global keyword

* gotta fix this too

redbot/core/bot.py

@@ -18,6 +18,8 @@ from .help_formatter import Help, help as help_
 from .rpc import RPCMixin
 from .utils import common_filters
 
+CUSTOM_GROUPS = "CUSTOM_GROUPS"
+
 
 def _is_submodule(parent, child):
     return parent == child or child.startswith(parent + ".")
@@ -74,6 +76,9 @@ class RedBase(commands.GroupMixin, commands.bot.BotBase, RPCMixin):
 
         self.db.register_user(embeds=None)
 
+        self.db.init_custom(CUSTOM_GROUPS, 2)
+        self.db.register_custom(CUSTOM_GROUPS)
+
         async def prefix_manager(bot, message):
             if not cli_flags.prefix:
                 global_prefix = await bot.db.prefix()

redbot/core/config.py

@@ -12,11 +12,22 @@ from .drivers import get_driver, IdentifierData
 if TYPE_CHECKING:
     from .drivers.red_base import BaseDriver
 
+__all__ = ["Config", "get_latest_confs"]
+
 log = logging.getLogger("red.config")
 
 _T = TypeVar("_T")
 
 _config_cache = weakref.WeakValueDictionary()
+_retrieved = weakref.WeakSet()
+
+
+def get_latest_confs() -> Tuple["Config"]:
+    global _retrieved
+    ret = set(_config_cache.values()) - set(_retrieved)
+    _retrieved |= ret
+    # noinspection PyTypeChecker
+    return tuple(ret)
 
 
 class _ValueCtxManager(Awaitable[_T], AsyncContextManager[_T]):

redbot/core/events.py

@@ -15,6 +15,7 @@ from pkg_resources import DistributionNotFound
 
 from .. import __version__ as red_version, version_info as red_version_info, VersionInfo
 from . import commands
+from .config import get_latest_confs
 from .data_manager import storage_type
 from .utils.chat_formatting import inline, bordered, format_perms_list, humanize_timedelta
 from .utils import fuzzy_command_search, format_fuzzy_results
@@ -305,6 +306,14 @@ def init_events(bot, cli_flags):
             if command_obj is not None:
                 command_obj.enable_in(guild)
 
+    @bot.event
+    async def on_cog_add(cog: commands.Cog):
+        confs = get_latest_confs()
+        for c in confs:
+            uuid = c.unique_identifier
+            group_data = c.custom_groups
+            await bot.db.custom("CUSTOM_GROUPS", c.cog_name, uuid).set(group_data)
+
 
 def _get_startup_screen_specs():
     """Get specs for displaying the startup screen on stdout.