From 1d33e46fd80486fd322bab50953ae2012f0c262e Mon Sep 17 00:00:00 2001
From: Luna Mendes <lnmds@protonmail.com>
Date: Fri, 19 Oct 2018 19:16:29 -0300
Subject: [PATCH] pubsub: add lazy_guild

---
 README.md                     |  8 +++
 litecord/pubsub/channel.py    |  1 -
 litecord/pubsub/guild.py      |  1 -
 litecord/pubsub/lazy_guild.py | 94 +++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100644 litecord/pubsub/lazy_guild.py

diff --git a/README.md b/README.md
index 4658055..5f5c9c4 100644
--- a/README.md
+++ b/README.md
@@ -7,8 +7,16 @@ This project is a rewrite of [litecord-reference].
 
 [litecord-reference]: https://gitlab.com/luna/litecord-reference
 
+## Notes
+
+ - There are no testing being run on the current codebase. Which means the code is definitely unstable.
+ - No voice is planned to be developed, for now.
+ - You must figure out connecting to the server yourself. Litecord will not distribute
+    Discord's official client code nor provide ways to modify the client.
+
 ## Install
 
+Requirements:
 - Python 3.6 or higher
 - PostgreSQL
 - [Pipenv]
diff --git a/litecord/pubsub/channel.py b/litecord/pubsub/channel.py
index 3c3cb2c..621eeff 100644
--- a/litecord/pubsub/channel.py
+++ b/litecord/pubsub/channel.py
@@ -1,5 +1,4 @@
 from typing import Any
-from collections import defaultdict
 
 from logbook import Logger
 
diff --git a/litecord/pubsub/guild.py b/litecord/pubsub/guild.py
index a05373a..6896d93 100644
--- a/litecord/pubsub/guild.py
+++ b/litecord/pubsub/guild.py
@@ -1,4 +1,3 @@
-from collections import defaultdict
 from typing import Any
 
 from logbook import Logger
diff --git a/litecord/pubsub/lazy_guild.py b/litecord/pubsub/lazy_guild.py
new file mode 100644
index 0000000..ba8a451
--- /dev/null
+++ b/litecord/pubsub/lazy_guild.py
@@ -0,0 +1,94 @@
+from collections import defaultdict
+from typing import Any
+
+from logbook import Logger
+
+from .dispatcher import Dispatcher
+
+log = Logger(__name__)
+
+
+class GuildMemberList():
+    def __init__(self, guild_id: int):
+        self.guild_id = guild_id
+
+        # TODO: initialize list with actual member info
+        self._uninitialized = True
+        self.member_list = []
+
+        #: holds the state of subscribed users
+        self.state = set()
+
+    async def _init_check(self):
+        """Check if the member list is initialized before
+        messing with it."""
+        if self._uninitialized:
+            await self._init_member_list()
+
+    async def _init_member_list(self):
+        """Fill in :attr:`GuildMemberList.member_list`
+        with information about the guilds' members."""
+        pass
+
+    async def sub(self, user_id: int):
+        """Subscribe a user to the member list."""
+        await self._init_check()
+        self.state.add(user_id)
+
+    async def unsub(self, user_id: int):
+        """Unsubscribe a user from the member list"""
+        self.state.discard(user_id)
+
+        # once we reach 0 subscribers,
+        # we drop the current member list we have (for memory)
+        # but keep the GuildMemberList running (as
+        #  uninitialized) for a future subscriber.
+
+        if not self.state:
+            self.member_list = []
+            self._uninitialized = True
+
+    async def dispatch(self, event: str, data: Any):
+        """The dispatch() method here, instead of being
+        about dispatching a single event to the subscribed
+        users and forgetting about it, is about storing
+        the actual member list information so that we
+        can generate the respective events to the users.
+
+        GuildMemberList stores the current guilds' list
+        in its :attr:`GuildMemberList.member_list` attribute,
+        with that attribute being modified via different
+        calls to :meth:`GuildMemberList.dispatch`
+        """
+
+        if self._uninitialized:
+            # if the list is currently uninitialized,
+            # no subscribers actually happened, so
+            # we can safely drop the incoming event.
+            return
+
+
+class LazyGuildDispatcher(Dispatcher):
+    """Main class holding the member lists for lazy guilds."""
+    KEY_TYPE = int
+    VAL_TYPE = int
+
+    def __init__(self, main):
+        super().__init__(main)
+        self.state = defaultdict(GuildMemberList)
+
+    async def sub(self, guild_id, user_id):
+        await self.state[guild_id].sub(user_id)
+
+    async def unsub(self, guild_id, user_id):
+        await self.state[guild_id].unsub(user_id)
+
+    async def dispatch(self, guild_id: int, event: str, data):
+        """Dispatch an event to the member list.
+
+        GuildMemberList will make sure of converting it to
+        GUILD_MEMBER_LIST_UPDATE events.
+        """
+        member_list = self.state[guild_id]
+        await member_list.dispatch(event, data)
+