Use MongoDB to store pinned message IDs (#126)

Author: IsaacG

.github/workflows/lint.yml

@@ -24,8 +24,9 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install click discord.py python-dotenv
-        pip install prometheus_client
-        pip install requests sentry_sdk python-logging-loki aiohttp systemd-python
+        pip install prometheus_client sentry_sdk python-logging-loki
+        pip install requests aiohttp systemd-python
+        pip install pymongo
     - name: Install linters
       run: |
         pip install flake8 mypy pylint

cogs/base_cog.py

@@ -3,6 +3,7 @@
 import collections
 from typing import Any, Callable
 
+import pymongo.mongo_client  # type: ignore
 from discord.ext import commands
 
 
@@ -15,10 +16,12 @@ def __init__(
         self,
         bot: commands.Bot,
         exercism_guild_id: int,
+        mongodb: None | pymongo.mongo_client.MongoClient = None,
     ) -> None:
         self.bot = bot
         self.exercism_guild_id = exercism_guild_id
         self.usage_stats: dict[str, Any] = collections.defaultdict(self.STATS_TYPE)
+        self.mongodb = mongodb
 
     def details(self) -> str:
         """Return cog details."""

cogs/pinned_message.py

@@ -3,6 +3,7 @@
 import logging
 
 import discord
+import pymongo.mongo_client
 from discord.ext import commands
 
 from cogs import base_cog
@@ -25,6 +26,11 @@ def __init__(
         self.bot = bot
         self.messages: dict[int, str] = messages
         self.last_message: dict[int, discord.Message] = {}
+        self.mongo: pymongo.mongo_client.database.Collection | None
+        if isinstance(self.mongodb, pymongo.mongo_client.database.Database):
+            self.mongo = self.mongodb.get_collection("pinned_messages")
+        else:
+            self.mongo = None
 
     @commands.Cog.listener()
     async def on_ready(self) -> None:
@@ -41,6 +47,15 @@ async def find_prior_message(self, channel_id: int, content: str) -> None | disc
         for guild in self.bot.guilds:
             channel = guild.get_channel(channel_id)
             if isinstance(channel, discord.TextChannel):
+                if self.mongo is not None:
+                    try:
+                        got = self.mongo.find_one({"channel": channel_id})
+                        if got is not None:
+                            message_id = got["message"]
+                            return await channel.get_partial_message(message_id).fetch()
+                    except Exception as e:  # pylint: disable=broad-exception-caught
+                        logger.error("Failed to get message via MongoDB: %s", e)
+
                 async for message in channel.history(limit=50, oldest_first=None):
                     if message.author.id == self.bot.user.id and message.content == content:
                         return message
@@ -52,6 +67,16 @@ async def bump_message(self, channel: discord.TextChannel) -> None:
             await last.delete()
 
         msg = await channel.send(self.messages[channel.id], silent=True)
+        if self.mongo is not None:
+            try:
+                self.mongo.replace_one(
+                    {"channel": channel.id},
+                    {"channel": channel.id, "message": msg.id},
+                    True,
+                )
+            except Exception as e:  # pylint: disable=broad-exception-caught
+                logger.error("Failed to save message to MongoDB: %s", e)
+
         self.last_message[channel.id] = msg
 
     @commands.Cog.listener()

conf.py

@@ -152,7 +152,7 @@
 # PinnedMessage
 PINNED_MESSAGES = {
     # Test channel in test server.
-    1091223069407842306: "This is a pinned message.",
+    CHANNEL_ID["test"]: "This is a pinned message.",
     # Exercism #photo channel
     CHANNEL_ID["Exercism #photos"]: """\
 > **📸 Pinned Reminder 📸**

exercism_discord_bot.py

@@ -14,6 +14,8 @@
 import dotenv
 import logging_loki  # type: ignore
 import prometheus_client  # type: ignore
+import pymongo.mongo_client  # type: ignore
+import pymongo.server_api  # type: ignore
 import sentry_sdk  # type: ignore
 import systemd.journal  # type: ignore
 from discord.ext import commands
@@ -73,11 +75,23 @@ async def setup_hook(self):
                 dsn=find_setting("SENTRY_URI"),
                 traces_sample_rate=1.0,
             )
+
         guild = discord.Object(id=self.exercism_guild_id)
         standard_args = {
             "bot": self,
             "exercism_guild_id": self.exercism_guild_id,
         }
+
+        if has_setting("MONGODB_URL"):
+            try:
+                mongo_uri = find_setting("MONGODB_URL")
+                mongo_api = pymongo.server_api.ServerApi("1")
+                client = pymongo.mongo_client.MongoClient(mongo_uri, server_api=mongo_api)
+                standard_args["mongodb"] = client.get_database("exercism_discord")
+                logger.debug("Connected to MongoDB.")
+            except Exception as e:  # pylint: disable=broad-exception-caught
+                logger.error("Failed to connect to MongoDB: %s", e)
+
         for cog, kwargs in self.get_cogs().items():
             combined = standard_args | kwargs
             logger.info("Loading cog %s", cog.__name__)