Fixed newly discovered streams never sending notifications.

The rate limit logic has been updated to account for streams going down temporarily and factor in when the stream title changes. I think I've accounted for most of the ways these events can happen, but there's probably still a few race conditions left over. It runs well enough in the development environment, it's time to collect some data in production.

owncastsentry.py

@@ -8,6 +8,7 @@ import sqlite3
 import aiohttp
 import json
 import asyncio
+import time
 
 from maubot import Plugin, MessageEvent
 from maubot.handlers import command
@@ -28,6 +29,16 @@ USER_AGENT = (
     "OwncastSentry/1.0.3 (bot; +https://git.logal.dev/LogalDeveloper/OwncastSentry)"
 )
 
+# Hard minimum amount of time between when notifications can be sent for a stream. Prevents spamming notifications for glitchy or malicious streams.
+SECONDS_BETWEEN_NOTIFICATIONS = 20 * 60  # 20 minutes in seconds
+
+# I'm not sure the best way to name or explain this variable, so let's just say what uses it:
+#
+# After a stream goes offline, a timer is started. Then, ...
+# - If a stream comes back online with the same title within this time, no notification is sent.
+# - If a stream comes back online with a different title, a rename notification is sent.
+# - If this time period passes entirely and a stream comes back online after, it's treated as regular going live.
+TEMPORARY_OFFLINE_NOTIFICATION_COOLDOWN = 7 * 60  # 7 minutes in seconds
 
 # ===== DATABASE MIGRATIONS =====
 upgrade_table = UpgradeTable()
@@ -81,6 +92,12 @@ class OwncastSentry(Plugin):
         headers=headers, cookie_jar=cookie_jar, timeout=timeouts, connector=baseconnctor
     )
 
+    # Keeps track of when a notification was last sent for streams.
+    notification_timers_cache = {}
+
+    # Keeps track of when streams last went offline.
+    offline_timer_cache = {}
+
     @classmethod
     def get_db_upgrade_table(cls) -> UpgradeTable | None:
         """
@@ -254,9 +271,15 @@ class OwncastSentry(Plugin):
         :return: Nothing.
         """
 
-        # A flag indicating whether to send a notification.
-        # Used for the first state update of a brand-new stream to avoid sending notifications if its already live.
-        send_notifications = True
+        # A flag indicating whether this is the first state update of a brand-new stream to avoid sending notifications if its already live.
+        first_update = False
+
+        # A flag indicating whether to update the stream's state in the databased.
+        # Used to avoid writing to the database when a stream's state hasn't changed at all.
+        update_database = False
+
+        # Holds the stream's latest configuration, if fetched and deemed necessary during the update process.
+        stream_config = {}
 
         # Fetch the latest stream state from the server.
         new_state = await self.get_stream_state(domain)
@@ -265,8 +288,14 @@ class OwncastSentry(Plugin):
         if new_state == {}:
             return
 
+        # Fix possible race conditions with timers
+        if domain not in self.offline_timer_cache:
+            self.offline_timer_cache[domain] = 0
+        if domain not in self.notification_timers_cache:
+            self.notification_timers_cache[domain] = 0
+
         # Fetch the last known stream state from the database.
-        query = "SELECT last_connect_time, last_disconnect_time FROM streams WHERE domain=$1"
+        query = "SELECT * FROM streams WHERE domain=$1"
         async with self.database.acquire() as connection:
             old_state = await connection.fetchrow(query, domain)
 
@@ -276,60 +305,152 @@ class OwncastSentry(Plugin):
             and old_state["last_disconnect_time"] is None
         ):
             # Yes, this is the first update. Don't send any notifications.
-            send_notifications = False
+            update_database = True
+            first_update = True
 
         # Does the latest stream state have a last connect time and the old state not have one?
         if (
             new_state["lastConnectTime"] is not None
             and old_state["last_connect_time"] is None
         ):
-            # Yes! This stream is now live. Send notifications and log it, if allowed.
-            if send_notifications:
-                self.log.info(
-                    f"[{domain}] Stream is now live! Notifying subscribed rooms..."
-                )
-                await self.notify_rooms_of_stream_online(
-                    domain, new_state["streamTitle"]
-                )
+            # Yes! This stream is now live.
+            update_database = True
+            stream_config = await self.get_stream_config(domain)
+
+            self.log.info(f"[{domain}] Stream is now live!")
+
+            # Calculate how many seconds since the stream last went offline
+            seconds_since_last_offline = round(
+                time.time() - self.offline_timer_cache[domain]
+            )
+
+            # Have we queried this stream before? (In other words, is this not the first state update ever?)
+            if not first_update:
+                # Yes. Has this stream been offline for a short amount of time?
+                if seconds_since_last_offline < TEMPORARY_OFFLINE_NOTIFICATION_COOLDOWN:
+                    # Yes. Did the stream title change?
+                    if old_state["title"] != new_state["streamTitle"]:
+                        # Yes. The stream was only down for a short time, send a special notification indicating the stream changed its name.
+                        await self.notify_rooms_of_stream_online(
+                            domain,
+                            stream_config["name"],
+                            new_state["streamTitle"],
+                            True,
+                            stream_config["tags"],
+                        )
+                    else:
+                        # No. The stream was only down for a short time and didn't change its title. Don't send a notification.
+                        self.log.info(
+                            f"[{domain}] Not sending notifications. Stream was only offline for {seconds_since_last_offline} of {TEMPORARY_OFFLINE_NOTIFICATION_COOLDOWN} seconds and did not change its title."
+                        )
+                else:
+                    # This stream has been offline for a while. Send a normal notification.
+                    await self.notify_rooms_of_stream_online(
+                        domain,
+                        stream_config["name"],
+                        new_state["streamTitle"],
+                        False,
+                        stream_config["tags"],
+                    )
             else:
+                # No, this is the first time we're querying 
                 self.log.info(
-                    f"[{domain}] Stream is live, but performed first update. WIll not notify subscribed rooms."
+                    f"[{domain}] Not sending notifications. This is the first state update for this stream."
                 )
 
+        if (
+            new_state["lastConnectTime"] is not None
+            and old_state["last_connect_time"] is not None
+        ):
+            # Did the stream title change mid-session?
+            if old_state["title"] != new_state["streamTitle"]:
+                self.log.info(f"[{domain}] Stream title was changed!")
+                update_database = True
+                stream_config = await self.get_stream_config(domain)
+
+                # This is a fun case to account for... Let's try and explain this.
+                # Was the last time this stream sent a notification before it last went offline?
+                if (
+                    self.offline_timer_cache[domain]
+                    > self.notification_timers_cache[domain]
+                ):
+                    # Yes. Send a regular go live notification.
+                    # Why? A title change notification could be confusing to users in this case.
+                    # How? If a stream goes offline before its next allowed notification, it'll get rate limited. If it then changes its title, this part of the code will send a title change notification. This can be a little confusing, so override to a normal go live notification in this case.
+                    await self.notify_rooms_of_stream_online(
+                        domain,
+                        stream_config["name"],
+                        new_state["streamTitle"],
+                        False,
+                        stream_config["tags"],
+                    )
+                else:
+                    # No. Send a normal title change notification.
+                    await self.notify_rooms_of_stream_online(
+                        domain,
+                        stream_config["name"],
+                        new_state["streamTitle"],
+                        True,
+                        stream_config["tags"],
+                    )
+
         # Does the latest stream state no longer have a last connect time but the old state does?
         elif (
             new_state["lastConnectTime"] is None
             and old_state["last_connect_time"] is not None
         ):
             # Yep. This stream is now offline. Log it.
-            if send_notifications:
-                self.log.info(f"[{domain}] Stream is now offline.")
-            else:
+            update_database = True
+            stream_config = await self.get_stream_config(domain)
+            self.offline_timer_cache[domain] = time.time()
+            if first_update:
                 self.log.info(f"[{domain}] Stream is offline.")
+            else:
+                self.log.info(f"[{domain}] Stream is now offline.")
 
-        # Update the database with the current stream state.
-        # TODO: Only update the database if a change actually occurred. This is probably generating useless writes.
-        update_query = "UPDATE streams SET name=$1, last_connect_time=$2, last_disconnect_time=$3 WHERE domain=$4"
-        async with self.database.acquire() as connection:
-            await connection.execute(
-                update_query,
-                new_state["streamTitle"],
-                new_state["lastConnectTime"],
-                new_state["lastDisconnectTime"],
-                domain,
-            )
+        # Update the database with the current stream state, if needed.
+        if update_database:
+            self.log.debug(f"[{domain}] Updating stream state in database...")
+            update_query = "UPDATE streams SET name=$1, title=$2, last_connect_time=$3, last_disconnect_time=$4 WHERE domain=$5"
+            async with self.database.acquire() as connection:
+                await connection.execute(
+                    update_query,
+                    stream_config["name"],
+                    new_state["streamTitle"],
+                    new_state["lastConnectTime"],
+                    new_state["lastDisconnectTime"],
+                    domain,
+                )
 
         # All done.
         self.log.debug(f"[{domain}] State update completed.")
 
-    async def notify_rooms_of_stream_online(self, domain: str, title: str) -> None:
+    async def notify_rooms_of_stream_online(
+        self, domain: str, name: str, title: str, title_change: bool, tags: list[str]
+    ) -> None:
         """
         Sends notifications to rooms with subscriptions to the provided stream domain.
 
         :param domain: The domain of the stream to send notifications for.
         :param title: The title of the stream to include in the message.
+        :param renamed: Whether or not this is for a stream changing its title rather than going live.
         :return: Nothing.
         """
+
+        # Has enough time passed since the last notification was sent?
+        if domain in self.notification_timers_cache:
+            seconds_since_last_notification = round(
+                time.time() - self.notification_timers_cache[domain]
+            )
+            if seconds_since_last_notification < SECONDS_BETWEEN_NOTIFICATIONS:
+                self.log.info(
+                    f"[{domain}] Not sending notifications. Only {seconds_since_last_notification} of required {SECONDS_BETWEEN_NOTIFICATIONS} seconds has passed since last notification."
+                )
+                return
+
+        # Yes. Log the current time and proceed with sending notifications.
+        self.notification_timers_cache[domain] = time.time()
+
         # Get a list of room IDs with active subscriptions to the stream domain.
         query = "SELECT room_id FROM subscriptions WHERE stream_domain=$1"
         async with self.database.acquire() as connection:
@@ -339,15 +460,19 @@ class OwncastSentry(Plugin):
         successful_notifications = 0
         failed_notifications = 0
 
-        stream_config = await self.get_stream_config(domain)
+        # Time to start building the body text for the notifications.
 
-        # Build the message body text.
-        if "name" in stream_config:
-            body_text = "🎥 " + stream_config["name"] + " is now live!"
+        # Turns out it is possible to set an empty name for an Owncast stream if you know how.
+        # We'll account for that... Just in case.
+        stream_name = name if name else domain
+
+        # If the stream changed its title, send a different title change notification.
+        if title_change:
+            self.log.info(f"[{domain}] Sending title change notifications...")
+            body_text = "📝 " + name + " has changed its stream title!"
         else:
-            # Turns out it is possible to set an empty name for an Owncast stream if you know how.
-            # We'll account for that... Just in case.
-            body_text = "🎥 " + domain + " is now live!"
+            self.log.info(f"[{domain}] Sending going live notifications...")
+            body_text = "🎥 " + name + " is now live!"
 
         # Streams can have no title. If there is none, don't even mention it.
         if title != "":
@@ -355,9 +480,9 @@ class OwncastSentry(Plugin):
 
         body_text += "\n\nTo tune in, visit: https://" + domain + "/"
 
-        if "tags" in stream_config and len(stream_config["tags"]) > 0:
+        if "tags" and len(tags) > 0:
             body_text += "\n\n"
-            body_text += " ".join("#" + tag for tag in stream_config["tags"])
+            body_text += " ".join("#" + tag for tag in tags)
 
         # Iterate over the subscribed rooms and try to send a message to each.
         # TODO: This should probably be made async.