Keep track of seen blog posts

.gitignore

@@ -1,3 +1,4 @@
 .vscode/*
 log.log
-.env
+.env
+seen_posts.txt

src/rss.py

@@ -1,5 +1,6 @@
 import asyncio
-from typing import Optional
+import os
+from typing import List
 
 import discord
 import feedparser
@@ -16,23 +17,27 @@ def get_feed_channel(bot: BotClient) -> discord.TextChannel:
             return channel
 
 
-async def get_last_blog_post(channel: discord.TextChannel) -> str | None:
-    # TODO: This doesn't work when the bot is restarted, store the URL instead
-    last_message: Optional[discord.Message] = channel.last_message
-    if last_message is not None and len(last_message.embeds) > 0:
-        return last_message.embeds[0].url
+def get_seen_posts() -> List[str]:
+    if os.path.exists('seen_posts.txt'):
+        with open('seen_posts.txt', 'r') as f:
+            return f.readlines()
 
-    return None
+    return []
+
+
+def add_seen_post(post_id: str) -> None:
+    with open('seen_posts.txt', 'a') as f:
+        f.write(post_id + '\n')
 
 
 async def check_posts(bot: BotClient):
     feed = feedparser.parse(FEED_URL)
     channel = get_feed_channel(bot)
     post = feed.entries[0]
-    newest_post_url = post.link
-    last_message_url = await get_last_blog_post(channel)
-    if newest_post_url != last_message_url:
+
+    if post.id + "\n" not in get_seen_posts():
         await channel.send(embed=create_embed(post))
+        add_seen_post(post.id)
 
 
 def create_embed(post: FeedParserDict) -> discord.Embed: