Created PEP news task + minor changes in `News`

- Created task `post_pep_news` that pull existing news message IDs from API, do checks and send new PEP when it's not already sent.
- Removed `get_webhook`
- Removed `self.webhook`

1 files changed, 69 insertions, 4 deletions

diff --git a/bot/cogs/news.py b/bot/cogs/news.py
index 3aa57442a..6e9441997 100644
--- a/bot/cogs/news.py
+++ b/bot/cogs/news.py
@@ -1,9 +1,18 @@
+import logging
+from datetime import datetime
+
 import discord
+import feedparser
 from discord.ext.commands import Cog
+from discord.ext.tasks import loop
 
 from bot import constants
 from bot.bot import Bot
 
+PEPS_RSS_URL = "https://www.python.org/dev/peps/peps.rss/"
+
+log = logging.getLogger(__name__)
+
 
 class News(Cog):
     """Post new PEPs and Python News to `#python-news`."""
@@ -11,7 +20,8 @@ class News(Cog):
     def __init__(self, bot: Bot):
         self.bot = bot
         self.bot.loop.create_task(self.sync_maillists())
-        self.webhook = self.bot.loop.create_task(self.get_webhook())
+
+        self.post_pep_news.start()
 
     async def sync_maillists(self) -> None:
         """Sync currently in-use maillists with API."""
@@ -29,9 +39,64 @@ class News(Cog):
 
         await self.bot.api_client.put("bot/bot-settings/news", json=response)
 
-    async def get_webhook(self) -> discord.Webhook:
-        """Get #python-news channel webhook."""
-        return await self.bot.fetch_webhook(constants.PythonNews.webhook)
+    @loop(minutes=20)
+    async def post_pep_news(self) -> None:
+        """Fetch new PEPs and when they don't have announcement in #python-news, create it."""
+        # Wait until everything is ready and http_session available
+        await self.bot.wait_until_guild_available()
+
+        async with self.bot.http_session.get(PEPS_RSS_URL) as resp:
+            data = feedparser.parse(await resp.text())
+
+        news_channel = self.bot.get_channel(constants.PythonNews.channel)
+        webhook = await self.bot.fetch_webhook(constants.PythonNews.webhook)
+
+        news_listing = await self.bot.api_client.get("bot/bot-settings/news")
+        payload = news_listing.copy()
+        pep_news_ids = news_listing["data"]["pep"]
+        pep_news = []
+
+        for pep_id in pep_news_ids:
+            message = discord.utils.get(self.bot.cached_messages, id=pep_id)
+            if message is None:
+                message = await news_channel.fetch_message(pep_id)
+                if message is None:
+                    log.warning(f"Can't fetch news message with ID {pep_id}. Deleting it entry from DB.")
+                    payload["data"]["pep"].remove(pep_id)
+            pep_news.append((message.embeds[0].title, message.embeds[0].timestamp))
+
+        # Reverse entries to send oldest first
+        data["entries"].reverse()
+        for new in data["entries"]:
+            try:
+                new_datetime = datetime.strptime(new["published"], "%a, %d %b %Y %X %Z")
+            except ValueError:
+                log.warning(f"Wrong datetime format passed in PEP new: {new['published']}")
+                continue
+            if (
+                any(pep_new[0] == new["title"] for pep_new in pep_news)
+                and any(pep_new[1] == new_datetime for pep_new in pep_news)
+            ):
+                continue
+
+            embed = discord.Embed(
+                title=new["title"],
+                description=new["summary"],
+                timestamp=new_datetime,
+                url=new["link"],
+                colour=constants.Colours.soft_green
+            )
+
+            pep_msg = await webhook.send(
+                embed=embed,
+                username=data["feed"]["title"],
+                avatar_url="https://www.python.org/static/opengraph-icon-200x200.png",
+                wait=True
+            )
+            payload["data"]["pep"].append(pep_msg.id)
+
+        # Apply new sent news to DB to avoid duplicate sending
+        await self.bot.api_client.put("bot/bot-settings/news", json=payload)
 
 
 def setup(bot: Bot) -> None: