Fix Deployment (Docker/Pillow/Fonts) & Implement Advanced Alerts Cog

[soadmahmud]

Summary

This PR fixes critical deployment issues preventing the bot from running on modern Docker environments (Debian 12/Ubuntu 24.04). It also completely re-implements the missing alerts module with robust contest reminders, ranklists, and milestone celebrations.

🔧 Infrastructure & Bug Fixes

• Dockerfile Fixes:

  • Updated system dependencies (libcairo2-dev, pkg-config, libgirepository1.0-dev) to allow pycairo and PyGObject to compile correctly on Python 3.11.

  • Fixed AttributeError: 'FreeTypeFont' object has no attribute 'getsize' by pinning Pillow<10.0.0.

• Font Downloader Fix:

  • Replaced broken Google Storage links (403 Forbidden) with direct GitHub raw links for NotoSansCJK.

  • Removed zip extraction logic as the new source provides raw .ttc files.

• Configuration (constants.py):

  • Added logic to automatically convert Role IDs from strings to integers in .env, preventing MissingAnyRole errors.

• Database Handling:

  • Fixed a crash in alerts logic where user data was returned as tuples instead of objects, causing AttributeError: 'tuple' object has no attribute 'handle'.

🚀 New Features (Alerts Cog)

Re-wrote tle/cogs/alerts.py from scratch with the following features:

1. Robust Contest Reminders

• Supports Codeforces, AtCoder, LeetCode, and CodeChef.

• Direct API Connections:

  • Codeforces: Uses official API directly (bypassing internal wrapper to prevent attribute errors).

  • AtCoder: Uses Kenkoooo API for stability.

  • Others: Uses kontests.net as a fallback.

• Sends alerts 24 hours, 1 hour, and 15 minutes before contests.

2. Automatic Ranklists & Rating Updates

• Automatically detects when a Codeforces round finishes and ratings are updated.

• Filters results to show only server members.

• Smart Retry Logic: Looks back 14 days with a 5-day timeout to catch delayed Div. 4 rating updates without getting stuck in infinite loops.

• Instant Role Update: Triggers a cache reload immediately after posting results to update Discord role colors faster.

3. Milestone Celebrations

• Detects when a user promotes to a new rank (e.g., Pupil → Specialist).

• Posts a congratulatory embed with the user's Codeforces Profile Picture.

• Automatically triggers the ;plot rating command to show their progress graph.

📝 New Commands

Command	Description
;subscribe list	Shows a dashboard of all active subscriptions for the server.
;subscribe [platform/all]	Subscribe channel to reminders (Codeforces, AtCoder, etc).
;subscribe ratings	Subscribe channel to Ranklists & Rating Updates.
;subscribe milestones	Subscribe channel to Rank-up celebrations.
;unsubscribe [category/all]	Stop receiving specific alerts.
;trigger_alert <contest_id>	Manually force a ranklist update for a specific contest (Admin only).
;test_milestone	Debug command to simulate a rank-up event (Admin only).

[algmyr]

I think it's very unlikely we will accept much other than bugfixes. Fixing the font download is a bugfix I'm happy to accept. Similar for the docker setup issues, but there we have a bunch of PRs already.

[soadmahmud]

Understood. I’ll submit a pull request only if I find any bugs or issues in the existing codebase.

[algmyr]

Extracted the relevant fixes into #543. Added you as co-author to the relevant commits.