✨ feat: Enhance /daily command with automatic monthly challenge fetching

[cxyfer]

Summary

• Automatically fetch entire month's daily challenges when queried date not found in database
• Prioritize processing requested date first for immediate response
• Process remaining dates in background task to populate database

Details

When users query a historical date using /daily command:

1. First checks database for cached data
2. If not found, fetches entire month's challenges from LeetCode API
3. Immediately processes and returns the requested date
4. Remaining dates are processed in background with 0.5s delay between each

Benefits

• Reduces response time from 30+ seconds to 1-2 seconds
• Populates database for future queries automatically
• No blocking of user interaction
• Graceful error handling for background tasks

Limitations

• Only works for leetcode.com domain (monthly API not available on leetcode.cn)
• Background task adds slight load but includes delays to prevent API overwhelm

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

Enhance the /daily command to automatically fetch and cache an entire month’s challenges when a specific date is missing, returning the requested date immediately and processing the rest in the background.

• Integrated fetch_monthly_daily_challenges into get_daily_challenge with priority handling for the requested date.
• Added background task support (tracking, semaphore control, shutdown) for non-blocking backfill.
• Updated CLI (--monthly flag), configuration (monthly_fetch_delay), and comprehensive unit tests.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/test_monthly_fetch.py	New async tests covering monthly fetch success, errors, background, concurrency, and cancellation.
tests/README.md	Instructions for running tests, including setup and commands.
leetcode.py	Added monthly fetch methods, background task management, semaphore control, and CLI integration.
config.toml.example	Introduced monthly_fetch_delay setting under the [leetcode] section.

Comments suppressed due to low confidence (2)

tests/README.md:6

• [nitpick] Clarify what uv refers to or provide a link/reference, since it may not be familiar to all users and could cause confusion during setup.

This project uses `uv` as the package manager. Make sure pytest and required dependencies are installed:

leetcode.py:966

• Ensure the configuration key path matches the structure in config.toml; consider accessing monthly_fetch_delay directly from the leetcode section rather than via a dotted key to avoid mismatches.

                            delay = config.get("leetcode.monthly_fetch_delay", 0.5)

[Copilot]

[nitpick] The monthly-fetch block in get_daily_challenge is fairly large and duplicates processing logic; extracting it into a dedicated helper method would improve readability and maintainability.

Suggested change

	logger.info(f"No data found for {date_str}, attempting to fetch monthly data...")
	year, month, _ = date_str.split('-')
	year_int = int(year)
	month_int = int(month)
	monthly_data = await self.fetch_monthly_daily_challenges(year_int, month_int)
	if monthly_data and 'challenges' in monthly_data:
	logger.info(f"Fetched {len(monthly_data['challenges'])} daily challenges for {year}-{month}")
	info = await self.handle_monthly_fetch(date_str, domain)
	if info:
	return info

[Copilot]

[nitpick] Challenges are fetched sequentially inside the loop, so the semaphore never limits concurrent requests; consider spawning tasks (e.g., with asyncio.gather) up to the semaphore limit to better leverage concurrency.