MateCheck 🤝

A Rust application that helps you stay in touch with friends by tracking calendar meetings and sending automated reminders via Telegram and WhatsApp.

Status: ✅ Production Ready - Fully automated with GitHub Actions + Firebase state

What It Does

MateCheck connects to your Google Calendar, identifies meetings with friends, and sends you Telegram reminders when you haven't seen someone in a while. It runs automatically every day via GitHub Actions.

Features ✅

Core Functionality

• Google Calendar Integration - Fetches events with OAuth 2.0 authentication
• Smart Friend Matching - Matches events to friends by:
  • Email addresses (primary method)
  • Event titles with name/alias matching (fallback)
• All-Day Event Support - Tracks both timed and all-day calendar events
• Recurring Event Filtering - Automatically filters out birthdays and anniversaries

Configuration Management

• Firestore Configuration - Store friends config in Firebase Firestore
• Web UI - Mobile-responsive web interface for managing friends
  • Add, edit, and delete friends via intuitive UI
  • No YAML editing required
  • Deployed on GitHub Pages
  • Google Sign-In authentication
• Automatic YAML Fallback - Seamlessly falls back to local friends.yaml if Firestore unavailable

Smart Reminders

• Automatic Early Warnings - Reminds you 15% before your target frequency
  • 10 days → remind at day 8 (2 days early)
  • 30 days → remind at day 25 (5 days early)
  • 45 days → remind at day 38 (7 days early)
• Future Meeting Awareness - Skips reminders if meeting already scheduled
• Friend Aliases - Match calendar events with nicknames (e.g., "Lou" matches "Louise")
• Snooze Functionality ⭐ NEW - Temporarily pause reminders for specific friends
  • Click inline buttons in Telegram: 3 days, 1 week, or 2 weeks
  • Powered by Firebase Firestore + Cloud Functions
  • Fail-open design (works even if Firebase is unavailable)
• Do Not Disturb Mode - Automatically pauses ALL reminders during specific periods
  • Create all-day calendar events with 🔕 emoji or [DND] text
  • Examples: "🔕 Vacation in Paris", "[DND] Focus Week"
  • Works with single-day and multi-day events
  • Only all-day events count (timed events ignored)

Notifications

• Telegram Integration - Sends formatted reminders with clickable links
• WhatsApp Support - Creates WhatsApp deep links for friends without Telegram
• Smart Fallback - Telegram username → WhatsApp → plain name

Automation

• GitHub Actions - Runs automatically on schedule
  • Weekdays: 8:00 AM Berlin time
  • Weekends: 9:30 AM Berlin time
• Manual Testing - Can be triggered manually for testing

Tech Stack

• Language: Rust 🦀 (2021 edition) + TypeScript (Cloud Functions)
• APIs: Google Calendar API v3, Telegram Bot API
• Database: Firebase Firestore (state persistence + config storage)
• Backend: Firebase Cloud Functions (webhook for button callbacks)
• Frontend: Vanilla JavaScript + Firebase SDK (web UI)
• Key Crates: tokio, serde, chrono, clap, reqwest, firestore
• Auth: OAuth 2.0 for Google Calendar, Firebase Service Account, Google Sign-In (web UI)
• CI/CD: GitHub Actions
• Hosting: GitHub Pages (web UI)
• Tests: 79 passing tests (Rust)

Project Structure

matecheck/
├── src/
│   ├── main.rs              # CLI entry point
│   ├── config.rs            # Friend configuration loader (Firestore + YAML)
│   ├── calendar/            # Google Calendar integration
│   │   ├── client.rs        # OAuth & API client
│   │   ├── types.rs         # Event types
│   │   └── dnd.rs           # Do Not Disturb detection
│   ├── firestore/           # Firebase Firestore integration
│   │   ├── client.rs        # Firestore connection
│   │   ├── snoozes.rs       # Snooze repository (CRUD)
│   │   └── types.rs         # Firestore data types
│   ├── matcher.rs           # Event-to-friend matching logic
│   ├── reminder/
│   │   └── engine.rs        # Reminder calculation logic
│   └── telegram/            # Telegram integration
│       ├── client.rs        # Bot API client
│       └── formatter.rs     # Message formatting + inline buttons
├── docs/                    # Web UI (GitHub Pages)
│   ├── index.html           # Friends management interface
│   ├── README.md            # Web UI setup instructions
│   └── SETUP.md             # Deployment guide
├── functions/               # Firebase Cloud Functions (TypeScript)
│   ├── src/
│   │   └── index.ts         # Webhook handler for button callbacks
│   ├── package.json
│   └── tsconfig.json
├── .github/
│   └── workflows/
│       └── daily-check.yml  # Automated deployment
├── friends.yaml             # Fallback config (gitignored, optional)
├── friends.example.yaml     # Example configuration
├── firebase.json            # Firebase configuration
└── Cargo.toml              # Rust dependencies

Setup

Prerequisites

• Rust (latest stable)
• Node.js 22+ (for Firebase Functions)
• Google Calendar API credentials
• Telegram bot token
• Firebase project (free tier)
• GitHub account (for automation)

Local Development

1. Clone and configure:

   git clone <your-repo>
   cd matecheck
   cp friends.example.yaml friends.yaml
   # Edit friends.yaml with your friends

2. Set up Google Calendar API:

   • Create a project in Google Cloud Console
   • Enable Google Calendar API
   • Create OAuth 2.0 credentials (Desktop app)
   • Download as credentials.json in project root
   • Run once locally to authenticate: cargo run -- --debug

3. Set up Telegram Bot:

   • Create bot via @BotFather
   • Get your chat ID: cargo run --bin get_chat_id
   • Create .env file:

     TELEGRAM_BOT_TOKEN=your_bot_token
     TELEGRAM_CHAT_ID=your_chat_id
     

4. Run locally:

   cargo run                    # Normal run
   cargo run -- --debug         # Debug mode with verbose output
   cargo run -- --test-telegram # Test Telegram integration

GitHub Actions Deployment

1. Push code to GitHub:

   git push origin master

2. Set up Firebase (optional, for snooze feature):

   • Create Firebase project
   • Enable Firestore Database
   • Enable billing (required for Secret Manager, but stays on free tier)
   • Create service account, download as service-account.json
   • Deploy Cloud Function: cd functions && npm install && firebase deploy --only functions
   • Set Telegram webhook to Cloud Function URL

3. Add repository secrets (Settings → Secrets → Actions):

   • GOOGLE_CREDENTIALS - Content of credentials.json
   • GOOGLE_OAUTH_TOKEN - Content of token.json (refresh tokens last 6+ months)
   • TELEGRAM_BOT_TOKEN - Your bot token
   • TELEGRAM_CHAT_ID - Your chat ID
   • FRIENDS_CONFIG - Content of friends.yaml
   • FIREBASE_SERVICE_ACCOUNT - Content of service-account.json (if using snooze)

4. Test workflow:

   • Go to Actions tab
   • Select "Daily Friend Reminder Check"
   • Click "Run workflow"

5. Done! Reminders run automatically on schedule.

Web UI Deployment (Optional but Recommended)

Deploy the friends management interface to GitHub Pages:

1. Enable GitHub Pages:

   • Go to repo Settings → Pages
   • Source: Deploy from a branch
   • Branch: master, Folder: /docs
   • Save and wait 1-2 minutes

2. Configure Firebase for web access:

   • Follow the detailed setup guide in docs/SETUP.md
   • Enable Google Sign-In authentication
   • Update Firestore security rules
   • Add your GitHub Pages domain to authorized domains

3. Access your web UI:

   • Visit https://YOUR_USERNAME.github.io/matecheck/
   • Sign in with Google
   • Manage friends through the interface

See docs/README.md for complete setup instructions.

Configuration

MateCheck supports two configuration methods:

1. Firestore (Recommended) - Store friends in Firebase Firestore, edit via web UI
2. YAML (Fallback) - Local friends.yaml file (automatically used if Firestore unavailable)

Firestore Configuration (via Web UI)

The easiest way to manage friends is through the web UI:

1. Deploy web UI to GitHub Pages (see docs/SETUP.md)
2. Visit your GitHub Pages URL
3. Sign in with Google
4. Add/edit/delete friends via the interface

Changes take effect immediately - no deployment needed!

friends.yaml Example (Fallback)

friends:
  - id: "alice"
    name: "Alice Smith"
    email: "alice@example.com"
    telegram_username: "alice_tg"
    frequency_days: 30

  - id: "bob"
    name: "Bob Johnson"
    email: "bob@example.com"
    whatsapp_phone: "+1 234 567 8900" # For friends without Telegram
    aliases: ["Bobby"] # Match "Bobby" in calendar
    frequency_days: 14

  - id: "charlie"
    name: "Charlie"
    frequency_days: 60 # No contact info = plain name

Field Reference

• id (required) - Unique identifier
• name (required) - Friend's display name
• email (optional) - For calendar matching
• telegram_username (optional) - Creates t.me/username link
• whatsapp_phone (optional) - Creates WhatsApp link (+ and spaces auto-stripped)
• aliases (optional) - Alternative names for calendar matching
• frequency_days (required) - How often you want to meet (in days)

How It Works

1. Loads Active Snoozes - Queries Firestore for snoozed friends (fail-open if unavailable)
2. Fetches Calendar Events - Gets events from last 90 days + future events
3. Checks Do Not Disturb - Exits early if DND event detected (skips all reminders)
4. Matches Friends - Identifies which events involved which friends
5. Calculates Last Meeting - Finds most recent past meeting per friend
6. Checks Future Meetings - Looks for upcoming scheduled meetings
7. Applies Smart Logic:
   • Filters out snoozed friends
   • Reminds at 85% of target frequency (15% buffer)
   • Skips reminder if meeting already scheduled
   • Ignores recurring events (birthdays)
8. Sends Telegram Message - Formatted list with inline snooze buttons
9. Button Callback - Cloud Function handles button clicks, updates Firestore

Development

Run Tests

cargo test                    # All tests
cargo test --lib              # Library tests only
cargo test test_name          # Specific test

Utilities

cargo run --bin get_chat_id   # Get your Telegram chat ID

License

MIT License - See LICENSE file

Learning Project

This project was built as a learning exercise to understand Rust coming from a Go background. It covers:

• Rust ownership, borrowing, and lifetimes
• Async/await with tokio
• OAuth 2.0 authentication
• API integration (Google Calendar, Telegram, Firestore)
• Firebase Cloud Functions (TypeScript)
• State persistence with Firestore
• GitHub Actions CI/CD
• Error handling with Result types
• Testing and test-driven development
• Graceful degradation (fail-open patterns)