COVID-19 Data Analytics Bot 🤖

Intelligent Telegram bot providing real-time COVID-19 statistics with automated data validation and multi-format support. Built with Node.js and modern API integration.

Live Demo: @stay_aware_of_covid19_bot

🚀 Key Features

• Real-time Data: Fetches live COVID-19 statistics from Johns Hopkins University via disease.sh API
• Multi-language Support: Accepts country names in English, Russian, and other languages
• Smart Fallback Logic: Automatically switches between today's/yesterday's data when API returns zero values
• Data Validation: Handles null/undefined values gracefully with "Нет данных" placeholders
• User-friendly Interface: Interactive keyboard with flags, emoji-enhanced responses
• Error Handling: Robust retry logic for API failures and invalid country names

🛠 Technical Stack

• Runtime: Node.js
• Framework: Telegraf (Telegram Bot Framework)
• API Integration: disease.sh (Johns Hopkins University data)
• Data Processing: Custom formatting with toLocaleString() for readability
• Environment: dotenv for secure token management
• Development: nodemon for auto-restart during development

🎯 Challenges & Solutions

Challenge 1: API Migration

Problem: Original covid19-api library became deprecated and returned HTML errors instead of JSON. Solution: Migrated to direct API integration with disease.sh, implementing custom HTTPS request handling with proper error management.

Challenge 2: Data Accuracy

Problem: Many countries report 0 new cases for "today" due to reporting delays. Solution: Implemented intelligent fallback using yesterday's data when today returns 0, ensuring users always see meaningful statistics.

Challenge 3: Multi-format Input

Problem: Users input country names with flags (🇺🇸 США), mixed case, or various spellings. Solution: Created comprehensive mapping dictionary with 100+ country aliases and flag-to-name conversion.

📊 Data Processing Pipeline

1. Input Sanitization: Removes emoji flags, special characters, normalizes case
2. Country Mapping: Extensive dictionary supporting 100+ countries in multiple languages
3. API Request: Direct HTTPS call to disease.sh with retry logic
4. Data Validation: Checks for null/NaN/undefined before formatting
5. Response Formatting: Structured Markdown output with timestamps

🌟 Usage Examples

Users can interact with the bot using:

• Button clicks: 🇺🇸 США, 🇷🇺 Россия, 🇰🇿 Казахстан
• Text input: "USA", "usa", "США", "Россия", "russia"
• Mixed formats: "🇺🇸 USA", "russia", "Турция"

📝 What I Learned

• API Integration: Handling rate limits, errors, and data inconsistencies in third-party APIs
• Data Validation: Implementing robust null-checking and fallback strategies for unreliable data sources
• Internationalization: Supporting multiple input formats and languages in a single interface
• Error Resilience: Building systems that gracefully handle failures while maintaining user experience
• Telegram Bot Architecture: Understanding webhook vs polling, message handling, and UI design with keyboards

🚀 Deployment

Railway (Recommended)

1. Push code to GitHub
2. Connect Railway to repository
3. Add environment variable BOT_TOKEN
4. Deploy automatically

Fly.io

1. Install flyctl: brew install flyctl
2. Login: fly auth login
3. Initialize: fly launch
4. Set secret: fly secrets set BOT_TOKEN=your_token
5. Deploy: fly deploy

📂 Project Structure

├── bot.js           # Main bot logic
├── constants.js     # Country list for /help
├── package.json     # Dependencies
├── .env.example     # Environment variables template
└── README.md        # Documentation

🔒 Security

• Tokens and secrets stored in environment variables (never commit to Git!)
• .gitignore protects sensitive files
• Environment examples provided in .env.example

📞 Contacts

• Telegram Bot: @stay_aware_of_covid19_bot
• GitHub: nodejs-telegram-bot-covid19

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