feat: Comprehensive OpenAPI specification with 30+ endpoints and detailed schemas

[Copilot]

Overview

This PR addresses the request to enhance the OpenAPI specification by adding comprehensive documentation for all available endpoints. The specification has been expanded from 23 to 30 endpoints with detailed schemas, proper validation, and enhanced descriptions.

Key Changes

🎯 Endpoint Coverage (30 total endpoints)

• Problems API (11 endpoints): Enhanced problem filtering with difficulty-specific endpoints (/problems/easy, /problems/medium, /problems/hard), topic-based filtering (/problems/by-tag/{tag}), search functionality (/problems/search), and popular problems
• User Details API (10 endpoints): Comprehensive user profile endpoints including badges, submissions, calendar data, and statistics
• Contest API (3 endpoints): Contest rankings, history, and performance data
• Discussion API (3 endpoints): Discussion topics, comments, and trending discussions
• Statistics API (2 endpoints): Language statistics and global platform metrics
• Root API (1 endpoint): Enhanced API documentation endpoint

📋 Schema Enhancements

Added 15 comprehensive schema definitions based on actual response structures:

• DailyProblem - Detailed daily challenge structure
• ProblemList - Paginated problem listing with metadata
• UserProfile - Complete user profile information
• UserBadges - Badge system with achievements
• LanguageStats - Programming language usage statistics
• And 10 additional schemas for various data types

🔧 Technical Improvements

• Parameter Validation: Added proper validation rules, examples, and enum constraints
• Error Handling: Comprehensive error response documentation with proper HTTP status codes
• Response Schemas: Replaced generic type: object with detailed, structured schemas
• Server Configuration: Added both production and local development server endpoints
• Tag Organization: Logical grouping of endpoints into 6 categories for better navigation

🚀 New Endpoint Variations

# Difficulty-specific problem endpoints
GET /problems/easy
GET /problems/medium  
GET /problems/hard

# Topic-based filtering
GET /problems/by-tag/{tag}

# Search functionality
GET /problems/search?q=binary+tree

# Popular problems
GET /problems/popular

# Global statistics
GET /statistics/global

📝 Enhanced Documentation

• Detailed descriptions for all endpoints with usage examples
• Comprehensive parameter documentation with validation rules
• Realistic response examples based on actual code analysis
• Improved error handling with proper status codes and messages

Validation Results

• ✅ OpenAPI 3.0.3 compliant
• ✅ All existing tests pass
• ✅ Build successful
• ✅ JSON syntax validated
• ✅ All endpoints have proper operations and responses

Benefits

1. Developer Experience: Clear, comprehensive API documentation with examples
2. API Discovery: 30 well-documented endpoints covering all functionality
3. Integration Ready: Proper schemas enable code generation and validation
4. Maintainability: Structured documentation that's easy to update and extend

The enhanced OpenAPI specification now provides a complete and accurate representation of the API's capabilities, making it easier for developers to integrate with and understand the available endpoints.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• leetcode.com
  • Triggering command: node /home/REDACTED/work/alfa-leetcode-api/alfa-leetcode-api/node_modules/.bin/ts-node src/index.ts (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Created from VS Code via the GitHub Pull Request extension.

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