Player-Skill-Rating-and-ELO-System

SKILL_RATING_IMPLEMENTATION_SUMMARY.md

@@ -0,0 +1,202 @@
+# Player Skill Rating and ELO System - Implementation Summary
+
+## Overview
+Successfully implemented a comprehensive ELO-based skill rating system for the quest-service backend. This system provides advanced player skill tracking, matchmaking support, and performance analytics.
+
+## Files Created
+
+### Core Implementation
+1. **`src/skill-rating/entities/player-rating.entity.ts`** - Player rating entity with tier system
+2. **`src/skill-rating/entities/rating-history.entity.ts`** - Rating change history tracking
+3. **`src/skill-rating/entities/season.entity.ts`** - Season management entity
+4. **`src/skill-rating/skill-rating.module.ts`** - Main module configuration
+5. **`src/skill-rating/skill-rating.service.ts`** - Core business logic service
+6. **`src/skill-rating/skill-rating.controller.ts`** - REST API endpoints
+7. **`src/skill-rating/elo.service.ts`** - ELO calculation algorithms
+
+### Data Transfer Objects
+8. **`src/skill-rating/dto/player-rating.dto.ts`** - Player rating DTO
+9. **`src/skill-rating/dto/update-rating.dto.ts`** - Rating update DTO
+
+### Database Migration
+10. **`src/migrations/1738000000000-CreateSkillRatingTables.ts`** - Database schema migration
+
+### Documentation
+11. **`src/skill-rating/README.md`** - Comprehensive system documentation
+
+### Tests
+12. **`src/skill-rating/elo.service.spec.ts`** - Unit tests for ELO calculations
+13. **`test/skill-rating.e2e-spec.ts`** - End-to-end integration tests
+
+## Key Features Implemented
+
+### 1. ELO Rating System
+- **Standard ELO Formula**: Mathematical rating calculation based on player vs puzzle difficulty
+- **Performance Multipliers**: 
+  - Time-based bonuses/penalties (±15 points for speed)
+  - Hint usage penalties (-5 points per hint)
+  - Attempt count penalties (-3 points per extra attempt)
+  - Difficulty weighting (1.0x to 1.5x multiplier)
+- **Adaptive K-Factor**: Ranges from 10-40 based on player experience
+- **Rating Bounds**: Minimum rating of 100 to prevent negative values
+
+### 2. Skill Tier System
+Seven-tier ranking system:
+- **Bronze** (< 1200): New players
+- **Silver** (1200-1399): Developing skills
+- **Gold** (1400-1599): Intermediate players
+- **Platinum** (1600-1799): Advanced players
+- **Diamond** (1800-1999): Expert players
+- **Master** (2000-2399): Elite players
+- **Grandmaster** (≥ 2400): Top-tier players
+
+### 3. Seasonal System
+- **Time-based Seasons**: Default 3-month periods
+- **Configurable Resets**: Optional seasonal rating resets
+- **Status Tracking**: Active/Ended/Reset status management
+- **Season History**: Performance tracking across multiple seasons
+
+### 4. Inactivity Decay
+- **Automatic Decay**: 2 points per week after 30 days of inactivity
+- **Cron Job**: Daily execution at 3 AM
+- **Minimum Protection**: Rating cannot fall below 100
+- **History Tracking**: Decay events recorded in rating history
+
+### 5. Comprehensive Tracking
+- **Detailed History**: Complete record of all rating changes
+- **Performance Metrics**: Time taken, hints used, attempts, completion status
+- **Change Reasons**: Completion, failure, decay, seasonal reset, admin adjustment
+- **Metadata Storage**: Expected win probability, K-factor, bonus factors
+
+## API Endpoints
+
+### Player Rating Management
+- `GET /skill-rating/player/:userId` - Get current player rating
+- `POST /skill-rating/puzzle-completion` - Update rating on puzzle completion
+- `GET /skill-rating/history/:userId` - Get rating change history
+- `GET /skill-rating/rank/:userId` - Get player's leaderboard rank
+
+### Leaderboard
+- `GET /skill-rating/leaderboard` - Get current season leaderboard
+
+### Season Management
+- `GET /skill-rating/season/current` - Get current active season
+- `GET /skill-rating/seasons` - Get all seasons
+- `POST /skill-rating/season/:seasonId/end` - End a season (admin)
+
+## Database Schema
+
+### Player Ratings Table
+- Tracks individual player ratings per season
+- Stores win/loss statistics and streaks
+- Maintains performance statistics
+- Links to users via foreign key
+
+### Rating History Table
+- Records every rating change event
+- Stores performance context (time, hints, attempts)
+- Tracks change reasons and metadata
+- Enables detailed analytics
+
+### Seasons Table
+- Manages seasonal periods
+- Stores season configuration
+- Tracks season status and dates
+- Supports seasonal resets
+
+## Integration Points
+
+### Puzzle Completion Integration
+The system integrates seamlessly with the existing puzzle completion flow:
+
+```typescript
+// In puzzle completion handler
+const completionData = {
+  userId: 'user-uuid',
+  puzzleId: 'puzzle-uuid',
+  puzzleDifficulty: 'medium',
+  difficultyRating: 5,
+  wasCompleted: true,
+  timeTaken: 120,
+  hintsUsed: 0,
+  attempts: 1,
+  basePoints: 100
+};
+
+await skillRatingService.updateRatingOnPuzzleCompletion(completionData);
+```
+
+### Matchmaking Support
+- Provides ELO ratings for skill-based matchmaking
+- Tier information for balanced game creation
+- Performance history for advanced matching algorithms
+
+## Testing Coverage
+
+### Unit Tests
+- ELO calculation accuracy
+- Skill tier assignment
+- Inactivity decay logic
+- Performance multiplier calculations
+
+### Integration Tests
+- Complete rating update flow
+- History tracking
+- Leaderboard functionality
+- Season management
+
+## Configuration Options
+
+### Season Configuration
+```json
+{
+  "decayEnabled": true,
+  "decayPeriodDays": 30,
+  "decayAmount": 2,
+  "minRating": 100,
+  "kFactor": 32,
+  "tierThresholds": {
+    "bronze": 1200,
+    "silver": 1400,
+    "gold": 1600,
+    "platinum": 1800,
+    "diamond": 2000,
+    "master": 2400
+  }
+}
+```
+
+## Performance Considerations
+
+- **Indexing**: Strategic indexes on frequently queried fields
+- **History Pagination**: Configurable history limits
+- **Caching**: Natural caching through season-based data
+- **Batch Operations**: Efficient bulk season management
+
+## Future Enhancements
+
+1. **Glicko-2 Implementation**: More sophisticated rating confidence
+2. **Advanced Analytics**: Rating prediction and trend analysis
+3. **Achievement Integration**: Milestone-based achievements
+4. **Matchmaking API**: Direct integration with game matching
+5. **Rating Volatility**: Track rating stability over time
+6. **Peer Comparison**: Compare performance against similar players
+
+## Acceptance Criteria Verification
+
+✅ **ELO ratings calculated correctly** - Implemented standard ELO with performance multipliers
+✅ **Ratings adjust based on performance and difficulty** - Time, hints, attempts, and difficulty all factor in
+✅ **Tier system functional** - Seven-tier system with proper thresholds
+✅ **Decay applies to inactive players** - Automatic decay after 30 days via cron job
+✅ **Seasonal resets work** - Configurable seasonal reset functionality
+✅ **Tests verify all calculations** - Comprehensive unit and integration tests
+
+## Deployment Notes
+
+1. Run the database migration to create tables
+2. The system is automatically integrated into the main app module
+3. Cron jobs will start automatically with the application
+4. Initial season is created during migration
+5. API endpoints are immediately available
+
+The implementation provides a production-ready skill rating system that enhances player engagement through competitive ranking and performance tracking.

src/app.module.ts

@@ -41,6 +41,7 @@ import { QuestsModule } from './quests/quests.module';
 import { IntegrationsModule } from './integrations/integrations.module';
 import { BlockchainTransactionModule } from './blockchain-transaction/blockchain-transaction.module';
 import { PrivacyModule } from './privacy/privacy.module';
+import { SkillRatingModule } from './skill-rating/skill-rating.module';
 import { WalletAuthModule } from './auth/wallet-auth.module';
 
 @Module({
@@ -122,6 +123,7 @@ import { WalletAuthModule } from './auth/wallet-auth.module';
     IntegrationsModule,
     BlockchainTransactionModule,
     PrivacyModule,
+    SkillRatingModule,
     WalletAuthModule,
   ],
   controllers: [AppController],