# Modularization Summary

## New File Structure

```
src/
├── index.ts                  # Main worker entry point (clean, ~90 lines)
├── types.ts                  # All TypeScript interfaces (complete)
├── config.ts                 # USE_CASE_CONFIGS and i18n messages (complete)
├── utils.ts                  # Utility functions (~650 lines, complete)
├── handlers/
│   ├── health.ts            # GET /api/health (complete)
│   ├── servers.ts           # GET /api/servers (complete)
│   └── recommend.ts         # POST /api/recommend (~1100 lines)
```

## Functions by Module

### index.ts (NEW)
- Main fetch handler
- Route handling
- CORS setup
- Rate limit checking

### types.ts (COMPLETE)
All interfaces extracted from original index.ts

### config.ts (COMPLETE)
- USE_CASE_CONFIGS
- i18n messages

### utils.ts (COMPLETE)
- jsonResponse()
- hashString()
- sanitizeCacheValue()
- generateCacheKey()
- escapeLikePattern()
- Type guards: isValidServer(), isValidVPSBenchmark(), etc.
- validateRecommendRequest()
- getAllowedOrigin()
- findUseCaseConfig()
- getDauMultiplier()
- getActiveUserRatio()
- estimateBandwidth()
- getProviderBandwidthAllocation()
- calculateBandwidthInfo()
- checkRateLimit()

### handlers/health.ts (COMPLETE)
- handleHealth()

### handlers/servers.ts (COMPLETE)
- handleGetServers()

### handlers/recommend.ts (TO CREATE)
- handleRecommend() - Main handler
- queryCandidateServers() - D1 query for servers
- queryBenchmarkData() - Phoronix benchmarks
- getBenchmarkReference() - Match benchmarks to servers
- queryVPSBenchmarks() - Geekbench data
- queryVPSBenchmarksBatch() - Batch benchmark query
- formatVPSBenchmarkSummary() - Format for AI prompt
- formatBenchmarkSummary() - Format for AI prompt
- queryTechSpecs() - Tech stack specs
- formatTechSpecsForPrompt() - Format for AI prompt
- getAIRecommendations() - OpenAI GPT-4o-mini call
- parseAIResponse() - Parse AI JSON response

## Migration Status

✅ types.ts - DONE
✅ config.ts - DONE
✅ utils.ts - DONE
✅ handlers/health.ts - DONE
✅ handlers/servers.ts - DONE
⏳ handlers/recommend.ts - IN PROGRESS (extracted functions ready)
⏳ index.ts - NEW version created (index.new.ts)

## Next Steps

1. Create handlers/recommend.ts with all extracted functions
2. Backup original index.ts
3. Replace index.ts with index.new.ts
4. Run TypeScript typecheck
5. Test with `npm run dev`

## Size Reduction

Original: index.ts (2381 lines)
New distribution:
- index.ts: ~90 lines (97% reduction)
- types.ts: ~175 lines
- config.ts: ~140 lines
- utils.ts: ~650 lines
- handlers/: ~1300 lines total

Total: ~2355 lines (modular + maintainable)