# DI Container Configuration Simplification

## Overview

We've simplified the dependency injection container setup across all backend services by creating a new `createServiceContainerFromConfig` function that directly accepts the AppConfig, eliminating repetitive configuration mapping code.

## Before vs After

### Before (30+ lines per service)
```typescript
// In each service's index.ts
const awilixConfig = {
  redis: {
    host: config.database.dragonfly.host,
    port: config.database.dragonfly.port,
    db: config.database.dragonfly.db,
  },
  mongodb: {
    uri: config.database.mongodb.uri,
    database: config.database.mongodb.database,
  },
  postgres: {
    host: config.database.postgres.host,
    port: config.database.postgres.port,
    database: config.database.postgres.database,
    user: config.database.postgres.user,
    password: config.database.postgres.password,
  },
  questdb: {
    enabled: false,
    host: config.database.questdb.host,
    httpPort: config.database.questdb.httpPort,
    pgPort: config.database.questdb.pgPort,
    influxPort: config.database.questdb.ilpPort,
    database: config.database.questdb.database,
  },
};

container = createServiceContainer(awilixConfig);
```

### After (2-3 lines per service)
```typescript
// In each service's index.ts
container = createServiceContainerFromConfig(config, {
  enableQuestDB: false, // Service-specific options
  enableMongoDB: true,
  enablePostgres: true,
  // ... other options
});
```

## Benefits

1. **Code Reduction**: ~30 lines reduced to 2-3 lines per service
2. **Centralized Mapping**: Configuration structure mapping is now in one place
3. **Service-Specific Control**: Each service can enable/disable specific components
4. **Type Safety**: Direct use of AppConfig ensures type safety
5. **Maintainability**: Changes to config structure only need updates in one place

## Service Configurations

### Data Ingestion Service
```typescript
container = createServiceContainerFromConfig(config, {
  enableQuestDB: false,   // Not needed yet
  enableMongoDB: true,    // Stores raw data
  enablePostgres: true,   // Stores metadata
  enableCache: true,      // For rate limiting
  enableQueue: true,      // Job processing
  enableBrowser: true,    // Web scraping
  enableProxy: true,      // Proxy rotation
});
```

### Data Pipeline Service
```typescript
container = createServiceContainerFromConfig(config, {
  enableQuestDB: config.database.questdb?.enabled || false,
  enableMongoDB: true,    // Reads raw data
  enablePostgres: true,   // Writes processed data
  enableCache: true,      // Query caching
  enableQueue: true,      // Job processing
  enableBrowser: false,   // Not needed
  enableProxy: false,     // Not needed
});
```

### Web API Service
```typescript
container = createServiceContainerFromConfig(config, {
  enableQuestDB: false,   // Not needed
  enableMongoDB: true,    // Reads data
  enablePostgres: true,   // Reads data
  enableCache: true,      // API caching
  enableQueue: false,     // No job processing
  enableBrowser: false,   // Not needed
  enableProxy: false,     // Not needed
});
```

## Implementation Details

The new function in `@stock-bot/di/awilix-container.ts`:
- Accepts the standard AppConfig from `@stock-bot/config`
- Maps the nested config structure to what Awilix expects
- Provides sensible defaults for all options
- Only creates services that are enabled for the specific service

## Migration Guide

To migrate a service:

1. Change the import:
   ```typescript
   // Before
   import { createServiceContainer, ... } from '@stock-bot/di';
   
   // After
   import { createServiceContainerFromConfig, ... } from '@stock-bot/di';
   ```

2. Replace the config mapping:
   ```typescript
   // Before
   const awilixConfig = { /* 30+ lines of mapping */ };
   container = createServiceContainer(awilixConfig);
   
   // After
   container = createServiceContainerFromConfig(config, {
     // Service-specific options
   });
   ```

3. Choose which services to enable based on your service's needs

## Result

- **3 services updated**: data-ingestion, data-pipeline, web-api
- **~90 lines of code removed** (30 lines × 3 services)
- **Cleaner, more maintainable codebase**
- **Easier to add new services** with minimal boilerplate