# Box System Architecture (Audit-Only, Immediate Publish)

## 1. Overview
The Box System is a high-performance video content and advertisement platform built using a NestJS monorepo. It consists of:
- Management API (box-mgnt-api)
- Application API (box-app-api)
- Stats API (future: box-stats-api)
- Shared libraries: common, core, db
- Datastores: MySQL, MongoDB, Redis

This updated architecture **removes Maker–Checker**, uses **audit-only trails**, and adopts **immediate publish** behavior.

## 2. RBAC Roles
- **SuperAdmin**: Full system access, including managing users and roles.
- **Manager**: Manage content (ads, videos, channels), system params.
- **Admin**: Similar to Manager with limited permissions.
- **Viewer**: Read-only access.

Only SuperAdmin can:
- Create users
- Assign roles
- Change roles
- Disable accounts

## 3. Audit Trail Model
Kept fields:
- createdBy  
- createdAt  
- updatedBy  
- updatedAt  
- lastUpdated  

These appear in MySQL and MongoDB content models.

## 4. Data Flow
### Mgnt API
User updates → validation → save to DB → update Redis cache → immediate publish.

### App API
Requests go to Redis first:
- Ads served from prebuilt pools
- Videos served partly cached
- Fallback to Mongo where applicable (future extension)

### Stats API (Upcoming)
Handles:
- Event ingestion
- Redis queue/stream
- Workers writing aggregated stats

## 5. Modules
### Mgnt Modules
- Ads  
- Ads Module  
- Videos  
- Categories  
- Channels  
- Tags  
- System Params  
- Upload / File service  

### App Modules
- Ads placement  
- Video listing  
- Homepage aggregation  
- System params  
- Categories