# Nexstar Graphs

Real-time sales and stock dashboard for Nexstar. The app receives Tiny ERP data through n8n webhooks, stores it in PostgreSQL, and renders sales, products, clients, stock, and WhatsApp campaign data in a React dashboard.

## Stack

- Frontend: React, TypeScript, Vite, Tailwind CSS, Recharts
- Backend: Node.js, Express, PostgreSQL, JWT, API-key webhook auth
- Runtime: Docker Compose, Nginx, n8n

## Main Flows

### Sales Ingestion

```text
n8n -> POST /api/data -> PostgreSQL orders -> dashboard
```

The endpoint accepts a single order item or an array. Requests must include:

```text
x-api-key: <API_KEY>
Content-Type: application/json
```

### Stock Ingestion

```text
n8n -> POST /api/stock -> PostgreSQL stock + campaign queue
```

Positive stock deltas are queued for WhatsApp campaigns. The scheduled processor groups pending queue rows by base product name and sends a campaign only when the accumulated pending delta reaches at least `100`.

### Scheduled WhatsApp Campaigns

```text
n8n schedule at 12:00/18:00 BRT
-> POST /api/internal/process-stock-campaigns
-> backend calls N8N_WHATSAPP_TRIGGER_URL
-> n8n WhatsApp workflow sends templates
```

The scheduled endpoint is API-key protected and returns a summary:

```json
{
  "claimed": 0,
  "sentGroups": 0,
  "skippedGroups": 0,
  "failedGroups": 0,
  "pendingBelowThresholdGroups": 0
}
```

## Local Development

Start PostgreSQL:

```bash
docker compose up -d db
```

Start the backend:

```bash
cd backend
npm install
npm start
```

Start the frontend:

```bash
npm install
npm run dev
```

Default local URLs:

```text
Frontend: http://127.0.0.1:3001
Backend:  http://127.0.0.1:3004
```

Vite may choose a different frontend port if `3001` is already in use.

## Environment

Copy `.env.example` and configure production secrets in the runtime environment:

```text
POSTGRES_USER
POSTGRES_PASSWORD
POSTGRES_DB
API_KEY
N8N_WHATSAPP_TRIGGER_URL
ADMIN_EMAIL
ADMIN_PASSWORD
JWT_SECRET
```

## Validation

```bash
npm run lint
npm run build
```

For backend syntax checks:

```bash
cd backend
node --check index.js
node --check services/campaignService.js
node --check services/stockService.js
```