# Authentication & Authorization

Negareh API supports two actor types — **users** (customers) and **admins** (back-office). Both authenticate via **phone OTP** and receive **JWT access tokens** with **refresh tokens**.

## Overview

```
┌─────────────┐     OTP request      ┌─────────────┐
│   Client    │ ──────────────────►  │  Auth API   │
│             │ ◄──────────────────  │  (SMS/Redis)│
└─────────────┘     OTP code         └─────────────┘
       │                                    │
       │         OTP verify                 │
       └──────────────────────────────────► │
                                            ▼
                              ┌─────────────────────────┐
                              │ Access JWT + Refresh    │
                              │ token (hashed in DB)    │
                              └─────────────────────────┘
```

## OTP flow

### User (public)

| Endpoint | Method | Description |
|----------|--------|-------------|
| `/public/auth/otp/request` | POST | Send OTP to phone (creates user on verify) |
| `/public/auth/otp/verify` | POST | Verify OTP → returns tokens + user profile |
| `/public/auth/refresh` | POST | Exchange refresh token for new token pair |

### Admin

| Endpoint | Method | Description |
|----------|--------|-------------|
| `/admin/auth/otp/request` | POST | Send OTP (phone must exist in `admins` table) |
| `/admin/auth/otp/verify` | POST | Verify OTP → returns tokens + admin profile |
| `/admin/auth/refresh` | POST | Exchange refresh token for new token pair |

### OTP details

- Phone numbers are normalized to local format via `normalizePhoneToLocal()` (`09xxxxxxxxx`).
- OTP codes are 5-digit numeric values stored in **Redis** with TTL (`OTP_EXPIRATION_TIME`, default 240 seconds).
- OTP request endpoints are rate-limited (`@Throttle`: 3 requests per 180 seconds).
- SMS delivery uses SMS.ir patterns (configured via `SMS_*` env vars).

### Request / verify DTOs

```typescript
// Request OTP
{ "phone": "09362532122" }

// Verify OTP
{ "phone": "09362532122", "otp": "12345" }
```

## JWT tokens

### Access token

- Signed with `JWT_SECRET`.
- Expiration: `JWT_EXPIRATION_TIME` (seconds).
- Sent as `Authorization: Bearer <token>`.

**User payload:**

```typescript
{ userId: string }
```

**Admin payload:**

```typescript
{ adminId: string }
```

### Refresh token

- Opaque 64-character hex string (not a JWT).
- Stored **hashed** (SHA-256) in the `refresh_tokens` table.
- Expiration: `REFRESH_TOKEN_EXPIRE` (days).
- Rotated on each refresh — old token is deleted in the same transaction as the new pair.
- Type field distinguishes `user` vs `admin` tokens.

### Refresh response shape

```json
{
  "accessToken": { "token": "...", "expire": 1710000000000 },
  "refreshToken": { "token": "...", "expire": 1711000000000 }
}
```

`expire` values are Unix timestamps in milliseconds.

## Guards

### `AuthGuard` (users)

- Applied with `@UseGuards(AuthGuard)` on public routes that require a logged-in user.
- Verifies JWT from `Authorization` header.
- Sets `request.userId` from the token payload.
- Extract identity in controllers with `@UserId()`.

### `AdminAuthGuard` (admins)

- Applied with `@UseGuards(AdminAuthGuard)` on admin routes.
- Verifies JWT and sets `request.adminId`.
- Extract identity with `@AdminId()`.
- Reads `@Permissions(...)` metadata from the handler/class for RBAC checks.

## Role-based access control (RBAC)

Admins have a **role** with attached **permissions**. Permission names are defined in `PermissionEnum` (e.g. `view_orders`, `create_invoice`, `manage_admins`).

### Declaring required permissions

```typescript
@Get('admin/orders')
@UseGuards(AdminAuthGuard)
@Permissions(PermissionEnum.VIEW_ORDERS)
findAllAsAdmin(@Query() dto: FindOrdersDto) {
  return this.orderService.findOrdersAsAdmin(dto);
}
```

The `@Permissions()` decorator stores required permission keys in metadata. `AdminAuthGuard` reads them via `Reflector`.

> **Note:** Permission enforcement against the database/cache is partially implemented. The guard structure and decorators are in place; ensure permission checks are active before relying on them in production.

## Route prefixes

Routes are namespaced by audience in the controller path (not a global prefix):

| Prefix | Audience | Guard |
|--------|----------|-------|
| `public/` | End users | `AuthGuard` (when protected) |
| `admin/` | Back-office | `AdminAuthGuard` |

Unauthenticated routes use `public/auth/...` or `admin/auth/...` without guards.

## WebSocket auth

Admin WebSocket connections use `WsAdminAuthGuard` in the notifications module. Follow the same JWT verification pattern as HTTP admin auth.

## Environment variables

| Variable | Purpose |
|----------|---------|
| `JWT_SECRET` | Signing key for access tokens |
| `JWT_EXPIRATION_TIME` | Access token TTL (seconds) |
| `REFRESH_TOKEN_EXPIRE` | Refresh token TTL (days) |
| `OTP_EXPIRATION_TIME` | OTP cache TTL (seconds) |
| `REDIS_URI` / `REDIS_HOST` | OTP and cache storage |
| `SMS_BASE_URL`, `SMS_API_KEY`, `SMS_PATTERN_OTP` | SMS delivery |

## Security practices

- Refresh tokens are hashed at rest; raw tokens are only returned once to the client.
- Token refresh runs inside a database transaction to prevent race conditions.
- Rate limiting on OTP and refresh endpoints reduces brute-force risk.
- Never log tokens, OTP codes, or secrets.
- Use HTTPS in production; CORS is enabled with `credentials: true` for cookie support if needed.

## Client integration checklist

1. Request OTP with normalized Iranian mobile number.
2. Verify OTP and store both `accessToken.token` and `refreshToken.token`.
3. Send `Authorization: Bearer <accessToken>` on protected requests.
4. On 401, call the refresh endpoint with the refresh token.
5. Replace stored tokens with the new pair from the refresh response.