# 🧠 Backend Developer Take-Home Assignment: Rule Engine API

## 📌 Objective

Build a lightweight **Rule Engine API** using **Django** and **Django REST Framework**. The system should allow admins to define dynamic rules and let clients evaluate JSON payloads against those rules. The outcome should be either **APPROVED** or **REJECTED** based on whether the payload satisfies the rules.

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## 🎯 Requirements

### 1. Authentication

Implement JWT-based authentication.

- Two roles: `admin` and `client`.
- **Admins** can create and manage rules.
- **Clients** can only evaluate payloads.

### 2. Rule Management

Admins should be able to:

- Create, list, update, and delete rules.
- Each rule consists of:
- `name`: A unique rule name.
- `condition`: JSON logic to define conditions (see example below).
- `is_active`: Boolean flag.

#### 🧾 Example Rule Condition

{
  "field": "age",
  "operator": ">=",
  "value": 18
}

Supported operators:

- `==`, `!=`, `>`, `<`, `>=`, `<=`, `contains`

**Bonus**: Support nested conditions using `AND`, `OR`.

### 3. Payload Evaluation Endpoint
Create an endpoint:

POST /api/evaluate/

✅ Input Example

{
  "rules": ["Minimum Age Check", "Country Check"],
  "payload": {
    "age": 21,
    "country": "Thailand"
  }
}

🔄 Output Example

{
  "result": "APPROVED",
  "passed_rules": ["Minimum Age Check", "Country Check"],
  "failed_rules": []
}

If **at least one rule fails**, the result should be `"REJECTED"`.

✅ Bonus Points
- Unit tests for rule evaluation logic
- Swagger/OpenAPI documentation
- Optional: Background job queue (e.g., Celery) to evaluate payloads asynchronously
- Docker setup

## 🔍 Evaluation Criteria
|Area |What We're Looking For |
|--|--|
|Code Quality | Clean, readable, modular code |
|Django/DRF Practices| Correct use of models, serializers, viewsets, etc.|
|Business Logic | Robust and flexible rule evaluation|
|Security | Role-based access control |
| Testing (Bonus) | Unit/integration tests for rules and evaluation logic |
| Documentation (Bonus) | Instructions for setup and API usage

## 📦 Submission Guidelines
- Share a GitHub repo or downloadable zip file.
- Include setup instructions in a `README.md`.
- Keep it simple but functional — you are not expected to build a production-grade engine.