# 🌐 Aggregated Insights API

An ASP.NET Core Web API that aggregates data from three external sources — weather, tech news,
and global country metadata — into a single unified response. Designed for fast, parallel data fetching,
clean JSON output, and enhanced control via sorting, filtering, authentication, and rate limiting.

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## 🚀 Features

- 🌤 **Weather Data** from Open-Meteo
- 📰 **Tech News Item** from Hacker News API
- 🌍 **Country Metadata** from World Bank API
- 🔐 **JWT Authentication** for secure access
- 📊 **Request Performance Monitoring** via custom middleware
- ⏱️ **Rate Limiting** per IP using ASP.NET Core's built-in limiter
- 📈 **Logging** with Serilog (console + rolling file logs)

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## 📦 Aggregated Endpoint

### `GET /api/Aggregation`

Retrieves weather info, a Hacker News item, and country metadata in one call.

#### 🔧 Query Parameters

| Name               | Type     | Required | Description                                                                 |
|--------------------|----------|----------|-----------------------------------------------------------------------------|
| `city`             | string   | ✅       | City name for weather lookup                                               |
| `hackerNewsItemId` | int      | ✅       | Hacker News item ID                                                        |
| `countryCode`      | string   | ✅       | ISO 2-letter country code (e.g. `GR`)                                      |
| `sortBy`           | enum     | ❌       | Optional. Sort response by `Date`                                          |
| `sortOrder`        | enum     | ❌       | Optional. Sort direction: `Asc` or `Desc`                                  |
| `category`         | enum     | ❌       | Optional. Filter response by category: `Weather`, `HackerNews`, `WorldBank` |

---

### 📘 Example Request

```http
GET https://localhost:7145/api/Aggregation?City=Athens&CountryCode=GR&HackerNewsItemId=1312&Category=HackerNews

---

✅ Example Response

{
  "items": [
    {
      "source": "HackerNews",
      "category": "HackerNews",
      "date": "2007-02-27T01:48:57Z",
      "rawData": {
        "by": "Alex3917",
        "id": 1312,
        "parent": 1245,
        "text": "...",
        "time": 1172548137,
        "type": "comment",
        "createdAt": "2007-02-27T01:48:57Z",
        "category": "HackerNews"
      }
    }
  ]
}

---

🔐 Authentication

This API uses JWT Bearer Tokens for authentication.

🔑 Login Endpoint

POST /api/Auth/login

Request Body

{
  "username": "your-username",
  "password": "your-password"
}

⚠️ Note: Password validation is currently simulated. Replace with real user authentication logic in production.

Response

{
  "token": "your-jwt-token"
}

Use this token in the Authorization header for authenticated requests:

Authorization: Bearer your-jwt-token

---

⏱️ Rate Limiting

• Policy: Fixed window
• Limit: 10 requests per minute per IP
• Queue: Up to 5 requests
• Applied via [EnableRateLimiting] on controllers

---

📊 Request Stats

GET /api/Stats

Returns average execution time per endpoint.

Example Response

{
  "/api/Aggregation": {
    "averageDurationMs": 123.45,
    "requestCount": 10
  }
}

---

🧱 Architecture Overview

• OpenMeteoService → Fetches weather data using static city coordinates
• HackerNewsService → Retrieves a single Hacker News item by ID
• WorldBankCountryService → Fetches country metadata by ISO code
• AggregationService → Combines all three into a single response, applies sort/filter logic
• RequestStatsMiddleware → Measures and stores request durations
• PerformanceAnalyzerService → Background service for performance monitoring
• JwtTokenService → Generates JWT tokens
• IRequestStatsStore → In-memory store for request metrics

---

🛠️ Running the Project in Visual Studio

1. Open the solution in Visual Studio.
2. Build and run the project.
3. Navigate to the Swagger UI to explore and test the endpoints:

https://localhost:7145/swagger/index.html

💡 The Swagger interface provides a convenient way to interact with the /api/Aggregation endpoint and view live responses.

---

📁 Folder Structure (Simplified)

ApiAggregator/
├── API/
│   ├── Controllers/
│   ├── Middleware/
│   └── Constants/
├── Core/
│   ├── DTOs/
│   ├── Interfaces/
│   ├── Models/
│   └── Enums/
├── Infrastructure/
│   ├── Services/
│   └── Monitoring/

---

🧪 Testing

Unit tests are written using xUnit and Moq. To run tests:

dotnet test