System Description

This application was developed during the Santander Dev Week 2024 by the DIO platform.

The application allows users to select a champion from League of Legends, ask a question, and receive a response from a Chat Completion model that impersonates the selected champion.

Front-end

This front-end was built using the Horizontal Timeline theme to display League of Legends champions in a carousel format.

Running the Application

To run the application, simply open the index.html file located in the project root directory.

Back-end

About the API

REST API developed with Java Spring. This API enables users to engage in interactive conversations with League of Legends champions, using a large language model (LLM) integrated through an external service.

Installation Guide

1. Running the Application with Docker Compose

Prerequisites

• Docker Desktop

Steps

1. Obtain an API Key for the Chat Completion Service

The API connects to the Llama3-8b-8192 model provided by Groq Cloud. To acquire an API key, follow these instructions and add the key to the GROQ_CLOUD_API_KEY environment variable in the docker-compose.yaml file.

2. Starting Containers

Run the following command to start the containers:

docker-compose up -d

2. Running the Application with Maven

Prerequisites

• Docker Desktop
• Java 21
• Apache Maven 3.9.8 or later

Steps

1. Start the PostgreSQL Database Container

docker-compose up db -d

2. Create application-dev.properties

The application.properties file is configured to run the Spring dev profile by default. To enable this, create a file named application-dev.properties in src/main/resources with the following settings:

server.port=8080

spring.datasource.url=jdbc:postgresql://localhost:3003/lol
spring.datasource.username=postgres
spring.datasource.password=1234
spring.datasource.driver-class-name=org.postgresql.Driver

spring.jpa.open-in-view=false
spring.jpa.hibernate.ddl-auto=none

groq-cloud.base-url=https://api.groq.com/openai

# Replace this with your API key
groq-cloud.api-key=your_api_key

Note: Make sure to obtain an API key as shown here and assign it to groq-cloud.api-key. The database settings above are provided for example purposes. If you choose to modify them, ensure that the database settings in docker-compose.yaml are updated accordingly.

3. Run the Application

In the project root directory, run:

mvn clean install -DskipTests
mvn spring-boot:run

Architecture

The project follows the Clean Architecture principles, as illustrated below.

It includes five main directories:

• application: Contains use cases and interfaces for accessing resources such as databases and HTTP clients.
• domain: Defines system entities and business-rule exceptions.
• infrastructure Implements the application layer's gateways, providing access to database
• repositories, HTTP client interfaces, controllers, DTOs, framework-specific exceptions,
• and other Spring resources.
• configuration Holds configuration files with dependency injection beans.
• shared Contains utility classes accessible across multiple layers.

Tests

Run the following commands in the terminal, from the application root directory:

• For unit tests:

mvn test

• For integration tests:

mvn verify -Pfailsafe

Note: Ensure Docker is running, as the application uses TestContainers to create a PostgreSQL database in Docker for each integration test class.

Documentation

API Endpoints Preview

GET /champions - Retrieve a list of champions.

POST /champions/ask/{id} - Ask a question to a specific champion by ID and retrieve the champion's response.

OpenAPI Documentation

• To view the full API documentation, including endpoints and data schemas, open the Swagger UI at: /swagger-ui/index.html

• For API documentation in JSON format suitable for tools like Postman, Insomnia, and other API clients, go to: /v3/api-docs.