sc_mower

Overview

This project demonstrates a DDD-inspired, modular, and testable architecture using Kotlin and Maven.

The application allows controlling robotic mowers on a rectangular plateau, processing movement instructions and reporting their final positions.

Architecture

• model-layer: Domain model (value objects, business logic)
• service-layer: Application logic (MowerEngine, validation, handlers)
• adapter-layer: Parsers/adapters for input/output (used by web and CLI)
• web-layer: REST API (Spring Boot, controllers, OpenAPI/Swagger)
• cli-layer: Command-line interface for interactive use
• docs/: PlantUML diagrams for each layer

Note: Persistence is not supported, as it was not required in the problem statement.

How it works

• The plateau is defined by its top-right coordinates (bottom-left is always 0,0).
• Each mower is initialized with a position (x, y, direction) and a sequence of actions (L, R, M).
• Mowers are processed sequentially: the next mower starts only after the previous one finishes.
• The system prevents mowers from leaving the plateau or overlapping.
• Input and output formats match the problem statement (see below).

Assumptions & Decisions

• Only one plateau is supported (as per MVP scope).
• Input is received as a multiline string (via HTTP POST or CLI).
• Directions are N, E, S, W. Actions are L (left), R (right), M (move forward).
• If a mower tries to move to an invalid or occupied position, it stays in place.
• The domain and service layers are pure Kotlin, with no Spring dependencies.
• Parsers and mappers are placed in the adapter-layer for reuse across interfaces.
• Some model classes are visible in the web-layer because they are simple. More complex models are encapsulated in the service layer (ex: Plateau).
• The previous one is to apply KISS. If the system grows it would be a good idea to encapsulate the model and create whole DTO objects to communicate with the service-layer.

How to run

Web API

1. Build the project:

   mvn clean install

2. Run the web application:

   cd web-layer
   mvn spring-boot:run

3. Access Swagger UI:
   • Open http://localhost:8080/swagger-ui/index.html

CLI

NOTE: The CLI application needs JDK 17 or higher to run.

1. Build and run the CLI application:

   sh ./cli-layer/run-cli.sh
   # or, from inside cli-layer
   sh ./run-cli.sh

   • You will be prompted to enter the plateau size, mower positions, and actions interactively.

Example input (for both web and CLI)

5 5
1 2 N
LMLMLMLMM
3 3 E
MMRMMRMRRM

Expected output:

1 3 N
5 1 E

Testing

• Run all tests:

  mvn test

• Includes unit tests (domain, service, adapter) and integration tests (controller, E2E)

Diagrams

• See docs/ for PlantUML diagrams of each layer.

License

MIT