# Table of Contents
* [Scope](#scope)
* [Design](#design)
  * [Cell](#cell)
  * [Dice](#dice)
  * [GameBoard](#gameboard)
  * [Gameplay](#gameplay)
  * [Player](#player)
* [Installation](#installation)
  * [Runtime](#runtime)
  * [Dependencies](#dependencies)
  * [Testing](#testing)
  * [Gem](#gem)
* [Usage](#usage)
  * [CLI](#cli)
  * [Help](help)

# Scope
This gem is the Ruby implementation of the `Goose Game` code-kata (for more information refer to the [OBJECTIVES](https://github.com/costajob/goose_game/blob/master/OBJECTIVES.md)).

# Design
The code design follows the single responsibility principle by using a dedicated class/module for any specific task. Each class exposes a minimal public API, when meaningful by using the `call` method, thus behaving like a plain `Proc` object.

## Cell
The cell of the game board. They are responsible to compute the position of the player and properly display the output messages. Polymorphism is used to reduce conditional logic.

## Dice
The class represents the two dice used to move players (creating a single Die class brings little benefit to the design). A factory class rolls dice with random values (within 1 to 6), constructor accepts any convertible integers, the absolute value is taken and limited to 6.

## Gameboard
The board class uses a `Hash` for its data representation: this data structure grants quick access by key. 

## Gameplay
The main interface with the game core logic is enclosed within the `Gameplay` class: it recognizes input commands, performs actions by creating players, rolling dice and printing appropriate messages to the terminal. The whole game runs within an endless loop.

## Player
The player of the game, record both current and previous position.

# Installation

## Runtime
This library supports from `Ruby 2.4.1` on.

## Dependencies
There are no runtime dependencies, but some developments ones (testing).  
Just clone the repository, move to the directory and use `bundler`:
```shell
bundle install
```

## Testing
The code is covered by fast, isolated unit testing.  
Move to the installation path and run them by:
```shell
bundle exec rake
```

## Gem
The library is packaged as a `gem`. Build and install it by:
```shell
gem build goose_game.gemspec
...
gem install --local ./goose_game.gem
```

# Usage

## CLI
The gem provides a CLI interface, once installed you will be able to start the game from the terminal:
```shell
goose_game
```

## Help
The game starts with no prompts, type `help` to see the available commands:
```shell
available commands:
* add player <player_name>
* move <player_name> 4, 5
* move <player_name>
* help
* exit
```