package ie.dcu.segment.options;

/**
 * Abstract implementation of the {@link Option} interface.
 * 
 * @author Kevin McGuinness
 */
public abstract class AbstractOption<T> implements Option<T> {
	private final OptionType type;
	private final String name;
	private final String description;
	private final T defaultValue;
	private T value;


	protected AbstractOption(
			OptionType type, String name, String description, T defaultValue) {
		
		// Preconditions
		assert (type != null);
		assert (name != null);
		assert (description != null);
		assert (defaultValue != null);
		
		// Assign
		this.type = type;
		this.name = name;
		this.description = description;
		this.defaultValue = defaultValue;
		this.value = defaultValue;
	}


	public OptionType getType() {
		return type;
	}


	public String getName() {
		return name;
	}


	public String getDescription() {
		return description;
	}


	public T getDefaultValue() {
		return defaultValue;
	}


	public T getValue() {
		return value;
	}


	public void setValue(Object value) {
		if (value == null) {
			this.value = defaultValue;
		} else {
			Conversion<T> conv = convert(value);
			if (conv.isOk()) {
				this.value = conv.getResult();
			} else {
				this.value = defaultValue;
			}
		}
	}


	public T[] values() {
		return null;
	}


	protected Conversion<T> valid(T result) {
		return new Conversion<T>(result, null);
	}


	protected Conversion<T> invalid(String message) {
		return new Conversion<T>(null, message);
	}


	protected Conversion<T> invalid(String format, Object... args) {
		return new Conversion<T>(null, String.format(format, args));
	}
}