package ie.dcu.segment.options;

/**
 * A decimal (floating point) segmentation algorithm parameter.
 * 
 * @author Kevin McGuinness
 */
public class DecimalOption extends AbstractOption<Double> {
	private final double min;
	private final double max;

	
	/**
	 * Create a decimal option with the given name, description, and default
	 * value.
	 * 
	 * @param name
	 *        The option name
	 * @param description
	 *        A description of the option
	 * @param def
	 *        The default value for the option
	 */
	public DecimalOption(String name, String description, double def) {
		this(name, description, def, Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY);
	}
	
	/**
	 * Create a decimal option with the given name, description, default
	 * value, minimum allowable value, and maximum allowable value.
	 * 
	 * @param name
	 *        The option name
	 * @param description
	 *        A description of the option
	 * @param def
	 *        The default value for the option
	 * @param min
	 *        The minimum allowable value for the option
	 * @param max
	 *        The maximum allowable value for the option
	 */
	public DecimalOption(String name, String description, double def, double min, double max) {
		super(OptionType.Decimal, name, description, def);
		this.min = min;
		this.max = max;
	}

	public Conversion<Double> convert(Object value) {
		if (value instanceof Double) {
			return valid((Double) value);
		} else if (value != null) {
			try {
				return checkRange(new Double(value.toString().trim()));
			} catch (NumberFormatException e) {
				// Invalid
				String mesg = e.getLocalizedMessage();
				return invalid("%s is not an decimal number: %s", getName(), mesg);
			}
		}
		return invalid("value is null");
	}
	
	
	private Conversion<Double> checkRange(double val) {
		if (val >= min && val <= max) {
			// OK
			return valid(val);
			
		} 
		
		// Out of range
		String format = "%s must be in ther range (%f, %f), value is %f";
		return invalid(format, getName(), min, max, val);
	}
}