package org.bukkit.conversations;

import org.apache.commons.lang.math.NumberUtils;

/**
 * NumericPrompt is the base class for any prompt that requires a {@link
 * Number} response from the user.
 */
public abstract class NumericPrompt extends ValidatingPrompt
{
	public NumericPrompt()
	{
		super();
	}

	@Override
	protected boolean isInputValid(ConversationContext context, String input)
	{
		return NumberUtils.isNumber(input) && isNumberValid(context, NumberUtils.createNumber(input));
	}

	/**
	 * Override this method to do further validation on the numeric player
	 * input after the input has been determined to actually be a number.
	 *
	 * @param context Context information about the conversation.
	 * @param input   The number the player provided.
	 * @return The validity of the player's input.
	 */
	protected boolean isNumberValid(ConversationContext context, Number input)
	{
		return true;
	}

	@Override
	protected Prompt acceptValidatedInput(ConversationContext context, String input)
	{
		try
		{
			return acceptValidatedInput(context, NumberUtils.createNumber(input));
		} catch(NumberFormatException e)
		{
			return acceptValidatedInput(context, NumberUtils.INTEGER_ZERO);
		}
	}

	/**
	 * Override this method to perform some action with the user's integer
	 * response.
	 *
	 * @param context Context information about the conversation.
	 * @param input   The user's response as a {@link Number}.
	 * @return The next {@link Prompt} in the prompt graph.
	 */
	protected abstract Prompt acceptValidatedInput(ConversationContext context, Number input);

	@Override
	protected String getFailedValidationText(ConversationContext context, String invalidInput)
	{
		if(NumberUtils.isNumber(invalidInput))
		{
			return getFailedValidationText(context, NumberUtils.createNumber(invalidInput));
		}
		else
		{
			return getInputNotNumericText(context, invalidInput);
		}
	}

	/**
	 * Optionally override this method to display an additional message if the
	 * user enters an invalid number.
	 *
	 * @param context      Context information about the conversation.
	 * @param invalidInput The invalid input provided by the user.
	 * @return A message explaining how to correct the input.
	 */
	protected String getInputNotNumericText(ConversationContext context, String invalidInput)
	{
		return null;
	}

	/**
	 * Optionally override this method to display an additional message if the
	 * user enters an invalid numeric input.
	 *
	 * @param context      Context information about the conversation.
	 * @param invalidInput The invalid input provided by the user.
	 * @return A message explaining how to correct the input.
	 */
	protected String getFailedValidationText(ConversationContext context, Number invalidInput)
	{
		return null;
	}
}