package com.jaalee.sdk.internal;
/**
 * @author JAALEE, Inc
 * 
 * @Support dev@jaalee.com
 * @Sales: sales@jaalee.com
 * 
 * @see http://www.jaalee.com/
 */

public class Preconditions
{
	public static <T> T checkNotNull(T reference, Object errorMessage)
	{
		if (reference == null) {
			throw new NullPointerException(String.valueOf(errorMessage));
		}
		return reference;
	}

	public static <T> T checkNotNull(T reference)
	{
		if (reference == null) {
			throw new NullPointerException();
		}
		return reference;
	}

	public static void checkArgument(boolean expression)
	{
		if (!expression)
			throw new IllegalArgumentException();
	}

	public static void checkArgument(boolean expression, Object errorMessage)
	{
		if (!expression)
			throw new IllegalArgumentException(String.valueOf(errorMessage));
	}

	public static void checkArgument(boolean expression, String errorMessageTemplate, Object[] errorMessageArgs)
	{
		if (!expression)
			throw new IllegalArgumentException(format(errorMessageTemplate, errorMessageArgs));
	}

	static String format(String template, Object[] args)
	{
		template = String.valueOf(template);

		StringBuilder builder = new StringBuilder(template.length() + 16 * args.length);

		int templateStart = 0;
		int i = 0;
		while (i < args.length) {
			int placeholderStart = template.indexOf("%s", templateStart);
			if (placeholderStart == -1) {
				break;
			}
			builder.append(template.substring(templateStart, placeholderStart));
			builder.append(args[(i++)]);
			templateStart = placeholderStart + 2;
		}
		builder.append(template.substring(templateStart));

		if (i < args.length) {
			builder.append(" [");
			builder.append(args[(i++)]);
			while (i < args.length) {
				builder.append(", ");
				builder.append(args[(i++)]);
			}
			builder.append(']');
		}

		return builder.toString();
	}
}