/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 developers-payu-latam
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.payu.sdk.helper;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Locale;

import org.apache.commons.codec.digest.DigestUtils;

import com.payu.sdk.model.Order;

/**
 * The PayU SDK Helper for signature creation
 *
 * @author PayU Latam
 * @since 1.0.0
 * @version 1.0.0, 21/08/2013
 */
public final class SignatureHelper {

	/** MD5 algorithm used */
	public static final String MD5_ALGORITHM = "md5";
	/** SHA algorithm used */
	public static final String SHA_ALGORITHM = "sha";

	/** Decimal format with no decimals */
	public static final String DECIMAL_FORMAT_1 = "###";
	/** Decimal format with one decimal */
	public static final String DECIMAL_FORMAT_2 = "###.0";
	/** Decimal format with two decimals */
	public static final String DECIMAL_FORMAT_3 = "###.00";

	/** The transaction value */
	public static final String TX_VALUE = "TX_VALUE";

	/**
	 * Private constructor
	 */
	private SignatureHelper() {}

	/**
	 * builds the signature for the transaction
	 *
	 * @param order The order that will have the signature
	 * @param merchantId The merchantId into the signature
	 * @param key The apiKey of the merchant
	 * @param valueFormat The format to use for decimal values
	 * @param algorithm The algorithm to use
	 * @return the full signature to use
	 */
	public static String buildSignature(Order order, Integer merchantId, String key,
			String valueFormat, String algorithm) {

		String message = buildMessage(order, merchantId, key, valueFormat);

		if (MD5_ALGORITHM.equalsIgnoreCase(algorithm)) {
			return DigestUtils.md5Hex(message);
		}
		else if (SHA_ALGORITHM.equalsIgnoreCase(algorithm)) {
			return DigestUtils.shaHex(message);
		}
		else {
			throw new IllegalArgumentException("Could not create signature. Invalid algoritm");
		}
	}

	/**
	 * The message the signature will use
	 *
	 * @param order The order that will have the signature
	 * @param merchantId The merchantId into the signature
	 * @param key The apiKey of the merchant
	 * @param valueFormat The format to use for decimal values
	 * @return the message that will go into the signature
	 */
	private static String buildMessage(Order order, Integer merchantId,
			String key, String valueFormat) {

		validateOrder(order, merchantId);

		DecimalFormat df = (DecimalFormat) NumberFormat.getInstance(Locale.US);
		df.applyPattern(valueFormat);

		StringBuffer message = new StringBuffer();
		message.append(key);
		message.append("~");
		message.append(merchantId);
		message.append("~");
		message.append(order.getReferenceCode());
		message.append("~");
		message.append(df.format(order.getAdditionalValue(TX_VALUE).getValue()
				.doubleValue()));
		message.append("~");
		message.append(order.getAdditionalValue(TX_VALUE).getCurrency().toString());

		return message.toString();
	}

	/**
	 * Validates that the order is valid
	 *
	 * @param order The order to be validated
	 * @param merchantId The merchantId to be validated
	 */
	private static void validateOrder(Order order, Integer merchantId) {

		if (merchantId == null) {
			throw new IllegalArgumentException("The merchant id may not be null");
		} else if (order.getReferenceCode() == null) {
			throw new IllegalArgumentException("The reference code may not be null");
		} else if (order.getAdditionalValue(TX_VALUE) == null) {
			throw new IllegalArgumentException("The order additional value TX_VALUE may not be null");
		} else if (order.getAdditionalValue(TX_VALUE).getCurrency() == null) {
			throw new IllegalArgumentException("The order currency may not be null");
		} else if (order.getAdditionalValue(TX_VALUE).getValue() == null) {
			throw new IllegalArgumentException("The order value may not be null");
		}
	}

}

@@ -3541,18 +3541,19 @@
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 er messa
@@ -3573,10 +3573,11 @@
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Update SignatureHelper.java