/*-
 * ============LICENSE_START=======================================================
 * sdc-distribution-client
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END=========================================================
 */

package org.openecomp.sdc.utils;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;

import org.apache.commons.codec.binary.Base64;
import org.openecomp.sdc.api.results.IDistributionClientResult;
import org.openecomp.sdc.impl.DistributionClientResultImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fj.data.Either;

public class GeneralUtils {
	private static final Logger log = LoggerFactory.getLogger(GeneralUtils.class.getName());
	public static String calculateMD5 (String data){
		String calculatedMd5 = org.apache.commons.codec.digest.DigestUtils.md5Hex(data);
		// encode base-64 result
		byte[] encodeBase64 = Base64.encodeBase64(calculatedMd5.getBytes());
		String encodeBase64Str = new String(encodeBase64);
		return encodeBase64Str;

	} 
	
	public static String calculateMD5(byte[] decodedPayload) {
		String decodedMd5 = org.apache.commons.codec.digest.DigestUtils.md5Hex(decodedPayload);
		byte[] encodeMd5 = Base64.encodeBase64(decodedMd5.getBytes());
		return new String(encodeMd5);
	}
	
	public static boolean isBase64Encoded(String str){
		 boolean isEncoded = false;
	       try
	       {
	           // If no exception is caught, then it is possibly a base64 encoded string
	           byte[] data = Base64.decodeBase64(str);
	           // checks if the string was properly padded to the
	           isEncoded=  ((str.length() % 4 == 0) && (Pattern.matches("\\A[a-zA-Z0-9/+]+={1,2}\\z", str)));
	          
	       }
	       catch (Exception e)
	       {
	           // If exception is caught, then it is not a base64 encoded string
	    	   isEncoded=  false;
	       }
	       return isEncoded;
	}


	public static Either<List<String>, IDistributionClientResult> convertToValidHostName(List<String> msgBusAddresses) {
		List<String> uebLocalHostsNames = new ArrayList<>();
		for(String name : msgBusAddresses){
			try {
				uebLocalHostsNames.add(InetAddress.getByName(name).getHostName());
			} catch (UnknownHostException e) {
				log.debug("UnknownHost: {}", e.getMessage(), e);
			}
		}
		Either<List<String>, IDistributionClientResult> response;
		if( uebLocalHostsNames.isEmpty() ){
			response = 	Either.right(new DistributionClientResultImpl(DistributionActionResultEnum.CONF_INVALID_MSG_BUS_ADDRESS, "configuration is invalid: " + DistributionActionResultEnum.CONF_INVALID_MSG_BUS_ADDRESS.name()));

		}
		else{
			response = Either.left(uebLocalHostsNames);
		}
		return response;
	}
}