/*
 * Copyright 2013-2015 Guardtime, Inc.
 *
 * This file is part of the Guardtime client SDK.
 *
 * 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, CONDITIONS, OR OTHER LICENSES OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 * "Guardtime" and "KSI" are trademarks or registered trademarks of
 * Guardtime, Inc., and no license to trademarks is granted; Guardtime
 * reserves and retains all trademark rights.
 */

package com.guardtime.ksi.unisignature.verifier.rules;

import com.guardtime.ksi.exceptions.KSIException;
import com.guardtime.ksi.unisignature.AggregationChainLink;
import com.guardtime.ksi.unisignature.AggregationHashChain;
import com.guardtime.ksi.unisignature.verifier.VerificationContext;
import com.guardtime.ksi.unisignature.verifier.VerificationErrorCode;
import com.guardtime.ksi.unisignature.verifier.VerificationResultCode;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

/**
 * This rule verifies that aggregation chain indices are matching corresponding aggregation chains (e.g all left and
 * right links are correctly defined in the chain index).
 */
public final class AggregationHashChainIndexConsistencyRule extends BaseRule {

    private static final Logger LOGGER = LoggerFactory.getLogger(AggregationHashChainIndexConsistencyRule.class);

    public VerificationResultCode verifySignature(VerificationContext context) throws KSIException {
        AggregationHashChain[] aggregationChains = context.getAggregationHashChains();

        for (AggregationHashChain chain : aggregationChains) {
            List<Long> chainIndexList = chain.getChainIndex();
            String chainIndex = Long.toBinaryString(chainIndexList.get(chainIndexList.size() - 1));
            String chainToChainIndex = convertChainToChainIndex(chain);

            if (!chainIndex.equals(chainToChainIndex)) {
                LOGGER.info("Chain index {} does not match corresponding chain {}", chainIndex, chainToChainIndex);
                return VerificationResultCode.FAIL;
            }
        }
        return VerificationResultCode.OK;
    }

    private String convertChainToChainIndex(AggregationHashChain chain) {
        StringBuilder chainIndex = new StringBuilder();
        for (AggregationChainLink link : chain.getChainLinks()) {
            chainIndex.append(link.isLeft() ? "1" : "0");
        }
        return chainIndex.append("1").reverse().toString();
    }

    public VerificationErrorCode getErrorCode() {
        return VerificationErrorCode.INT_10;
    }


}

@@ -2011,33 +2011,71 @@
     
-List%3CLong%3E chainIndexList
+int size = chain.getChainIndex().size();%0A            long index
  = c
@@ -2094,16 +2094,30 @@
 nIndex()
+.get(size - 1)
 ;%0A      
@@ -2122,28 +2122,26 @@
         
-Stri
+lo
 ng chain
 Index = 
@@ -2132,24 +2132,26 @@
 ng chain
+To
 Index = 
 Long.toB
@@ -2146,102 +2146,207 @@
 x = 
-Long.toBinaryString(chainIndexList
+0;%0A%0A            List%3CAggregationChainLink%3E links = chain
 .get
-(c
+C
 hain
-IndexList.size() - 1));%0A            String
+Links();%0A            for (int i = 0; i %3C links.size(); i++) %7B%0A                if (links.get(i).isLeft()) %7B%0A                   
  chainTo
 Chai
@@ -2345,51 +2345,102 @@
 inTo
-Chain
 Index 
+%7C
 = 
-convertChainToChainIndex(chain
+1L %3C%3C i;%0A                %7D%0A            %7D%0A            chainToIndex %7C= 1 %3C%3C links.size(
 );%0A%0A
@@ -2459,46 +2459,30 @@
 if (
-!chainIndex.equals(
+index != 
 chainTo
-Chain
 Index)
-)
  %7B%0A 
@@ -2564,22 +2564,17 @@
 in %7B%7D%22, 
-chainI
+i
 ndex, ch
@@ -2574,29 +2574,24 @@
 dex, chainTo
-Chain
 Index);%0A    
@@ -2715,339 +2715,8 @@
  %7D%0A%0A
-    private String convertChainToChainIndex(AggregationHashChain chain) %7B%0A        StringBuilder chainIndex = new StringBuilder();%0A        for (AggregationChainLink link : chain.getChainLinks()) %7B%0A            chainIndex.append(link.isLeft() ? %221%22 : %220%22);%0A        %7D%0A        return chainIndex.append(%221%22).reverse().toString();%0A    %7D%0A%0A
     
@@ -2812,12 +2812,10 @@
 ;%0A    %7D%0A
-%0A%0A
 %7D%0A

Use bit shift operations to calculate index