package com.jsql.model.injection.strategy;
   
   import com.jsql.model.InjectionModel;
   import com.jsql.model.accessible.DataAccess;
   import com.jsql.model.bean.util.Interaction;
   import com.jsql.model.bean.util.Request;
   import com.jsql.model.exception.JSqlException;
   import com.jsql.model.injection.vendor.model.VendorYaml;
   import com.jsql.model.suspendable.AbstractSuspendable;
  import com.jsql.model.suspendable.SuspendableGetIndexes;
  import com.jsql.util.I18nUtil;
  import com.jsql.util.LogLevelUtil;
  import com.jsql.util.StringUtil;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  import java.util.regex.Pattern;
  
  public class StrategyUnion extends AbstractStrategy {
      
      private static final Logger LOGGER = LogManager.getRootLogger();
  
      protected String visibleIndex;  // matching index
      protected String sourceIndexesFound = StringUtils.EMPTY;  // matching page source
      private int nbIndexesFound = 0;
  
      private String performanceLength = "0";
      
      public StrategyUnion(InjectionModel injectionModel) {
          super(injectionModel);
      }
  
      @Override
      public void checkApplicability() throws JSqlException {
          if (this.injectionModel.getMediatorUtils().getPreferencesUtil().isStrategyUnionDisabled()) {
              LOGGER.log(LogLevelUtil.CONSOLE_INFORM, AbstractStrategy.FORMAT_SKIP_STRATEGY_DISABLED, this.getName());
              return;
          }
  
          this.logChecking();
  
          this.injectionModel.setIndexesInUrl(new SuspendableGetIndexes(this.injectionModel).run());
  
          // Define visibleIndex, i.e, 2 in "..union select 1,2,..", if 2 is found in HTML body
          if (StringUtils.isNotEmpty(this.injectionModel.getIndexesInUrl())) {
              this.visibleIndex = this.getVisibleIndex(this.sourceIndexesFound);
          }
          
          this.isApplicable = StringUtils.isNotEmpty(this.injectionModel.getIndexesInUrl())
              && Integer.parseInt(this.injectionModel.getMediatorStrategy().getUnion().getPerformanceLength()) > 0
              && StringUtils.isNotBlank(this.visibleIndex);
          
          if (this.isApplicable) {
              LOGGER.log(
                  LogLevelUtil.CONSOLE_SUCCESS,
                  "{} [{}] at index [{}] showing [{}] characters",
                  () -> I18nUtil.valueByKey("LOG_VULNERABLE"),
                  this::getName,
                  () -> this.visibleIndex,
                  () -> this.performanceLength
              );
              this.allow();
          } else {
              this.unallow();
          }
      }
  
      @Override
      public void allow(int... i) {
          this.injectionModel.appendAnalysisReport(
              StringUtil.formatReport(LogLevelUtil.COLOR_BLU, "### Strategy: " + this.getName())
              + this.injectionModel.getReportWithIndexes(
                  this.injectionModel.getMediatorVendor().getVendor().instance().sqlUnion(StringUtil.formatReport(LogLevelUtil.COLOR_GREEN, "<query>"), "0", true),
                  "metadataInjectionProcess"
              )
          );
          this.markVulnerability(Interaction.MARK_UNION_VULNERABLE);
      }
  
      @Override
      public void unallow(int... i) {
          this.markVulnerability(Interaction.MARK_UNION_INVULNERABLE);
      }
  
      @Override
      public String inject(String sqlQuery, String startPosition, AbstractSuspendable stoppable, String metadataInjectionProcess) {
          return this.injectionModel.injectWithIndexes(
              this.injectionModel.getMediatorVendor().getVendor().instance().sqlUnion(sqlQuery, startPosition, false),
              metadataInjectionProcess
          );
      }
  
      @Override
      public void activateWhenApplicable() {
         if (this.injectionModel.getMediatorStrategy().getStrategy() == null && this.isApplicable()) {
             LOGGER.log(
                 LogLevelUtil.CONSOLE_INFORM,
                 "{} [{}]",
                 () -> I18nUtil.valueByKey("LOG_USING_STRATEGY"),
                 this::getName
             );
             this.injectionModel.getMediatorStrategy().setStrategy(this);
 
             var request = new Request();
             request.setMessage(Interaction.MARK_UNION_STRATEGY);
             this.injectionModel.sendToViews(request);
         }
     }
     
     /**
      * Runnable class, search the most efficient index.<br>
      * Some indexes will display a lots of characters, others won't,
      * so sort them by order of efficiency:<br>
      * find the one that displays the most number of characters.
      * @return Integer index with most efficiency and visible in source code
      */
     public String getVisibleIndex(String firstSuccessPageSource) {
         // Parse all indexes found
         // Fix #4007 (initialize firstSuccessPageSource to empty String instead of null)
         String regexAllIndexes = String.format(VendorYaml.FORMAT_INDEX, "(\\d+?)");
         var regexSearch = Pattern.compile("(?s)"+ regexAllIndexes).matcher(firstSuccessPageSource);
         
         List<String> foundIndexes = new ArrayList<>();
         while (regexSearch.find()) {
             foundIndexes.add(regexSearch.group(1));
         }
 
         String[] indexes = foundIndexes.toArray(new String[0]);
 
         // Make url shorter, replace useless indexes from 1337[index]7331 to 1
         String regexAllExceptIndexesFound = String.format(
             VendorYaml.FORMAT_INDEX,
             "(?!"+ String.join("|", indexes) +"7331)\\d*"
         );
         String indexesInUrl = this.injectionModel.getIndexesInUrl().replaceAll(regexAllExceptIndexesFound, "1");
 
         // Replace correct indexes from 1337(index)7331 to
         // ==> ${lead}(index)######...######
         // Search for index that displays the most #
         String performanceQuery = this.injectionModel.getMediatorVendor().getVendor().instance().sqlCapacity(indexes);
         String performanceSourcePage = this.injectionModel.injectWithoutIndex(performanceQuery, "union#size");
 
         // Build a 2D array of string with:
         //     column 1: index
         //     column 2: # found, so #######...#######
         regexSearch = Pattern.compile("(?s)"+ DataAccess.LEAD +"(\\d+)("+ VendorYaml.CALIBRATOR_SQL +"+)").matcher(performanceSourcePage);
         List<String[]> performanceResults = new ArrayList<>();
         while (regexSearch.find()) {
             performanceResults.add(new String[]{regexSearch.group(1), regexSearch.group(2)});
         }
 
         if (performanceResults.isEmpty()) {
             this.performanceLength = "0";
             return null;
         }
         
         // Switch from previous array to 2D integer array
         //     column 1: length of #######...#######
         //     column 2: index
         var lengthFields = new Integer[performanceResults.size()][2];
         
         for (var i = 0 ; i < performanceResults.size() ; i++) {
             lengthFields[i] = new Integer[] {
                 performanceResults.get(i)[1].length() + performanceResults.get(i)[0].length(),
                 Integer.parseInt(performanceResults.get(i)[0])
             };
         }
 
         // Sort by length of #######...#######
         Arrays.sort(lengthFields, Comparator.comparing((Integer[] s) -> s[0]));
         Integer[] bestLengthFields = lengthFields[lengthFields.length - 1];
         this.performanceLength = bestLengthFields[0].toString();
 
         // Reduce all others indexes
         String regexAllIndexesExceptBest = String.format(
             VendorYaml.FORMAT_INDEX,
             "(?!"+ bestLengthFields[1] +"7331)\\d*"
         );
         indexesInUrl = indexesInUrl.replaceAll(regexAllIndexesExceptBest, "1");
         
         this.injectionModel.setIndexesInUrl(indexesInUrl);
         
         return Integer.toString(bestLengthFields[1]);
     }
     
     
     // Getters and setters
     
     @Override
     public String getPerformanceLength() {
         return this.performanceLength;
     }
     
     @Override
     public String getName() {
         return "Union";
     }
 
     public String getVisibleIndex() {
         return this.visibleIndex;
     }
 
     public void setVisibleIndex(String visibleIndex) {
         this.visibleIndex = visibleIndex;
     }
 
     public void setSourceIndexesFound(String sourceIndexesFound) {
         this.sourceIndexesFound = sourceIndexesFound;
     }
 
     public int getNbIndexesFound() {
         return this.nbIndexesFound;
     }
 
     public void setNbIndexesFound(int nbIndexesFound) {
         this.nbIndexesFound = nbIndexesFound;
     }
 }