package com.jsql.model.injection.strategy.blind;
   
   import com.jsql.model.InjectionModel;
   import com.jsql.model.exception.StoppedByUserSlidingException;
   import com.jsql.model.injection.strategy.blind.callable.CallableBlindBit;
   import com.jsql.util.LogLevelUtil;
   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.Collection;
  import java.util.List;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Future;
  
  import static name.fraser.neil.plaintext.diff_match_patch.Diff;
  
  /**
   * A blind attack class using concurrent threads.
   */
  public class InjectionBlindBit extends AbstractInjectionMonobit<CallableBlindBit> {
      
      /**
       * Log4j logger sent to view.
       */
      private static final Logger LOGGER = LogManager.getRootLogger();
  
      // Source code of the TRUE web page (usually ?id=1)
      private String sourceReferencePage;
  
      /**
       * List of string differences found in all the FALSE queries, compared
       * to the reference page. Each FALSE pages should contain
       * at least one same string, which shouldn't be present in all
       * the TRUE queries.
       */
      private List<Diff> falseDiffs = new ArrayList<>();
  
      /**
       * Create blind attack initialization.
       * If every false diffs are not in true diffs and every true diffs are in
       * true diffs, then Blind attack is confirmed.
       */
      public InjectionBlindBit(InjectionModel injectionModel, BlindOperator blindMode) {
          super(injectionModel, blindMode);
          
          // No blind
          if (this.falsyBit.isEmpty() || this.injectionModel.isStoppedByUser()) {
              return;
          }
          
          // Call the SQL request which must be TRUE (usually ?id=1)
          this.sourceReferencePage = this.callUrl(StringUtils.EMPTY, "bit#ref");
  
          // Concurrent calls to the FALSE statements,
          // it will use inject() from the model
          ExecutorService taskExecutor = this.injectionModel.getMediatorUtils().getThreadUtil().getExecutor("CallableGetBlindBitTagFalse");
          Collection<CallableBlindBit> callablesFalseTest = new ArrayList<>();
          for (String falseTest: this.falsyBit) {
              callablesFalseTest.add(new CallableBlindBit(
                  falseTest,
                  injectionModel,
                  this,
                  blindMode,
                  "bit#falsy"
              ));
          }
          
          // Delete junk from the results of FALSE statements,
          // keep only diffs found in each and every FALSE pages.
          // Allow the user to stop the loop
          try {
              List<Future<CallableBlindBit>> futuresFalseTest = taskExecutor.invokeAll(callablesFalseTest);
              this.injectionModel.getMediatorUtils().getThreadUtil().shutdown(taskExecutor);
              for (Future<CallableBlindBit> futureFalseTest: futuresFalseTest) {
                  if (this.injectionModel.isStoppedByUser()) {
                      return;
                  }
                  if (this.falseDiffs.isEmpty()) {
                      this.falseDiffs = futureFalseTest.get().getDiffsWithReference();  // Init diffs
                  } else {
                      this.falseDiffs.retainAll(futureFalseTest.get().getDiffsWithReference());  // Clean un-matching diffs
                  }
              }
          } catch (ExecutionException e) {
              LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
          } catch (InterruptedException e) {
              LOGGER.log(LogLevelUtil.IGNORE, e, e);
              Thread.currentThread().interrupt();
          }
  
          if (this.injectionModel.isStoppedByUser()) {
              return;
          }
          
          this.cleanTrueDiffs(injectionModel, blindMode);
      }
 
     private void cleanTrueDiffs(InjectionModel injectionModel, BlindOperator blindMode) {
         // Concurrent calls to the TRUE statements,
         // it will use inject() from the model.
         ExecutorService taskExecutor = this.injectionModel.getMediatorUtils().getThreadUtil().getExecutor("CallableGetBlindBitTagTrue");
         Collection<CallableBlindBit> callablesTrueTest = new ArrayList<>();
         for (String trueTest: this.truthyBit) {
             callablesTrueTest.add(new CallableBlindBit(
                 trueTest,
                 injectionModel,
                 this,
                 blindMode,
                 "bit#truthy"
             ));
         }
         
         // Remove TRUE diffs in the FALSE diffs, because
         // a significant FALSE statement shouldn't contain any TRUE diff.
         // Allow the user to stop the loop.
         try {
             List<Future<CallableBlindBit>> futuresTrueTest = taskExecutor.invokeAll(callablesTrueTest);
             this.injectionModel.getMediatorUtils().getThreadUtil().shutdown(taskExecutor);
             for (Future<CallableBlindBit> futureTrueTest: futuresTrueTest) {
                 if (this.injectionModel.isStoppedByUser()) {
                     return;
                 }
                 this.falseDiffs.removeAll(futureTrueTest.get().getDiffsWithReference());
             }
         } catch (ExecutionException e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         } catch (InterruptedException e) {
             LOGGER.log(LogLevelUtil.IGNORE, e, e);
             Thread.currentThread().interrupt();
         }
     }
 
     // todo should not be shared
     @Override
     public CallableBlindBit getCallableBitTest(String sqlQuery, int indexChar, int bit) {
         return new CallableBlindBit(
             sqlQuery,
             indexChar,
             bit,
             this.injectionModel,
             this,
             this.blindOperator,
             "bit#" + indexChar + "~" + bit
         );
     }
 
     @Override
     public boolean isInjectable() throws StoppedByUserSlidingException {
         if (this.injectionModel.isStoppedByUser()) {
             throw new StoppedByUserSlidingException();
         }
         var blindTest = new CallableBlindBit(
             this.injectionModel.getMediatorVendor().getVendor().instance().sqlBlindConfirm(),
             this.injectionModel,
             this,
             this.blindOperator,
             "bit#confirm"
         );
         try {
             blindTest.call();
         } catch (Exception e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         }
         return blindTest.isTrue() && !this.falseDiffs.isEmpty();
     }
 
     @Override
     public String getInfoMessage() {
         return "- Strategy Blind bit: query True when Diffs are matching " + this.falseDiffs + "\n\n";
     }
     
     
     // Getter and setter
 
     public String getSourceReferencePage() {
         return this.sourceReferencePage;
     }
     
     public List<Diff> getFalseDiffs() {
         return this.falseDiffs;
     }
 }