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;
  import static name.fraser.neil.plaintext.diff_match_patch.Operation;
  
  /**
   * A blind attack class using concurrent threads.
   */
  public class InjectionBlindBit extends AbstractInjectionMonobit<CallableBlindBit> {
  
      private static final Logger LOGGER = LogManager.getRootLogger();
  
      private String sourceReferencePage;  // Source code of the TRUE web page (usually ?id=1)
  
      /**
       * 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<>();
      private List<Diff> trueDiffs = 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 blindOperator) {
          super(injectionModel, blindOperator);
  
          List<String> falsys = this.injectionModel.getMediatorVendor().getVendor().instance().getFalsyBit();
          if (falsys.isEmpty() || this.injectionModel.isStoppedByUser()) {
              return;
          }
          
          // Call the SQL request which must be TRUE (usually ?id=1)
          this.sourceReferencePage = this.callUrl(StringUtils.EMPTY, "bit#ref:"+ blindOperator.toString().toLowerCase());
  
          // Concurrent calls to the FALSE statements,
          // it will use inject() from the model
          ExecutorService taskExecutor = this.injectionModel.getMediatorUtils().getThreadUtil().getExecutor("CallableGetBlindBitTagFalse");
          Collection<CallableBlindBit> callablesFalsys = new ArrayList<>();
          for (String falsy: falsys) {
              callablesFalsys.add(new CallableBlindBit(
                  falsy,
                  injectionModel,
                  this,
                  blindOperator,
                  "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>> futuresFalsys = taskExecutor.invokeAll(callablesFalsys);
              this.injectionModel.getMediatorUtils().getThreadUtil().shutdown(taskExecutor);
              for (Future<CallableBlindBit> futureFalsy: futuresFalsys) {
                  if (this.injectionModel.isStoppedByUser()) {
                      return;
                  }
                  if (this.falseDiffs.isEmpty()) {
                      this.falseDiffs = futureFalsy.get().getDiffsWithReference();  // Init diffs
                  } else {
                      this.falseDiffs.retainAll(futureFalsy.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, blindOperator);
      }
  
      private void cleanTrueDiffs(InjectionModel injectionModel, BlindOperator blindOperator) {
         ExecutorService taskExecutor = this.injectionModel.getMediatorUtils().getThreadUtil().getExecutor("CallableGetBlindBitTagTrue");
         Collection<CallableBlindBit> callablesTruthys = new ArrayList<>();
         List<String> truthys = this.injectionModel.getMediatorVendor().getVendor().instance().getTruthyBit();
         for (String truthy: truthys) {
             callablesTruthys.add(new CallableBlindBit(
                 truthy,
                 injectionModel,
                 this,
                 blindOperator,
                 "bit#truthy"
             ));
         }
 
         // Remove TRUE diffs in the FALSE diffs as FALSE statement shouldn't contain any TRUE diff.
         try {
             List<Future<CallableBlindBit>> futuresTruthys = taskExecutor.invokeAll(callablesTruthys);
             this.injectionModel.getMediatorUtils().getThreadUtil().shutdown(taskExecutor);
             for (Future<CallableBlindBit> futureTruthy: futuresTruthys) {
                 if (this.injectionModel.isStoppedByUser()) {
                     return;
                 }
                 if (this.trueDiffs.isEmpty()) {
                     this.trueDiffs = futureTruthy.get().getDiffsWithReference();  // Init diffs
                 } else {
                     this.trueDiffs.retainAll(futureTruthy.get().getDiffsWithReference());  // Clean un-matching diffs
                 }
                 this.falseDiffs.removeAll(futureTruthy.get().getDiffsWithReference());
             }
         } catch (ExecutionException e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         } catch (InterruptedException e) {
             LOGGER.log(LogLevelUtil.IGNORE, e, e);
             Thread.currentThread().interrupt();
         }
     }
 
     @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 callable = new CallableBlindBit(
             this.injectionModel.getMediatorVendor().getVendor().instance().sqlBlindConfirm(),
             this.injectionModel,
             this,
             this.blindOperator,
             "bit#confirm"
         );
         try {
             callable.call();
         } catch (Exception e) {
             LOGGER.log(LogLevelUtil.CONSOLE_JAVA, e, e);
         }
         return callable.isTrue()
             // when insertionChar = true then pages ref == truthy == falsy == confirm => falsy cleaned empty, truthy with opcode EQUAL not reliable
             && this.trueDiffs.stream().anyMatch(diff -> !Operation.EQUAL.equals(diff.operation))
             || this.falseDiffs.stream().anyMatch(diff -> !Operation.EQUAL.equals(diff.operation));
     }
 
     @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;
     }
 
     public List<Diff> getTrueDiffs() {
         return this.trueDiffs;
     }
 }