package com.jsql.model.injection.strategy.blind;
   
   import com.jsql.model.InjectionModel;
   import com.jsql.model.injection.strategy.blind.AbstractInjectionBinary.BinaryMode;
   import com.jsql.model.injection.strategy.blind.patch.Diff;
   import com.jsql.model.injection.strategy.blind.patch.DiffMatchPatch;
   
   import java.util.LinkedList;
   import java.util.List;
  import java.util.concurrent.CopyOnWriteArrayList;
  
  /**
   * Define a call HTTP to the server, require the associated url, character
   * position and bit. Diffs represent the differences between
   * the reference page, and the current page.
   */
  public class CallableBlind extends AbstractCallableBinary<CallableBlind> {
      
      // List of differences found between the reference page, and the current page
      private LinkedList<Diff> diffsWithReference = new LinkedList<>();
      
      private static final DiffMatchPatch DIFF_MATCH_PATCH = new DiffMatchPatch();
  
      private final InjectionBlind injectionBlind;
      
      private final InjectionModel injectionModel;
      private final String metadataInjectionProcess;
      
      /**
       * Constructor for preparation and blind confirmation.
       */
      public CallableBlind(String sqlQuery, InjectionModel injectionModel, InjectionBlind injectionBlind, BinaryMode blindMode, String metadataInjectionProcess) {
          this.injectionModel = injectionModel;
          this.injectionBlind = injectionBlind;
          this.metadataInjectionProcess = metadataInjectionProcess;
          this.booleanUrl = this.injectionModel.getMediatorVendor().getVendor().instance().sqlTestBlind(sqlQuery, blindMode);
      }
      
      /**
       * Constructor for bits test.
       */
      public CallableBlind(
          String sqlQuery,
          int indexCharacter,
          int bit,
          InjectionModel injectionModel,
          InjectionBlind injectionBlind,
          BinaryMode blindMode,
          String metadataInjectionProcess
      ) {
          this(sqlQuery, injectionModel, injectionBlind, blindMode, metadataInjectionProcess);
          this.booleanUrl = this.injectionModel.getMediatorVendor().getVendor().instance().sqlBitTestBlind(sqlQuery, indexCharacter, bit, blindMode);
          this.currentIndex = indexCharacter;
          this.currentBit = bit;
      }
  
      /**
       * Check if a result page means the SQL query is true,
       * confirm that nothing in the resulting page is also defined
       * in the pages from every FALSE SQL queries.
       * @return true if the current SQL query is true
       */
      @Override
      public boolean isTrue() {
          // Fix #95426: ConcurrentModificationException on iterator.next()
          List<Diff> falseDiffs = new CopyOnWriteArrayList<>(this.injectionBlind.getFalseDiffs());
          for (Diff falseDiff: falseDiffs) {
              // Fix #4386: NullPointerException on contains()
              // diffsWithReference is initialized to an empty new LinkedList<>()
              if (this.diffsWithReference.contains(falseDiff)) {
                  return false;
              }
          }
          return true;
      }
  
      /**
       * Process the URL HTTP call, use function inject() from the model.
       * Build the list of differences found between TRUE and the current page.
       * @return Functional Blind Callable
       */
      @Override
      public CallableBlind call() {
          String result = this.injectionBlind.callUrl(this.booleanUrl, this.metadataInjectionProcess, this);
          this.diffsWithReference = CallableBlind.DIFF_MATCH_PATCH.diffMain(this.injectionBlind.getSourceReferencePage(), result, true);
          CallableBlind.DIFF_MATCH_PATCH.diffCleanupEfficiency(this.diffsWithReference);
          return this;
      }
      
      public List<Diff> getDiffsWithReference() {
          return this.diffsWithReference;
      }
  }