package com.jsql.model.injection.strategy.blind.callable;
   
   import com.jsql.model.injection.strategy.blind.InjectionCharInsertion;
   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. Opcodes represent the differences between
   * the reference page, and the resulting page.
   */
  public class CallableCharInsertion extends AbstractCallableBit<CallableCharInsertion> {
  
      private LinkedList<Diff> opcodes = new LinkedList<>();  // List of differences found between the reference page, and the present page
  
      private static final DiffMatchPatch DIFF_MATCH_PATCH = new DiffMatchPatch();
  
      private final InjectionCharInsertion injectionCharInsertion;
  
      private final String metadataInjectionProcess;
  
      /**
       * Constructor for preparation and blind confirmation.
       */
      public CallableCharInsertion(String inj, InjectionCharInsertion injectionCharInsertion, String metadataInjectionProcess) {
          this.injectionCharInsertion = injectionCharInsertion;
          this.metadataInjectionProcess = metadataInjectionProcess;
          this.booleanUrl = inj;
      }
  
      /**
       * 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 #95422: ConcurrentModificationException on iterator.next()
          List<Diff> copyTrueMarks = new CopyOnWriteArrayList<>(this.injectionCharInsertion.getConstantTrueMark());
          for (Diff trueDiff: copyTrueMarks) {
              try {  // Fix #96229: NullPointerException on contains()
                  if (!this.opcodes.contains(trueDiff)) {
                      return false;
                  }
              } catch (NullPointerException e) {
                  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 CallableCharInsertion call() {
          String source = this.injectionCharInsertion.callUrl(this.booleanUrl, this.metadataInjectionProcess, this);
  
          this.opcodes = CallableCharInsertion.DIFF_MATCH_PATCH.diffMain(
              this.injectionCharInsertion.getBlankFalseMark(),
              source,
              false
          );
  
          CallableCharInsertion.DIFF_MATCH_PATCH.diffCleanupEfficiency(this.opcodes);
          return this;
      }
  
      public List<Diff> getOpcodes() {
          return this.opcodes;
      }
  }