/*
    * Portions of this software was developed by employees of the National Institute
    * of Standards and Technology (NIST), an agency of the Federal Government and is
    * being made available as a public service. Pursuant to title 17 United States
    * Code Section 105, works of NIST employees are not subject to copyright
    * protection in the United States. This software may be subject to foreign
    * copyright. Permission in the United States and in foreign countries, to the
    * extent that NIST may hold copyright, to use, copy, modify, create derivative
    * works, and distribute this software and its documentation without fee is hereby
   * granted on a non-exclusive basis, provided that this notice and disclaimer
   * of warranty appears in all copies.
   *
   * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
   * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
   * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
   * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
   * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
   * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
   * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
   * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
   * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
   * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
   * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
   */
  
  package gov.nist.secauto.metaschema.core.metapath;
  
  import gov.nist.secauto.metaschema.core.metapath.function.library.FnData;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IAnyAtomicItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IBooleanItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IDayTimeDurationItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IDecimalItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.INumericItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IUntypedAtomicItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IYearMonthDurationItem;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  class GeneralComparison
      extends AbstractComparison {
  
    /**
     * Create a new value comparison expression.
     *
     * @param left
     *          the expression to compare against
     * @param operator
     *          the comparison operator
     * @param right
     *          the expression to compare with
     */
    protected GeneralComparison(@NonNull IExpression left, @NonNull Operator operator, @NonNull IExpression right) {
      super(left, operator, right);
    }
  
    @Override
    public <RESULT, CONTEXT> RESULT accept(IExpressionVisitor<RESULT, CONTEXT> visitor, CONTEXT context) {
      return visitor.visitGeneralComparison(this, context);
    }
  
    @Override
    public ISequence<? extends IBooleanItem> accept(DynamicContext dynamicContext, ISequence<?> focus) {
      ISequence<? extends IAnyAtomicItem> leftItems = FnData.fnData(getLeft().accept(dynamicContext, focus));
      ISequence<? extends IAnyAtomicItem> rightItems = FnData.fnData(getRight().accept(dynamicContext, focus));
      return ISequence.of(valueCompairison(leftItems, getOperator(), rightItems));
    }
  
    /**
     * Compare the sets of atomic items.
     *
     * @param leftItems
     *          the first set of items to compare
     * @param operator
     *          the comparison operator
     * @param rightItems
     *          the second set of items to compare
     * @return a or an empty {@link ISequence} if either item is {@code null}
     */
    @NonNull
    protected IBooleanItem valueCompairison( // NOPMD - acceptable complexity
        @NonNull ISequence<? extends IAnyAtomicItem> leftItems,
        @NonNull Operator operator,
        @NonNull ISequence<? extends IAnyAtomicItem> rightItems) {
  
      IBooleanItem retval = IBooleanItem.FALSE;
      for (IAnyAtomicItem left : leftItems.asList()) {
        assert left != null;
        for (IAnyAtomicItem right : rightItems.asList()) {
          assert right != null;
          IAnyAtomicItem leftCast;
          IAnyAtomicItem rightCast;
          if (left instanceof IUntypedAtomicItem) {
            if (right instanceof IUntypedAtomicItem) {
              leftCast = IStringItem.cast(left);
              rightCast = IStringItem.cast(right);
            } else {
              leftCast = applyGeneralComparisonCast(right, left);
             rightCast = right;
           }
         } else if (right instanceof IUntypedAtomicItem) {
           leftCast = left;
           rightCast = applyGeneralComparisonCast(left, right);
         } else {
           leftCast = left;
           rightCast = right;
         }
 
         assert leftCast != null;
         IBooleanItem result = compare(leftCast, operator, rightCast);
         if (IBooleanItem.TRUE.equals(result)) {
           retval = IBooleanItem.TRUE;
         }
       }
     }
     return retval;
   }
 
   /**
    * Attempts to cast the provided {@code other} item to the type of the
    * {@code item}.
    *
    * @param item
    *          the item whose type the other item is to be cast to
    * @param other
    *          the item to cast
    * @return the casted item
    */
   @NonNull
   protected IAnyAtomicItem applyGeneralComparisonCast(@NonNull IAnyAtomicItem item, @NonNull IAnyAtomicItem other) {
     IAnyAtomicItem retval;
     if (item instanceof INumericItem) {
       retval = IDecimalItem.cast(other);
     } else if (item instanceof IDayTimeDurationItem) {
       retval = IDayTimeDurationItem.cast(other);
     } else if (item instanceof IDayTimeDurationItem) {
       retval = IYearMonthDurationItem.cast(other);
     } else {
       retval = item.getJavaTypeAdapter().cast(other);
     }
     return retval;
   }
 }