/*
    * 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.function.library;
  
  import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
  import gov.nist.secauto.metaschema.core.metapath.DynamicMetapathException;
  import gov.nist.secauto.metaschema.core.metapath.ISequence;
  import gov.nist.secauto.metaschema.core.metapath.MetapathConstants;
  import gov.nist.secauto.metaschema.core.metapath.MetapathException;
  import gov.nist.secauto.metaschema.core.metapath.MetapathExpression;
  import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
  import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
  import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
  import gov.nist.secauto.metaschema.core.metapath.item.IItem;
  import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
  import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
  import gov.nist.secauto.metaschema.core.util.ObjectUtils;
  
  import java.util.List;
  import java.util.stream.Stream;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  public final class MpRecurseDepth {
    // private static final Logger logger = LogManager.getLogger(FnDoc.class);
  
    @NonNull
    static final IFunction SIGNATURE_ONE_ARG = IFunction.builder()
        .name("recurse-depth")
        .namespace(MetapathConstants.NS_METAPATH)
        .deterministic()
        .contextDependent()
        .focusDependent()
        .argument(IArgument.newBuilder()
            .name("recursePath")
            .type(IStringItem.class)
            .one()
            .build())
        .returnType(INodeItem.class)
        .returnZeroOrMore()
        .functionHandler(MpRecurseDepth::executeOneArg)
        .build();
  
    @NonNull
    static final IFunction SIGNATURE_TWO_ARG = IFunction.builder()
        .name("recurse-depth")
        .namespace(MetapathConstants.NS_METAPATH)
        .deterministic()
        .contextDependent()
        .focusIndependent()
        .argument(IArgument.newBuilder()
            .name("context")
            .type(INodeItem.class)
            .zeroOrMore()
            .build())
        .argument(IArgument.newBuilder()
            .name("recursePath")
            .type(IStringItem.class)
            .one()
            .build())
        .returnType(INodeItem.class)
        .returnZeroOrMore()
        .functionHandler(MpRecurseDepth::executeTwoArg)
        .build();
  
    private MpRecurseDepth() {
      // disable construction
    }
  
    @SuppressWarnings("unused")
    @NonNull
    private static ISequence<INodeItem> executeOneArg(
        @NonNull IFunction function,
        @NonNull List<ISequence<?>> arguments,
        @NonNull DynamicContext dynamicContext,
       IItem focus) {
 
     ISequence<INodeItem> initalContext = ISequence.of(FunctionUtils.requireType(INodeItem.class, focus));
 
     ISequence<? extends IStringItem> arg = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0)));
     IStringItem recursionPath = FunctionUtils.requireFirstItem(arg, true);
 
     return recurseDepth(initalContext, recursionPath, dynamicContext);
   }
 
   @SuppressWarnings("unused")
   @NonNull
   private static ISequence<INodeItem> executeTwoArg(
       @NonNull IFunction function,
       @NonNull List<ISequence<?>> arguments,
       @NonNull DynamicContext dynamicContext,
       IItem focus) {
 
     ISequence<INodeItem> initalContext = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0)));
 
     ISequence<? extends IStringItem> arg = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(1)));
     IStringItem recursionPath = FunctionUtils.requireFirstItem(arg, true);
 
     return recurseDepth(initalContext, recursionPath, dynamicContext);
   }
 
   @NonNull
   private static ISequence<INodeItem> recurseDepth(
       @NonNull ISequence<INodeItem> initialContext,
       @NonNull IStringItem recursionPath,
       @NonNull DynamicContext dynamicContext) {
 
     MetapathExpression recursionMetapath;
     try {
       recursionMetapath = MetapathExpression.compile(recursionPath.asString());
     } catch (MetapathException ex) {
       throw new DynamicMetapathException(DynamicMetapathException.INVALID_PATH_GRAMMAR, ex.getMessage(), ex);
     }
 
     return recurseDepth(initialContext, recursionMetapath, dynamicContext);
   }
 
   @NonNull
   public static ISequence<INodeItem> recurseDepth(
       @NonNull ISequence<INodeItem> initialContext,
       @NonNull MetapathExpression recursionMetapath,
       @NonNull DynamicContext dynamicContext) {
 
     return ISequence.of(ObjectUtils.notNull(initialContext.asStream()
         .flatMap(item -> {
           @NonNull ISequence<INodeItem> metapathResult
               = recursionMetapath.evaluate(item, dynamicContext);
           ISequence<INodeItem> result = recurseDepth(metapathResult, recursionMetapath, dynamicContext);
           return ObjectUtils.notNull(Stream.concat(result.asStream(), Stream.of(item)));
         })));
   }
 }