/*
    * Licensed to the Apache Software Foundation (ASF) under one   *
    * or more contributor license agreements.  See the NOTICE file *
    * distributed with this work for additional information        *
    * regarding copyright ownership.  The ASF licenses this file   *
    * to you under the Apache License, Version 2.0 (the            *
    * "License"); you may not use this file except in compliance   *
    * with the License.  You may obtain a copy of the License at   *
    *                                                              *
   *   http://www.apache.org/licenses/LICENSE-2.0                 *
   *                                                              *
   * Unless required by applicable law or agreed to in writing,   *
   * software distributed under the License is distributed on an  *
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
   * KIND, either express or implied.  See the License for the    *
   * specific language governing permissions and limitations      *
   * under the License.                                           *
   */
  package org.apache.rat.document;
  
  import java.io.File;
  import java.io.FileFilter;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Optional;
  import java.util.Set;
  import java.util.function.Predicate;
  
  import org.apache.rat.ConfigurationException;
  import org.apache.rat.config.exclusion.plexus.MatchPattern;
  import org.apache.rat.config.exclusion.plexus.MatchPatterns;
  
  import static java.lang.String.format;
  
  /**
   * Matches document names.
   */
  public final class DocumentNameMatcher {
  
      /** The predicate that does the actual matching. */
      private final Predicate<DocumentName> predicate;
      /** The name of this matcher. */
      private final String name;
      /** {@code true} if this matcher is a collection of matchers. */
      private final boolean isCollection;
  
      /**
       * A matcher that matches all documents.
       */
      public static final DocumentNameMatcher MATCHES_ALL = new DocumentNameMatcher("TRUE", (Predicate<DocumentName>) x -> true);
  
      /**
       * A matcher that matches no documents.
       */
      public static final DocumentNameMatcher MATCHES_NONE = new DocumentNameMatcher("FALSE", (Predicate<DocumentName>) x -> false);
  
      /**
       * Constructs a DocumentNameMatcher from a name and a DocumentName predicate.
       * @param name the name for this matcher.
       * @param predicate the predicate to determine matches.
       */
      public DocumentNameMatcher(final String name, final Predicate<DocumentName> predicate) {
          this.name = name;
          this.predicate = predicate;
          this.isCollection = predicate instanceof CollectionPredicate;
      }
  
      /**
       * Constructs a DocumentNameMatcher from a name and a delegate DocumentNameMatcher.
       * @param name the name for this matcher.
       * @param delegate the delegate to defer to.
       */
      public DocumentNameMatcher(final String name, final DocumentNameMatcher delegate) {
          this(name, delegate::matches);
      }
  
      /**
       * Constructs a DocumentNameMatcher from a name a MatchPatterns instance and the DocumentName for the base name.
       * @param name the name of this matcher.
       * @param patterns the patterns in the matcher.
       * @param basedir the base directory for the scanning.
       */
      public DocumentNameMatcher(final String name, final MatchPatterns patterns, final DocumentName basedir) {
          this(name, new MatchPatternsPredicate(basedir, patterns));
      }
  
      /**
       * Tokenizes name for faster Matcher processing.
       * @param name the name to tokenize.
       * @param dirSeparator the directory separator.
       * @return the tokenized name.
       */
      private static char[][] tokenize(final String name, final String dirSeparator) {
          String[] tokenizedName = MatchPattern.tokenizePathToString(name, dirSeparator);
          char[][] tokenizedNameChar = new char[tokenizedName.length][];
          for (int i = 0; i < tokenizedName.length; i++) {
             tokenizedNameChar[i] = tokenizedName[i].toCharArray();
         }
         return tokenizedNameChar;
     }
 
     /**
      * Constructs a DocumentNameMatcher from a name and a DocumentName predicate.
      * @param name the name of the matcher.
      * @param matchers fully specified matchers.
      */
     public DocumentNameMatcher(final String name, final MatchPatterns matchers) {
         this(name, new CollectionPredicate() {
             @Override
             public Iterable<DocumentNameMatcher> getMatchers() {
                 final List<DocumentNameMatcher> result = new ArrayList<>();
                 matchers.patterns().forEach(p -> result.add(new DocumentNameMatcher(p.source(),
                         (Predicate<DocumentName>) x -> MatchPatterns.from("/", p.source()).matches(x.getName(), x.isCaseSensitive()))));
                 return result;
             }
 
             @Override
             public boolean test(final DocumentName documentName) {
                 return matchers.matches(documentName.getName(), documentName.isCaseSensitive());
             }
         });
     }
 
     /**
      * Creates a DocumentNameMatcher from a File filter.
      * @param name The name of this matcher.
      * @param fileFilter the file filter to execute.
      */
     public DocumentNameMatcher(final String name, final FileFilter fileFilter) {
         this(name, new FileFilterPredicate(fileFilter));
     }
 
     /**
      * Creates a DocumentNameMatcher from a File filter.
      * @param fileFilter the file filter to execute.
      */
     public DocumentNameMatcher(final FileFilter fileFilter) {
         this(fileFilter.toString(), fileFilter);
     }
 
     public boolean isCollection() {
         return isCollection;
     }
 
     /**
      * Returns the predicate that this DocumentNameMatcher is using.
      * @return The predicate that this DocumentNameMatcher is using.
      */
     public Predicate<DocumentName> getPredicate() {
         return predicate;
     }
 
     @Override
     public String toString() {
         return name;
     }
 
     /**
      * Decomposes the matcher execution against the candidate.
      * @param candidate the candidate to check.
      * @return a list of {@link DecomposeData} for each evaluation in the matcher.
      */
     public List<DecomposeData> decompose(final DocumentName candidate) {
         final List<DecomposeData> result = new ArrayList<>();
         decompose(0, this, candidate, result);
         return result;
     }
 
     private void decompose(final int level, final DocumentNameMatcher matcher, final DocumentName candidate, final List<DecomposeData> result) {
         final Predicate<DocumentName> pred = matcher.getPredicate();
         result.add(new DecomposeData(level, matcher, candidate, pred.test(candidate)));
     }
 
     /**
      * Performs the match against the DocumentName.
      * @param documentName the document name to check.
      * @return true if the documentName matchers this DocumentNameMatcher.
      */
     public boolean matches(final DocumentName documentName) {
         return predicate.test(documentName);
     }
 
     /**
      * Performs a logical {@code NOT} on a DocumentNameMatcher.
      * @param nameMatcher the matcher to negate.
      * @return a PathMatcher that is the negation of the argument.
      */
     public static DocumentNameMatcher not(final DocumentNameMatcher nameMatcher) {
         if (nameMatcher == MATCHES_ALL) {
             return MATCHES_NONE;
         }
         if (nameMatcher == MATCHES_NONE) {
             return MATCHES_ALL;
         }
 
         return new DocumentNameMatcher(format("not(%s)", nameMatcher), new NotPredicate(nameMatcher));
     }
 
     /**
      * Joins a collection of DocumentNameMatchers together to create a list of the names.
      * @param matchers the matchers to extract the names from.
      * @return the String of the concatenation of the names.
      */
     private static String join(final Collection<DocumentNameMatcher> matchers) {
         List<String> children = new ArrayList<>();
         matchers.forEach(s -> children.add(s.toString()));
         return String.join(", ", children);
     }
 
     private static Optional<DocumentNameMatcher> standardCollectionCheck(final Collection<DocumentNameMatcher> matchers, final DocumentNameMatcher override) {
         if (matchers.isEmpty()) {
             throw new ConfigurationException("Empty matcher collection");
         }
         if (matchers.size() == 1) {
             return Optional.of(matchers.iterator().next());
         }
         if (matchers.contains(override)) {
             return Optional.of(override);
         }
         return Optional.empty();
     }
 
     /**
      * Performs a logical {@code OR} across the collection of matchers.
      * @param matchers the matchers to check.
      * @return a matcher that returns {@code true} if any of the enclosed matchers returns {@code true}.
      */
     public static DocumentNameMatcher or(final Collection<DocumentNameMatcher> matchers) {
         Optional<DocumentNameMatcher> opt = standardCollectionCheck(matchers, MATCHES_ALL);
         if (opt.isPresent()) {
             return opt.get();
         }
 
         // preserve order
         Set<DocumentNameMatcher> workingSet = new LinkedHashSet<>();
         for (DocumentNameMatcher matcher : matchers) {
             // check for nested or
             if (matcher.predicate instanceof Or) {
                 ((Or) matcher.predicate).getMatchers().forEach(workingSet::add);
             } else {
                 workingSet.add(matcher);
             }
         }
         return standardCollectionCheck(matchers, MATCHES_ALL)
                 .orElseGet(() -> new DocumentNameMatcher(format("or(%s)", join(workingSet)), new Or(workingSet)));
     }
 
     /**
      * Performs a logical {@code OR} across the collection of matchers.
      * @param matchers the matchers to check.
      * @return a matcher that returns {@code true} if any of the enclosed matchers returns {@code true}.
      */
     public static DocumentNameMatcher or(final DocumentNameMatcher... matchers) {
         return or(Arrays.asList(matchers));
     }
 
     /**
      * Performs a logical {@code AND} across the collection of matchers.
      * @param matchers the matchers to check.
      * @return a matcher that returns {@code true} if all the enclosed matchers return {@code true}.
      */
     public static DocumentNameMatcher and(final Collection<DocumentNameMatcher> matchers) {
         Optional<DocumentNameMatcher> opt = standardCollectionCheck(matchers, MATCHES_NONE);
         if (opt.isPresent()) {
             return opt.get();
         }
 
         // preserve order
         Set<DocumentNameMatcher> workingSet = new LinkedHashSet<>();
         for (DocumentNameMatcher matcher : matchers) {
             //  check for nexted And
             if (matcher.predicate instanceof And) {
                 ((And) matcher.predicate).getMatchers().forEach(workingSet::add);
             } else {
                 workingSet.add(matcher);
             }
         }
         opt = standardCollectionCheck(matchers, MATCHES_NONE);
         return opt.orElseGet(() -> new DocumentNameMatcher(format("and(%s)", join(workingSet)), new And(workingSet)));
     }
 
     /**
      * A particular matcher that will not match any excluded unless they are listed in the includes.
      * @param includes the DocumentNameMatcher to match the includes.
      * @param excludes the DocumentNameMatcher to match the excludes.
      * @return a DocumentNameMatcher with the specified logic.
      */
     public static DocumentNameMatcher matcherSet(final DocumentNameMatcher includes,
                                                  final DocumentNameMatcher excludes) {
         if (excludes == MATCHES_NONE) {
             return MATCHES_ALL;
         } else {
             if (includes == MATCHES_NONE) {
                 return not(excludes);
             }
         }
         if (includes == MATCHES_ALL) {
             return MATCHES_ALL;
         }
         List<DocumentNameMatcher> workingSet = Arrays.asList(includes, excludes);
         return new DocumentNameMatcher(format("matcherSet(%s)", join(workingSet)),
                 new DefaultCollectionPredicate(workingSet) {
                     @Override
                     public boolean test(final DocumentName documentName) {
                         if (includes.matches(documentName)) {
                             return true;
                         }
                         return !excludes.matches(documentName);
                     }
                 });
     }
 
     /**
      * Performs a logical {@code AND} across the collection of matchers.
      * @param matchers the matchers to check.
      * @return a matcher that returns {@code true} if all the enclosed matchers return {@code true}.
      */
     public static DocumentNameMatcher and(final DocumentNameMatcher... matchers) {
         return and(Arrays.asList(matchers));
     }
 
     /**
      * A DocumentName predicate that uses {@link MatchPatterns}.
      */
     public static final class MatchPatternsPredicate implements Predicate<DocumentName> {
         /** The base directory for the pattern matches. */
         private final DocumentName basedir;
         /** The pattern matchers. */
         private final MatchPatterns patterns;
 
         private MatchPatternsPredicate(final DocumentName basedir, final MatchPatterns patterns) {
             this.basedir = basedir;
             this.patterns = patterns;
         }
 
         @Override
         public boolean test(final DocumentName documentName) {
             return patterns.matches(documentName.getName(),
                     tokenize(documentName.getName(), basedir.getDirectorySeparator()),
                     basedir.isCaseSensitive());
         }
 
         @Override
         public String toString() {
             return patterns.toString();
         }
     }
 
     /**
      * A DocumentName predicate that reverses another DocumentNameMatcher.
      */
     public static final class NotPredicate implements Predicate<DocumentName> {
         /** The document name matcher to reverse */
         private final DocumentNameMatcher nameMatcher;
 
         private NotPredicate(final DocumentNameMatcher nameMatcher) {
             this.nameMatcher = nameMatcher;
         }
 
         @Override
         public boolean test(final DocumentName documentName) {
             return !nameMatcher.matches(documentName);
         }
 
         @Override
         public String toString() {
             return nameMatcher.predicate.toString();
         }
     }
 
     /**
      * A DocumentName predicate that uses {@link FileFilter}.
      */
     public static final class FileFilterPredicate implements Predicate<DocumentName> {
         /** The file filter. */
         private final FileFilter fileFilter;
 
         private FileFilterPredicate(final FileFilter fileFilter) {
             this.fileFilter = fileFilter;
         }
 
         @Override
         public boolean test(final DocumentName documentName) {
             return fileFilter.accept(new File(documentName.getName()));
         }
 
         @Override
         public String toString() {
             return fileFilter.toString();
         }
     }
 
     /**
      * A marker interface to indicate this predicate contains a collection of matchers.
      */
     interface CollectionPredicate extends Predicate<DocumentName> {
         Iterable<DocumentNameMatcher> getMatchers();
     }
     /**
      * A {@link CollectionPredicate} implementation.
      */
     abstract static class DefaultCollectionPredicate implements CollectionPredicate {
         /** The collection for matchers that make up this predicate */
         private final Iterable<DocumentNameMatcher> matchers;
 
         /**
          * Constructs a collection predicate from the collection of matchers.
          * @param matchers the collection of matchers to use.
          */
         protected DefaultCollectionPredicate(final Iterable<DocumentNameMatcher> matchers) {
             this.matchers = matchers;
         }
 
         /**
          * Gets the internal matchers.
          * @return an iterable over the internal matchers.
          */
         public Iterable<DocumentNameMatcher> getMatchers() {
             return matchers;
         }
 
         @Override
         public String toString() {
             StringBuilder builder = new StringBuilder(this.getClass().getName()).append(": ").append(System.lineSeparator());
             for (DocumentNameMatcher matcher : matchers) {
                 builder.append(matcher.predicate.toString()).append(System.lineSeparator());
             }
             return builder.toString();
         }
     }
 
     /**
      * An implementation of "and" logic across a collection of DocumentNameMatchers.
      */
     // package private for testing access
     static class And extends DefaultCollectionPredicate {
         And(final Iterable<DocumentNameMatcher> matchers) {
             super(matchers);
         }
 
         @Override
         public boolean test(final DocumentName documentName) {
             for (DocumentNameMatcher matcher : getMatchers()) {
                 if (!matcher.matches(documentName)) {
                     return false;
                 }
             }
             return true;
         }
     }
 
     /**
      * An implementation of "or" logic across a collection of DocumentNameMatchers.
      */
     // package private for testing access
     static class Or extends DefaultCollectionPredicate {
         Or(final Iterable<DocumentNameMatcher> matchers) {
             super(matchers);
         }
 
         @Override
         public boolean test(final DocumentName documentName) {
             for (DocumentNameMatcher matcher : getMatchers()) {
                 if (matcher.matches(documentName)) {
                     return true;
                 }
             }
             return false;
         }
     }
 
     /**
      * Data from a {@link DocumentNameMatcher#decompose(DocumentName)} call.
      */
     public static final class DecomposeData {
         /** The level this data was generated at. */
         private final int level;
         /** The name of the DocumentNameMatcher that created this result. */
         private final DocumentNameMatcher matcher;
         /** The result of the check. */
         private final boolean result;
         /** The candidate */
         private final DocumentName candidate;
 
         private DecomposeData(final int level, final DocumentNameMatcher matcher, final DocumentName candidate, final boolean result) {
             this.level = level;
             this.matcher = matcher;
             this.result = result;
             this.candidate = candidate;
         }
 
         @Override
         public String toString() {
             final String fill = createFill(level);
             return format("%s%s: >>%s<< %s%n%s",
                     fill, matcher.toString(), result,
                     level == 0 ? candidate.getName() : "",
                     matcher.predicate instanceof CollectionPredicate ?
                             decompose(level + 1, (CollectionPredicate) matcher.predicate, candidate) :
                     String.format("%s%s >>%s<<", createFill(level + 1), matcher.predicate.toString(), matcher.predicate.test(candidate)));
         }
 
         private String createFill(final int level) {
             final char[] chars = new char[level * 2];
             Arrays.fill(chars, ' ');
             return new String(chars);
         }
 
         private String decompose(final int level, final CollectionPredicate predicate, final DocumentName candidate) {
             List<DecomposeData> result = new ArrayList<>();
 
             for (DocumentNameMatcher nameMatcher : predicate.getMatchers()) {
                 nameMatcher.decompose(level, nameMatcher, candidate, result);
             }
             StringBuilder sb = new StringBuilder();
             result.forEach(x -> sb.append(x).append(System.lineSeparator()));
             return sb.toString();
         }
     }
 }