/**************************************************************************
    *
    * Copyright (c) 2016-2020 Yawg project contributors.
    *
    **************************************************************************/
   
   package com.varmateo.yawg.util;
   
   import java.nio.file.FileSystem;
  import java.nio.file.FileSystems;
  import java.nio.file.Path;
  import java.nio.file.PathMatcher;
  import java.util.function.Predicate;
  import java.util.regex.PatternSyntaxException;
  
  import io.vavr.collection.Array;
  import io.vavr.collection.Seq;
  
  
  /**
   * A predicate for checking if a path matches a given collection of
   * glob patterns.
   */
  public final class GlobMatcher
          implements Predicate<Path> {
  
  
      private static final FileSystem DEFAULT_FILESYSTEM =
              FileSystems.getDefault();
  
  
      private final Seq<String> _globPatterns;
      private final Seq<PathMatcher> _matchers;
  
  
      private GlobMatcher(final Builder builder) {
  
          _globPatterns = builder._globPatterns;
          _matchers = builder._matchers;
      }
  
  
      /**
       *
       */
      public static GlobMatcher create(final String... globPatterns) {
  
          final Builder builder = builder();
  
          for ( final String globPattern : globPatterns ) {
              builder.addGlobPattern(globPattern);
          }
  
          return builder.build();
      }
  
  
      /**
       * Creates a new builder with no initializations.
       *
       * @return A newly created <code>Builder</code> instance.
       */
      public static Builder builder() {
  
          return new Builder();
      }
  
  
      /**
       * Creates a new builder initialized with the data from the given
       * <code>GlobMatcher</code>.
       *
       * @param data Used for initializing the builder state.
       *
       * @return A newly created <code>Builder</code> instance.
       */
      public static Builder builder(final GlobMatcher data) {
  
          return new Builder(data);
      }
  
  
      /**
       * Checks if the given path matches the glob pattern represented
       * by this object.
       *
       * @param path The path to be checked.
       *
       * @return True if the given path matches our glob pattern. False
       * otherwise.
       */
      @Override
      public boolean test(final Path path) {
  
          final Path name = path.getFileName();
          final Predicate<PathMatcher> isMatch = matcher -> matcher.matches(name);
  
          return _matchers
                  .filter(isMatch)
                 .headOption()
                 .isDefined();
     }
 
 
     /**
      * Intended for logging or debugging.
      *
      * @return The string representation of our glob pattern.
      */
     @Override
     public String toString() {
 
         // This implementation is not particularly performant. Let us
         // hope client code only uses this method for sporadic logging
         // or debugging.
 
         return String.join(",", _globPatterns);
     }
 
 
 
 
 
     /**
      * A builder of <code>GlobMatcher</code> instances.
      */
     public static final class Builder {
 
 
         private Seq<String> _globPatterns;
         private Seq<PathMatcher> _matchers;
 
 
         /**
          *
          */
         /* default */ Builder() {
 
             _globPatterns = Array.of();
             _matchers = Array.of();
         }
 
 
         /**
          *
          */
         /* default */ Builder(final GlobMatcher globMatcher) {
 
             _globPatterns = globMatcher._globPatterns;
             _matchers = globMatcher._matchers;
         }
 
 
         /**
          *
          *
          * @throws PatternSyntaxException If the given glob pattern is
          * invalid.
          */
         public Builder addGlobPattern(final String globPattern) {
 
             final PathMatcher matcher = DEFAULT_FILESYSTEM.getPathMatcher("glob:" + globPattern);
 
             _globPatterns = _globPatterns.append(globPattern);
             _matchers = _matchers.append(matcher);
 
             return this;
         }
 
 
         /**
          *
          */
         public Builder addGlobMatcher(final GlobMatcher globMatcher) {
 
             _globPatterns = _globPatterns.appendAll(globMatcher._globPatterns);
             _matchers = _matchers.appendAll(globMatcher._matchers);
 
             return this;
         }
 
 
         /**
          *
          */
         public GlobMatcher build() {
 
             return new GlobMatcher(this);
         }
 
 
     }
 
 
 }