package org.apache.maven.plugins.war.util;

/*
 * 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.
 */

import org.codehaus.plexus.util.DirectoryScanner;

import java.io.File;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;

/**
 * Set of file's paths.
 * 
 * The class extends functionality of a "normal" set of strings by a process of the paths normalization. All paths are
 * converted to unix form (slashes) and they don't start with starting /.
 *
 * @author Piotr Tabor
 */

public class PathSet
    implements Iterable<String>
{
    private static final String SEPARATOR = "/";
    private static final char SEPARATOR_CHAR = SEPARATOR.charAt( 0 );
    /**
     * Set of normalized paths
     */
    private Set<String> pathsSet = new LinkedHashSet<>();

    static String normalizeSubPath( String path )
    {
        if ( path.isEmpty() )
        {
            return path;
        }
        String cleanPath = path.replaceAll( "[\\\\]+", SEPARATOR )
                .replaceAll( "[/]+" , SEPARATOR );
        cleanPath = cleanPath.charAt( 0 ) == SEPARATOR_CHAR ? cleanPath.substring( 1 ) : cleanPath;
        if ( cleanPath.isEmpty() )
        {
            return cleanPath;
        }
        if ( cleanPath.charAt( cleanPath.length() - 1 ) == SEPARATOR_CHAR )
        {
            return cleanPath.substring( 0, cleanPath.length() - 1 );
        }
        return cleanPath;
    }

    /*-------------------- Business interface ------------------------------*/

    /**
     * Creates an empty paths set
     */
    public PathSet()
    {
        /* Empty default constructor */
    }

    /**
     * Creates paths set and normalizate and adds all 'paths'. The source 'paths' will not be changed
     *
     * @param paths to be added
     */
    public PathSet( Collection<String> paths )
    {
        addAll( paths );
    }

    /**
     * Creates paths set and normalizate and adds all 'paths'. The source 'paths' will not be changed
     *
     * @param paths to be added
     */
    public PathSet( String[] paths )
    {
        addAll( paths );
    }

    /**
     * Normalizes and adds given path to the set.
     *
     * @param path to be added
     */
    public void add( String path )
    {
        pathsSet.add( normalizeSubPath( path ) );
    }

    /**
     * Normalizes and adds given paths (collection of strings) to the set. The source collection will not be changed
     *
     * @param paths - collection of strings to be added
     * @param prefix added to all given paths
     */
    public void addAll( Collection<String> paths, String prefix )
    {
        for ( String val : paths )
        {
            add( prefix + SEPARATOR +  val );
        }
    }

    /**
     * Normalizes and adds given paths to the set. The source collection will not be changed
     *
     * @param paths to be added
     * @param prefix added to all given paths
     */
    public void addAll( String[] paths, String prefix )
    {
        for ( String val : paths )
        {
            add( prefix + SEPARATOR + val );
        }
    }

    /**
     * Adds given paths to the set. The source collection will not be changed
     *
     * @param paths to be added
     * @param prefix added to all given paths
     */
    public void addAll( PathSet paths, String prefix )
    {
        for ( String path : paths )
        {
            add( prefix + SEPARATOR + path );
        }
    }

    /**
     * Normalizes and adds given paths (collection of strings) to the set. The source collection will not be changed
     *
     * @param paths - collection of strings to be added
     */
    public void addAll( Collection<String> paths )
    {
        addAll( paths, "" );
    }

    /**
     * Normalizes and adds given paths to the set. The source collection will not be changed
     *
     * @param paths to be added
     */
    public void addAll( String[] paths )
    {
        addAll( paths, "" );
    }

    /**
     * Adds given paths to the set. The source collection will not be changed
     *
     * @param paths to be added
     */
    public void addAll( PathSet paths )
    {
        addAll( paths, "" );
    }

    /**
     * Checks if the set constains given path. The path is normalized before check.
     *
     * @param path we are looking for in the set.
     * @return information if the set constains the path.
     */
    public boolean contains( String path )
    {
        return pathsSet.contains( normalizeSubPath( path ) );
    }

    /**
     * Removes the specified path if it exists.
     *
     * @param path the path to remove
     * @return true if the path was removed, false if it did not existed
     */
    boolean remove( String path )
    {
        return pathsSet.remove( normalizeSubPath( path ) );
    }

    /**
     * Returns iterator of normalized paths (strings)
     *
     * @return iterator of normalized paths (strings)
     */
    @Override
    public Iterator<String> iterator()
    {
        return pathsSet.iterator();
    }

    /**
     * @return {@link #pathsSet}
     */
    public Collection<String> paths()
    {
        return pathsSet;
    }

    /**
     * Adds given prefix to all paths in the set.
     * 
     * The prefix should be ended by '/'. The generated paths are normalized.
     *
     * @param prefix to be added to all items
     */
    public void addPrefix( String prefix )
    {
        final Set<String> newSet = new HashSet<>();
        for ( String path : pathsSet )
        {
            newSet.add( normalizeSubPath( prefix + path ) );
        }
        pathsSet = newSet;
    }

    /**
     * Returns count of the paths in the set
     *
     * @return count of the paths in the set
     */
    public int size()
    {
        return pathsSet.size();
    }

    /**
     * Adds to the set all files in the given directory
     *
     * @param directory that will be searched for file's paths to add
     * @param prefix to be added to all found files
     */
    public void addAllFilesInDirectory( File directory, String prefix )
    {
        DirectoryScanner scanner = new DirectoryScanner();
        scanner.setBasedir( directory );
        scanner.scan();
        addAll( scanner.getIncludedFiles(), prefix );
    }

}