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/*
 * Copyright (c) 2002-2015 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.kernel.impl.util;

import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import org.neo4j.function.Function;

public class Converters
{
    public static  Function mandatory()
    {
        return new Function()
        {
            @Override
            public T apply( String key )
            {
                throw new IllegalArgumentException( "Missing argument '" + key + "'" );
            }
        };
    }

    public static  Function optional()
    {
        return new Function()
        {
            @Override
            public T apply( String from )
            {
                return null;
            }
        };
    }

    public static  Function withDefault( final T defaultValue )
    {
        return new Function()
        {
            @Override
            public T apply( String from )
            {
                return defaultValue;
            }
        };
    }

    public static Function toFile()
    {
        return new Function()
        {
            @Override
            public File apply( String from )
            {
                return new File( from );
            }
        };
    }

    public static final Comparator BY_FILE_NAME = new Comparator()
    {
        @Override
        public int compare( File o1, File o2 )
        {
            return o1.getName().compareTo( o2.getName() );
        }
    };

    public static final Comparator BY_FILE_NAME_WITH_CLEVER_NUMBERS = new Comparator()
    {
        @Override
        public int compare( File o1, File o2 )
        {
            return NumberAwareStringComparator.INSTANCE.compare( o1.getAbsolutePath(), o2.getAbsolutePath() );
        }
    };

    public static Function regexFiles( final boolean cleverNumberRegexSort )
    {
        return new Function()
        {
            @Override
            public File[] apply( String name ) throws RuntimeException
            {
                Comparator sorting = cleverNumberRegexSort ? BY_FILE_NAME_WITH_CLEVER_NUMBERS : BY_FILE_NAME;
                List files = Validators.matchingFiles( new File( name ) );
                Collections.sort( files, sorting );
                return files.toArray( new File[files.size()] );
            }
        };
    }

    public static Function toFiles( final String delimiter,
            final Function eachFileConverter )
    {
        return new Function()
        {
            @Override
            public File[] apply( String from )
            {
                if ( from == null )
                {
                    return new File[0];
                }

                String[] names = from.split( delimiter );
                List files = new ArrayList<>();
                for ( String name : names )
                {
                    for ( File file : eachFileConverter.apply( name ) )
                    {
                        files.add( file );
                    }
                }
                return files.toArray( new File[files.size()] );
            }
        };
    }

    public static Function toCharacter()
    {
        return new Function()
        {
            @Override
            public Character apply( String value )
            {
                if ( value.length() > 1 )
                {
                    throw new IllegalArgumentException( "Invalid delimiter '" +
                            value + "', expected one character" );
                }
                return value.charAt( 0 );
            }
        };
    }

    public static Function toInt()
    {
        return new Function()
        {
            @Override
            public Integer apply( String from )
            {
                return new Integer( from );
            }
        };
    }
}