/*
 * [Chop.java]
 *
 * Summary: Chops tail ends off files.
 *
 * Copyright: (c) 2014-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2014-05-18 initial version
 *  1.1 2014-07-13 do search for marker starting at the end. Add Behead.
 */
package com.mindprod.chop;

import com.mindprod.commandline.CommandLine;
import com.mindprod.common18.EIO;
import com.mindprod.common18.ST;
import com.mindprod.filter.AllButSVNDirectoriesFilter;
import com.mindprod.filter.ExtensionListFilter;
import com.mindprod.hunkio.HunkIO;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;

import static java.lang.System.*;

/**
 * Chops tail ends off files.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 2014-07-13 do search for marker starting at the end. Add Behead.
 * @since 2014-05-18
 */
public class Chop
    {
    // declarations

    /**
     * true if want extra output
     */
    private static final boolean DEBUGGING = false;

    /**
     * when program first copyrighted
     */
    private static final int FIRST_COPYRIGHT_YEAR = 2014;

    /**
     * undisplayed copyright notice
     */
    @SuppressWarnings( { "UnusedDeclaration" } )
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2014-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    @SuppressWarnings( { "UnusedDeclaration" } )
    private static final String RELEASE_DATE = "2014-07-13";

    /**
     * how to use the command line
     *
     * @see Behead
     */
    private static final String USAGE = "\nchop.jar [-q] [-charset=\"UTF-8\"] [-before=\"xxx\"] [-after=\"xxx\"] [-s] dirs/files...";

    /**
     * embedded version string.
     */
    @SuppressWarnings( { "UnusedDeclaration" } )
    private static final String VERSION_STRING = "1.1";
    // /declarations
    // methods

    /**
     * sort items in one file
     *
     * @param file      file to process
     * @param marker    chop at first occurence of this string.
     * @param chopAfter true chop just after marker. false chop just before marker.
     * @param charset   Character set
     * @param quiet     true, suppress progress messages.
     */
    private static void processOneFile( final File file,
                                        final String marker,
                                        final boolean chopAfter,
                                        final Charset charset,
                                        final boolean quiet
    )
            throws IOException
        {
        final String contents = HunkIO.readEntireFile( file, charset );
        final int place = contents.lastIndexOf( marker );
        if ( place < 0 )
            {
            if ( !quiet )
                {
                out.println( EIO.getCanOrAbsPath( file ) + " left as is." );
                return;
                }
            }
        final int end = chopAfter ? place + marker.length() : place;
        HunkIO.writeEntireFile( file, contents.substring( 0, end ), charset );
        if ( !quiet )
            {
            out.println( "File " + EIO.getCanOrAbsPath( file ) + " chopped to " + end + " characters." );
            }
        }// /method

    /**
     * @param args -before="xxx" -after="xxx" [-s] dirs/files...
     *
     * @throws java.io.IOException
     */
    public static void main( final String[] args ) throws IOException
        {
        String before = null;
        String after = null;
        boolean quiet = false;
        Charset charset = null;
        for ( int i = 0; i < args.length; i++ )
            {
            final String arg = args[ i ];
            final int equalPlace = arg.indexOf( '=' );
            if ( arg.startsWith( "-" ) && equalPlace >= 0 )
                {
                final String key = arg.substring( 1, equalPlace ).trim();
                final String value = arg.substring( equalPlace + 1 ).trim();
                // mark this arg handled so it will not fool the command line processor
                args[ i ] = null;
                // command line processor has already stripped " " out of parm.
                switch ( key )
                    {
                    case "before":
                        before = value;
                        break;
                    case "charset":
                        charset = Charset.forName( value );
                        break;
                    case "after":
                        after = value;
                        break;
                    case "q":
                    case "v":
                    case "s": /* ignore, part of files */
                        break;
                    default:
                        throw new IllegalArgumentException( "unrecognised option " + arg + "\n" + USAGE );
                    }
                }
            else
                {
                //  filenames.  CommandLine will deal with it later
                }
            }  // end for
        if ( ST.isEmpty( before ) && ST.isEmpty( after ) )
            {
            throw new IllegalArgumentException( "Must have either -before= or -after=.\n" + USAGE );
            }
        if ( !ST.isEmpty( before ) && !ST.isEmpty( after ) )
            {
            throw new IllegalArgumentException( "Cannot have both -before= and -after=.\n" + USAGE );
            }
        final String marker;
        final boolean chopAfter;
        if ( ST.isEmpty( after ) )
            {
            marker = before;
            chopAfter = false;
            }
        else
            {
            marker = after;
            chopAfter = true;
            }
        if ( charset == null )
            {
            charset = Charset.defaultCharset();
            }
        CommandLine commandLine = new CommandLine( args,
                new AllButSVNDirectoriesFilter(),
                new ExtensionListFilter( ExtensionListFilter.COMMON_TEXT_EXTENSIONS ) );
        quiet = commandLine.isQuiet();
        if ( commandLine.size() == 0 )
            {
            throw new IllegalArgumentException( "No files found to process\n" + USAGE );
            }
        for ( File file : commandLine )
            {
            processOneFile( file, marker, chopAfter, charset, quiet );
            }
        }// /method
    // /methods
    }