/*
 * [FS.java]
 *
 * Summary: Gets info about all instances of a file or wildcard in the current tree.
 *
 * Copyright: (c) 2016-2017 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 2016-11-10 initial release
 *  1.1 2016-12-09 make patterns case-insensitive
 */
package com.mindprod.fs;

import com.mindprod.common18.EIO;
import com.mindprod.common18.ST;
import com.mindprod.filter.OnlyDirectoriesFilter;
import com.mindprod.filter.WildcardFilter;

import java.io.File;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;

import static java.lang.System.*;

/**
 * Gets info about all instances of a file or wildcard in the current tree.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 2016-12-09 make patterns case-insensitive
 * @since 2016-11-10
 */
public class FS
    {
    /**
     * Modified Zulu format mask 2008-06-22T07:57+46.438
     */
    private static final SimpleDateFormat SDF = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm'+'ss'.'SSS  " );

    /**
     * undisplayed copyright notice
     */
    @SuppressWarnings( { "UnusedDeclaration" } )
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2016-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    /**
     * date this version was released.
     */
    @SuppressWarnings( { "UnusedDeclaration" } )
    private static final String RELEASE_DATE = "2016-12-09";

    private static final int FIRST_COPYRIGHT_YEAR = 2016;

    /**
     * how to use the command line
     */
    private static final String USAGE = "\nFS requires unqualified file name, or wildcard in quotes.";

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

    private static final OnlyDirectoriesFilter DIRS_ONLY = new OnlyDirectoriesFilter();

    private static final DecimalFormat SIZE_FORMAT = new DecimalFormat( "#,##0  " );

    /**
     * Scan file for all occurrences of the file.
     *
     * @param dir to start the recursive search
     *
     * @throws IOException if trouble reading directory tree.
     */
    private static void scanDirForFile( File dir, String filename ) throws IOException
        {
        final File hit = new File( dir, filename );
        if ( hit.exists() )
            {
            // output stats on this file.
            // format length
            final long length = hit.length();
            final String lengthDisplay = ST.leftPad( SIZE_FORMAT.format( length ), 13, false );
            // format date
            final long date = hit.lastModified();
            final String dateDisplay = SDF.format( date );
            out.println( lengthDisplay + dateDisplay +
                         EIO.getCanOrAbsPath( hit ) );
            }
        // continue scanning nested dirs
        final String[] dirs = dir.list( DIRS_ONLY );
        if ( dirs != null )
            {
            for ( String subdir : dirs )
                {
                scanDirForFile( new File( dir, subdir ), filename );
                }
            }
        } // end scanFile

    /**
     * Scan file for all occurrences of the wildcard.
     *
     * @param dir to start the recursive search
     *
     * @throws IOException if trouble reading directory tree.
     */
    private static void scanDirForWildcard( File dir, WildcardFilter wildcardFilter ) throws IOException
        {
        final String[] fileHits = dir.list( wildcardFilter );
        if ( fileHits != null )
            {
            for ( String i : fileHits )
                {
                // output stats on this file.
                // format length
                final File hit = new File( dir, i );
                final long length = hit.length();
                final String lengthDisplay = ST.leftPad( SIZE_FORMAT.format( length ), 13, false );
                // format date
                final long date = hit.lastModified();
                final String dateDisplay = SDF.format( date );
                out.println( lengthDisplay + dateDisplay +
                             EIO.getCanOrAbsPath( hit ) );
                }
            }
        // continue scanning nested dirs
        final String[] dirs = dir.list( DIRS_ONLY );
        if ( dirs != null )
            {
            for ( String subdir : dirs )
                {
                scanDirForWildcard( new File( dir, subdir ), wildcardFilter );
                }
            }
        }

    /**
     * compacts HTML files.
     *
     * @param args regex, output file, then names of files to process, dirs, files, -s, *.*, no wildcards.
     */
    public static void main( String[] args )
        {
        if ( args.length != 1 )
            {
            err.println( USAGE );
            for ( String arg : args )
                {
                err.print( "[" + arg + "] " );
                }
            err.println();
            System.exit( 2 );
            }
        // will throw an detailed exception if this is not a valid string.
        final String filename = args[ 0 ];
        try
            {
            if ( filename.indexOf( '*' ) >= 0 || filename.indexOf( '?' ) >= 0 )
                {
                scanDirForWildcard( new File( "." ), new WildcardFilter( filename ) );
                }
            else
                {
                scanDirForFile( new File( "." ), filename );
                }
            }
        catch ( IOException e )
            {
            err.println( "io error scanning for " + filename );
            }
        } // end main
    }