/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package build.tools.stripproperties;

import java.io.BufferedInputStream;

import java.io.BufferedWriter;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.io.IOException;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.Enumeration;

import java.util.List;

import java.util.Properties;

/**

 * Reads a properties file from standard input and writes an equivalent

 * properties file without comments to standard output.

 */

public class StripProperties {

    private static void error(String msg, Exception e) {

        System.err.println("ERROR: stripproperties: " + msg);

        if ( e != null ) {

            System.err.println("EXCEPTION: " + e.toString());

            e.printStackTrace();

        }

    }

    private static List<String> parseOptions(String args[]) {

        List<String> files = new ArrayList<String>();

        for ( int i = 0; i < args.length ; i++ ) {

            if ( "-optionsfile".equals(args[i]) && i+1 < args.length ) {

                String filename = args[++i];

                FileInputStream finput = null;

                byte contents[] = null;

                try {

                    finput = new FileInputStream(filename);

                    int byteCount = finput.available();

                    if ( byteCount <= 0 ) {

                        error("The -optionsfile file is empty", null);

                        files = null;

                    } else {

                        contents = new byte[byteCount];

                        int bytesRead = finput.read(contents);

                        if ( byteCount != bytesRead ) {

                            error("Cannot read all of -optionsfile file", null);

                            files = null;

                        }

                    }

                } catch ( IOException e ) {

                    error("cannot open " + filename, e);

                    files = null;

                }

                if ( finput != null ) {

                    try {

                        finput.close();

                    } catch ( IOException e ) {

                        files = null;

                        error("cannot close " + filename, e);

                    }

                }

                if ( files != null && contents != null ) {

                    String tokens[] = (new String(contents)).split("\\s+");

                    if ( tokens.length > 0 ) {

                        List<String> ofiles = parseOptions(tokens);

                        if ( ofiles != null ) {

                            files.addAll(ofiles);

                        } else {

                            error("No files found in file", null);

                            files = null;

                        }

                    }

                }

                if ( files == null ) {

                    break;

                }

            } else {

                files.add(args[i]);

            }

        }

        return files;

    }

    private static boolean stripFiles(List<String> files) {

        boolean ok = true;

        for ( String file : files ) {

            Properties prop = new Properties();

            InputStream in = null;

            try {

                in = new BufferedInputStream(new FileInputStream(file));

                prop.load(in);

            } catch ( FileNotFoundException e ) {

                error("Cannot access file " + file, e);

                ok = false;

            } catch ( IOException e ) {

                error("IO exception processing file " + file, e);

                ok = false;

            }

            if ( in != null ) {

                try {

                    in.close();

                } catch ( IOException e ) {

                    error("IO exception closing file " + file, e);

                    ok = false;

                }

            }

            if ( !ok ) {

                break;

            }

            OutputStream out = null;

            try {

                out = new FileOutputStream(file);

                storeProperties(prop, out);

                out.flush();

            } catch ( IOException e ) {

                error("IO exception processing file " + file, e);

                ok = false;

            }

            if ( out != null ) {

                try {

                    out.close();

                } catch ( IOException e ) {

                    error("IO exception closing file " + file, e);

                    ok = false;

                }

            }

            if ( !ok ) {

                break;

            }

        }

        return ok;

    }

    /**

     * Strip the properties filenames supplied, replacing their contents.

     * @param args Names of properties files to process and replace contents

     */

    public static void main(String args[]) {

        List<String> files = parseOptions(args);

        if ( files == null || !stripFiles(files) ) {

            System.exit(1);

        }

    }

    // --- code below here is adapted from java.util.Properties ---

    private static final String specialSaveChars = "=: \t\r\n\f#!";

    /*

     * Converts unicodes to encoded \uxxxx

     * and writes out any of the characters in specialSaveChars

     * with a preceding slash

     */

    private static String saveConvert(String theString, boolean escapeSpace) {

        int len = theString.length();

        StringBuffer outBuffer = new StringBuffer(len*2);

        for(int x=0; x<len; x++) {

            char aChar = theString.charAt(x);

            switch(aChar) {

                case ' ':

                    if (x == 0 || escapeSpace) {

                        outBuffer.append('\\');

                    }

                    outBuffer.append(' ');

                    break;

                case '\\':

                    outBuffer.append('\\');

                    outBuffer.append('\\');

                    break;

                case '\t':

                    outBuffer.append('\\');

                    outBuffer.append('t');

                    break;

                case '\n':

                    outBuffer.append('\\');

                    outBuffer.append('n');

                    break;

                case '\r':

                    outBuffer.append('\\');

                    outBuffer.append('r');

                    break;

                case '\f':

                    outBuffer.append('\\');

                    outBuffer.append('f');

                    break;

                default:

                    if ((aChar < 0x0020) || (aChar == 0x007e) || (aChar > 0x00ff)) {

                        outBuffer.append('\\');

                        outBuffer.append('u');

                        outBuffer.append(toHex((aChar >> 12) & 0xF));

                        outBuffer.append(toHex((aChar >>  8) & 0xF));

                        outBuffer.append(toHex((aChar >>  4) & 0xF));

                        outBuffer.append(toHex( aChar        & 0xF));

                    } else {

                        if (specialSaveChars.indexOf(aChar) != -1) {

                            outBuffer.append('\\');

                        }

                        outBuffer.append(aChar);

                    }

            }

        }

        return outBuffer.toString();

    }

    /**

     * Writes the content of <code>properties</code> to <code>out</code>.

     * The format is that of Properties.store with the following modifications:

     * <ul>

     * <li>No header or date is written

     * <li>Latin-1 characters are written as single bytes, not escape sequences

     * <li>Line breaks are indicated by a single \n independent of platform

     * <ul>

     */

    private static void storeProperties(Properties properties, OutputStream out)

    throws IOException {

        BufferedWriter awriter;

        awriter = new BufferedWriter(new OutputStreamWriter(out, "8859_1"));

        for (Enumeration e = properties.keys(); e.hasMoreElements();) {

            String key = (String)e.nextElement();

            String val = (String)properties.get(key);

            key = saveConvert(key, true);

            /* No need to escape embedded and trailing spaces for value, hence

             * pass false to flag.

             */

            val = saveConvert(val, false);

            writeln(awriter, key + "=" + val);

        }

        awriter.flush();

    }

    private static void writeln(BufferedWriter bw, String s) throws IOException {

        bw.write(s);

        bw.write("\n");

    }

    /**

     * Convert a nibble to a hex character

     * @param   nibble  the nibble to convert.

     */

    private static char toHex(int nibble) {

        return hexDigit[(nibble & 0xF)];

    }

    /** A table of hex digits */

    private static final char[] hexDigit = {

        '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'

    };

}