// serverByteBuffer.java 
// ---------------------------
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 11.03.2004
//
// This program 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 2 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, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.

package de.anomic.server;

import java.io.*;
import java.util.*;

public class serverByteBuffer {
    
    public static final byte singlequote = (byte) 39;
    public static final byte doublequote = (byte) 34;
    public static final byte equal       = (byte) '=';
    
    private byte[] buffer;
    private int offset;
    private int length;

    public serverByteBuffer() {
	buffer = new byte[80];
	length = 0;
	offset = 0;
    }

    public serverByteBuffer(byte[] bb) {
	buffer = bb;
	length = bb.length;
	offset = 0;
    }

    public serverByteBuffer(byte[] bb, int of, int le) {
	if (of * 2 > bb.length) {
	    buffer = new byte[le];
	    System.arraycopy(bb, of, buffer, 0, le);
	    length = le;
	    offset = 0;
	} else {
	    buffer = bb;
	    length = le;
	    offset = of;
	}
    }

    public serverByteBuffer(serverByteBuffer bb) {
	buffer = bb.buffer;
	length = bb.length;
	offset = bb.offset;
    }

    public serverByteBuffer(File f) throws IOException {
	// initially fill the byte buffer with the content of a file
	if (f.length() > (long) Integer.MAX_VALUE) throw new IOException("file is too large for buffering");

	length = (int) f.length();
	buffer = new byte[length];
	offset = 0;

	try {
	    FileInputStream fis = new FileInputStream(f);
	    byte buf[] = new byte[512];
	    int p = 0;
	    int l;
	    while ((l = fis.read(buf)) > 0) {
		System.arraycopy(buf, 0, buffer, p, l);
		p += l;
	    }
	    fis.close();
	} catch (FileNotFoundException e) {
	    throw new IOException("File not found: " + f.toString() + "; " + e.getMessage());
	}
    }

    public int length() {
	return length;
    }

    private void grow() {
	byte[] tmp = new byte[buffer.length * 2 + 1];
	System.arraycopy(buffer, offset, tmp, 0, length);
	buffer = tmp;
	tmp = null;
	offset = 0;
    }

    public serverByteBuffer append(byte b) {
	if (offset + length + 1 > buffer.length) grow();
	buffer[offset + length++] = b;
	return this;
    }

    public serverByteBuffer append(byte[] bb) {
	return append(bb, 0, bb.length);
    }

    public serverByteBuffer append(byte[] bb, int of, int le) {
	while (offset + length + le > buffer.length) grow();
	System.arraycopy(bb, of, buffer, offset + length, le);
	length += le;
	return this;
    }

    public serverByteBuffer append(String s) {
	return append(s.getBytes());
    }

    public serverByteBuffer append(serverByteBuffer bb) {
	return append(bb.buffer, bb.offset, bb.length);
    }

    public serverByteBuffer append(Object o) {
        if (o instanceof String) return append((String) o);
        if (o instanceof byte[]) return append((byte[]) o);
        return null;
    }
    
    public byte byteAt(int pos) {
	if (pos > length) return -1;
	return buffer[offset + pos];
    }

    public int indexOf(byte b) {
	return indexOf(b, 0);
    }

    public int indexOf(byte b, int start) {
	if (start >= length) return -1;
	for (int i = start; i < length; i++) if (buffer[offset + i] == b) return i;
	return -1;
    }

    public int lastIndexOf(byte b) {
	for (int i = length - 1; i >= 0; i--) if (buffer[offset + i] == b) return i;
	return -1;
    }

    public byte[] getBytes() {
	return getBytes(0);
    }

    public byte[] getBytes(int start) {
	return getBytes(start, length);
    }

    public byte[] getBytes(int start, int end) {
	// start is inclusive, end is exclusive
	if (end > length) throw new IndexOutOfBoundsException("getBytes: end > length");
	if (start > length) throw new IndexOutOfBoundsException("getBytes: start > length");
	byte[] tmp = new byte[end - start];
	System.arraycopy(buffer, offset + start, tmp, 0, end - start);
	return tmp;
    }

    private serverByteBuffer trim(int start) {
	if (start > length) throw new IndexOutOfBoundsException("trim: start > length");
	offset = offset + start;
	length = length - start;
	return this;
    }

    private serverByteBuffer trim(int start, int end) {
	if (end > length) throw new IndexOutOfBoundsException("trim: end > length");
	trim(start);
	length = end - start;
	return this;
    }

    public serverByteBuffer trim() {
	int l = 0; while ((l < length) && (buffer[l] <= 32)) l++;
	int r = length; while ((r > 0) && (buffer[r - 1] <= 32)) r--;
	if ((l <= r) && (l < length)) return trim(l, r);
	return this;
    }

    public String toString() {
	return new String(getBytes());
    }

    public Properties propParser() {
	// extract a=b or a="b" - relations from the buffer
	int pos = offset;
	int start;
	String key;
	Properties p = new Properties();
	// eat up spaces at beginning
	while ((pos < length) && (buffer[pos] <= 32)) pos++;
	while (pos < length) {
	    // pos is at start of next key
	    start = pos;
	    while ((pos < length) && (buffer[pos] != equal)) pos++;
	    if (pos >= length) break; // this is the case if we found no equal
	    key = new String(buffer, start, pos - start).trim().toLowerCase();
	    // we have a key
	    pos++;
	    // find start of value
	    while ((pos < length) && (buffer[pos] <= 32)) pos++;
	    // doublequotes are obligatory. However, we want to be fuzzy if they are ommittet
	    if (pos >= length) {
		// error case: input ended too early
		break;
	    } else if (buffer[pos] == doublequote) {
		// search next doublequote
		pos++;
		start = pos;
		while ((pos < length) && (buffer[pos] != doublequote)) pos++;
		if (pos >= length) break; // this is the case if we found no parent doublequote
		p.setProperty(key, new String(buffer, start, pos - start).trim());
		pos++;
	    } else if (buffer[pos] == singlequote) {
		// search next singlequote
		pos++;
		start = pos;
		while ((pos < length) && (buffer[pos] != singlequote)) pos++;
		if (pos >= length) break; // this is the case if we found no parent singlequote
		p.setProperty(key, new String(buffer, start, pos - start).trim());
		pos++;
	    } else {
		// search next whitespace
		start = pos;
		while ((pos < length) && (buffer[pos] > 32)) pos++;
		p.setProperty(key, new String(buffer, start, pos - start).trim());
	    }
	    // pos should point now to a whitespace: eat up spaces
	    while ((pos < length) && (buffer[pos] <= 32)) pos++;
	    // go on with next loop
	}
	return p;
    }
    
    public static boolean equals(byte[] buffer, byte[] pattern) {
        return equals(buffer, 0, pattern);
    }
    
        public static boolean equals(byte[] buffer, int offset, byte[] pattern) {
        // compares two byte arrays: true, if pattern appears completely at offset position
        if (buffer.length < offset + pattern.length) return false;
        for (int i = 0; i < pattern.length; i++) if (buffer[offset + i] != pattern[i]) return false;
        return true;
    }
    
}