/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2001-06 Wolfgang M. Meier
 *  wolfgang@exist-db.org
 *  http://exist.sourceforge.net
 *  
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  $Id$
 */
package org.exist.dom;

import org.exist.collections.Collection;
import org.exist.security.Group;
import org.exist.security.SecurityManager;
import org.exist.security.User;
import org.exist.storage.BrokerPool;
import org.exist.storage.btree.Paged.Page;
import org.exist.storage.io.VariableByteInput;
import org.exist.storage.io.VariableByteOutputStream;
import org.exist.xmldb.XmldbURI;

import java.io.EOFException;
import java.io.IOException;

/**
 * Represents a binary resource. Binary resources are just stored
 * as binary data in a single overflow page. However, class BinaryDocument
 * extends {@link org.exist.dom.DocumentImpl} and thus provides the 
 * same interface.
 * 
 * @author wolf
 */
public class BinaryDocument extends DocumentImpl {
	
	private long pageNr = Page.NO_PAGE;
    
    private int realSize = 0;
    
    public BinaryDocument(BrokerPool pool) {
        super(pool, null, null);
    } 
    
	public BinaryDocument(BrokerPool pool, Collection collection) {
		super(pool, collection);
	}

    public BinaryDocument(BrokerPool pool, XmldbURI fileURI) {
        super(pool, null, fileURI);
    }    

	public BinaryDocument(BrokerPool pool, Collection collection, XmldbURI fileURI) {
		super(pool, collection, fileURI);
	}
	
	/* (non-Javadoc)
	 * @see org.exist.dom.DocumentImpl#getResourceType()
	 */
	public byte getResourceType() {
		return BINARY_FILE;
	}
    
	public void setPage(long page) {
		this.pageNr = page;
	}

	public long getPage() {
		return pageNr;
	}

    public int getContentLength() {
        return realSize;
    }
    
    public void setContentLength(int length) {
        this.realSize = length;
    }
    
	public void write(VariableByteOutputStream ostream) throws IOException {
		ostream.writeInt(getDocId());
		ostream.writeUTF(getFileURI().toString());
		ostream.writeLong(pageNr);
		SecurityManager secman = getBrokerPool().getSecurityManager();
		if (secman == null) {
            //TODO : explain those 2 values -pb
			ostream.writeInt(1);
			ostream.writeInt(1);
		} else {
			User user = secman.getUser(permissions.getOwner());
			Group group = secman.getGroup(permissions.getOwnerGroup());
			ostream.writeInt(user.getUID());
			ostream.writeInt(group.getId());
		}

                /*
                 Errata - the permissions should be read/written as an int and not a byte
                 however changing this in 1.4.x would break .dbx
                 backward compatibility in the 1.4 line.
                 */
		ostream.writeByte((byte) permissions.getPermissions());

                ostream.writeInt(realSize);
		getMetadata().write(getBrokerPool(), ostream);
	}

	public void read(VariableByteInput istream)
		throws IOException, EOFException {
		setDocId(istream.readInt());
		setFileURI(XmldbURI.create(istream.readUTF()));
		pageNr = istream.readLong();
		final SecurityManager secman = getBrokerPool().getSecurityManager();
		final int uid = istream.readInt();
		final int groupId = istream.readInt();

                /*
                 Errata - the permissions should be read/written as an int and not a byte
                 however changing this in 1.4.x would break .dbx
                 backward compatibility in the 1.4 line.
                 */
		final int perm = (istream.readByte() & 0777);

                if (secman == null) {
			permissions.setOwner(SecurityManager.DBA_USER);
			permissions.setGroup(SecurityManager.DBA_GROUP);
		} else {
			permissions.setOwner(secman.getUser(uid));
            Group group = secman.getGroup(groupId);
            if (group != null)
                permissions.setGroup(group.getName());
		}
		permissions.setPermissions(perm);
		realSize = istream.readInt();
        
        DocumentMetadata metadata = new DocumentMetadata();
        metadata.read(getBrokerPool(), istream);
        setMetadata(metadata);
	}
}