/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2023 jPOS Software SRL
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso.packager;

import org.jpos.iso.*;
import org.jpos.util.LogEvent;
import org.jpos.util.LogSource;
import org.jpos.util.Logger;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;

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

/**
 * packs/unpacks ISOMsgs from jPOS logs
 *
 * @author apr@cs.com.uy
 * @version $Id$
 * @see ISOPackager
 */
@SuppressWarnings("unchecked")
public class LogPackager extends DefaultHandler
                         implements ISOPackager, LogSource
{
    protected Logger logger = null;
    protected String realm = null;
    private ByteArrayOutputStream out;
    private PrintStream p;
    private XMLReader reader = null;
    private Stack stk;

    public static final String LOG_TAG       = "log";
    public static final String ISOMSG_TAG    = "isomsg";
    public static final String ISOFIELD_TAG  = "field";
    public static final String ID_ATTR       = "id";
    public static final String VALUE_ATTR    = "value";
    public static final String TYPE_ATTR     = "type";
    public static final String TYPE_BINARY   = "binary";
    public static final String TYPE_BITMAP   = "bitmap";

    public LogPackager() throws ISOException {
        super();
        out = new ByteArrayOutputStream();
        p   = new PrintStream(out);
        stk = new Stack();
        try {
            reader = XMLReaderFactory.createXMLReader(
                System.getProperty( "sax.parser",
                                    "org.apache.crimson.parser.XMLReaderImpl")
            );
            reader.setFeature ("http://xml.org/sax/features/validation",false);
            reader.setContentHandler(this);
            reader.setErrorHandler(this);
        } catch (Exception e) {
            throw new ISOException (e.toString());
        }
    }
    public byte[] pack (ISOComponent c) throws ISOException {
        LogEvent evt = new LogEvent (this, "pack");
        try {
            if (!(c instanceof ISOMsg))
                throw new ISOException ("cannot pack "+c.getClass());
            ISOMsg m = (ISOMsg) c;
            byte[] b;
            synchronized (this) {
                p.println ("<log>");
                c.dump (p, " ");
                p.println ("</log>");
                b = out.toByteArray();
                out.reset();
            }
            if (logger != null)
                evt.addMessage (m);
            return b;
        } catch (ISOException e) {
            evt.addMessage (e);
            throw e;
        } finally {
            Logger.log(evt);
        }
    }

    public synchronized int unpack (ISOComponent c, byte[] b) 
        throws ISOException
    {
        LogEvent evt = new LogEvent (this, "unpack");
        try {
            if (!(c instanceof ISOMsg))
                throw new ISOException 
                    ("Can't call packager on non Composite");

            while (!stk.empty())    // purge from possible previous error
                stk.pop();

            InputSource src = new InputSource (new ByteArrayInputStream(b));
            reader.parse (src);
            if (!stk.empty()) {
                ISOMsg m = (ISOMsg) c;
                m.merge ((ISOMsg) stk.pop());
                if (logger != null)     
                    evt.addMessage (m);
            }
        } catch (ISOException e) {
            evt.addMessage (e);
            // throw e;
        } catch (IOException e) {
            evt.addMessage (e);
            // throw new ISOException (e.toString());
        } catch (SAXException e) {
            evt.addMessage (e);
            // throw new ISOException (e.toString());
        } finally {
            Logger.log (evt);
        }
        return b.length;
    }

    public synchronized void unpack (ISOComponent c, InputStream in) 
        throws ISOException, IOException
    {
        LogEvent evt = new LogEvent (this, "unpack");
        try {
            if (!(c instanceof ISOMsg))
                throw new ISOException 
                    ("Can't call packager on non Composite");

            while (!stk.empty())    // purge from possible previous error
                stk.pop();

            reader.parse (new InputSource (in));
            if (!stk.empty()) {
                ISOMsg m = (ISOMsg) c;
                m.merge ((ISOMsg) stk.pop());
                if (logger != null)     
                    evt.addMessage (m);
            }
        } catch (ISOException e) {
            evt.addMessage (e);
            // throw e;
        } catch (IOException e) {
            evt.addMessage (e);
            // throw new ISOException (e.toString());
        } catch (SAXException e) {
            evt.addMessage (e);
            // throw new ISOException (e.toString());
        } finally {
            Logger.log (evt);
        }
    }

    public void startElement 
        (String ns, String name, String qName, Attributes atts)
        throws SAXException
    {
        int fieldNumber = -1;
        try {
            String id       = atts.getValue(ID_ATTR);
            if (id != null) {
                try {
                    fieldNumber = Integer.parseInt (id);
                } catch (NumberFormatException ex) { }
            }
            if (name.equals (ISOMSG_TAG)) {
                if (fieldNumber >= 0) {
                    if (stk.empty())
                        throw new SAXException ("inner without outter");

                    ISOMsg inner = new ISOMsg(fieldNumber);
                    ((ISOMsg)stk.peek()).set (inner);
                    stk.push (inner);
                } else {
                    stk.push (new ISOMsg(0));
                }
            } else if (name.equals (ISOFIELD_TAG)) {
                ISOMsg m     = (ISOMsg) stk.peek();
                String value = atts.getValue(VALUE_ATTR);
                String type  = atts.getValue(TYPE_ATTR);
                if (id == null || value == null)
                    throw new SAXException ("invalid field");   
                if (TYPE_BINARY.equals (type)) {
                    m.set (new ISOBinaryField (
                        fieldNumber, 
                            ISOUtil.hex2byte (
                                value.getBytes(), 0, value.length()/2
                            )
                        )
                    );
                }
                else {
                    m.set (new ISOField (fieldNumber, value));
                }
            }
        } catch (ISOException e) {
            throw new SAXException 
                ("ISOException unpacking "+fieldNumber);
        }
    }

    public void endElement (String ns, String name, String qname) 
        throws SAXException
    {
        if (name.equals (ISOMSG_TAG)) {
            ISOMsg m = (ISOMsg) stk.pop();
            if (stk.empty())
                stk.push (m); // push outter message
        }
    }

    public String getFieldDescription(ISOComponent m, int fldNumber) {
        return "<notavailable/>";
    }
    public String getDescription () {
        return getClass().getName();
    }    
    public void setLogger (Logger logger, String realm) {
        this.logger = logger;
        this.realm  = realm;
    }
    public String getRealm () {
        return realm;
    }
    public Logger getLogger() {
        return logger;
    }
    public ISOMsg createISOMsg() {
        return new ISOMsg();
    }
}

