Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.joran.event;

import static ch.qos.logback.core.CoreConstants.XML_PARSING;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;

import ch.qos.logback.core.Context;
import ch.qos.logback.core.joran.spi.ElementPath;
import ch.qos.logback.core.joran.spi.JoranException;
import ch.qos.logback.core.spi.ContextAware;
import ch.qos.logback.core.spi.ContextAwareImpl;
import ch.qos.logback.core.status.Status;

public class SaxEventRecorder extends DefaultHandler implements ContextAware {

    final ContextAwareImpl cai;

    public SaxEventRecorder(Context context) {
        cai = new ContextAwareImpl(context, this);
    }

    public List<SaxEvent> saxEventList = new ArrayList<SaxEvent>();
    Locator locator;
    ElementPath globalElementPath = new ElementPath();

    final public void recordEvents(InputStream inputStream) throws JoranException {
        recordEvents(new InputSource(inputStream));
    }

    public List<SaxEvent> recordEvents(InputSource inputSource) throws JoranException {
        SAXParser saxParser = buildSaxParser();
        try {
            saxParser.parse(inputSource, this);
            return saxEventList;
        } catch (IOException ie) {
            handleError("I/O error occurred while parsing xml file", ie);
        } catch (SAXException se) {
            // Exception added into StatusManager via Sax error handling. No need to add it again
            throw new JoranException("Problem parsing XML document. See previously reported errors.", se);
        } catch (Exception ex) {
            handleError("Unexpected exception while parsing XML document.", ex);
        }
        throw new IllegalStateException("This point can never be reached");
    }

    private void handleError(String errMsg, Throwable t) throws JoranException {
        addError(errMsg, t);
        throw new JoranException(errMsg, t);
    }

    private SAXParser buildSaxParser() throws JoranException {
        try {
            SAXParserFactory spf = SAXParserFactory.newInstance();
            spf.setValidating(false);
            spf.setNamespaceAware(true);
            return spf.newSAXParser();
        } catch (Exception pce) {
            String errMsg = "Parser configuration error occurred";
            addError(errMsg, pce);
            throw new JoranException(errMsg, pce);
        }
    }

    public void startDocument() {
    }

    public Locator getLocator() {
        return locator;
    }

    public void setDocumentLocator(Locator l) {
        locator = l;
    }

    public void startElement(String namespaceURI, String localName, String qName, Attributes atts) {

        String tagName = getTagName(localName, qName);
        globalElementPath.push(tagName);
        ElementPath current = globalElementPath.duplicate();
        saxEventList.add(new StartEvent(current, namespaceURI, localName, qName, atts, getLocator()));
    }

    public void characters(char[] ch, int start, int length) {
        String bodyStr = new String(ch, start, length);
        SaxEvent lastEvent = getLastEvent();
        if (lastEvent instanceof BodyEvent) {
            BodyEvent be = (BodyEvent) lastEvent;
            be.append(bodyStr);
        } else {
            // ignore space only text if the previous event is not a BodyEvent
            if (!isSpaceOnly(bodyStr)) {
                saxEventList.add(new BodyEvent(bodyStr, getLocator()));
            }
        }
    }

    boolean isSpaceOnly(String bodyStr) {
        String bodyTrimmed = bodyStr.trim();
        return (bodyTrimmed.length() == 0);
    }

    SaxEvent getLastEvent() {
        if (saxEventList.isEmpty()) {
            return null;
        }
        int size = saxEventList.size();
        return saxEventList.get(size - 1);
    }

    public void endElement(String namespaceURI, String localName, String qName) {
        saxEventList.add(new EndEvent(namespaceURI, localName, qName, getLocator()));
        globalElementPath.pop();
    }

    String getTagName(String localName, String qName) {
        String tagName = localName;
        if ((tagName == null) || (tagName.length() < 1)) {
            tagName = qName;
        }
        return tagName;
    }

    public void error(SAXParseException spe) throws SAXException {
        addError(XML_PARSING + " - Parsing error on line " + spe.getLineNumber() + " and column " + spe.getColumnNumber());
        addError(spe.toString());
        
    }

    public void fatalError(SAXParseException spe) throws SAXException {
        addError(XML_PARSING + " - Parsing fatal error on line " + spe.getLineNumber() + " and column " + spe.getColumnNumber());
        addError(spe.toString());
    }

    public void warning(SAXParseException spe) throws SAXException {
        addWarn(XML_PARSING + " - Parsing warning on line " + spe.getLineNumber() + " and column " + spe.getColumnNumber(), spe);
    }

    public void addError(String msg) {
        cai.addError(msg);
    }

    public void addError(String msg, Throwable ex) {
        cai.addError(msg, ex);
    }

    public void addInfo(String msg) {
        cai.addInfo(msg);
    }

    public void addInfo(String msg, Throwable ex) {
        cai.addInfo(msg, ex);
    }

    public void addStatus(Status status) {
        cai.addStatus(status);
    }

    public void addWarn(String msg) {
        cai.addWarn(msg);
    }

    public void addWarn(String msg, Throwable ex) {
        cai.addWarn(msg, ex);
    }

    public Context getContext() {
        return cai.getContext();
    }

    public void setContext(Context context) {
        cai.setContext(context);
    }

    public List<SaxEvent> getSaxEventList() {
        return saxEventList;
    }

}