// This software is released into the Public Domain.  See copying.txt for details.
//
// (c) 2007-2013 OpenStreetMap Foundation http://www.openstreetmap.org
// Original: https://github.com/openstreetmap/osmosis/blob/master/osmosis-xml/src/main/java/org/openstreetmap/osmosis/xml/v0_6/XmlReader.java
//
package org.locationtech.geogig.osm.internal;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.logging.Level;
import java.util.logging.Logger;

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

import org.openstreetmap.osmosis.core.OsmosisRuntimeException;
import org.openstreetmap.osmosis.core.task.v0_6.RunnableSource;
import org.openstreetmap.osmosis.core.task.v0_6.Sink;
import org.openstreetmap.osmosis.xml.common.CompressionActivator;
import org.openstreetmap.osmosis.xml.common.CompressionMethod;
import org.openstreetmap.osmosis.xml.v0_6.impl.OsmHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * An OSM data source reading from an xml file. The entire contents of the file are read.
 * <p>
 * This is a modified version of the original {@link org.openstreetmap.osmosis.xml.v0_6.XmlReader}
 * to support an InputStream as argument instead of just a {@link File}
 * </p>
 * 
 * @author Brett Henderson
 */
class XmlReader implements RunnableSource {

    private static Logger log = Logger.getLogger(XmlReader.class.getName());

    private Sink sink;

    private InputStream file;

    private boolean enableDateParsing;

    private CompressionMethod compressionMethod;

    /**
     * Creates a new instance.
     * 
     * @param file The file to read.
     * @param enableDateParsing If true, dates will be parsed from xml data, else the current date
     *        will be used thus saving parsing time.
     * @param compressionMethod Specifies the compression method to employ.
     */
    public XmlReader(InputStream file, boolean enableDateParsing,
            CompressionMethod compressionMethod) {
        this.file = file;
        this.enableDateParsing = enableDateParsing;
        this.compressionMethod = compressionMethod;
    }

    /**
     * {@inheritDoc}
     */
    public void setSink(Sink sink) {
        this.sink = sink;
    }

    /**
     * Creates a new SAX parser.
     * 
     * @return The newly created SAX parser.
     */
    private SAXParser createParser() {
        try {
            return SAXParserFactory.newInstance().newSAXParser();

        } catch (ParserConfigurationException e) {
            throw new OsmosisRuntimeException("Unable to create SAX Parser.", e);
        } catch (SAXException e) {
            throw new OsmosisRuntimeException("Unable to create SAX Parser.", e);
        }
    }

    /**
     * Reads all data from the file and send it to the sink.
     */
    public void run() {
        InputStream inputStream = this.file;

        try {
            SAXParser parser;

            sink.initialize(Collections.<String, Object> emptyMap());

            // make "-" an alias for /dev/stdin
            // if (file.getName().equals("-")) {
            // inputStream = System.in;
            // } else {
            // inputStream = new FileInputStream(file);
            // }

            inputStream = new CompressionActivator(compressionMethod)
                    .createCompressionInputStream(inputStream);

            parser = createParser();

            parser.parse(inputStream, new OsmHandler(sink, enableDateParsing));

            sink.complete();

        } catch (SAXParseException e) {
            throw new OsmosisRuntimeException("Unable to parse xml file " + file + ".  publicId=("
                    + e.getPublicId() + "), systemId=(" + e.getSystemId() + "), lineNumber="
                    + e.getLineNumber() + ", columnNumber=" + e.getColumnNumber() + ".", e);
        } catch (SAXException e) {
            throw new OsmosisRuntimeException("Unable to parse XML.", e);
        } catch (IOException e) {
            throw new OsmosisRuntimeException("Unable to read XML file " + file + ".", e);
        } finally {
            sink.release();

            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    log.log(Level.SEVERE, "Unable to close input stream.", e);
                }
                inputStream = null;
            }
        }
    }
}