// This software is released into the Public Domain.  See copying.txt for details.
package org.openstreetmap.osmosis.xml.v0_6;

import org.openstreetmap.osmosis.core.OsmosisRuntimeException;
import org.openstreetmap.osmosis.core.task.v0_6.ChangeSink;
import org.openstreetmap.osmosis.core.task.v0_6.RunnableChangeSource;
import org.openstreetmap.osmosis.xml.common.CompressionActivator;
import org.openstreetmap.osmosis.xml.common.CompressionMethod;
import org.openstreetmap.osmosis.xml.common.SaxParserFactory;
import org.openstreetmap.osmosis.xml.v0_6.impl.OsmChangeHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import javax.xml.parsers.SAXParser;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.logging.Level;
import java.util.logging.Logger;


/**
 * A change source reading from an xml file. The entire contents of the file
 * are read.
 *
 * @author Brett Henderson
 */
public class XmlChangeReader implements RunnableChangeSource {

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

	private ChangeSink changeSink;
	private File 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 XmlChangeReader(File file, boolean enableDateParsing, CompressionMethod compressionMethod) {
		this.file = file;
		this.enableDateParsing = enableDateParsing;
		this.compressionMethod = compressionMethod;
	}


	/**
	 * {@inheritDoc}
	 */
	public void setChangeSink(ChangeSink changeSink) {
		this.changeSink = changeSink;
	}


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

		try {
			SAXParser parser;

			changeSink.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 = SaxParserFactory.createParser();

			parser.parse(inputStream, new OsmChangeHandler(changeSink, enableDateParsing));

			changeSink.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 {
			changeSink.close();

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