package eu.dnetlib.miscutils.iterators.xml;

import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.zip.GZIPInputStream;
import java.util.zip.ZipInputStream;

import org.apache.commons.io.IOUtils;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.SAXReader;
import org.junit.Before;
import org.junit.Test;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

public class IterableXmlParserTest {

	private Resource xmlZip = new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/opendoar.zip");

	private Resource xmlGz = new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/opendoar.xml.gz");

	private Resource xmlZipErr = new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/opendoarErr.zip");

	private Resource xmlSingle = new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/singleRepo.xml");

	private String element = "repository";

	private IterableXmlParser parser;

	private SAXReader reader;

	@Before
	public void setUp() throws Exception {
		reader = new SAXReader();
	}

	@Test
	public void testGz() throws Exception {
		doTest(new GZIPInputStream(xmlGz.getInputStream()), element);
	}

	@Test
	public void test() throws Exception {
		doTest(read(new ZipInputStream(xmlZip.getInputStream())), element);
	}

	@Test
	public void testErr() throws Exception {
		doTest(read(new ZipInputStream(xmlZipErr.getInputStream())), element);
	}

	@Test
	public void testSingle() throws Exception {
		doTest(xmlSingle.getInputStream(), element);
	}

	@Test
	public void testOaiRecord() throws Exception {
		int count = doTest(new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/oaiRecord.xml").getInputStream(), "record");
		assertTrue(count == 1);
	}

	@Test
	public void testWeird() throws Exception {
		int count = doTest(new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/weirdRecords.xml").getInputStream(), "record");
		assertTrue(count == 3);
	}

	@Test
	public void testWeirdGz() throws Exception {
		int count = doTest(new GZIPInputStream(new ClassPathResource("eu/dnetlib/miscutils/iterators/xml/weirdRecords.xml.gz").getInputStream()), "record");
		assertTrue(count == 3);
	}

	private int doTest(final InputStream stream, final String element) throws DocumentException {
		parser = new IterableXmlParser(element, stream);
		int count = 0;
		for (String xml : parser) {
			//System.out.println(xml);
			Document doc = reader.read(new StringReader(xml));
			assertNotNull(doc);
			assertNotNull(doc.selectSingleNode("//" + element));
			count++;
		}
		return count;
	}

	// helper method, reads the compressed text out of the xmlZip file
	private InputStream read(final ZipInputStream zis) throws IOException {

		final StringWriter sw = new StringWriter();
		while (zis.getNextEntry() != null) {

			byte[] buffer = new byte[1];

			while (zis.read(buffer) != -1) {
				IOUtils.write(buffer, sw, "UTF-8");
			}
		}
		zis.close();
		sw.close();

		return new ByteArrayInputStream(sw.toString().getBytes());
	}

}