D-Net

package eu.dnetlib.data.collector.plugins.datasets;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.Iterator;

import java.util.Map;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import com.google.common.collect.Maps;

/**

 * The Class DatasetsByProjectIterator.

 */

public class DatasetsByProjectIterator implements Iterable<String>, Iterator<String> {

	private static final String SPLIT_REGEX = ";";

	/** The project id key. */

	public static String PROJECT_ID_KEY = "id";

	/** The project name key. */

	public static String PROJECT_NAME_KEY = "name";

	/** The project corda id key. */

	public static String PROJECT_CORDA_ID_KEY = "corda_id";

	/** The current iterator. */

	private Iterator<String> currentIterator;

	/** The csv reader. */

	private BufferedReader csvReader;

	/** The current project. */

	private Map<String, String> currentProject;

	/** The logger. */

	private static final Log log = LogFactory.getLog(DatasetsByProjectIterator.class);

	/**

	 * Instantiates a new datasets by project iterator.

	 *

	 * @param csvInputStream

	 *            the csv input stream

	 * @throws IOException

	 *             Signals that an I/O exception has occurred.

	 */

	public DatasetsByProjectIterator(final InputStreamReader csvInputStream) throws IOException {

		this.csvReader = new BufferedReader(csvInputStream);

		this.currentProject = extractNextLine();

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see java.util.Iterator#hasNext()

	 */

	@Override

	public boolean hasNext() {

		// CASE WHEN WE REACH THE LAST ITEM ON CSV

		// OR WE HAD SOME PROBLEM ON GET NEXT CSV ITEM

		if (this.currentProject == null) { return false; }

		// IN THIS CASE WE HAVE ANOTHER DATASETS

		// FOR THE CURRENT PROJECT AND RETURN TRUE

		if (currentIterator != null && currentIterator.hasNext()) { return true; }

		// OTHERWISE WE FINISHED TO ITERATE THE CURRENT

		// SETS OF DATASETS FOR A PARTICULAR PROJECT

		// SO WE HAVE TO RETRIEVE THE NEXT ITERATOR WITH

		// ITEMS

		this.currentProject = extractNextLine();

		while (this.currentProject != null) {

			currentIterator = getNextIterator();

			// IF THE NEXT ITERATOR HAS ITEMS RETURN YES

			// OTHERWISE THE CICLE CONTINUE

			if (currentIterator.hasNext()) { return true; }

			this.currentProject = extractNextLine();

		}

		return false;

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see java.util.Iterator#next()

	 */

	@Override

	public String next() {

		return this.currentIterator.next();

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see java.util.Iterator#remove()

	 */

	@Override

	public void remove() {}

	/*

	 * (non-Javadoc)

	 * 

	 * @see java.lang.Iterable#iterator()

	 */

	@Override

	public Iterator<String> iterator() {

		if (this.currentProject != null) {

			currentIterator = getNextIterator();

			return this;

		}

		return null;

	}

	private Iterator<String> getNextIterator() {

		QueryField q = new QueryField();

		RequestField r = new RequestField();

		r.setQuery(q);

		q.getTerm().put("ft-techkeyword", this.currentProject.get(PROJECT_ID_KEY));

		return new DatasetsIterator(r, this.currentProject.get(PROJECT_CORDA_ID_KEY), null).iterator();

	}

	/**

	 * Extract next line.

	 *

	 * @return the map

	 * @throws IOException

	 *             Signals that an I/O exception has occurred.

	 */

	private Map<String, String> extractNextLine() {

		String line;

		try {

			line = this.csvReader.readLine();

		} catch (IOException e) {

			return null;

		}

		// WE REACH THE END OF THE CSV

		if (line == null) { return null; }

		log.debug("splitting line: " + line);

		String[] values = line.split(SPLIT_REGEX);

		if (values == null || values.length != 4) {

			log.error("Error on splitting line, the length must be 4");

			return null;

		}

		int id = Integer.parseInt(values[0]);

		String project_name = values[2];

		String cordaId = values[3];

		Map<String, String> splittedMap = Maps.newHashMap();

		splittedMap.put(PROJECT_CORDA_ID_KEY, cordaId);

		splittedMap.put(PROJECT_ID_KEY, "project" + id);

		splittedMap.put(PROJECT_NAME_KEY, project_name);

		log.debug(String.format("found project %s with id Corda: %s and id for API: %s", project_name, cordaId, "project" + id));

		return splittedMap;

	}

}