package eu.dnetlib.data.collector.plugins.ariadneplus.ads;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.google.common.collect.Iterators;

import eu.dnetlib.data.collector.plugins.filesystem.FileSystemIterator;
import eu.dnetlib.rmi.data.CollectorServiceException;
import eu.dnetlib.rmi.data.InterfaceDescriptor;


public class FolderCollectorPlugin extends FileJSONCollectorPlugin {
	
	private Iterator<String> recordIterator;
	private URL basePath;
	
	/** The Constant log. */
	private static final Log log = LogFactory.getLog(FolderCollectorPlugin.class);
	
	@Override
	public Iterable<String> collect(final InterfaceDescriptor interfaceDescriptor, final String fromDate, final String untilDate)
			throws CollectorServiceException {

		final String baseUrl = interfaceDescriptor.getBaseUrl();
		if (baseUrl == null || baseUrl.isEmpty()) { throw new CollectorServiceException("Param 'baseurl' is null or empty"); }
		String url = "file://".concat(baseUrl);
		try {
			basePath = new URL(url);
		} catch (MalformedURLException mue) {
			log.error("Failed collecting json from base url " + url, mue);
			throw new CollectorServiceException(mue);
		}

		File baseDir = new File(basePath.getPath());
		if (!baseDir.exists()) { throw new CollectorServiceException(String.format("The base ULR %s, does not exist", basePath.getPath())); }
		
		log.debug("Start collecting json from folder " + baseDir + " ...");
		final FileSystemIterator fsi = new FileSystemIterator(baseDir.getAbsolutePath(), "json");
		
		boolean emptyIterator = true;
		while (fsi.hasNext()) {
			String nextFilePath = fsi.next();
			interfaceDescriptor.setBaseUrl("file://".concat(nextFilePath));
			try {
				log.debug("Add iterator from " + nextFilePath);
				if (emptyIterator) {
					recordIterator = super.collect(interfaceDescriptor, fromDate, untilDate).iterator();
					emptyIterator = false;
				}
				else {
					recordIterator = Iterators.concat(recordIterator, super.collect(interfaceDescriptor, fromDate, untilDate).iterator());
				}
			} catch (CollectorServiceException e) {
				log.error("Failed collecting json from path: " + nextFilePath, e);
			}
		}
		return new ADSIterable(recordIterator);
	}
	
}