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

import com.google.common.collect.Iterators;
import eu.dnetlib.data.collector.plugins.FileCollectorPlugin;
import eu.dnetlib.data.collector.plugins.filesystem.FileSystemIterator;
import eu.dnetlib.data.collector.plugins.oai.engine.HttpConnector;
import eu.dnetlib.miscutils.iterators.xml.XMLIterator;
import eu.dnetlib.rmi.data.CollectorServiceException;
import eu.dnetlib.rmi.data.InterfaceDescriptor;
import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.BufferedInputStream;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Iterator;

public class XMLsFolderCollectorPlugin extends FileCollectorPlugin {

    private Iterator<String> recordIterator;
    @Autowired
    private HttpConnector httpConnector;

    /** The Constant log. */
    private static final Log log = LogFactory.getLog(eu.dnetlib.data.collector.plugins.ariadneplus.XMLsFolderCollectorPlugin.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 srf = interfaceDescriptor.getParams().get("singleRemoteFile");
        boolean singleRemoteFile = Boolean.valueOf(srf);
        log.debug("bool singleRemoteFile? "+singleRemoteFile);
        final String namespaceList = interfaceDescriptor.getParams().get("namespaceList");
        if (namespaceList == null || namespaceList.isEmpty()) { throw new CollectorServiceException("Param 'namespaceList' is null or empty"); }
        if(!singleRemoteFile) {
            String url = (baseUrl.startsWith("file://")) ? baseUrl : "file://".concat(baseUrl);
            URL basePath;
            try {
                basePath = new URL(url);
            } catch (MalformedURLException mue) {
                log.error("Failed collecting 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 URL %s, does not exist", basePath.getPath()));
            }

            log.debug("Start collecting from folder " + baseDir + " ...");
            final FileSystemIterator fsi = new FileSystemIterator(baseDir.getAbsolutePath(), "xml");

            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 = new XMLsFolderIterator(super.collect(interfaceDescriptor, fromDate, untilDate).iterator(), namespaceList);
                        emptyIterator = false;
                    } else {
                        recordIterator = Iterators.concat(recordIterator, new XMLsFolderIterator(super.collect(interfaceDescriptor, fromDate, untilDate).iterator(), namespaceList));
                    }
                } catch (CollectorServiceException e) {
                    log.error("Failed collecting from path: " + nextFilePath, e);
                }
            }
            return new XMLsFolderIterable(recordIterator);
        }
        else {
            //singleRemoteFile
            return collectFromSingleRemoteFile(baseUrl, interfaceDescriptor.getParams().get("splitOnElement"), namespaceList);
        }
    }

    public Iterable<String> collectFromSingleRemoteFile(final String baseUrl, final String splitOnElement, final String namespaceList) throws CollectorServiceException {
        final String xml = httpConnector.getInputSource(baseUrl);
        BufferedInputStream bis =  new BufferedInputStream(IOUtils.toInputStream(xml, Charset.forName("utf-8")));
        return new XMLsFolderIterable(new XMLsFolderIterator(new XMLIterator(splitOnElement, bis), namespaceList));
    }

    public Iterator<String> getRecordIterator() {
        return recordIterator;
    }

    public void setRecordIterator(Iterator<String> recordIterator) {
        this.recordIterator = recordIterator;
    }

    public HttpConnector getHttpConnector() {
        return httpConnector;
    }

    public void setHttpConnector(HttpConnector httpConnector) {
        this.httpConnector = httpConnector;
    }
}