package net.foben.schematizer.parse;

import java.io.FileWriter;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import org.openrdf.model.Statement;
import org.openrdf.rio.RDFHandler;
import org.openrdf.rio.RDFHandlerException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class GraphExtractHandler implements RDFHandler {
    private int stcount = 0;
    private Logger _log;
    private Set<String> graphs;
    private double now, last;
    private String outfile_base;
    private String outfile;
    private int outcount = 0;

    public GraphExtractHandler(String filename) throws IOException{
        this._log = LoggerFactory.getLogger(GraphExtractHandler.class);
        this.outfile_base = filename;
        this.outfile = filename + "_0";
        graphs = new HashSet<String>(3000000);
        last = System.nanoTime();
    }

    @Override
    public void startRDF() throws RDFHandlerException { }

    @Override
    public void endRDF() throws RDFHandlerException {
        writeOut();

    }

    private void writeOut(){
        try {
            String linesep = System.getProperty("line.separator");
            FileWriter out = new FileWriter(outfile);
            int lines = 0;
            for(String graph : graphs){
                lines++;
                out.write(graph);
                out.write(linesep);
                if(lines%10000 == 0){
                    _log.info("Flushing 10,000 lines");
                    out.flush();
                }
            }
            out.flush();
            out.close();
        } catch (IOException e) {
            _log.error("Exception occurred while writing statistics!");
            _log.error(e.getStackTrace().toString());
            System.exit(-1);
        }
        outcount++;
        graphs = new HashSet<String>();
        outfile = outfile_base + "_" + outcount;

    }

    @Override
    public void handleComment(String arg0) throws RDFHandlerException { }

    @Override
    public void handleNamespace(String arg0, String arg1)
            throws RDFHandlerException { }


    @Override
    public void handleStatement(Statement arg0) throws RDFHandlerException {

        try {
            stcount++;
            if(stcount%1000000 == 0){
                _log.info(stcount/1000000 + " million lines parsed. Speed: " + measure());
                if(stcount%100000000 == 0) writeOut();
            }

            graphs.add(arg0.getContext().stringValue());

        } catch (IllegalArgumentException ia){
            _log.warn("IAE occured: " + ia.getMessage());
        }
    }

    private String measure() {
        now = System.nanoTime();
        double dur = (now - last) / 1000000000d;
        String result = ("" + dur);
        last = now;
        return result;
    }

}