package org.deri.grefine.rdf.commands;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.deri.grefine.rdf.app.ApplicationContext;
import org.deri.grefine.rdf.vocab.VocabularyImporter;
import org.json.JSONException;
import org.json.JSONObject;
import org.openrdf.repository.Repository;
import org.openrdf.repository.RepositoryConnection;
import org.openrdf.repository.sail.SailRepository;
import org.openrdf.rio.RDFFormat;
import org.openrdf.sail.inferencer.fc.ForwardChainingRDFSInferencer;
import org.openrdf.sail.memory.MemoryStore;


public class AddPrefixFromFileCommand extends RdfCommand{

    public AddPrefixFromFileCommand(ApplicationContext ctxt) {
		super(ctxt);
	}

	@Override
	public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
		try {
			FileItemFactory factory = new DiskFileItemFactory();

			// Create a new file upload handler
			ServletFileUpload upload = new ServletFileUpload(factory);

			String uri = null, prefix = null, format = null, projectId = null, filename="";
			InputStream in = null;
			@SuppressWarnings("unchecked")
			List<FileItem> items = upload.parseRequest(request);
			for(FileItem item:items){
				if(item.getFieldName().equals("vocab-prefix")){
					prefix = item.getString(); 
				}else if(item.getFieldName().equals("vocab-uri")){
					uri = item.getString();
				}else if(item.getFieldName().equals("file_format")){
					format = item.getString();
				}else if(item.getFieldName().equals("project")){
					projectId = item.getString();
				}else{
					filename = item.getName();
					in = item.getInputStream();
				}
			}
			
			Repository repository = new SailRepository(
					new ForwardChainingRDFSInferencer(new MemoryStore()));
			repository.initialize();
			RepositoryConnection con = repository.getConnection();
			RDFFormat rdfFromat;
			if(format.equals("auto-detect")){
				rdfFromat = guessFormat(filename);
			}else if(format.equals("TTL")){
				rdfFromat = RDFFormat.TURTLE;
			}else if(format.equals("N3")){
				rdfFromat = RDFFormat.N3;
			}else if(format.equals("NTRIPLE")) {
				rdfFromat = RDFFormat.NTRIPLES;
			}else{
				rdfFromat = RDFFormat.RDFXML;
			}
			con.add(in, "", rdfFromat);
			con.close();
			
			getRdfSchema(request).addPrefix(prefix, uri);
        	getRdfContext().getVocabularySearcher().importAndIndexVocabulary(prefix, uri, repository, projectId, new VocabularyImporter());
        	//success
        	PrintWriter out = response.getWriter();
			out.print("<html><body><textarea>\n{\"code\":\"ok\"}\n</textarea></body></html>");
			out.flush();
		} catch (Exception e) {
			try{
				JSONObject o = new JSONObject();
				o.put("code", "error");
				o.put("message", e.getMessage());

				StringWriter sw = new StringWriter();
				PrintWriter pw = new PrintWriter(sw);
				e.printStackTrace(pw);
				pw.flush();
				sw.flush();

				o.put("stack", sw.toString());

				response.setCharacterEncoding("UTF-8");
				respond(response, "<html><body><textarea>\n" + o.toString() + "\n</textarea></body></html>");
			} catch (JSONException e1) {
	            e.printStackTrace(response.getWriter());
	        }
		}
	}
    
	private RDFFormat guessFormat(String filename){
		if(filename.lastIndexOf('.')!=-1){
			String extension = filename.substring(filename.lastIndexOf('.')).toLowerCase();
			if(extension.equals(".ttl")){
				return RDFFormat.TURTLE;
			}else if(extension.equals(".rdf")){
				return RDFFormat.RDFXML;
			}else if(extension.equals(".owl")){
				return RDFFormat.RDFXML;
			}else if(extension.equals(".nt")){
				return RDFFormat.NTRIPLES;
			}else if(extension.equals(".n3")){
				return RDFFormat.N3;
			}
		}
		return RDFFormat.RDFXML;
	}

}