nlphub/src/main/java/org/gcube/nlphub/NLPUploader.java

package org.gcube.nlphub;

import static org.gcube.common.authorization.client.Constants.authorizationService;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

import org.apache.log4j.Logger;
import org.gcube.nlphub.legacy.Constants;
import org.gcube.nlphub.legacy.JsonManager;
import org.gcube.nlphub.legacy.NlpHubException;

/**
 * Servlet implementation class NLPUploader
 */
// @WebServlet("/NLPUploader")
@WebServlet(asyncSupported = true, name = "NLPUploader", urlPatterns = { "/nlphub-uploader-servlet" })
@MultipartConfig
public class NLPUploader extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private Logger logger = Logger.getLogger(NLPUploader.class.getSimpleName());
	private boolean devMode = true;
	private String token = "df2cc5f5-63ee-48c1-b2a6-1210030c57b8-843339462";

	/**
	 * @see HttpServlet#HttpServlet()
	 */
	public NLPUploader() {
		super();
		// TODO Auto-generated constructor stub
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doWork(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doWork(request, response);
	}

	private void doWork(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("application/json;charset=UTF-8");
		if (request.getParameter("freetext") == null)
			handleFileUpload(request, response);
		else
			handleFreeText(request, response);
	}

	private void handleFreeText(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String freeText = request.getParameter("freetext");
		System.out.println(freeText);
		byte[] content = freeText.getBytes("UTF-8");
		String fileName = generateFileName();
		PrintWriter writer = response.getWriter();
		try {
			if (!uploadFile(content, fileName, Constants.DEFAULT_DESCRIPTION, token)) {
				writer.println(new JsonManager().getErrorJsonResponse(
						"Error uploading file. A file called '" + fileName + "' is already in the workspace?"));
				return;
			}
			String link = getPublicLink(fileName, token);
			writer.println(new JsonManager().getSuccessJsonResponse("" + link));
		} catch (Exception x) {
			x.printStackTrace();
			logger.error(x.getClass().getName() + ": " + x.getLocalizedMessage());
			writer.println(new JsonManager().getErrorJsonResponse(x.getLocalizedMessage()));
		}
	}

	private void handleFileUpload(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		int contentLength = request.getContentLength();

		Part filePart = request.getPart("mytxtfile");

		String fileName = getFileName(filePart);

		PrintWriter writer = response.getWriter();
		// allocate a buffer of request size
		byte[] buffer = new byte[contentLength];
		byte[] bufferedContent;
		try {
			InputStream fileContent = filePart.getInputStream();
			int offset = 0, len = 100, byteRead = 0;
			byte[] readBuffer = new byte[len];
			while (byteRead > -1) {
				byteRead = fileContent.read(readBuffer, 0, len);
				// System.out.println(byteRead);
				if (byteRead > 0) {
					System.arraycopy(readBuffer, 0, buffer, offset, byteRead);
					offset += byteRead;
				}
			}

			if (offset < contentLength) {
				bufferedContent = new byte[offset];
				System.arraycopy(buffer, 0, bufferedContent, 0, offset);
			} else
				bufferedContent = buffer;

			deleteFile(fileName, token);

			if (!uploadFile(bufferedContent, fileName, Constants.DEFAULT_DESCRIPTION, token)) {
				writer.println(new JsonManager().getErrorJsonResponse(
						"Error uploading file. A file called '" + fileName + "' is already in the workspace?"));
				return;
			}

			String link = getPublicLink(fileName, token);
			writer.println(new JsonManager().getSuccessJsonResponse("" + link));
		} catch (Exception x) {
			x.printStackTrace();
			logger.error(x.getClass().getName() + ": " + x.getLocalizedMessage());
			writer.println(new JsonManager().getErrorJsonResponse(x.getLocalizedMessage()));
		}

	}

	private String getFileName(Part part) {
		String partHeader = part.getHeader("content-disposition");
		logger.debug("Part Header: " + partHeader);
		for (String content : part.getHeader("content-disposition").split(";")) {
			if (content.trim().startsWith("filename")) {
				return content.substring(content.indexOf('=') + 1).trim().replace("\"", "");
			}
		}
		return null;
	}

	private String getPublicLink(String fileName, String token) throws NlpHubException {
		try {
			String link = "";
			String user = authorizationService().get(token).getClientInfo().getId();
			String wsRoot = "/Home/" + user + "/Workspace/";
			String webapp = "https://workspace-repository.d4science.org/home-library-webapp";
			String uri = webapp + "/rest/GetPublicLink?absPath=" + URLEncoder.encode(wsRoot + fileName, "UTF-8")
					+ "&shortUrl=false";
			URL url = new URL(uri);

			// System.out.println(uri);

			HttpURLConnection connection = (HttpURLConnection) url.openConnection();
			connection.setRequestProperty(Constants.TOKEN_PARAMETER, token);
			connection.setDoInput(true);
			connection.setDoOutput(true);
			connection.setUseCaches(false);
			connection.setRequestMethod("GET");

			BufferedReader r = new BufferedReader(new InputStreamReader(connection.getInputStream()));

			StringBuffer response = new StringBuffer();
			String inputLine;
			while ((inputLine = r.readLine()) != null) {
				response.append(inputLine);
			}

			String xmlOut = response.toString();
			// System.out.println("xmlOut: " + xmlOut);

			String begin = "<string>";
			String end = "</string>";
			int b = xmlOut.indexOf(begin);
			int e = xmlOut.indexOf(end);

			if (xmlOut.contains("Exception") || (e < 0) || (b < 0)) {
				String message = "Invalid link: " + URLEncoder.encode(xmlOut, "UTF-8");
				logger.error(message);
				throw new NlpHubException(message, null);
			}

			link = xmlOut.substring(b + begin.length(), e);
			return link;

		} catch (Exception e) {
			logger.error(e.getLocalizedMessage());
			throw new NlpHubException(e.getLocalizedMessage(), e);
		}
	}

	private void deleteFile(String fileName, String token) throws NlpHubException {
		try {
			String user = authorizationService().get(token).getClientInfo().getId();
			String wsRoot = "/Home/" + user + "/Workspace/";
			String webapp = "https://workspace-repository.d4science.org/home-library-webapp";
			String uri = webapp + "/rest/Delete?absPath=" + URLEncoder.encode(wsRoot + fileName, "UTF-8");
			URL url = new URL(uri);

			// System.out.println(uri);

			HttpURLConnection connection = (HttpURLConnection) url.openConnection();
			connection.setRequestProperty(Constants.TOKEN_PARAMETER, token);
			connection.setDoInput(true);
			connection.setDoOutput(true);
			connection.setUseCaches(false);
			connection.setRequestMethod("GET");

			BufferedReader r = new BufferedReader(new InputStreamReader(connection.getInputStream()));

			StringBuffer response = new StringBuffer();
			String inputLine;
			while ((inputLine = r.readLine()) != null) {
				response.append(inputLine);
			}

			String xmlOut = response.toString();
			// System.out.println(xmlOut);
		} catch (Exception e) {
			logger.error(e.getLocalizedMessage());
			throw new NlpHubException(e.getLocalizedMessage(), e);
		}
	}

	private boolean uploadFile(byte[] in, String name, String description, String token) throws NlpHubException {
		OutputStream output = null;
		try {
			String user = authorizationService().get(token).getClientInfo().getId();
			String wsRoot = "/Home/" + user + "/Workspace/";
			String webapp = "https://workspace-repository.d4science.org/home-library-webapp";
			String uri = webapp + "/rest/Upload?name=" + URLEncoder.encode(name, "UTF-8") + "&description="
					+ URLEncoder.encode(description, "UTF-8") + "&parentPath=" + URLEncoder.encode(wsRoot, "UTF-8");
			URL url = new URL(uri);

			// System.out.println(uri);

			HttpURLConnection connection = (HttpURLConnection) url.openConnection();
			connection.setRequestProperty(Constants.TOKEN_PARAMETER, token);
			connection.setDoInput(true);
			connection.setDoOutput(true);
			connection.setUseCaches(false);
			connection.setRequestProperty(Constants.CONTENT_TYPE, Constants.MIME_TEXT);
			connection.setRequestMethod("POST");
			output = connection.getOutputStream();
			output.write(in);

			BufferedReader r = new BufferedReader(new InputStreamReader(connection.getInputStream()));

			StringBuffer response = new StringBuffer();
			String inputLine;
			while ((inputLine = r.readLine()) != null) {
				response.append(inputLine);
			}

			String xmlOut = response.toString();
			// System.out.println(xmlOut);
			if (xmlOut.contains("Exception"))
				return false;
			return true;

		} catch (Exception e) {
			logger.error(e.getLocalizedMessage());
			throw new NlpHubException(e.getLocalizedMessage(), e);
		} finally {
			// output stream must be closed anyway...
			if (output != null)
				try {
					output.close();
				} catch (IOException e) {
					logger.error(e.getLocalizedMessage());
				}
		}
	}

	private String generateFileName() {
		long now = System.currentTimeMillis();
		return "auto-nlp-" + now;
	}
}