Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2011 Regents of the University of California and the

 *              National Center for Ecological Analysis and Synthesis

 *

 *   '$Author: Serhan AKIN $'

 *     '$Date: 2009-06-13 15:28:13 +0300  $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.restservice;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.security.PrivateKey;

import java.security.cert.X509Certificate;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Timer;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.io.IOUtils;

import org.apache.log4j.Logger;

import org.dataone.client.auth.CertificateManager;

import org.dataone.mimemultipart.MultipartRequest;

import org.dataone.mimemultipart.MultipartRequestResolver;

import org.dataone.portal.PortalCertificateManager;

import org.dataone.service.exceptions.BaseException;

import org.dataone.service.exceptions.InvalidRequest;

import org.dataone.service.exceptions.ServiceFailure;

import org.dataone.service.types.v1.Group;

import org.dataone.service.types.v1.Person;

import org.dataone.service.types.v1.Session;

import org.dataone.service.types.v1.Subject;

import org.dataone.service.types.v1.SubjectInfo;

import edu.ucsb.nceas.metacat.MetacatHandler;

import edu.ucsb.nceas.metacat.properties.PropertyService;

import edu.ucsb.nceas.metacat.service.SessionService;

import edu.ucsb.nceas.metacat.util.RequestUtil;

import edu.ucsb.nceas.metacat.util.SessionData;

import edu.ucsb.nceas.utilities.PropertyNotFoundException;

/**

 * 

 * Base class for handling D1 REST calls in Metacat

 * 

 * @author leinfelder

 */

public class D1ResourceHandler {

    /**HTTP Verb GET*/

    public static final byte GET = 1;

    /**HTTP Verb POST*/

    public static final byte POST = 2;

    /**HTTP Verb PUT*/

    public static final byte PUT = 3;

    /**HTTP Verb DELETE*/

    public static final byte DELETE = 4;

    /**HTTP Verb HEAD*/

    public static final byte HEAD = 5;

    /*

     * API Resources

     */

    protected static final String RESOURCE_BASE_URL = "d1";

    protected static final String RESOURCE_OBJECTS = "object";

    protected static final String RESOURCE_META = "meta";

    protected static final String RESOURCE_LOG = "log";

    protected static final String RESOURCE_QUERY = "query";

    protected static final String RESOURCE_IS_AUTHORIZED = "isAuthorized";

    protected static final String RESOURCE_ACCESS_RULES = "accessRules";

    /*

     * API Functions used as URL parameters

     */

    protected static final String FUNCTION_NAME_INSERT = "insert";

    protected static final String FUNCTION_NAME_UPDATE = "update";

    protected ServletContext servletContext;

    protected Logger logMetacat;

    protected MetacatHandler handler;

    protected HttpServletRequest request;

    protected HttpServletResponse response;

    protected Hashtable<String, String[]> params;

    protected Map<String, List<String>> multipartparams;

    // D1 certificate-based authentication

    protected Session session;

    /**Initializes new instance by setting servlet context,request and response*/

    public D1ResourceHandler(ServletContext servletContext,

            HttpServletRequest request, HttpServletResponse response) {

        this.servletContext = servletContext;

        this.request = request;

        this.response = response;

    }

    /**

     * This function is called from REST API servlet and handles each request 

     * 

     * @param httpVerb (GET, POST, PUT or DELETE)

     */

    public void handle(byte httpVerb) {

        logMetacat = Logger.getLogger(D1ResourceHandler.class);

        try {

        	// initialize the session - three options

        	// #1

        	// load session from certificate in request

            session = CertificateManager.getInstance().getSession(request);

            // #2

            if (session == null) {

	        	// check for session-based certificate from the portal

            	try {

		        	String configurationFileName = servletContext.getInitParameter("oa4mp:client.config.file");

		        	String configurationFilePath = servletContext.getRealPath(configurationFileName);

		        	PortalCertificateManager portalManager = new PortalCertificateManager(configurationFilePath);

		        	logMetacat.debug("Initialized the PortalCertificateManager using config file: " + configurationFilePath);

		        	X509Certificate certificate = portalManager.getCertificate(request);

		        	logMetacat.debug("Retrieved certificate: " + certificate);

			    	PrivateKey key = portalManager.getPrivateKey(request);

			    	logMetacat.debug("Retrieved key: " + key);

			    	if (certificate != null && key != null) {

			        	request.setAttribute("javax.servlet.request.X509Certificate", certificate);

			        	logMetacat.debug("Added certificate to the request: " + certificate.toString());

			    	}

		            // reload session from certificate that we jsut set in request

		            session = CertificateManager.getInstance().getSession(request);

            	} catch (Throwable t) {

            		// don't require configured OAuth4MyProxy

            		logMetacat.error(t.getMessage(), t);

            	}

            }

            // #3

            // last resort, check for Metacat sessionid

            if (session == null) {

	            SessionData sessionData = RequestUtil.getSessionData(request);

				if (sessionData != null) {

					// is it not the public session?

					if (!SessionService.getInstance().getPublicSession().getUserName().equals(sessionData.getUserName())) {

						session = new Session();

						String userName = sessionData.getUserName();

						String[] groupNames = sessionData.getGroupNames();

						Subject userSubject = new Subject();

						userSubject.setValue(userName);

						session.setSubject(userSubject);

						SubjectInfo subjectInfo = new SubjectInfo();

						Person person = new Person();

						person.setSubject(userSubject);

						if (groupNames != null && groupNames.length > 0) {

							for (String groupName: groupNames) {

								Group group = new Group();

								group.setGroupName(groupName);

								Subject groupSubject = new Subject();

								groupSubject.setValue(groupName);

								group.setSubject(groupSubject);

								subjectInfo.addGroup(group);

								person.addIsMemberOf(groupSubject);

							}

						}

						subjectInfo.addPerson(person);

						session.setSubjectInfo(subjectInfo);

					}

				}

            }

            // initialize the parameters

            params = new Hashtable<String, String[]>();

            initParams();

            // create the handler for interacting with Metacat

            Timer timer = new Timer();

            handler = new MetacatHandler(timer);

        } catch (Exception e) {

        	// TODO: more D1 structure when failing here

        	response.setStatus(400);

            printError("Incorrect resource!", response);

            logMetacat.error(e.getClass() + ": " + e.getMessage(), e);

        }

    }

    /**

     * subclasses should provide a more useful implementation

     * @return

     */

    protected boolean isD1Enabled() {

    	return true;	

    }

    protected String parseTrailing(String resource, String token) {

    	// get the rest

        String extra = null;

        if (resource.indexOf(token) != -1) {

        	// what comes after the token?

            extra = resource.substring(resource.indexOf(token) + token.length());

            // remove the slash

            if (extra.startsWith("/")) {

            	extra = extra.substring(1);

            }

            // is there anything left?

            if (extra.length() == 0) {

            	extra = null;

            }

        }

        return extra;

    }

    /**

     * Parse string parameters from the mime multipart entity of the request.

     * Populates the multipartparams map

     * 

     * @throws IOException

     * @throws FileUploadException

     * @throws Exception

     */

    protected void collectMultipartParams() 

        throws IOException, FileUploadException, Exception {

        File tmpDir = getTempDirectory();

        MultipartRequest mr = null;

        // Read the incoming data from its Mime Multipart encoding

        logMetacat.debug("Parsing rights holder info from the mime multipart entity");

        // handle MMP inputs

        MultipartRequestResolver mrr = 

            new MultipartRequestResolver(tmpDir.getAbsolutePath(),1000000000, 0);

        mr = mrr.resolveMultipart(request);

        logMetacat.debug("Resolved the rights holder info from the mime multipart entity.");

        // we only have params in this MMP entity

        multipartparams = mr.getMultipartParameters();

    }

    /**

     * Process the MMP request that includes files for each param

     * @return map of param key and the temp file that contains the encoded information

     * @throws ServiceFailure

     * @throws InvalidRequest

     */

    protected Map<String, File> collectMultipartFiles() 

        throws ServiceFailure, InvalidRequest {

        // Read the incoming data from its Mime Multipart encoding

        logMetacat.debug("Disassembling MIME multipart form");

        // handle MMP inputs

        File tmpDir = getTempDirectory();

        logMetacat.debug("temp dir: " + tmpDir.getAbsolutePath());

        MultipartRequestResolver mrr = 

        	new MultipartRequestResolver(tmpDir.getAbsolutePath(), 1000000000, 0);

        MultipartRequest mr = null;

		    try {

		    	  mr = mrr.resolveMultipart(request);

		    } catch (Exception e) {

                throw new ServiceFailure("1202", 

                		"Could not resolve multipart files: " + e.getMessage());

		    }

        logMetacat.debug("resolved multipart request");

        Map<String, File> files = mr.getMultipartFiles();

        if (files == null) {

            throw new ServiceFailure("1202", "no multipart files found");

        }

        logMetacat.debug("got multipart files");

        if (files.keySet() == null) {

            logMetacat.error("No file keys in MMP request.");

            throw new ServiceFailure("1202", "No file keys found in MMP.");

        }

        multipartparams = mr.getMultipartParameters();

		    // for logging purposes, dump out the key-value pairs that constitute the request

		    // 3 types exist: request params, multipart params, and multipart files

        if (logMetacat.isDebugEnabled()) {

	        Iterator<String> it = files.keySet().iterator();

	        logMetacat.debug("iterating through files");

	        while (it.hasNext()) {

	            String key = it.next();

	            logMetacat.debug("files key: " + key);

	            logMetacat.debug("files value: " + files.get(key));

	        }

	        it = multipartparams.keySet().iterator();

	        logMetacat.debug("iterating through multipartparams");

	        while (it.hasNext()) {

	            String key = (String)it.next();

	            logMetacat.debug("multipartparams key: " + key);

	            logMetacat.debug("multipartparams value: " + multipartparams.get(key));

	        }

	        it = params.keySet().iterator();

	        logMetacat.debug("iterating through params");

	        while (it.hasNext()) {

	            String key = (String)it.next();

	            logMetacat.debug("param key: " + key);

	            logMetacat.debug("param value: " + params.get(key));

	        }

	        logMetacat.debug("done iterating the request...");

        }

        return files;

    }

		/**

     *  copies request parameters to a hashtable which is given as argument to 

     *  native metacathandler functions  

     */

    protected void initParams() {

        String name = null;

        String[] value = null;

        Enumeration paramlist = request.getParameterNames();

        while (paramlist.hasMoreElements()) {

            name = (String) paramlist.nextElement();

            value = request.getParameterValues(name);

            params.put(name, value);

        }

    }

    /**

     * Collect the multipart params from the request

     * @throws Exception 

     */

	protected void initMultipartParams() throws Exception {

		// Read the incoming data from its Mime Multipart encoding

		logMetacat.debug("Disassembling MIME multipart form");

		// handle MMP inputs

		File tmpDir = getTempDirectory();

		logMetacat.debug("temp dir: " + tmpDir.getAbsolutePath());

		MultipartRequestResolver mrr = 

			new MultipartRequestResolver(tmpDir.getAbsolutePath(), 1000000000, 0);

		MultipartRequest mr = mrr.resolveMultipart(request);

		multipartparams = mr.getMultipartParameters();

	}

    /**

     * locate the boundary marker for an MMP

     * @param is

     * @return

     * @throws IOException

     */

    protected static String[] findBoundaryString(InputStream is)

        throws IOException {

        String[] endResult = new String[2];

        String boundary = "";

        String searchString = "boundary=";

        byte[] b = new byte[1024];

        int numbytes = is.read(b, 0, 1024);

        while(numbytes != -1)

        {

            String s = new String(b, 0, numbytes);

            int searchStringIndex = s.indexOf(searchString);

            if(s.indexOf("\"", searchStringIndex + searchString.length() + 1) == -1)

            { //the end of the boundary is in the next byte array

                boundary = s.substring(searchStringIndex + searchString.length() + 1, s.length());

            }

            else if(!boundary.startsWith("--"))

            { //we can read the whole boundary from this byte array

                boundary = s.substring(searchStringIndex + searchString.length() + 1, 

                    s.indexOf("\"", searchStringIndex + searchString.length() + 1));

                boundary = "--" + boundary;

                endResult[0] = boundary;

                endResult[1] = s.substring(s.indexOf("\"", searchStringIndex + searchString.length() + 1) + 1,

                        s.length());

                break;

            }

            else

            { //we're now reading the 2nd byte array to get the rest of the boundary

                searchString = "\"";

                searchStringIndex = s.indexOf(searchString);

                boundary += s.substring(0, searchStringIndex);

                boundary = "--" + boundary;

                endResult[0] = boundary;

                endResult[1] = s.substring(s.indexOf("\"", searchStringIndex + searchString.length() + 1) + 1,

                        s.length());

                break;

            }

        }

        return endResult;

    }

    /**

     * return the directory where temp files are stored

     * @return

     */

    protected static File getTempDirectory()

    {

        File tmpDir = null;

        Logger logMetacat = Logger.getLogger(D1ResourceHandler.class);

        try {

            tmpDir = new File(PropertyService.getProperty("application.tempDir"));

        }

        catch(PropertyNotFoundException pnfe) {

            logMetacat.error("D1ResourceHandler.writeMMPPartstoFiles: " +

                    "application.tmpDir not found.  Using /tmp instead.");

            tmpDir = new File("/tmp");

        }

        return tmpDir;

    }

    /**

     * Prints xml response

     * @param message Message to be displayed

     * @param response Servlet response that xml message will be printed 

     * */

    protected void printError(String message, HttpServletResponse response) {

        try {

            logMetacat.error("D1ResourceHandler: Printing error to servlet response: " + message);

            PrintWriter out = response.getWriter();

            response.setContentType("text/xml");

            out.println("<?xml version=\"1.0\"?>");

            out.println("<error>");

            out.println(message);

            out.println("</error>");

            out.close();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    /**

     * serialize a D1 exception using jibx

     * @param e

     * @param out

     */

    protected void serializeException(BaseException e, OutputStream out) {

        // TODO: Use content negotiation to determine which return format to use

        response.setContentType("text/xml");

        response.setStatus(e.getCode());

        logMetacat.error("D1ResourceHandler: Serializing exception with code " + e.getCode() + ": " + e.getMessage());

        e.printStackTrace();

        try {

            IOUtils.write(e.serialize(BaseException.FMT_XML), out);

        } catch (IOException e1) {

            logMetacat.error("Error writing exception to stream. " 

                    + e1.getMessage());

        }

    }

}