package org.restafarian.id.servlets;
   
   import java.io.IOException;
   import java.io.PrintWriter;
   import java.sql.Connection;
   import java.sql.ResultSet;
   import java.sql.SQLException;
   import java.sql.Statement;
   import java.util.Hashtable;
  
  import javax.naming.Context;
  import javax.naming.InitialContext;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.sql.DataSource;
  
  import org.restafarian.core.beans.Person;
  import org.restafarian.core.security.AuthenticatedUserManager;
  import org.restafarian.core.servlets.RestServletBase;
  import org.restafarian.core.utils.BetwixtTool;
  
  /***
   * <p>This servlet handles users.</p>
   */
  public class UserServlet extends RestServletBase {
  	private static final long serialVersionUID = 1;
  	private DataSource dataSource = getDataSource();
  
  	/***
  	 * <p>The Servlet "doGet()" method.</p>
  	 *
  	 * @param req the <code>HttpServletRequest</code> object
  	 * @param res the <code>HttpServletResponse</code> object
  	 * @throws ServletException
  	 * @throws IOException
  	 */
  	public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
  		String id = getIdFromUrl(req, "/user/");
  
  		// log request, if enabled
  		if (log.isDebugEnabled()) {
  			String message = "Processing GET request; id=" + id;
  			if (req.getQueryString() != null && req.getQueryString().length() > 0) {
  				message += "; query string=" + req.getQueryString();
  			}
  			log.debug(message);
  		}
  
  		if (id != null && id.length() > 0) {
  			// send requested user
  			sendUser(id, req, res);
  		} else {
  			// send query results
  			sendError(req, res, 404, "The requested resource was not found on this server. If you entered the URL manually please check your spelling and try again.");
  		}
  	}
  
  	/***
  	 * <p>The Servlet "doPost()" method.</p>
  	 * 
  	 * @param req the <code>HttpServletRequest</code> object
  	 * @param res the <code>HttpServletResponse</code> object
  	 * @throws ServletException
  	 * @throws IOException
  	 */
  	public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
  		sendError(req, res, 405, "Method Not Allowed. Use the \"GET\" method for this URL");
  	}
  
  	/***
  	 * <p>The Servlet "doPut()" method.</p>
  	 *
  	 * @param req the <code>HttpServletRequest</code> object
  	 * @param res the <code>HttpServletResponse</code> object
  	 * @throws ServletException
  	 * @throws IOException
  	 */
  	public void doPut(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
  		sendError(req, res, 405, "Method Not Allowed. Use the \"GET\" method for this URL");
  	}
  
  	/***
  	 * <p>The Servlet "doDelete()" method.</p>
  	 *
  	 * @param req the <code>HttpServletRequest</code> object
  	 * @param res the <code>HttpServletResponse</code> object
  	 * @throws ServletException
  	 * @throws IOException
  	 */
  	public void doDelete(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
  		sendError(req, res, 405, "Method Not Allowed. Use the \"GET\" method for this URL");
  	}
  
  	/***
  	 * <p>Handles a get request for a single user.</p>
  	 *
  	 * @param id the id of the requested user
  	 * @param req the <code>HttpServletRequest</code> object
 	 * @param res the <code>HttpServletResponse</code> object
 	 */
 	private void sendUser(String id, HttpServletRequest req, HttpServletResponse res) throws IOException {
 		Person user = getUser(id, req);
 
 		if (user != null) {
 			PrintWriter pw = res.getWriter();
 			if (pw != null && !pw.equals("")) {
 				pw.print(BetwixtTool.toXml(user, "/id/xsl/user.xsl"));
 			} else {
 				sendError(req, res, 500, "There was a technical error while attempting to access this resource. Details of this error have been logged on the server.");
 			}
 		} else {
 			sendError(req, res, 404, "The requested resource was not found on this server. If you entered the URL manually please check your spelling and try again.");
 		}
 	}
 
 	/***
 	 * <p>Returns the requested user.</p>
 	 *
 	 * @param userId the id of the requested user
 	 * @return the requested user
 	 */
 	private Person getUser(String userId, HttpServletRequest req) {
 		Person user = null;
 		
 		if ("current".equalsIgnoreCase(userId)) {
 			user = AuthenticatedUserManager.getAuthenticatedUser(req);
 		} else {
 			user = fetchUser(userId);
 		}
 
 		return user;
 	}
 
 	/***
 	 * <p>Fetches the user from the database.</p>
 	 *
 	 * @param userId the id of the requested user
 	 * @return the requested user
 	 */
 	private Person fetchUser(String userId) {
 		Person user = null;
 
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = dataSource.getConnection();
 			conn.setAutoCommit(false);
 			stmt = conn.createStatement();
 			String qs = "select * from user where id = '" + userId + "'";
 			rs = stmt.executeQuery(qs);
 			if (rs.next()) {
 				user = new Person();
 				user.setId(userId);
 				user.setName(rs.getString("name"));
 				user.setUri(rs.getString("uri"));
 				user.setEmail(rs.getString("email"));
 			}
 		} catch (SQLException e) {
 			log.error("SQL error: " + e.toString() + "; " +  e.getMessage(), e);
 		} finally {
 			if (rs != null) {
 				try {
 					rs.close();
 				} catch (SQLException sqle) {
 					log.error("SQL error: " + sqle.toString() + "; " +  sqle.getMessage(), sqle);
 				}
 				rs = null;
 			}
 			if (stmt != null) {
 				try {
 					stmt.close();
 				} catch (SQLException sqle) {
 					log.error("SQL error: " + sqle.toString() + "; " +  sqle.getMessage(), sqle);
 				}
 				stmt = null;
 			}
 			if (conn != null) {
 				try {
 					conn.commit();
 					conn.close();
 				} catch (SQLException sqle) {
 					log.error("SQL error: " + sqle.toString() + "; " +  sqle.getMessage(), sqle);
 				}
 				conn = null;
 			}
 		}
 
 		return user;
 	}
 
 	/***
 	 * <p>Returns the DataSource.</p>
 	 */
 	private DataSource getDataSource() {
 		DataSource ds = null;
 
 		String dataSourceName = "java:comp/env/jdbc/user";
 		Hashtable parms = new Hashtable();
 		try {
 			Context ctx = new InitialContext(parms);
 			ds = (DataSource) ctx.lookup(dataSourceName);
 		} catch (Throwable t) {
 			log.error("Exception obtaining DataSource (\"" + dataSourceName + "\"): " + t.toString(), t);
 		}
 
 		return ds;
 	}
 }