BeginAssignment.java

package org.assistments.direct.student;

import java.io.IOException;
import java.net.URLEncoder;
import java.util.List;

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

import org.assistments.connector.controller.AssignmentController;
import org.assistments.connector.controller.StudentClassController;
import org.assistments.connector.domain.User;
import org.assistments.connector.utility.Constants;
import org.assistments.connector.utility.Response;
import org.assistments.dao.controller.ExternalAssignmentDAO;
import org.assistments.dao.controller.ExternalStudentClassDAO;
import org.assistments.dao.controller.ExternalUserDAO;
import org.assistments.dao.domain.ExternalAssignment;
import org.assistments.dao.domain.ExternalStudentClass;
import org.assistments.dao.domain.ExternalUser;
import org.assistments.direct.LiteUtility;
import org.assistments.direct.TransferUserException;

import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

@WebServlet({ "/beginAssignment", "/BeginAssignment" })
public class BeginAssignment extends HttpServlet {

	private static final long serialVersionUID = -8487938278071103716L;

	public BeginAssignment() {
		super();
	}
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		String firstName = req.getParameter("first_name").toLowerCase();
		String lastName = req.getParameter("last_name").toLowerCase();
//		String accessCode = req.getParameter("access_code");
		String assignmentRef = req.getParameter("assignment_ref");
		ExternalAssignmentDAO assignmentDAO = new ExternalAssignmentDAO(LiteUtility.PARTNER_REF);
		ExternalAssignment assignment = assignmentDAO.findByExternalRef(assignmentRef);
		
		if(assignment != null) {
			//create student account
			String teacherRef = new String();
			String studentClassRef = new String();
			String token = assignment.getAssistmentsAccessToken();
			ExternalStudentClassDAO classDAO = new ExternalStudentClassDAO(LiteUtility.PARTNER_REF);
			ExternalStudentClass esc = classDAO.findByAccessToken(token);
			studentClassRef = esc.getAssistmentsExternalRefernce();

			ExternalUserDAO userDAO = new ExternalUserDAO(LiteUtility.PARTNER_REF);
			ExternalUser user = userDAO.findByAccessToken(token);
			teacherRef = user.getAssistmentsExternalRefernce();
			User student = LiteUtility.populateStudentInfo(firstName.substring(0, 1).toUpperCase()+firstName.substring(1),
					lastName.substring(0, 1).toUpperCase() + lastName.substring(1));
			List<String> studentRefAccessToken = null;
			try {
				String partnerExternalRef = student.getDisplayName() +"_" +teacherRef;
				studentRefAccessToken = LiteUtility.transferStudent(student, partnerExternalRef);
			} catch(TransferUserException e) {
				String errorMessage = e.getMessage();
				String instruction = "The server seems to be unstable at this moment. Please take a break and try it again later.";
				LiteUtility.directToErrorPage(errorMessage, instruction, req, resp);
				return;
			}

			
			if(studentRefAccessToken != null) {
				String studentRef = studentRefAccessToken.get(0);
				String onBehalf = studentRefAccessToken.get(1);
				
				StudentClassController.enrollStudent(studentClassRef, studentRef, LiteUtility.PARTNER_REF, onBehalf);
//				String studentReportURL = Constants.ASSISSTments_URL+"external_tutor/student_class/report?partner_id="+LiteUtility.PARTNER_ID
//						+"&class_ref="+studentClassRef+"&assignment_ref="+assignmentRef;
//				String reportId = LiteUtility.generateStudentReportId(studentRef, assignmentRef);
//				ServletContext context = getServletContext();
//				context.setAttribute(reportId, studentReportURL);
				String onExit = LiteUtility.generateStudentReportURL(studentRef, assignmentRef);
				onExit = URLEncoder.encode(onExit, "UTF-8");
				onExit = URLEncoder.encode(onExit, "UTF-8");
				Response res = AssignmentController.getAssignment(assignmentRef, LiteUtility.PARTNER_REF, onBehalf, onExit);
				if(res.getHttpCode() == 200) {
					JsonElement jElement = new JsonParser().parse(res.getContent());
					JsonObject jObject = jElement.getAsJsonObject();
					String tutorURL = jObject.get("handler").getAsString();
					String loginURL = Constants.LOGIN_URL;
					String addressToGo = String.format("%1$s?partner=%2$s&access=%3$s&on_success=%4$s&on_failure=%5$s", 
							loginURL, LiteUtility.PARTNER_REF, onBehalf, tutorURL, LiteUtility.LOGIN_FAILURE);
					resp.sendRedirect(addressToGo);
				} else {
					String errorMessage = res.getContent();
					String instruction = "The server seems to be unstable at this moment. Please take a break and try it again later.";
					LiteUtility.directToErrorPage(errorMessage, instruction, req, resp);
				}
			} else {
				String errorMessage = "You just encountered an error. Please try it again.";
				String instruction = "The server seems to be unstable at this moment. Please take a break and try it again later.";
				LiteUtility.directToErrorPage(errorMessage, instruction, req, resp);
			}
		} else { // wrong access code
			String errorMessage = "It seems that the web page you just typed in doesn't exist.";
			String instruction = "If you entered the URL in by hand, double check that it is correct";
			LiteUtility.directToErrorPage(errorMessage, instruction, req, resp);
		}
	}
}