package fi.otavanopisto.pyramus.views.students;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import fi.internetix.smvc.controllers.PageRequestContext;
import fi.otavanopisto.pyramus.I18N.Messages;
import fi.otavanopisto.pyramus.breadcrumbs.Breadcrumbable;
import fi.otavanopisto.pyramus.dao.DAOFactory;
import fi.otavanopisto.pyramus.dao.students.StudentGroupContactLogEntryCommentDAO;
import fi.otavanopisto.pyramus.dao.students.StudentGroupContactLogEntryDAO;
import fi.otavanopisto.pyramus.dao.students.StudentGroupDAO;
import fi.otavanopisto.pyramus.domainmodel.students.StudentGroup;
import fi.otavanopisto.pyramus.domainmodel.students.StudentGroupContactLogEntry;
import fi.otavanopisto.pyramus.domainmodel.students.StudentGroupContactLogEntryComment;
import fi.otavanopisto.pyramus.domainmodel.students.StudentGroupStudent;
import fi.otavanopisto.pyramus.framework.PyramusViewController;
import fi.otavanopisto.pyramus.framework.UserRole;

/**
 * The controller responsible of the View Student Group view of the application.
 */
public class ViewStudentGroupViewController extends PyramusViewController implements Breadcrumbable {

  /**
   * Processes the page request by including the corresponding JSP page to the response.
   * 
   * @param pageRequestContext Page request context
   */
  public void process(PageRequestContext pageRequestContext) {
    StudentGroupDAO studentGroupDAO = DAOFactory.getInstance().getStudentGroupDAO();
    StudentGroupContactLogEntryDAO contactLogEntryDAO = DAOFactory.getInstance().getStudentGroupContactLogEntryDAO();
    StudentGroupContactLogEntryCommentDAO contactLogEntryCommentDAO = DAOFactory.getInstance().getStudentGroupContactLogEntryCommentDAO();

    // The student group to be edited
    
    StudentGroup studentGroup = studentGroupDAO.findById(pageRequestContext.getLong("studentgroup"));
    pageRequestContext.getRequest().setAttribute("studentGroup", studentGroup);
    
    List<StudentGroupStudent> studentGroupStudents = new ArrayList<>(studentGroup.getStudents());
    Collections.sort(studentGroupStudents, new Comparator<StudentGroupStudent>() {
      @Override
      public int compare(StudentGroupStudent o1, StudentGroupStudent o2) {
        int cmp = o1.getStudent().getLastName().compareToIgnoreCase(o2.getStudent().getLastName());
        if (cmp == 0)
          cmp = o1.getStudent().getFirstName().compareToIgnoreCase(o2.getStudent().getFirstName());
        return cmp;
      }
    });

    final Map<Long, List<StudentGroupContactLogEntryComment>> contactEntryComments = new HashMap<>();
    List<StudentGroupContactLogEntry> contactLogEntries = contactLogEntryDAO.listByStudentGroup(studentGroup);
    
    // Populate comments for each entry to lists
    
    for (int j = 0; j < contactLogEntries.size(); j++) {
      StudentGroupContactLogEntry entry = contactLogEntries.get(j);
      
      List<StudentGroupContactLogEntryComment> listComments = contactLogEntryCommentDAO.listByEntry(entry);
        
      Collections.sort(listComments, new Comparator<StudentGroupContactLogEntryComment>() {
        public int compare(StudentGroupContactLogEntryComment o1, StudentGroupContactLogEntryComment o2) {
          Date d1 = o1.getCommentDate();
          Date d2 = o2.getCommentDate();
          
          int val = d1 == null ? 
              d2 == null ? 0 : 1 :
                d2 == null ? -1 : d1.compareTo(d2);
          
          if (val == 0)
            return o1.getId().compareTo(o2.getId());
          else
            return val;
        }
      });
      
      contactEntryComments.put(entry.getId(), listComments);
    }
      
    // Now we can sort entries based on date of entry and/or dates of the comments on the entry
    
    Collections.sort(contactLogEntries, new Comparator<StudentGroupContactLogEntry>() {

      private Date getDateForEntry(StudentGroupContactLogEntry entry) {
        Date d = entry.getEntryDate();
        
        List<StudentGroupContactLogEntryComment> comments = contactEntryComments.get(entry.getId());
        
        for (int i = 0; i < comments.size(); i++) {
          StudentGroupContactLogEntryComment comment = comments.get(i);
          
          if (d == null) {
            d = comment.getCommentDate();
          } else {
            if (d.before(comment.getCommentDate()))
              d = comment.getCommentDate();
          }
        }
        
        return d;
      }
      
      public int compare(StudentGroupContactLogEntry o1, StudentGroupContactLogEntry o2) {
        Date d1 = getDateForEntry(o1);
        Date d2 = getDateForEntry(o2);

        int val = d1 == null ? 
            d2 == null ? 0 : 1 :
              d2 == null ? -1 : d2.compareTo(d1);

        if (val == 0)
          return o2.getId().compareTo(o1.getId());
        else
          return val;
      }
    });
      
    pageRequestContext.getRequest().setAttribute("contactEntries", contactLogEntries);
    pageRequestContext.getRequest().setAttribute("contactEntryComments", contactEntryComments);
    pageRequestContext.getRequest().setAttribute("studentGroupStudents", studentGroupStudents);
    
    pageRequestContext.setIncludeJSP("/templates/students/viewstudentgroup.jsp");
  }

  /**
   * Returns the roles allowed to access this page. Editing student groups is available for users with
   * {@link Role#MANAGER} or {@link Role#ADMINISTRATOR} privileges.
   * 
   * @return The roles allowed to access this page
   */
  public UserRole[] getAllowedRoles() {
    return new UserRole[] { UserRole.MANAGER, UserRole.STUDY_PROGRAMME_LEADER, UserRole.ADMINISTRATOR };
  }

  /**
   * Returns the localized name of this page. Used e.g. for breadcrumb navigation.
   * 
   * @param locale The locale to be used for the name
   * 
   * @return The localized name of this page
   */
  public String getName(Locale locale) {
    return Messages.getInstance().getText(locale, "students.viewStudentGroup.breadcrumb");
  }

}