/**

  * Copyright 2012 The Kuali Foundation Licensed under the

  * Educational Community License, Version 2.0 (the "License"); you may

  * not use this file except in compliance with the License. You may

  * obtain a copy of the License at

  *

  * http://www.osedu.org/licenses/ECL-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an "AS IS"

  * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

  * or implied. See the License for the specific language governing

  * permissions and limitations under the License.

  *

  * Created by Charles on 4/14/12

  */

 package org.kuali.student.r2.core.class1.appointment.service.impl;

 import org.kuali.student.r2.common.dto.ContextInfo;

 import org.kuali.student.r2.common.dto.StatusInfo;

 import org.kuali.student.r2.common.exceptions.*;

 import org.kuali.student.r2.common.util.constants.AtpServiceConstants;

 import org.kuali.student.r2.core.appointment.constants.AppointmentServiceConstants;

 import org.kuali.student.r2.core.appointment.dto.AppointmentInfo;

 import org.kuali.student.r2.core.appointment.dto.AppointmentSlotInfo;

 import org.kuali.student.r2.core.appointment.dto.AppointmentWindowInfo;

 import org.kuali.student.r2.core.class1.appointment.dao.AppointmentDao;

 import org.kuali.student.r2.core.class1.appointment.dao.AppointmentSlotDao;

 import org.kuali.student.r2.core.class1.appointment.dao.AppointmentWindowDao;

 import org.kuali.student.r2.core.class1.appointment.model.AppointmentEntity;

 import org.kuali.student.r2.core.class1.appointment.model.AppointmentSlotEntity;

 import org.kuali.student.r2.core.class1.appointment.model.AppointmentWindowEntity;

 import org.kuali.student.r2.core.population.service.PopulationService;

 import javax.annotation.Resource;

 import javax.jws.WebParam;

 import java.util.ArrayList;

 import java.util.Calendar;

 import java.util.Date;

 import java.util.List;

 /**

  * This class //TODO ...

  *

  * @author Kuali Student Team

  */

 public class AppointmentServiceImplHelper {

     private static int MILLIS_IN_SECOND = 1000;

     private static int MILLIS_IN_MINUTE = MILLIS_IN_SECOND * 60;

     private static int MINUTES_IN_HOUR = 60;

     private AppointmentWindowDao appointmentWindowDao;

     private AppointmentSlotDao appointmentSlotDao;

     private AppointmentDao appointmentDao;

     private PopulationService populationService;

     public AppointmentServiceImplHelper() {

     }

     public void setAppointmentWindowDao(AppointmentWindowDao appointmentWindowDao) {

         this.appointmentWindowDao = appointmentWindowDao;

     }

     public void setAppointmentSlotDao(AppointmentSlotDao appointmentSlotDao) {

         this.appointmentSlotDao = appointmentSlotDao;

     }

     public void setAppointmentDao(AppointmentDao appointmentDao) {

         this.appointmentDao = appointmentDao;

     }

     public void setPopulationService(PopulationService populationService) {

         this.populationService = populationService;

     }

     /*

     * This is pulled out so other methods can call this without the transactional behavior.

     */

     public AppointmentInfo createAppointmentNoTransact(String personId, String appointmentSlotId, String appointmentTypeKey, AppointmentInfo appointmentInfo, @WebParam(name = "contextInfo") ContextInfo contextInfo) throws DataValidationErrorException, DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException, ReadOnlyException {

         AppointmentEntity  appointmentEntity = new AppointmentEntity(appointmentInfo);

         appointmentEntity.setEntityCreated(contextInfo);

         // TODO: Determine if there should be a check between apptType/slotId and apptInfo counterparts

         // Need to manually set the entity since appointmentInfo only has an id for its corresponding AppointmentSlot

         AppointmentSlotEntity slotEntity = appointmentSlotDao.find(appointmentSlotId);

         if (null == slotEntity) {

             throw new DoesNotExistException(appointmentSlotId);

         }

         appointmentEntity.setSlotEntity(slotEntity); // This completes the initialization of appointmentSlotEntity

         appointmentDao.persist(appointmentEntity);

         return appointmentEntity.toDto();

     }

     // ------------------------------ Slot creation ------------------------

     public List<AppointmentSlotInfo> createOneSlotPerWindow(AppointmentWindowEntity apptWin, ContextInfo contextInfo)

             throws InvalidParameterException, OperationFailedException, MissingParameterException, PermissionDeniedException, ReadOnlyException, DataValidationErrorException, DoesNotExistException {

         AppointmentSlotInfo slotInfo = new AppointmentSlotInfo();

         slotInfo.setStartDate(apptWin.getStartDate());

         // Find end date

         _setEndDateToDropDate(slotInfo);

         // One slot per appointment window has no set end date and is defined by the end of the period

         slotInfo.setTypeKey(AppointmentServiceConstants.APPOINTMENT_SLOT_TYPE_OPEN_KEY);

         slotInfo.setStateKey(AppointmentServiceConstants.APPOINTMENT_SLOTS_STATE_ACTIVE_KEY);

         List<AppointmentSlotInfo> slots = new ArrayList<AppointmentSlotInfo>();

         slots.add(slotInfo);

         return slots;

     }

     // ------------------------------- delete public methods ----------------------------

     /**

      * Helper that is used both by deleteAppointmentWindow and deleteAppointmentSlotsByWindow

      * @param windowEntity An appointment window entity

      * @param shouldDeleteSlots true, if you want slots to also be deleted

      */

     public void deleteAppointmentsByWindow(AppointmentWindowEntity windowEntity, boolean shouldDeleteSlots) {

         List<AppointmentSlotEntity> slotList = _fetchSlotEntitiesByWindows(windowEntity.getId());

         if (slotList != null) {

             // Delete appointments, if any

             _deleteAppointmentsBySlotList_(slotList);

             // Delete slots, if any

             _deleteAppointmentSlots(slotList);

         }

         changeApptWinState(windowEntity, AppointmentServiceConstants.APPOINTMENT_WINDOW_STATE_DRAFT_KEY);

     }

     public void deleteAppointmentSlotsByWindowCascading(AppointmentWindowEntity windowEntity) {

         deleteAppointmentsByWindow(windowEntity, true); // also, delete slots

     }

     /**

      * Deletes appointment windows, slots, and appointments.

      * @param windowEntity The window (and its dependent parts) to be deleted.

      */

     public void deleteAppointmentWindowCascading(AppointmentWindowEntity windowEntity) {

         deleteAppointmentSlotsByWindowCascading(windowEntity);

         appointmentWindowDao.remove(windowEntity);

         // No need to update the state since the window is gone

     }

     public int deleteAppointmentsBySlotCascading(String slotId) {

         List<AppointmentEntity> apptList = appointmentDao.getAppointmentsBySlotId(slotId);

         if (apptList != null) {

             for (AppointmentEntity appt: apptList) {

                 appointmentDao.remove(appt);

             }

             return apptList.size();

         }

         return -1; // didn't find any appointments (does this really happen?)

     }

     /**

      * Changes the state of the appointment window (to draft or assigned)

      * Precondition: apptWinId and stateKey are valid

      * @param windowEntity The appointment window ID in the DB

      * @param stateKey Either AppointmentServiceConstants.APPOINTMENT_WINDOW_STATE_DRAFT_KEY or

      *                 AppointmentServiceConstants.APPOINTMENT_WINDOW_STATE_ASSIGNED_KEY

      */

     public void changeApptWinState(AppointmentWindowEntity windowEntity, String stateKey) {

         windowEntity.setApptWindowState(stateKey);

         appointmentWindowDao.update(windowEntity);

     }

     /**

      * Creates a list of AppointmentSlotInfo (but does not persist in DB).

      * @param apptWinInfo Appointment Window

      * @param contextInfo Context info

      * @return Object with 3 elements.  Object[0] is a list of AppointmentSlotInfo objects, Object[1] is number allocated

      * (only for max allocation, otherwise 0 for uniform), and Object[2] is number unallocated (again, only for max

      * allocation, otherwise 0 for uniform)

      */

     public Object[] createMultiSlots(AppointmentWindowInfo apptWinInfo, ContextInfo contextInfo)

             throws InvalidParameterException, MissingParameterException, DoesNotExistException,

                    OperationFailedException, PermissionDeniedException {

         String atpDurationTypeKey = apptWinInfo.getSlotRule().getSlotStartInterval().getAtpDurationTypeKey();

         if (!AtpServiceConstants.DURATION_MINUTES_TYPE_KEY.equals(atpDurationTypeKey)) {

             // Currently, only support minutes

             throw new InvalidParameterException("Only kuali.atp.duration.Minutes is implemented");

         }

         String apptWinTypeKey = apptWinInfo.getTypeKey();

         if (! (AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_MAX_KEY.equals(apptWinTypeKey) ||

               (AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_UNIFORM_KEY.equals(apptWinTypeKey)))) {

             throw new InvalidParameterException("Supported types: MAX and UNIFORM");

         }

         // Get parameters ready

         Calendar startDate = _convertDateToCalendar(apptWinInfo.getStartDate());

         Calendar endDate = _convertDateToCalendar(apptWinInfo.getEndDate());

         int maxPerSlot = apptWinInfo.getMaxAppointmentsPerSlot() == null ? 0 : apptWinInfo.getMaxAppointmentsPerSlot();

         int totalStudents = -1;

         if (AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_MAX_KEY.equals(apptWinInfo.getTypeKey())) {

             totalStudents = _computeTotalStudents(apptWinInfo, contextInfo);

         }

         int startTimeInMinutes = _computeMinuteOffsetSinceMidnight(apptWinInfo.getSlotRule().getStartTimeOfDay().getMilliSeconds());

         int endTimeInMinutes =  _computeMinuteOffsetSinceMidnight(apptWinInfo.getSlotRule().getEndTimeOfDay().getMilliSeconds());

         // TODO: Current implementation only supports minutes.  Except thrown at start of this method for any other

         int startIntervalInMinutes = apptWinInfo.getSlotRule().getSlotStartInterval().getTimeQuantity();

         int durationInMinutes = -1; // TODO: Currently, unsupported

         List<Integer> weekdays = apptWinInfo.getSlotRule().getWeekdays();

         // The big call!  Compute the slot times

         Object[] result = null;

         if (AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_MAX_KEY.equals(apptWinTypeKey)) {

             result = _computeSlotTimesMaxAllocation(startDate, endDate, totalStudents, maxPerSlot, startTimeInMinutes,

                                                     endTimeInMinutes, startIntervalInMinutes, 

                                                     durationInMinutes, weekdays);

         } else if (AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_UNIFORM_KEY.equals(apptWinTypeKey)) {

             result = _computeSlotTimesUniformAllocation(startDate, endDate, totalStudents, startTimeInMinutes,

                                                         endTimeInMinutes, startIntervalInMinutes, durationInMinutes, 

                                                         weekdays);

         }

         List<AppointmentSlotInfo> slotList = new ArrayList<AppointmentSlotInfo>();

         _computeApptSlotList(slotList, (List<Calendar>) result[0]);

         Object[] result2 = {slotList, result[1], result[2]};

         return result2;

     }

     public List<AppointmentSlotInfo> createAppointmentSlots(List<AppointmentSlotInfo> slotInfoList, String apptSlotTypeKey,

                                                               String apptWinId, ContextInfo contextInfo)

             throws InvalidParameterException, DataValidationErrorException, MissingParameterException,

                    DoesNotExistException, ReadOnlyException, PermissionDeniedException, OperationFailedException {

         List<AppointmentSlotInfo> newSlotInfoList = new ArrayList<AppointmentSlotInfo>();

         for (AppointmentSlotInfo slotInfo: slotInfoList) {

             slotInfo.setAppointmentWindowId(apptWinId);

             AppointmentSlotInfo newSlotInfo = createAppointmentSlot(apptWinId, apptSlotTypeKey, slotInfo, contextInfo);

             newSlotInfoList.add(newSlotInfo);

         }

         return newSlotInfoList;

     }

     public AppointmentSlotInfo createAppointmentSlot(String appointmentWindowId, String appointmentSlotTypeKey,

                                                      AppointmentSlotInfo appointmentSlotInfo, ContextInfo contextInfo)

             throws DataValidationErrorException, DoesNotExistException, InvalidParameterException,

             MissingParameterException, OperationFailedException, PermissionDeniedException, ReadOnlyException {

         AppointmentSlotEntity appointmentSlotEntity = new AppointmentSlotEntity(appointmentSlotTypeKey, appointmentSlotInfo);

         appointmentSlotEntity.setEntityCreated(contextInfo);

         // Need to manually set the entity since appointmentSlotInfo only has an id for its corresponding AppointmentWindow

         AppointmentWindowEntity windowEntity = appointmentWindowDao.find(appointmentWindowId);

         if (null == windowEntity) {

             throw new DoesNotExistException(appointmentWindowId);

         }

         appointmentSlotEntity.setApptWinEntity(windowEntity); // This completes the initialization of appointmentSlotEntity

         appointmentSlotDao.persist(appointmentSlotEntity);

         return appointmentSlotEntity.toDto();

     }

     public long countAppointmentsByApptWinId(String apptWinId) {

         long result = appointmentDao.countAppointmentsByWindowId(apptWinId);

         return result;

     }

     public List<AppointmentInfo> getAppointmentsBySlotNoTransact(String appointmentSlotId, ContextInfo contextInfo) throws InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

         List<AppointmentEntity> apptEntityList = appointmentDao.getAppointmentsBySlotId(appointmentSlotId);

         List<AppointmentInfo> apptInfoList = new ArrayList<AppointmentInfo>();

         for (AppointmentEntity entity: apptEntityList) {

             AppointmentInfo info = entity.toDto();

             apptInfoList.add(info);

         }

         return apptInfoList;

     }

     // maxSizePerSlot is likely to be null except in the max case, so leave it as an object here

     public void generateAppointments(String apptWinId,

                                      String appointmentTypeKey, Integer maxSizePerSlot,

                                      List<String> students, List<AppointmentSlotInfo> slotInfoList,

                                      ContextInfo contextInfo,

                                      StatusInfo statusInfo) throws OperationFailedException, InvalidParameterException, DataValidationErrorException, MissingParameterException, DoesNotExistException, ReadOnlyException, PermissionDeniedException {

         if (slotInfoList.isEmpty()) {

             throw new OperationFailedException("No slots");

         }

         // May want to adjust message in the status info

         if (appointmentTypeKey.equals(AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_ONE_SLOT_KEY)) {

             _generateAppointmentsOneSlotCase(students, slotInfoList, statusInfo, contextInfo);

         } else if (appointmentTypeKey.equals(AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_UNIFORM_KEY)) {

             _generateAppointmentsUniformCase(students, slotInfoList, statusInfo, contextInfo);

         } else if (appointmentTypeKey.equals(AppointmentServiceConstants.APPOINTMENT_WINDOW_TYPE_SLOTTED_MAX_KEY)) {

             _generateAppointmentsMaxCase(apptWinId, students, maxSizePerSlot, slotInfoList, statusInfo, contextInfo);

         } else {

             throw new OperationFailedException("Manual window allocation not supported");

         }

     }

     // =====================================================================================

     // ------------------------------- PRIVATE METHODS -------------------------------------

     // =====================================================================================

     // ---------------------------- Slot generation private

     /**

      *

      * @param startDate When appointments can start (including hour/minute)

      * @param endDate When appointments end (an appointment can be scheduled exactly at that time)

      * @param totalStudents How many students we need slots for.  If -1, we won't care

      * @param maxPerSlot How many students can be allocated per slot

      * @param startTimeInMinutes Offset from midnight in minutes for start of business day

      *                           (doesn't account for daylight saving transitions)

      * @param endTimeInMinutes Offset from midnight in minutes for start of business day

      *                         (same caveat)

      * @param startIntervalInMinutes Difference in minutes

      * @param durationInMinutes How long an appointment lasts in minutes (currently ignored)

      * @param weekdays List of integers representing which days of the week business hours occur

      *                 (1 - Sunday, 2 - Monday, ..., 7 - Saturday).  Must be non-empty, non-null

      * @return Object[0] contains List<Calendar> for slot times in chronological order.  Object[1]

      *         contains Integer for number of students allocated, Object[2] contains an Integer for

      *         number of students unallocated.  Object[1] + Object[2] adds to totalStudents.

      */

     private Object [] _computeSlotTimesMaxAllocation(Calendar startDate, Calendar endDate, int totalStudents,

                                                      int maxPerSlot, int startTimeInMinutes, int endTimeInMinutes,

                                                      int startIntervalInMinutes, int durationInMinutes,

                                                      List<Integer> weekdays) throws InvalidParameterException {

         if (totalStudents < 0) {

             throw new InvalidParameterException("totalStudents should be positive");

         }

         List<Calendar> slotTimes = new ArrayList<Calendar>();

         if (weekdays.isEmpty()) {

             Object[] result = {slotTimes, new Integer(0), new Integer(totalStudents)};

             return result;

         }

         Calendar date = _makeCopy(startDate);

         _setTime(date, startTimeInMinutes); // Set to start of day

         int numAllocated = 0; // Number of students accounted for by slots

         while (true) {

             // Exit if we're past the end date

             if (endDate != null && date.after(endDate)) {

                 break;

             }

             // Exit loop if we're allocated enough (but make sure we're checking for that)

             if (numAllocated >= totalStudents) {

                 break;

             }

             // -------------------- Now allocate slots for current day --------------------

             Calendar endOfToday = _makeCopy(date);

             _setTime(endOfToday, endTimeInMinutes);

             while (true) { // Iterate over slots for today

                 // Make sure first slot is >= startDate

                 _setTimePastStartDate(date, startDate, startIntervalInMinutes);

                 if (date.after(endOfToday) || date.after(endDate)) {

                     break; // quit out of if we've reached the end of the day or final end date

                 }

                 slotTimes.add(date); // Add next slot time

                 if (maxPerSlot > 0) {

                     numAllocated += maxPerSlot;

                 }

                 if (numAllocated >= totalStudents) {

                     break; // We have enough slots to account for all students, so quit

                 }

                 // Create next date

                 date = _makeCopy(date, startIntervalInMinutes);

             }

             // Searches for the start of the next available business day

             date = _getNextValidDate(date, startTimeInMinutes, weekdays, endDate);

             if (date == null) {

                 break;

             }

         }

         // We haven't really allocated, just computed how many we *would* allocate.

         if (numAllocated > totalStudents) {

             numAllocated = totalStudents;

         }

         int unallocated = totalStudents - numAllocated;

         Object[] result = {slotTimes, new Integer(numAllocated), new Integer(unallocated)};

         return result;

     }

     private Object [] _computeSlotTimesUniformAllocation(Calendar startDate, Calendar endDate, int totalStudents,

                                                          int startTimeInMinutes, int endTimeInMinutes,

                                                          int startIntervalInMinutes, int durationInMinutes,

                                                          List<Integer> weekdays) {

         List<Calendar> slotTimes = new ArrayList<Calendar>();

         if (weekdays.isEmpty()) {

             Object[] result = {slotTimes, new Integer(0), new Integer(totalStudents)};

             return result;

         }

         Calendar date = _makeCopy(startDate);

         _setTime(date, startTimeInMinutes); // Set to start of day

         while (true) {

             // Exit if we're past the end date

             if (endDate != null && date.after(endDate)) {

                 break;

             }

             // -------------------- Now allocate slots for current day --------------------

             Calendar endOfToday = _makeCopy(date);

             _setTime(endOfToday, endTimeInMinutes);

             while (true) { // Iterate over slots for today

                 // Make sure first slot is >= startDate

                 _setTimePastStartDate(date, startDate, startIntervalInMinutes);

                 if (date.after(endOfToday) || date.after(endDate)) {

                     break; // quit out of if we've reached the end of the day or final end date

                 }

                 slotTimes.add(date); // Add next slot time

                 // Create next date

                 date = _makeCopy(date, startIntervalInMinutes);

             }

             // Searches for the start of the next available business day

             date = _getNextValidDate(date, startTimeInMinutes, weekdays, endDate);

             if (date == null) {

                 break;

             }

         }

         // We haven't really allocated, just computed how many we *would* allocate.

         Object[] result = {slotTimes, new Integer(totalStudents), new Integer(0)};

         return result;

     }

     private void _computeApptSlotList(List<AppointmentSlotInfo> slotList, List<Calendar> slotTimes) {

         for (Calendar date: slotTimes) {    

             AppointmentSlotInfo slotInfo = _createApptSlotFromDate(date);

             slotList.add(slotInfo);

         }

     }

     private AppointmentSlotInfo _createApptSlotFromDate(Calendar day) {

         AppointmentSlotInfo slotInfo = new AppointmentSlotInfo();

         slotInfo.setStateKey(AppointmentServiceConstants.APPOINTMENT_SLOTS_STATE_ACTIVE_KEY);

         slotInfo.setTypeKey(AppointmentServiceConstants.APPOINTMENT_SLOT_TYPE_OPEN_KEY); // TODO: verify this is valid

         Date date = day.getTime();

         slotInfo.setStartDate(date);

         _setEndDateToDropDate(slotInfo);

         return slotInfo;

     }

     private int _computeTotalStudents(AppointmentWindowInfo apptWinInfo, ContextInfo contextInfo) throws InvalidParameterException, MissingParameterException, DoesNotExistException, PermissionDeniedException, OperationFailedException {

         List<String> ids = populationService.getMembers(apptWinInfo.getAssignedPopulationId(), contextInfo);

         if (ids != null) {

             return ids.size();

         } else {

             return 0;  // TODO: Perhaps do something else?  Throw an exception?

         }

     }

     // ---------------------------------- Calendar private methods ----------------------------------

     /**

      * Computes minutes since start of day (midnight).  We don't need millisecond granularity.

      * Assumption: We ignore daylight saving.  Thus, 9 AM is always 9 * 60 = 540 minutes from midnight.

      * @param milliseconds Milliseconds since start of day

      * @return Minutes since start of day

      */

     private int _computeMinuteOffsetSinceMidnight(Long milliseconds) {

         int minutes = (int) (milliseconds / MILLIS_IN_MINUTE);

         return minutes;

     }

     private Calendar _convertDateToCalendar(Date date) {

         if (date == null) {

             return null;

         }

         Calendar result = Calendar.getInstance();

         result.setTime(date);

         return result;

     }

     private void _zeroOutHoursMinutesEtc(Calendar cal) {

         cal.set(Calendar.HOUR_OF_DAY, 0);

         cal.set(Calendar.MINUTE, 0);

         cal.set(Calendar.SECOND, 0);

         cal.set(Calendar.MILLISECOND, 0);

     }

     private void _zeroOutSecondsMillis(Calendar cal) {

         cal.set(Calendar.SECOND, 0);

         cal.set(Calendar.MILLISECOND, 0);

     }

     private static int DAYS_OF_WEEK[] = {Calendar.SUNDAY, Calendar.MONDAY, Calendar.TUESDAY, Calendar.WEDNESDAY, Calendar.THURSDAY,

             Calendar.FRIDAY, Calendar.SATURDAY};

     // weekdays contains values 1 -7 (1: Sunday, ..., 7: Saturday)

     private boolean _isDayInWeekdays(Calendar date, List<Integer> weekdays) {

         int dayOfWeek = date.get(Calendar.DAY_OF_WEEK);

         for (int i = 0; i < weekdays.size(); i++) {

             int adjustedDayOfWeek = weekdays.get(i) - 1; // Shift to 0..6

             if (dayOfWeek == DAYS_OF_WEEK[adjustedDayOfWeek]) {

                 return true;

             }

         }

         return false;

     }

     private boolean _isSameDay(Calendar first, Calendar second) {

         return first.get(Calendar.YEAR) == second.get(Calendar.YEAR) &&

                 first.get(Calendar.MONTH) == second.get(Calendar.MONTH) &&

                 first.get(Calendar.DAY_OF_MONTH) == second.get(Calendar.DAY_OF_MONTH);

     }

     private Calendar _makeCopy(Calendar date) {

         Calendar copy = Calendar.getInstance();

         copy.setTimeInMillis(date.getTimeInMillis());

         return copy;

     }

     private Calendar _makeCopy(Calendar date, int offsetInMinutes) {

         Calendar copy = Calendar.getInstance();

         copy.setTimeInMillis(date.getTimeInMillis());

         copy.add(Calendar.MINUTE, offsetInMinutes);

         return copy;

     }

     private void _setTime(Calendar date, int minutesSinceMidnight) {

         int hours = minutesSinceMidnight / MINUTES_IN_HOUR;

         int minutes = minutesSinceMidnight % MINUTES_IN_HOUR;

         date.set(Calendar.HOUR_OF_DAY, hours);

         date.set(Calendar.MINUTE, minutes);

     }

     private Calendar _getNextValidDate(Calendar date, int startOfDayInMinutes, List<Integer> weekdays,

                                        Calendar endDate) {

         Calendar copy = _makeCopy(date);

         _setTime(copy, startOfDayInMinutes);

         copy.add(Calendar.DAY_OF_MONTH, 1); // Add a day

         int loopCount = 0;

         while (true) {

             if (endDate != null && copy.after(endDate)) {

                 return null;

             }

             if (_isDayInWeekdays(copy, weekdays)) {

                 return copy;

             }

             copy.add(Calendar.DAY_OF_MONTH, 1); // Add a day

             loopCount++;

             if (loopCount > 10) {

                 // TODO: Figure this out (should it be taken care of)

             }

         }

     }

     private boolean _sameDayMonthYear(Calendar date, Calendar startDate) {

         return date.get(Calendar.DAY_OF_MONTH) == startDate.get(Calendar.DAY_OF_MONTH) &&

                 date.get(Calendar.MONTH) == startDate.get(Calendar.MONTH) &&

                 date.get(Calendar.YEAR) == startDate.get(Calendar.YEAR);

     }

     private void _setTimePastStartDate(Calendar date, Calendar startDate, int startIntervalInMinutes) {

         if (_sameDayMonthYear(date, startDate)) {

             while (date.before(startDate)) {

                 date.add(Calendar.MINUTE, startIntervalInMinutes);

             }

         }

     }

     // ---------------------- DELETE Private Methods --------------------------------

     private List<AppointmentSlotEntity> _fetchSlotEntitiesByWindows(String apptWinId) {

         List<AppointmentSlotEntity> list = appointmentSlotDao.getSlotsByWindowIdSorted(apptWinId);

         return list;

     }

     private void _deleteAppointmentSlots(List<AppointmentSlotEntity> slotList) {

         if (slotList != null) {

             for (AppointmentSlotEntity entity: slotList) {

                 // Use dao since deleteAppointmentSlot is transactional per slot deletion (we want the entire

                 // delete operation to be one big transaction (cclin asks: correct?)

                 appointmentSlotDao.remove(entity);

             }

         }

     }

     /**

      * Deletes all appointments associated with this slot list.

      * Precondition: Don't call directly by public methods--doesn't change state of window

      * @param slotList Assume not-null

      */

     private void _deleteAppointmentsBySlotList_(List<AppointmentSlotEntity> slotList) {

         for (AppointmentSlotEntity slotEntity: slotList) {

             deleteAppointmentsBySlotCascading(slotEntity.getId());

         }

     }

     // ----------------------- Generate appts private methods ---------------------

     private void _generateAppointmentsOneSlotCase(List<String> studentIds, List<AppointmentSlotInfo> slotInfoList,

                                                   StatusInfo statusInfo, ContextInfo contextInfo)

             throws InvalidParameterException, MissingParameterException, DoesNotExistException,

                    PermissionDeniedException, OperationFailedException, DataValidationErrorException, ReadOnlyException {

         String slotId = slotInfoList.get(0).getId();  // Only one slot in the one slot case

         for (String studentId: studentIds) {

             AppointmentInfo apptInfo = _createAppointmentInfo(studentId, slotId);

             createAppointmentNoTransact(studentId, slotId, apptInfo.getTypeKey(), apptInfo, contextInfo);

         }

         // Set number of students allocated

         statusInfo.setMessage("" + studentIds.size());

     }

     private AppointmentInfo _createAppointmentInfo(String studentId, String slotId) {

         AppointmentInfo apptInfo = new AppointmentInfo();

         apptInfo.setPersonId(studentId);

         apptInfo.setSlotId(slotId);

         apptInfo.setTypeKey(AppointmentServiceConstants.APPOINTMENT_TYPE_REGISTRATION);

         apptInfo.setStateKey(AppointmentServiceConstants.APPOINTMENT_STATE_ACTIVE_KEY);

         return apptInfo;

     }

     // Used by both max/uniform allocation

     private void _allocateStudentsToSlotsCommon(int studentsPerSlot, List<AppointmentSlotInfo> slotInfoList,

                                                 List<String> studentIds, ContextInfo contextInfo)

             throws InvalidParameterException, DataValidationErrorException, MissingParameterException,

             DoesNotExistException, ReadOnlyException, PermissionDeniedException, OperationFailedException {

         int count = 0;

         int numStudents = studentIds.size();

         int numSlots = slotInfoList.size();

         boolean done = false;

         for (AppointmentSlotInfo slotInfo: slotInfoList) {

             List<String> sublist = null;

             // Grab sublist of students

             int endIndex = (count + 1) * studentsPerSlot;

             if (endIndex > numStudents) { // adjust end if we go past number of students

                 endIndex = numStudents;

                 done = true;

             }

             sublist = studentIds.subList(count * studentsPerSlot, endIndex);

             count++;

             // Make the assignments

             for (String studentId: sublist) {

                 String slotId = slotInfo.getId();

                 AppointmentInfo apptInfo = _createAppointmentInfo(studentId, slotId);

                 createAppointmentNoTransact(studentId, slotId, apptInfo.getTypeKey(), apptInfo, contextInfo);

             }

             if (done) {

                 break; // Some slots may be unassigned in the max allocation

             }

         }

     }

     /*

      * Precondition: At least one slot in the slotInfoList

      */

     private void _generateAppointmentsUniformCase(List<String> studentIds, List<AppointmentSlotInfo> slotInfoList,

                                                   StatusInfo statusInfo, ContextInfo contextInfo) throws InvalidParameterException,

             DataValidationErrorException, MissingParameterException, DoesNotExistException, ReadOnlyException,

             PermissionDeniedException, OperationFailedException {

         int numSlots = slotInfoList.size();

         int numStudents = studentIds.size();

         int studentsPerSlot = numStudents / numSlots;

         if (numStudents % numSlots != 0) {

             studentsPerSlot++; // Add 1 if numSlots does not evenly divide numStudents

         }

         _allocateStudentsToSlotsCommon(studentsPerSlot, slotInfoList, studentIds, contextInfo);

         statusInfo.setMessage("" + studentIds.size()); // Set to number of appointments

     }

     // The slot generation will take care of the end dates

     private void _generateAppointmentsMaxCase(String apptWinId,

                                               List<String> studentIds, int maxSizePerSlot,

                                               List<AppointmentSlotInfo> slotInfoList,

                                               StatusInfo statusInfo, ContextInfo contextInfo) throws InvalidParameterException,

             DataValidationErrorException, MissingParameterException, DoesNotExistException, ReadOnlyException,

             PermissionDeniedException, OperationFailedException {

         int numSlots = slotInfoList.size();

         int numStudents = studentIds.size();

         // Do we have enough slots for all the students?

         if (numStudents > numSlots * maxSizePerSlot) {

             // No, so quit without doing any more

             statusInfo.setSuccess(false);

             int diff = numStudents - (numSlots * maxSizePerSlot); // Would be unassigned

             statusInfo.setMessage("Not enough room for ["+ numStudents +"] appointments. numSlots[" + numSlots+ "] * maxPerSlot[" +maxSizePerSlot + "] = "

                     + "["+ (numSlots * maxSizePerSlot)+ "] available appointments. Please increase available slots or max per slot.");

             return; // And we're outta here

         }

         // Enough slots, so start assigning

         _allocateStudentsToSlotsCommon(maxSizePerSlot, slotInfoList, studentIds, contextInfo);

         // Count how many we assigned

         long numAppts = countAppointmentsByApptWinId(apptWinId);

         statusInfo.setMessage("" + numAppts); // Set to number of appointments

     }

     // ----------------------- MISC private methods -------------------------------

     private void _setEndDateToDropDate(AppointmentSlotInfo slotInfo) {

 //        // TODO: Figure out how to do this

 //        List<AtpInfo> infoList = atpService.getAtpsByMilestone(apptWin.getPeriodMilestoneId(), contextInfo);

 //        if (infoList.size() != 1) {

 //            throw new InvalidParameterException("Should only return one ATP");

 //        }

 //        AtpInfo info = infoList.get(0);

 //        List<MilestoneInfo> milestoneList = atpService.getMilestonesForAtp(info.getId(), contextInfo);

 //        boolean found = false;

 //        for (MilestoneInfo milestone: milestoneList) {

 //            if (milestone.getTypeKey().equals(AtpServiceConstants.MILESTONE_DROP_DATE_TYPE_KEY)) {

 //                slotInfo.setEndDate(milestone.getEndDate());

 //                found = true;

 //                break;

 //            }

 //        }

 //        if (!found) {

 //            throw new OperationFailedException("Drop date milestone not found");

 //        }

     }

 }