import java.util.Date;

import java.util.Map;

import java.util.HashMap;

import java.util.ArrayList;

/**

* A class Diary that represents a "diary" of shop item reservations.

*

* The diary is structured as a Map of entries in which each entry corresponds

* to a specific day. As the map is not accessed in a sequential fashion, it

* doesn't matter whether the actual map class is a TreeMap or a HashMap.

*

* @author D E Newton

*

*/

public class Diary

{

private Map<Date, DayInDiary> dayInDiaryMap;

/**

* Constructor for objects of class Diary

*/

public Diary()

{

// create diary as a map

dayInDiaryMap = new HashMap<Date, DayInDiary>();

}

/**

* Method for adding a reservation to the diary.

*

* @parameter shopItemReservation, of type ShopItemReservation

*/

public void addItemReservation(ShopItemReservation shopItemReservation)

{

Date date = shopItemReservation.getStartDate();

for(int day=1; day<=shopItemReservation.getNoOfDays(); day++)

{

if( !dayInDiaryMap.containsKey(date) )

{

// add new day to diary if no previous entries for this day

dayInDiaryMap.put(date, new DayInDiary(date));

}

dayInDiaryMap.get(date).addEntry(shopItemReservation, day);

date = DateUtil.nextDate(date);

}

}

/**

* Method for displaying the reservations between specified dates.

*

* @parameter startDate, of type Date

* @parameter endDate, of type Date

*/

public void printEntries(Date startDate, Date endDate)

{

if( DateUtil.daysBetween(startDate, endDate)<0 )

{

// startDate after endDate

System.out.println("*** Error in method displayEntries(): The specified end date is before the start date ***");

}

else

{

System.out.println("\n\nDiary: Reservations for period " + DateUtil.convertDateToShortString(startDate)

+ " to " + DateUtil.convertDateToShortString(endDate) + " inclusive");

System.out.println("=================================================================");

for(Date date=startDate; date.compareTo(endDate)<=0; date = DateUtil.nextDate(date))

{

String longDate = DateUtil.convertDateToLongString(date);

System.out.print(longDate + ":");

if( dayInDiaryMap.containsKey(date) )

{

DayInDiary dayInDiary = dayInDiaryMap.get(date);

dayInDiary.printEntries();

}

else

System.out.println(" No reservations\n");

}

}

}

/**

* Method for deleting a reservation from the diary.

*

* @parameter shopItemReservation, of type ShopItemReservation

*/

public void deleteItemReservation(ShopItemReservation shopItemReservation)

{

Date date = shopItemReservation.getStartDate();

for(int day=1; day<=shopItemReservation.getNoOfDays(); day++)

{

DayInDiary dayInDiary = dayInDiaryMap.get(date);

dayInDiary.deleteEntry(shopItemReservation);

if( dayInDiary.getDaysEntries().size()==0 )

dayInDiaryMap.remove(date);

date = DateUtil.nextDate(date);

}

}

/**

* Accessor method for returning all reservations that have entries

* in the diary for a particular date.

*

* @parameter date, of type Date

* @return an array of reservations, or null if no entry for that date

*/

public ShopItemReservation[] getItemReservations(Date date)

{

DayInDiary dayinDiary = dayInDiaryMap.get(date);

if( dayinDiary==null )

return null;

else

return dayinDiary.getReservations();

}

// inner class, only needed in the Diary class

private class DayInDiary

{

// reservations for the day

private ArrayList<Entry> daysEntries;

private Date date;

/*

* Constructor for objects of class DayInDiary

*/

private DayInDiary(Date date)

{

this.date = date;

daysEntries = new ArrayList<Entry>();

}

private ArrayList<Entry> getDaysEntries()

{

return daysEntries;

}

private ShopItemReservation[] getReservations()

{

int noOfEntries = daysEntries.size();

ShopItemReservation[] shopItemReservations = new ShopItemReservation[noOfEntries];

for(int i=0; i<noOfEntries; i++)

shopItemReservations[i] = daysEntries.get(i).getReservation();

return shopItemReservations;

}

private void addEntry(ShopItemReservation shopItemReservation, int dayNo)

{

daysEntries.add(new Entry(shopItemReservation, dayNo));

}

private void deleteEntry(ShopItemReservation shopItemReservation)

{

// find the entry for this reservation and delete it

Entry toBeDeletedEntry = null;

for(Entry entry : daysEntries)

{

if( entry.getReservation()==shopItemReservation ) // in this situation, this is better than using "equals()"

{

toBeDeletedEntry = entry;

break;

}

}

daysEntries.remove(toBeDeletedEntry);

}

private void printEntries()

{

int size = daysEntries.size();

if( size>0 )

{

System.out.println(" " + size + " reservation(s)");

for( Entry entry: daysEntries )

{

ShopItemReservation shopItemReservation = entry.getReservation();

int reservationDay = DateUtil.daysBetween(shopItemReservation.getStartDate(), date) + 1;;

System.out.println(" " + shopItemReservation + ", day " + reservationDay + " of " + shopItemReservation.getNoOfDays());

}

}

else

{

System.out.println("*** Unexpected error in displayEntries() ***");

System.out.println("*** No entries for this date so it should not be in the diary ***");

}

System.out.println();

}

// an inner class of the DaysDiary class

private class Entry

{

private ShopItemReservation shopItemReservation;

private int reservationDay; // e.g. second day is day 2 of 4 for a reservation spanning 4 days

private Entry(ShopItemReservation shopItemReservation, int reservationDay)

{

this.shopItemReservation = shopItemReservation;

this.reservationDay = reservationDay;

}

private ShopItemReservation getReservation()

{

return shopItemReservation;

}

}

}

}