/*
 * Copyright (c) 2005-2011 Grameen Foundation USA
 * All rights reserved.
 *
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-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.
 *
 * See also http://www.apache.org/licenses/LICENSE-2.0.html for an
 * explanation of the license and how it is applied.
 */

package org.mifos.accounts.savings.interest.schedule.internal;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.joda.time.LocalDate;
import org.mifos.accounts.savings.interest.schedule.InterestScheduledEvent;

/**
 * I represent an {@link InterestScheduledEvent} that occurs every number of months on the last day of that month.
 */
public class MonthlyOnLastDayOfMonthInterestScheduledEvent implements InterestScheduledEvent {

    private final int every;

    public MonthlyOnLastDayOfMonthInterestScheduledEvent(int every) {
        this.every = every;
    }

    @Override
    public LocalDate nextMatchingDateFromAlreadyMatchingDate(LocalDate validMatchingDate) {
        return lastDayOfMonthFor(validMatchingDate.plusMonths(every));
    }

    private LocalDate lastDayOfMonthFor(LocalDate date) {
        return new LocalDate(date.toDateTimeAtStartOfDay().dayOfMonth().withMaximumValue());
    }

    @Override
    public List<LocalDate> findAllMatchingDatesFromBaseDateUpToAndIncludingNearestMatchingEndDate(LocalDate baseDate, LocalDate cutOffDate) {
        List<LocalDate> allMatchingDates = new ArrayList<LocalDate>();

        LocalDate previousMatchingDate = baseDate.minusDays(1);
        LocalDate matchingDate = nextMatchingDateFromAlreadyMatchingDate(previousMatchingDate);
        while (matchingDate.isEqual(cutOffDate) || matchingDate.isBefore(cutOffDate)) {
            allMatchingDates.add(matchingDate);
            matchingDate = nextMatchingDateFromAlreadyMatchingDate(matchingDate);
        }

        if (!allMatchingDates.contains(matchingDate)) {
            allMatchingDates.add(matchingDate);
        }

        return allMatchingDates;
    }

    @Override
    public LocalDate findFirstDateOfPeriodForMatchingDate(LocalDate matchingDate) {
        LocalDate previousMatchingDate = lastDayOfMonthFor(matchingDate.minusMonths(every));
        return previousMatchingDate.plusDays(1);
    }

    @Override
    public boolean isAMatchingDate(LocalDate baseDate, LocalDate date) {
        List<LocalDate> allMatchingDates = findAllMatchingDatesFromBaseDateUpToAndIncludingNearestMatchingEndDate(baseDate, date);
        return allMatchingDates.contains(date);
    }

    @Override
    public LocalDate nextMatchingDateAfter(LocalDate baseDate, LocalDate after) {
        LocalDate cutOff = after.plusMonths(every+1);
        List<LocalDate> allMatchingDates = findAllMatchingDatesFromBaseDateUpToAndIncludingNearestMatchingEndDate(baseDate, cutOff);

        return findNextMatchingDateFromList(after, allMatchingDates);
    }

    private LocalDate findNextMatchingDateFromList(LocalDate after, List<LocalDate> allMatchingDates) {
        LocalDate nextMatchingDate = after;
        for (LocalDate matchingDate : allMatchingDates) {
            if (matchingDate.isAfter(after) || matchingDate.isEqual(after)) {
                nextMatchingDate = matchingDate;
                break;
            }
        }
        return nextMatchingDate;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof MonthlyOnLastDayOfMonthInterestScheduledEvent == false) {
            return false;
        }
        if (this == obj) {
            return true;
        }
        MonthlyOnLastDayOfMonthInterestScheduledEvent rhs = (MonthlyOnLastDayOfMonthInterestScheduledEvent) obj;
        return new EqualsBuilder().append(this.every, rhs.every).isEquals();
    }

    @Override
    public int hashCode() {
      return new HashCodeBuilder(17, 37).append(this.every).toHashCode();
    }
}