/*
* Copyright 2010-2014 Ning, Inc.
*
* Ning licenses this file to you 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.
*/
package org.killbill.billing.invoice.tree;
import java.math.BigDecimal;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.Set;
import java.util.UUID;
import org.joda.time.LocalDate;
import org.killbill.billing.invoice.tree.Item.ItemAction;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
/**
* Keeps track of all the items existing on a specified interval.
*/
public class ItemsInterval {
private final NodeInterval interval;
private LinkedList<Item> items;
public ItemsInterval(final NodeInterval interval) {
this(interval, null);
}
public ItemsInterval(final NodeInterval interval, final Item initialItem) {
this.interval = interval;
this.items = Lists.newLinkedList();
if (initialItem != null) {
items.add(initialItem);
}
}
public boolean containsItem(final UUID targetId) {
return Iterables.tryFind(items, new Predicate<Item>() {
@Override
public boolean apply(final Item input) {
return input.getId().equals(targetId);
}
}).orNull() != null;
}
public void setAdjustment(final BigDecimal amount, final UUID targetId) {
final Item item = Iterables.tryFind(items, new Predicate<Item>() {
@Override
public boolean apply(final Item input) {
return input.getId().equals(targetId);
}
}).get();
item.incrementAdjustedAmount(amount);
}
public List<Item> getItems() {
return items;
}
public void buildForMissingInterval(final LocalDate startDate, final LocalDate endDate, final List<Item> output, final boolean addRepair) {
final Item item = createNewItem(startDate, endDate, addRepair);
if (item != null) {
output.add(item);
}
}
/**
* Determines what is left based on the mergeMode and the action for each item.
*
* @param output
* @param mergeMode
* @return whether or not the parent should ignore the interval covered by the child interval
*/
public boolean buildFromItems(final List<Item> output, final boolean mergeMode) {
final ItemWithResult itemWithResult = getResultingItem(mergeMode);
if (itemWithResult.getItem() != null) {
output.add(itemWithResult.getItem());
}
return itemWithResult.isIgnorePeriod();
}
private ItemWithResult getResultingItem(final boolean mergeMode) {
return mergeMode ? getResulting_CANCEL_Item() : getResulting_ADD_Item();
}
private ItemWithResult getResulting_CANCEL_Item() {
Preconditions.checkState(items.size() == 0 || items.size() == 1);
return new ItemWithResult(Iterables.tryFind(items, new Predicate<Item>() {
@Override
public boolean apply(final Item input) {
return input.getAction() == ItemAction.CANCEL;
}
}).orNull(), true);
}
private ItemWithResult getResulting_ADD_Item() {
final Set<UUID> repairedIds = new HashSet<UUID>();
final ListIterator<Item> it = items.listIterator(items.size());
//
// We can have an {0,n} pairs of ADD/CANCEL (cancelling each other), and in addition to that we could have:
// a - One ADD that has not been cancelled => We want to return that item and let the parent (NodeInterval) know that it should ignore
// the period as this is accounted for with the item returned
// b - One CANCEL => We return NO item but we also want the parent to know that it should ignore
// the period as this is accounted -- period should remain unbilled.
// c - nothing => The parent should NOT ignore the period as there is no child element that can account for it.
//
while (it.hasPrevious()) {
final Item cur = it.previous();
switch (cur.getAction()) {
case ADD:
// If we found a CANCEL item pointing to that item then don't return it as it was repair (full repair scenario)
if (!repairedIds.contains(cur.getId())) {
// Case a
return new ItemWithResult(cur, true);
} else {
// Remove from the list so we know if there is anything else (case b or c)
repairedIds.remove(cur.getId());
}
case CANCEL:
// In all cases populate the set with the id of target item being repaired
if (cur.getLinkedId() != null) {
repairedIds.add(cur.getLinkedId());
}
break;
}
}
return repairedIds.size() > 0 ?
new ItemWithResult(null, true) : /* case b */
new ItemWithResult(null, false); /* case c */
}
// Just ensure that ADD items precedes CANCEL items
public void insertSortedItem(final Item item) {
items.add(item);
Collections.sort(items, new Comparator<Item>() {
@Override
public int compare(final Item o1, final Item o2) {
if (o1.getAction() == ItemAction.ADD && o2.getAction() == ItemAction.CANCEL) {
return -1;
} else if (o1.getAction() == ItemAction.CANCEL && o2.getAction() == ItemAction.ADD) {
return 1;
} else {
return 0;
}
}
});
}
public void cancelItems(final Item item) {
Preconditions.checkState(item.getAction() == ItemAction.ADD);
Preconditions.checkState(items.size() == 1);
Preconditions.checkState(items.get(0).getAction() == ItemAction.CANCEL);
items.clear();
}
/**
* Creates a new item.
* <p/>
* <ul>
* <li>In normal mode, we only consider ADD items. This happens when for instance an existing item was partially repaired
* and there is a need to create a new item which represents the part left -- that was not repaired.
* <li>In mergeMode, we allow to create new items that are the missing repaired items (CANCEL).
* </ul>
*
* @param startDate start date of the new item to create
* @param endDate end date of the new item to create
* @param mergeMode mode to consider.
* @return
*/
private Item createNewItem(LocalDate startDate, LocalDate endDate, final boolean mergeMode) {
final ItemWithResult itemWithResult = getResultingItem(mergeMode);
final Item item = itemWithResult.getItem();
if (item == null) {
return null;
}
final Item result = new Item(item.toProratedInvoiceItem(startDate, endDate), item.getAction());
if (item.getAction() == ItemAction.CANCEL && result != null) {
item.incrementCurrentRepairedAmount(result.getAmount());
}
return result;
}
private final class ItemWithResult {
private final Item item;
private final boolean ignorePeriod;
private ItemWithResult(final Item item, final boolean ignorePeriod) {
this.item = item;
this.ignorePeriod = ignorePeriod;
}
public Item getItem() {
return item;
}
public boolean isIgnorePeriod() {
return ignorePeriod;
}
}
}