Java tutorial
/* * Copyright 2014 The Billing Project, LLC * * 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.usage; import java.math.BigDecimal; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.UUID; import java.util.concurrent.atomic.AtomicBoolean; import org.joda.time.DateTimeZone; import org.joda.time.LocalDate; import org.killbill.billing.catalog.api.CatalogApiException; import org.killbill.billing.catalog.api.Currency; import org.killbill.billing.catalog.api.TieredBlock; import org.killbill.billing.catalog.api.Usage; import org.killbill.billing.invoice.api.InvoiceItem; import org.killbill.billing.invoice.api.InvoiceItemType; import org.killbill.billing.invoice.generator.BillingIntervalDetail; import org.killbill.billing.invoice.model.UsageInvoiceItem; import org.killbill.billing.junction.BillingEvent; import org.killbill.billing.usage.RawUsage; import org.killbill.billing.usage.api.RolledUpUnit; import org.killbill.billing.usage.api.RolledUpUsage; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Preconditions; import com.google.common.base.Predicate; import com.google.common.collect.ImmutableList; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import static org.killbill.billing.invoice.usage.UsageUtils.getConsumableInArrearTieredBlocks; import static org.killbill.billing.invoice.usage.UsageUtils.getConsumableInArrearUnitTypes; /** * There is one such class per subscriptionId, matching a given in arrear/consumable usage section and * referenced through a contiguous list of billing events. */ public class ContiguousIntervalConsumableInArrear { private static final Logger log = LoggerFactory.getLogger(ContiguousIntervalConsumableInArrear.class); private final List<LocalDate> transitionTimes; private final List<BillingEvent> billingEvents; private final Usage usage; private final Set<String> unitTypes; private final List<RawUsage> rawSubscriptionUsage; private final LocalDate targetDate; private final UUID invoiceId; private final AtomicBoolean isBuilt; private final LocalDate rawUsageStartDate; public ContiguousIntervalConsumableInArrear(final Usage usage, final UUID invoiceId, final List<RawUsage> rawSubscriptionUsage, final LocalDate targetDate, final LocalDate rawUsageStartDate) { this.usage = usage; this.invoiceId = invoiceId; this.unitTypes = getConsumableInArrearUnitTypes(usage); this.rawSubscriptionUsage = rawSubscriptionUsage; this.targetDate = targetDate; this.rawUsageStartDate = rawUsageStartDate; this.billingEvents = Lists.newLinkedList(); this.transitionTimes = Lists.newLinkedList(); this.isBuilt = new AtomicBoolean(false); } /** * Builds the transitionTimes associated to that usage section. Those are determined based on billing events for when to start and when to stop, * the per usage billingPeriod and finally the targetDate. * <p/> * Those transition dates define the well defined billing granularity periods that should be billed for that specific usage section. * * @param closedInterval whether there was a last billing event referencing the usage section or whether this is ongoing and * then targetDate will define the endDate. * @return */ public ContiguousIntervalConsumableInArrear build(final boolean closedInterval) { Preconditions.checkState(!isBuilt.get()); Preconditions.checkState( (!closedInterval && billingEvents.size() >= 1) || (closedInterval && billingEvents.size() >= 2)); final LocalDate startDate = new LocalDate(billingEvents.get(0).getEffectiveDate(), getAccountTimeZone()); if (targetDate.isBefore(startDate)) { return this; } final LocalDate endDate = closedInterval ? new LocalDate(billingEvents.get(billingEvents.size() - 1).getEffectiveDate(), getAccountTimeZone()) : targetDate; final BillingIntervalDetail bid = new BillingIntervalDetail(startDate, endDate, targetDate, getBCD(), usage.getBillingPeriod()); int numberOfPeriod = 0; // First billingCycleDate prior startDate LocalDate nextBillCycleDate = bid.getFutureBillingDateFor(numberOfPeriod); if (startDate.compareTo(rawUsageStartDate) >= 0) { transitionTimes.add(startDate); } while (!nextBillCycleDate.isAfter(endDate)) { if (nextBillCycleDate.isAfter(startDate)) { if (nextBillCycleDate.compareTo(rawUsageStartDate) >= 0) { transitionTimes.add(nextBillCycleDate); } } numberOfPeriod++; nextBillCycleDate = bid.getFutureBillingDateFor(numberOfPeriod); } isBuilt.set(true); return this; } /** * Compute the missing usage invoice items based on what should be billed and what has been billed ($ amount comparison). * * @param existingUsage existing on disk usage items for the subscription * @return * @throws CatalogApiException */ public List<InvoiceItem> computeMissingItems(final List<InvoiceItem> existingUsage) throws CatalogApiException { Preconditions.checkState(isBuilt.get()); if (transitionTimes.size() < 2) { return ImmutableList.of(); } final List<InvoiceItem> result = Lists.newLinkedList(); final List<RolledUpUsage> allUsage = getRolledUpUsage(); // We start by generating 'marker' USAGE items with $0 that will allow to correctly insert the next notification for when there is no USAGE to bill. // Those will be removed by the invoicing code later so as to not end up with superfluous $0 items LocalDate prevDate = null; for (LocalDate curDate : transitionTimes) { if (prevDate != null) { InvoiceItem item = new UsageInvoiceItem(invoiceId, getAccountId(), getBundleId(), getSubscriptionId(), getPlanName(), getPhaseName(), usage.getName(), prevDate, curDate, BigDecimal.ZERO, getCurrency()); result.add(item); } prevDate = curDate; } for (final RolledUpUsage ru : allUsage) { // Compute total price amount that should be billed for that period of time (and usage section) across unitTypes. BigDecimal toBeBilledUsage = BigDecimal.ZERO; for (final RolledUpUnit cur : ru.getRolledUpUnits()) { if (!unitTypes.contains(cur.getUnitType())) { log.warn("ContiguousIntervalConsumableInArrear is skipping unitType " + cur.getUnitType()); continue; } final BigDecimal toBeBilledForUnit = computeToBeBilledUsage(cur.getAmount(), cur.getUnitType()); toBeBilledUsage = toBeBilledUsage.add(toBeBilledForUnit); } // Retrieves current price amount billed for that period of time (and usage section) final Iterable<InvoiceItem> billedItems = getBilledItems(ru.getStart(), ru.getEnd(), existingUsage); final BigDecimal billedUsage = computeBilledUsage(billedItems); // Compare the two and add the missing piece if required. if (!billedItems.iterator().hasNext() || billedUsage.compareTo(toBeBilledUsage) < 0) { final BigDecimal amountToBill = toBeBilledUsage.subtract(billedUsage); if (amountToBill.compareTo(BigDecimal.ZERO) > 0) { InvoiceItem item = new UsageInvoiceItem(invoiceId, getAccountId(), getBundleId(), getSubscriptionId(), getPlanName(), getPhaseName(), usage.getName(), ru.getStart(), ru.getEnd(), amountToBill, getCurrency()); result.add(item); } } } return result; } @VisibleForTesting List<RolledUpUsage> getRolledUpUsage() { final Iterator<RawUsage> rawUsageIterator = rawSubscriptionUsage.iterator(); if (!rawUsageIterator.hasNext()) { return ImmutableList.of(); } final List<RolledUpUsage> result = new ArrayList<RolledUpUsage>(); // // Skip all items before our first transition date // // prevRawUsage keeps track of first unconsumed raw usage element RawUsage prevRawUsage = null; while (rawUsageIterator.hasNext()) { final RawUsage curRawUsage = rawUsageIterator.next(); if (curRawUsage.getDate().compareTo(transitionTimes.get(0)) >= 0) { prevRawUsage = curRawUsage; break; } } // Optimize path where all raw usage items are outside or our transitionTimes range if (prevRawUsage.getDate().compareTo(transitionTimes.get(transitionTimes.size() - 1)) >= 0) { return ImmutableList.of(); } // // Loop through each interval [prevDate, curDate) and consume as many rawSubscriptionUsage elements within that range // to create one RolledUpUsage per interval. If an interval does not have any rawSubscriptionUsage element, there will be no // matching RolledUpUsage for that interval, and we'll detect that in the 'computeMissingItems' logic // LocalDate prevDate = null; for (LocalDate curDate : transitionTimes) { if (prevDate != null) { // Allocate new perRangeUnitToAmount for this interval and populate with rawSubscriptionUsage items final Map<String, Long> perRangeUnitToAmount = new HashMap<String, Long>(); // Start consuming prevRawUsage element if it exists and falls into the range if (prevRawUsage != null) { if (prevRawUsage.getDate().compareTo(prevDate) >= 0 && prevRawUsage.getDate().compareTo(curDate) < 0) { Long currentAmount = perRangeUnitToAmount.get(prevRawUsage.getUnitType()); Long updatedAmount = (currentAmount != null) ? currentAmount + prevRawUsage.getAmount() : prevRawUsage.getAmount(); perRangeUnitToAmount.put(prevRawUsage.getUnitType(), updatedAmount); prevRawUsage = null; } } // // If prevRawUsage != null it means that our first and current rawSubscriptionUsage does not fall into that interval; we can't // just 'continue' as we need to correctly set next 'prevDate' // If prevRawUsage == null, then consume as much as we can for that interval. Note that the stop condition requires consuming // one additional element which will become the prevRawUsage for the next interval. // if (prevRawUsage == null) { while (rawUsageIterator.hasNext()) { final RawUsage curRawUsage = rawUsageIterator.next(); if (curRawUsage.getDate().compareTo(curDate) >= 0) { prevRawUsage = curRawUsage; break; } Long currentAmount = perRangeUnitToAmount.get(curRawUsage.getUnitType()); Long updatedAmount = (currentAmount != null) ? currentAmount + curRawUsage.getAmount() : curRawUsage.getAmount(); perRangeUnitToAmount.put(curRawUsage.getUnitType(), updatedAmount); } } // If we did find some usage for that date range, let's populate the result if (!perRangeUnitToAmount.isEmpty()) { final List<RolledUpUnit> rolledUpUnits = new ArrayList<RolledUpUnit>( perRangeUnitToAmount.size()); for (final String unitType : perRangeUnitToAmount.keySet()) { rolledUpUnits.add(new DefaultRolledUpUnit(unitType, perRangeUnitToAmount.get(unitType))); } result.add(new DefaultRolledUpUsage(getSubscriptionId(), prevDate, curDate, rolledUpUnits)); } } prevDate = curDate; } return result; } /** * @param nbUnits the number of used units for a given period * @param unitType the type of unit * @return the price amount that should be billed for that period/unitType * @throws CatalogApiException */ @VisibleForTesting BigDecimal computeToBeBilledUsage(final Long nbUnits, final String unitType) throws CatalogApiException { Preconditions.checkState(isBuilt.get()); BigDecimal result = BigDecimal.ZERO; final List<TieredBlock> tieredBlocks = getConsumableInArrearTieredBlocks(usage, unitType); int remainingUnits = nbUnits.intValue(); for (TieredBlock tieredBlock : tieredBlocks) { final int blockTierSize = tieredBlock.getSize().intValue(); final int tmp = remainingUnits / blockTierSize + (remainingUnits % blockTierSize == 0 ? 0 : 1); final int nbUsedTierBlocks; if (tmp > tieredBlock.getMax()) { nbUsedTierBlocks = tieredBlock.getMax().intValue(); remainingUnits -= tieredBlock.getMax() * blockTierSize; } else { nbUsedTierBlocks = tmp; remainingUnits = 0; } result = result .add(tieredBlock.getPrice().getPrice(getCurrency()).multiply(new BigDecimal(nbUsedTierBlocks))); } return result; } /** * @param filteredUsageForInterval the list of invoiceItem to consider * @return the price amount that was already billed for that period and usage section (across unitTypes) */ @VisibleForTesting BigDecimal computeBilledUsage(final Iterable<InvoiceItem> filteredUsageForInterval) { Preconditions.checkState(isBuilt.get()); BigDecimal billedAmount = BigDecimal.ZERO; for (InvoiceItem ii : filteredUsageForInterval) { billedAmount = billedAmount.add(ii.getAmount()); } // Return the billed $ amount (not the # of units) return billedAmount; } Iterable<InvoiceItem> getBilledItems(final LocalDate startDate, final LocalDate endDate, final List<InvoiceItem> existingUsage) { Preconditions.checkState(isBuilt.get()); return Iterables.filter(existingUsage, new Predicate<InvoiceItem>() { @Override public boolean apply(final InvoiceItem input) { if (input.getInvoiceItemType() != InvoiceItemType.USAGE) { return false; } // STEPH what happens if we discover usage period that overlap (one side or both side) the [startDate, endDate] interval final UsageInvoiceItem usageInput = (UsageInvoiceItem) input; return usageInput.getUsageName().equals(usage.getName()) && usageInput.getStartDate().compareTo(startDate) >= 0 && usageInput.getEndDate().compareTo(endDate) <= 0; } }); } @VisibleForTesting List<LocalDate> getTransitionTimes() { return transitionTimes; } public void addBillingEvent(final BillingEvent event) { Preconditions.checkState(!isBuilt.get()); billingEvents.add(event); } public Usage getUsage() { return usage; } public int getBCD() { return billingEvents.get(0).getBillCycleDayLocal(); } public UUID getAccountId() { return billingEvents.get(0).getAccount().getId(); } public UUID getBundleId() { return billingEvents.get(0).getSubscription().getBundleId(); } public UUID getSubscriptionId() { return billingEvents.get(0).getSubscription().getId(); } // STEPH_USAGE planName/phaseName,BCD,... might not be correct if we changed plan but Usage section was exactly similar public String getPlanName() { return billingEvents.get(0).getPlan().getName(); } public String getPhaseName() { return billingEvents.get(0).getPlanPhase().getName(); } public Currency getCurrency() { return billingEvents.get(0).getCurrency(); } public DateTimeZone getAccountTimeZone() { return billingEvents.get(0).getTimeZone(); } }