/*
 * Copyright 2010-2013 Ning, Inc.
 * Copyright 2014-2016 Groupon, Inc
 * Copyright 2014-2016 The Billing Project, LLC
 *
 * The Billing Project 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.junction.plumbing.billing;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.UUID;

import org.joda.time.DateTimeZone;
import org.killbill.billing.callcontext.InternalTenantContext;
import org.killbill.billing.catalog.api.BillingMode;
import org.killbill.billing.catalog.api.Usage;
import org.killbill.billing.junction.BillingEvent;
import org.killbill.billing.junction.BillingEventSet;
import org.killbill.billing.util.AccountDateAndTimeZoneContext;
import org.killbill.billing.util.timezone.DefaultAccountDateAndTimeZoneContext;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.common.collect.Sets;

public class DefaultBillingEventSet extends TreeSet<BillingEvent> implements SortedSet<BillingEvent>, BillingEventSet {

    private static final long serialVersionUID = 1L;

    private final boolean accountAutoInvoiceOff;
    private final List<UUID> subscriptionIdsWithAutoInvoiceOff;
    private final BillingMode recurringBillingMode;
    private final InternalTenantContext internalTenantContext;

    private DefaultAccountDateAndTimeZoneContext dateTimeZoneContext;

    public DefaultBillingEventSet(final boolean accountAutoInvoiceOff, final BillingMode recurringBillingMode, final InternalTenantContext internalTenantContext) {
        this.accountAutoInvoiceOff = accountAutoInvoiceOff;
        this.recurringBillingMode = recurringBillingMode;
        this.internalTenantContext = internalTenantContext;
        this.subscriptionIdsWithAutoInvoiceOff = new ArrayList<UUID>();
    }

    @Override
    public boolean add(final BillingEvent e) {
        if (dateTimeZoneContext == null) {
            this.dateTimeZoneContext = new DefaultAccountDateAndTimeZoneContext(e.getEffectiveDate(), internalTenantContext);
        }
        return super.add(e);
    }

    @Override
    public boolean addAll(final Collection<? extends BillingEvent> all) {
        if (dateTimeZoneContext == null) {
            this.dateTimeZoneContext = new DefaultAccountDateAndTimeZoneContext(all.iterator().next().getEffectiveDate(), internalTenantContext);
        }
        return super.addAll(all);
    }

    @Override
    public boolean isAccountAutoInvoiceOff() {
        return accountAutoInvoiceOff;
    }

    @Override
    public BillingMode getRecurringBillingMode() {
        return recurringBillingMode;
    }

    @Override
    public List<UUID> getSubscriptionIdsWithAutoInvoiceOff() {
        return subscriptionIdsWithAutoInvoiceOff;
    }

    @Override
    public AccountDateAndTimeZoneContext getAccountDateAndTimeZoneContext() {
        if (dateTimeZoneContext == null) {
            throw new IllegalArgumentException("AccountDateAndTimeZoneContext is not initialized because there is no billing event");
        }
        return dateTimeZoneContext;
    }

    @Override
    public Map<String, Usage> getUsages() {
        final Iterable<Usage> allUsages = Iterables.concat(Iterables.transform(this, new Function<BillingEvent, List<Usage>>() {
            @Override
            public List<Usage> apply(final BillingEvent input) {
                return input.getUsages();
            }
        }));
        if (!allUsages.iterator().hasNext()) {
            return Collections.emptyMap();
        }
        final Map<String, Usage> result = new HashMap<String, Usage>();
        for (Usage cur : Sets.<Usage>newHashSet(allUsages)) {
            result.put(cur.getName(), cur);
        }
        return result;
    }

    @Override
    public String toString() {
        return "DefaultBillingEventSet [accountAutoInvoiceOff=" + accountAutoInvoiceOff
               + ", subscriptionIdsWithAutoInvoiceOff=" + subscriptionIdsWithAutoInvoiceOff + ", Events="
               + super.toString() + "]";
    }
}
