/*
 * Copyright 2014-2015 Groupon, Inc
 * Copyright 2014-2015 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.payment.core.janitor;

import java.util.List;
import java.util.UUID;

import org.joda.time.DateTime;
import org.killbill.billing.account.api.AccountInternalApi;
import org.killbill.billing.callcontext.DefaultCallContext;
import org.killbill.billing.callcontext.InternalCallContext;
import org.killbill.billing.callcontext.InternalTenantContext;
import org.killbill.billing.osgi.api.OSGIServiceRegistration;
import org.killbill.billing.payment.core.sm.PaymentStateMachineHelper;
import org.killbill.billing.payment.core.sm.PluginRoutingPaymentAutomatonRunner;
import org.killbill.billing.payment.core.sm.RetryStateMachineHelper;
import org.killbill.billing.payment.dao.PaymentDao;
import org.killbill.billing.payment.plugin.api.PaymentPluginApi;
import org.killbill.billing.util.UUIDs;
import org.killbill.billing.util.callcontext.CallContext;
import org.killbill.billing.util.callcontext.CallOrigin;
import org.killbill.billing.util.callcontext.InternalCallContextFactory;
import org.killbill.billing.util.callcontext.TenantContext;
import org.killbill.billing.util.callcontext.UserType;
import org.killbill.billing.util.config.PaymentConfig;
import org.killbill.clock.Clock;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

abstract class CompletionTaskBase<T> implements Runnable {

    protected Logger log = LoggerFactory.getLogger(CompletionTaskBase.class);

    private final Janitor janitor;
    private final String taskName;

    protected final PaymentConfig paymentConfig;
    protected final Clock clock;
    protected final PaymentDao paymentDao;
    protected final InternalCallContext completionTaskCallContext;
    protected final InternalCallContextFactory internalCallContextFactory;
    protected final PaymentStateMachineHelper paymentStateMachineHelper;
    protected final RetryStateMachineHelper retrySMHelper;
    protected final AccountInternalApi accountInternalApi;
    protected final PluginRoutingPaymentAutomatonRunner pluginControlledPaymentAutomatonRunner;
    protected final OSGIServiceRegistration<PaymentPluginApi> pluginRegistry;

    public CompletionTaskBase(final Janitor janitor, final InternalCallContextFactory internalCallContextFactory, final PaymentConfig paymentConfig,
                              final PaymentDao paymentDao, final Clock clock, final PaymentStateMachineHelper paymentStateMachineHelper,
                              final RetryStateMachineHelper retrySMHelper, final AccountInternalApi accountInternalApi,
                              final PluginRoutingPaymentAutomatonRunner pluginControlledPaymentAutomatonRunner, final OSGIServiceRegistration<PaymentPluginApi> pluginRegistry) {
        this.janitor = janitor;
        this.internalCallContextFactory = internalCallContextFactory;
        this.paymentConfig = paymentConfig;
        this.paymentDao = paymentDao;
        this.clock = clock;
        this.paymentStateMachineHelper = paymentStateMachineHelper;
        this.retrySMHelper = retrySMHelper;
        this.accountInternalApi = accountInternalApi;
        this.pluginControlledPaymentAutomatonRunner = pluginControlledPaymentAutomatonRunner;
        this.pluginRegistry = pluginRegistry;
        // Limit the length of the username in the context (limited to 50 characters)
        this.taskName = this.getClass().getSimpleName();
        this.completionTaskCallContext = internalCallContextFactory.createInternalCallContext((Long) null, (Long) null, taskName, CallOrigin.INTERNAL, UserType.SYSTEM, UUIDs.randomUUID());
    }

    @Override
    public void run() {

        if (janitor.isStopped()) {
            log.info("Janitor Task " + taskName + " was requested to stop");
            return;
        }
        final List<T> items = getItemsForIteration();
        for (final T item : items) {
            if (janitor.isStopped()) {
                log.info("Janitor Task " + taskName + " was requested to stop");
                return;
            }
            try {
                doIteration(item);
            } catch (final IllegalStateException e) {
                log.warn(e.getMessage());
            }
        }
    }

    public abstract List<T> getItemsForIteration();

    public abstract void doIteration(final T item);

    protected CallContext createCallContext(final String taskName, final InternalTenantContext internalTenantContext) {
        final TenantContext tenantContext = internalCallContextFactory.createTenantContext(internalTenantContext);
        final CallContext callContext = new DefaultCallContext(tenantContext.getTenantId(), taskName, CallOrigin.INTERNAL, UserType.SYSTEM, UUIDs.randomUUID(), clock);
        return callContext;
    }

    protected DateTime getCreatedDateBefore() {
        final long delayBeforeNowMs = paymentConfig.getJanitorPendingCleanupTime().getMillis();
        return clock.getUTCNow().minusMillis((int) delayBeforeNowMs);
    }
}
