/*
 * ============LICENSE_START=======================================================
 * ONAP
 * ================================================================================
 * Copyright (C) 2020 AT&T Intellectual Property. 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.policy.controlloop;

import org.onap.policy.controlloop.drl.legacy.ControlLoopParams;
import org.onap.policy.controlloop.CanonicalOnset;
import org.onap.policy.controlloop.VirtualControlLoopEvent;
import org.onap.policy.controlloop.VirtualControlLoopNotification;
import org.onap.policy.controlloop.ControlLoopNotificationType;
import org.onap.policy.controlloop.eventmanager.ControlLoopEventManager2Drools;
import org.onap.policy.controlloop.eventmanager.ControlLoopEventManager2.NewEventStatus;
import org.onap.policy.controlloop.eventmanager.ControlLoopOperationManager2;
import org.onap.policy.controlloop.utils.ControlLoopUtils;
import org.onap.policy.models.tosca.authorative.concepts.ToscaPolicy;

import org.slf4j.LoggerFactory;
import org.slf4j.Logger;

import org.onap.policy.drools.system.PolicyEngineConstants;

/*
*
* Called when the ControlLoopParams object has been inserted into working memory from the BRMSGW.
*
*/
rule "INSERT.PARAMS"
    when
        $params : ControlLoopParams()
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {} : TOSCA-POLICY=[{}]", $params.getClosedLoopControlName(), $params.getPolicyName() + "."
        + drools.getRule().getName(), $params.getToscaPolicy());
end

/*
*
* Called when a Tosca Policy is present.
*
*/
rule "NEW.TOSCA.POLICY"
    when
        $policy : ToscaPolicy()
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: [{}|{}|{}|{}]: CONTENT: {}", drools.getRule().getName(),
                $policy.getType(), $policy.getTypeVersion(), $policy.getName(),
                $policy.getVersion(), $policy);

    ControlLoopParams params = ControlLoopUtils.toControlLoopParams($policy);
    if (params != null) {
        insert(params);
    }
end

/*
 * Remove Control Loop Parameters.
 */
rule "REMOVE.PARAMS"
    when
        $params : ControlLoopParams( $policyName :  getPolicyName(), $policyVersion : getPolicyVersion() )
        not ( ToscaPolicy( getName() == $policyName, getVersion() == $policyVersion ) )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: [{}|{}|{}]", drools.getRule().getName(),
                $params.getPolicyScope(), $params.getPolicyName(), $params.getPolicyVersion());

    retract($params);
end

/*
*
* This rule responds to DCAE Events where there is no manager yet. Either it is
* the first ONSET, or a subsequent badly formed Event (i.e. Syntax error, or is-closed-loop-disabled)
*
*/
rule "EVENT"
    when
        $params : ControlLoopParams( $clName : getClosedLoopControlName() )
        $event : CanonicalOnset( closedLoopControlName == $clName )
        not ( ControlLoopEventManager2Drools( closedLoopControlName == $event.getClosedLoopControlName(),
            getContext().getEvent() == $event ) )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {}.{}: event={}",
                $clName, $params.getPolicyName(), drools.getRule().getName(),
                $event);
    //
    // Retract the event from memory; it will be managed by the manager for now on
    //
    retract($event);

    VirtualControlLoopNotification notification;

    try {
        //
        // Check the event, because we need it to not be null when
        // we create the ControlLoopEventManager2Drools. The ControlLoopEventManager2Drools
        // will do extra syntax checking as well as check if the closed loop is disabled.
        //
        if ($event.getRequestId() == null) {
            notification = new VirtualControlLoopNotification($event);
            notification.setNotification(ControlLoopNotificationType.REJECTED);
            notification.setFrom("policy");
            notification.setMessage("Missing requestId");
            notification.setPolicyName($params.getPolicyName() + "." + drools.getRule().getName());
            notification.setPolicyScope($params.getPolicyScope());
            notification.setPolicyVersion($params.getPolicyVersion());

        } else {
            ControlLoopEventManager2Drools manager = new ControlLoopEventManager2Drools($params, $event, drools.getWorkingMemory());
            insert(manager);
            try {
                manager.start();
            } catch(Exception e) {
                retract(manager);
                throw e;
            }
            notification = manager.makeNotification();
            notification.setNotification(ControlLoopNotificationType.ACTIVE);
            notification.setPolicyName($params.getPolicyName() + "." + drools.getRule().getName());
        }
    } catch (Exception e) {
        logger.warn("{}: {}.{}", $clName, $params.getPolicyName(), drools.getRule().getName(), e);
        notification = new VirtualControlLoopNotification($event);
        notification.setNotification(ControlLoopNotificationType.REJECTED);
        notification.setMessage("Exception occurred: " + e.getMessage());
        notification.setPolicyName($params.getPolicyName() + "." + drools.getRule().getName());
        notification.setPolicyScope($params.getPolicyScope());
        notification.setPolicyVersion($params.getPolicyVersion());
    }
    //
    // Generate notification
    //
    try {
        PolicyEngineConstants.getManager().deliver("POLICY-CL-MGT", notification);

    } catch(RuntimeException e) {
        logger.warn("{}: {}.{}: event={} exception generating notification",
                $clName, $params.getPolicyName(), drools.getRule().getName(),
                $event, e);
    }
end

/*
*
* This rule happens when we get a subsequent event.
*
*/
rule "EVENT.MANAGER.NEW.EVENT"
    when
        $event : VirtualControlLoopEvent( )
        $manager : ControlLoopEventManager2Drools( closedLoopControlName == $event.getClosedLoopControlName(),
            getContext().getEvent() == $event )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {}.{}: event={} manager={}",
            $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
            $event, $manager);
    //
    // Remove the event from memory
    //
    retract($event);

    //
    // Check what kind of event this is
    //
    switch($manager.onNewEvent($event)) {
        case SYNTAX_ERROR:
            //
            // Ignore any bad syntax events
            //
            logger.warn("{}: {}.{}: syntax error",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName());
            break;

        case FIRST_ABATEMENT:
        case SUBSEQUENT_ABATEMENT:
            //
            // TODO: handle the abatement.  Currently, it's just discarded.
            //
            logger.info("{}: {}.{}: abatement",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName());
            break;

        case FIRST_ONSET:
        case SUBSEQUENT_ONSET:
        default:
            //
            // We don't care about subsequent onsets
            //
            logger.warn("{}: {}.{}: subsequent onset",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName());
            break;
    }
end

/*
*
* Step completed
*
*/
rule "EVENT.MANAGER.PROCESSING"
    when
        $manager : ControlLoopEventManager2Drools( isUpdated(), isActive(), $notification : getNotification() )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {}.{}: manager={}",
            $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
            $manager);
    //
    // Generate notification
    //
    try {
        $notification.setPolicyName($manager.getPolicyName() + "." + drools.getRule().getName());
        PolicyEngineConstants.getManager().deliver("POLICY-CL-MGT", $notification);

    } catch(RuntimeException e) {
        logger.warn("{}: {}.{}: manager={} exception generating notification",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
                $manager, e);
    }
    //
    // Generate Response notification
    //
    try {
        ControlLoopResponse clResponse = $manager.getControlLoopResponse();
        if (clResponse != null) {
            PolicyEngineConstants.getManager().deliver("DCAE_CL_RSP", clResponse);
        }

    } catch(RuntimeException e) {
        logger.warn("{}: {}.{}: manager={} exception generating Response notification",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
                $manager, e);
    }
    //
    // Discard this message and wait for the next response.
    //
    $manager.nextStep();
    update($manager);
end

/*
*
* Final step completed
*
*/
rule "EVENT.MANAGER.FINAL"
    when
        $manager : ControlLoopEventManager2Drools( !isActive(), $notification : getNotification() )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {}.{}: manager={}",
            $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
            $manager);
    //
    // Generate notification
    //
    try {
        $notification.setPolicyName($manager.getPolicyName() + "." + drools.getRule().getName());
        PolicyEngineConstants.getManager().deliver("POLICY-CL-MGT", $notification);

    } catch(RuntimeException e) {
        logger.warn("{}: {}.{}: manager={} exception generating notification",
                $manager.getClosedLoopControlName(), $manager.getPolicyName(), drools.getRule().getName(),
                $manager, e);
    }
    //
    // Retract and destroy the manager
    //
    retract($manager);
    $manager.destroy();
end

/*
*
* This rule will clean up any rogue events where there is no
* ControlLoopParams object corresponding to the onset event.
*
*/
rule "EVENT.CLEANUP"
    salience -1
    when
        $event : VirtualControlLoopEvent( $clName: closedLoopControlName )
    then

    Logger logger = LoggerFactory.getLogger(drools.getRule().getPackage());
    logger.info("{}: {}", $clName, drools.getRule().getName());
    logger.debug("{}: {}: orphan event={}",
                $clName, drools.getRule().getName(), $event);
    //
    // Retract the event
    //
    retract($event);
end

/*
*
* At this point, it appears that if we prevent the rules from getting messages from
* topics, then that will also prevent the actors from getting them.  So the following
* rules are here just to discard those messages.
*
* These have a higher salience so the objects are removed before the "FINAL" message
* is processed, so that the junit test can assume things are done once they see the
* "FINAL" message.  Otherwise, tests might fail sporadically.
*
*/
rule "APPC.Response.CLEANUP"
    salience 1
    when
        $msg : org.onap.policy.appc.Response( )
    then
        retract($msg);
end

rule "APPC.Request.CLEANUP"
    salience 1
    when
        $msg : org.onap.policy.appc.Request( )
    then
        retract($msg);
end

rule "APPC-LCM.Response.CLEANUP"
    salience 1
    when
        $msg : org.onap.policy.appclcm.AppcLcmDmaapWrapper( )
    then
        retract($msg);
end

rule "SDNR.Response.CLEANUP"
    salience 1
    when
        $msg : org.onap.policy.sdnr.PciResponseWrapper( )
    then
        retract($msg);
end