/*-
 * ============LICENSE_START=======================================================
 * ONAP
 * ================================================================================
 * Copyright (C) 2017-2021 AT&T Intellectual Property. All rights reserved.
 * Modifications Copyright (C) 2024 Nordix Foundation.
 * ================================================================================
 * 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.drools.system;

import java.util.Properties;
import lombok.AccessLevel;
import lombok.NoArgsConstructor;
import org.apache.commons.lang3.StringUtils;
import org.onap.policy.common.endpoints.event.comm.TopicEndpointManager;
import org.onap.policy.common.endpoints.http.client.HttpClientConfigException;
import org.onap.policy.common.endpoints.http.client.HttpClientFactoryInstance;
import org.onap.policy.common.endpoints.http.server.HttpServletServerFactoryInstance;
import org.onap.policy.common.utils.logging.LoggerUtils;
import org.onap.policy.common.utils.resources.MessageConstants;
import org.onap.policy.common.utils.security.CryptoUtils;
import org.onap.policy.drools.persistence.SystemPersistenceConstants;
import org.onap.policy.drools.properties.DroolsPropertyConstants;
import org.onap.policy.drools.utils.PropertyUtil;
import org.onap.policy.drools.utils.logging.MdcTransaction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Programmatic entry point to the management layer.
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class Main {
    /**
     * Symmetric Key to decode sensitive configuration data.
     */
    protected static final String SYSTEM_SYMM_KEY = "engine.symm.key";

    /**
     * main.
     *
     * @param args program arguments.
     */
    public static void main(String[] args) {    // NOSONAR
        /*
         * NOTE: it is up to the individual features to perform argument validation.
         * However, it doesn't appear that any of the features actually use the arguments,
         * so no validation is necessary, thus sonar is disabled.
         */

        /* start logger */
        var logger = LoggerFactory.getLogger(Main.class);

        /* system properties */
        setSystemProperties();

        /* 0. boot */
        PolicyEngineConstants.getManager().boot(args);

        /* 1.a. Configure Engine */
        configureEngine(logger);

        /* 1.b. Load Installation Environment(s) */
        for (Properties env : SystemPersistenceConstants.getManager().getEnvironmentProperties()) {
            PolicyEngineConstants.getManager().setEnvironment(env);
        }

        /* 2.a Add topics */
        for (Properties topicProperties : SystemPersistenceConstants.getManager().getTopicProperties()) {
            TopicEndpointManager.getManager().addTopics(topicProperties);
        }

        /* 2.b Add HTTP Servers */
        for (Properties serverProperties : SystemPersistenceConstants.getManager().getHttpServerProperties()) {
            HttpServletServerFactoryInstance.getServerFactory().build(serverProperties);
        }

        /* 2.c Add HTTP Clients */
        for (Properties clientProperties : SystemPersistenceConstants.getManager().getHttpClientProperties()) {
            try {
                HttpClientFactoryInstance.getClientFactory().build(clientProperties);
            } catch (HttpClientConfigException e) {
                logger.warn("Main: http client properties errors found.  Using default configuration.", e);
            }
        }

        /* 3. Start the Engine with the basic services only (no Policy Controllers) */
        MdcTransaction trans = startEngineOnly(logger);

        /* 4. Create and start the controllers */
        createAndStartControllers(logger, trans);

        /* 5. Open the engine for dynamic configuration */
        PolicyEngineConstants.getManager().open();

        if (logger.isInfoEnabled()) {
            logger.info(String.format(MessageConstants.START_SUCCESS_MSG, MessageConstants.POLICY_DROOLS_PDP));
        }
    }

    private static void setSystemProperties() {
        for (Properties systemProperties : SystemPersistenceConstants.getManager().getSystemProperties()) {
            if (!StringUtils.isBlank(systemProperties.getProperty(SYSTEM_SYMM_KEY))) {
                PropertyUtil.setDefaultCryptoCoder(new CryptoUtils(systemProperties.getProperty(SYSTEM_SYMM_KEY)));
            }
            PropertyUtil.setSystemProperties(systemProperties);
        }
    }

    private static void configureEngine(Logger logger) {
        Properties engineProperties;
        try {
            engineProperties = SystemPersistenceConstants.getManager().getEngineProperties();
        } catch (IllegalArgumentException iae) {
            logger.warn("Main: engine properties not found. Using default configuration. {}", iae.getMessage());
            engineProperties = PolicyEngineConstants.getManager().defaultTelemetryConfig();
        }

        PolicyEngineConstants.getManager().configure(engineProperties);
    }

    private static MdcTransaction startEngineOnly(Logger logger) {
        MdcTransaction trans =
                MdcTransaction.newTransaction(null, null)
                .setServiceName(Main.class.getSimpleName())
                .setTargetEntity("engine")
                .setTargetServiceName("start");
        try {
            final boolean success = PolicyEngineConstants.getManager().start();
            if (!success) {
                trans.setStatusCode(false).setResponseDescription("partial start").flush();
                logger.warn(
                        LoggerUtils.TRANSACTION_LOG_MARKER,
                        "Main: {} has been partially started",
                        PolicyEngineConstants.getManager());
                throw new PolicyDroolsPdpRuntimeException(
                        String.format(MessageConstants.START_FAILURE_MSG, MessageConstants.POLICY_DROOLS_PDP));
            } else {
                trans.setStatusCode(true).transaction();
            }
        } catch (final IllegalStateException e) {
            trans
                .setStatusCode(false)
                .setResponseCode(e.getClass().getSimpleName())
                .setResponseDescription(e.getMessage())
                .flush();
            logger.warn(
                    LoggerUtils.TRANSACTION_LOG_MARKER,
                    "Main: cannot start {} (bad state)",
                    PolicyEngineConstants.getManager());
            throw new PolicyDroolsPdpRuntimeException(
                    String.format(MessageConstants.START_FAILURE_MSG, MessageConstants.POLICY_DROOLS_PDP), e);
        } catch (final Exception e) {
            trans
                .setStatusCode(false)
                .setResponseCode(e.getClass().getSimpleName())
                .setResponseDescription(e.getMessage())
                .flush();
            logger.warn(
                    LoggerUtils.TRANSACTION_LOG_MARKER,
                    "Main: cannot start {}",
                    PolicyEngineConstants.getManager());
            throw new PolicyDroolsPdpRuntimeException(
                    String.format(MessageConstants.START_FAILURE_MSG, MessageConstants.POLICY_DROOLS_PDP), e);
        }
        return trans;
    }

    private static void createAndStartControllers(Logger logger, MdcTransaction trans) {
        for (final Properties controllerProperties :
            SystemPersistenceConstants.getManager().getControllerProperties()) {
            final String controllerName =
                    controllerProperties.getProperty(DroolsPropertyConstants.PROPERTY_CONTROLLER_NAME);
            try {
                trans =
                        MdcTransaction.newTransaction(null, null)
                        .setServiceName(Main.class.getSimpleName())
                        .setTargetEntity("controller:" + controllerName)
                        .setTargetServiceName("start");

                final var controller =
                        PolicyEngineConstants.getManager().createPolicyController(controllerName, controllerProperties);
                controller.start();

                trans
                    .setStatusCode(true)
                    .setResponseDescription(controller.getDrools().getCanonicalSessionNames().toString())
                    .transaction();
            } catch (final Exception e) {
                trans
                    .setStatusCode(false)
                    .setResponseCode(e.getClass().getSimpleName())
                    .setResponseDescription(e.getMessage())
                    .flush();
                logger.error(
                        LoggerUtils.TRANSACTION_LOG_MARKER,
                        "Main: cannot instantiate policy-controller {}",
                        controllerName);
                throw new PolicyDroolsPdpRuntimeException(
                        String.format(MessageConstants.START_FAILURE_MSG, MessageConstants.POLICY_DROOLS_PDP), e);
            } catch (final LinkageError e) {
                trans
                    .setStatusCode(false)
                    .setResponseCode(e.getClass().getSimpleName())
                    .setResponseDescription(e.getMessage())
                    .flush();
                logger.warn(
                        LoggerUtils.TRANSACTION_LOG_MARKER,
                        "Main: cannot instantiate policy-controller {} (linkage)",
                        controllerName);
                throw new PolicyDroolsPdpRuntimeException(
                        String.format(MessageConstants.START_FAILURE_MSG, MessageConstants.POLICY_DROOLS_PDP), e);
            }
        }
    }
}