/*-
 * ============LICENSE_START=======================================================
 * ONAP CLAMP
 * ================================================================================
 * 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.clamp.clds.client;

import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;

import org.apache.camel.CamelContext;
import org.apache.camel.Exchange;
import org.apache.camel.builder.ExchangeBuilder;
import org.onap.clamp.clds.config.ClampProperties;
import org.onap.clamp.clds.sdc.controller.installer.BlueprintMicroService;
import org.onap.clamp.loop.template.PolicyModel;
import org.onap.clamp.loop.template.PolicyModelId;
import org.onap.clamp.loop.template.PolicyModelsRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

/**
 * The class implements the communication with the Policy Engine to retrieve
 * policy models (tosca). It mainly delegates the physical calls to Camel
 * engine.
 *
 */
@Component
public class PolicyEngineServices {
    private final CamelContext camelContext;

    private final PolicyModelsRepository policyModelsRepository;

    private static final EELFLogger logger = EELFManager.getInstance().getLogger(PolicyEngineServices.class);
    private static final EELFLogger auditLogger = EELFManager.getInstance().getAuditLogger();
    private static final EELFLogger metricsLogger = EELFManager.getInstance().getMetricsLogger();
    private static int retryInterval = 0;
    private static int retryLimit = 1;

    public static final String POLICY_RETRY_INTERVAL = "policy.retry.interval";
    public static final String POLICY_RETRY_LIMIT = "policy.retry.limit";

    @Autowired
    public PolicyEngineServices(CamelContext camelContext, ClampProperties refProp,
            PolicyModelsRepository policyModelsRepository) {
        this.camelContext = camelContext;
        this.policyModelsRepository = policyModelsRepository;
        if (refProp.getStringValue(POLICY_RETRY_LIMIT) != null) {
            retryLimit = Integer.valueOf(refProp.getStringValue(POLICY_RETRY_LIMIT));
        }
        if (refProp.getStringValue(POLICY_RETRY_INTERVAL) != null) {
            retryInterval = Integer.valueOf(refProp.getStringValue(POLICY_RETRY_INTERVAL));
        }
    }

    public PolicyModel createPolicyModelFromPolicyEngine(String policyType, String policyVersion) {
        return new PolicyModel(policyType, this.downloadOnePolicy(policyType, policyVersion), policyVersion);
    }

    public PolicyModel createPolicyModelFromPolicyEngine(BlueprintMicroService microService) {
        return createPolicyModelFromPolicyEngine(microService.getModelType(), microService.getModelVersion());
    }

    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public void createPolicyInDbIfNeeded(PolicyModel policyModel) {
        if (!policyModelsRepository
                .existsById(new PolicyModelId(policyModel.getPolicyModelType(), policyModel.getVersion()))) {
            policyModelsRepository.save(policyModel);
        }
    }

    /**
     * This method can be used to download all policy types + data types defined in
     * policy engine.
     * 
     * @return A yaml containing all policy Types and all data types
     * @throws InterruptedException In case of issue when sleeping during the retry
     */
    public String downloadAllPolicies() {
        return callCamelRoute(ExchangeBuilder.anExchange(camelContext).build(), "direct:get-all-policy-models");
    }

    /**
     * This method can be used to download a policy tosca model on the engine.
     * 
     * @param policyType    The policy type (id)
     * @param policyVersion The policy version
     * @return A string with the whole policy tosca model
     * @throws InterruptedException In case of issue when sleeping during the retry
     */
    public String downloadOnePolicy(String policyType, String policyVersion) {
        return callCamelRoute(ExchangeBuilder.anExchange(camelContext).withProperty("policyModelName", policyType)
                .withProperty("policyModelVersion", policyVersion).build(), "direct:get-policy-model");
    }

    private String callCamelRoute(Exchange exchange, String camelFlow) {
        for (int i = 0; i < retryLimit; i++) {
            Exchange exchangeResponse = camelContext.createProducerTemplate().send(camelFlow, exchange);
            if (Integer.valueOf(200).equals(exchangeResponse.getIn().getHeader("CamelHttpResponseCode"))) {
                return (String) exchangeResponse.getIn().getBody();
            } else {
                logger.info("Policy query " + retryInterval + "ms before retrying ...");
                // wait for a while and try to connect to DCAE again
                try {
                    Thread.sleep(retryInterval);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
            }
        }
        return "";
    }
}