/*-
 * ============LICENSE_START=======================================================
 * feature-state-management
 * ================================================================================
 * Copyright (C) 2017-2019, 2021 AT&T Intellectual Property. All rights reserved.
 * Modifications Copyright (C) 2021 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.statemanagement;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiResponse;
import io.swagger.annotations.ApiResponses;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


@Api(value = "test")
@Path("/")
public class IntegrityMonitorRestManager {
    private static Logger logger = LoggerFactory.getLogger(IntegrityMonitorRestManager.class);
    private DroolsPdpIntegrityMonitor im;

    /**
     * Test interface for Integrity Monitor.
     *
     * @return Exception message if exception, otherwise empty
     */
    @ApiOperation(
            value = "Test endpoint for integrity monitor",
            notes = "The TEST command is used to request data from a subcomponent "
                    + "instance that can be used to determine its operational state. "
                    + "A 200/success response status code should be returned if the "
                    + "subcomponent instance is functioning properly and able to respond to requests.",
                    response = String.class)
    @ApiResponses(value = {
        @ApiResponse(
                    code = 200,
                    message = "Integrity monitor sanity check passed"),
        @ApiResponse(
                    code = 500,
                    message = "Integrity monitor sanity check encountered an exception. "
                        + "This can indicate operational state disabled or administrative state locked")
        })
    @GET
    @Path("test")
    public Response test() {
        logger.debug("integrity monitor /test accessed");
        // The responses are stored within the audit objects, so we need to
        // invoke the audits and get responses before we handle another
        // request.
        synchronized (IntegrityMonitorRestManager.class) {
            // will include messages associated with subsystem failures
            var body = new StringBuilder();

            // 200=SUCCESS, 500=failure
            var responseValue = 200;

            if (im == null) {
                try {
                    im = DroolsPdpIntegrityMonitor.getInstance();
                } catch (Exception e) {
                    logger.error("IntegrityMonitorRestManager: test() interface caught an exception", e);
                    body.append("\nException: " + e + "\n");
                    responseValue = 500;
                }
            }

            if (im != null) {
                try {
                    // call 'IntegrityMonitor.evaluateSanity()'
                    im.evaluateSanity();
                } catch (Exception e) {
                    // this exception isn't coming from one of the audits,
                    // because those are caught in 'subsystemTest()'
                    logger.error("DroolsPDPIntegrityMonitor.evaluateSanity()", e);

                    // include exception in HTTP response
                    body.append("\nException: " + e + "\n");
                    responseValue = 500;
                }
            }

            // send response, including the contents of 'body'
            // (which is empty if everything is successful)
            if (responseValue == 200) {
                return Response.status(Response.Status.OK).build();
            } else {
                return Response.status(Response.Status.INTERNAL_SERVER_ERROR).entity(body.toString()).build();
            }
        }
    }
}