/*-
 * ============LICENSE_START=======================================================
 * ONAP Policy API
 * ================================================================================
 * Copyright (C) 2019 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 * ============LICENSE_END=========================================================
 */

package org.onap.policy.api.main.rest;

import java.util.UUID;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;
import org.onap.policy.common.utils.coder.Coder;
import org.onap.policy.common.utils.coder.CoderException;
import org.onap.policy.common.utils.coder.StandardCoder;
import org.onap.policy.models.errors.concepts.ErrorResponseInfo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Super class from which REST controllers are derived.
 */
public class CommonRestController {

    private static final Logger LOGGER = LoggerFactory.getLogger(CommonRestController.class);

    private final Coder coder = new StandardCoder();


    protected Response makeOkResponse(UUID requestId, Object respEntity) {
        return addLoggingHeaders(addVersionControlHeaders(Response.status(Response.Status.OK)), requestId)
                        .entity(respEntity).build();
    }

    protected <T extends ErrorResponseInfo> Response makeErrorResponse(UUID requestId, T pfme) {
        return addLoggingHeaders(addVersionControlHeaders(Response.status(pfme.getErrorResponse().getResponseCode())),
                        requestId).entity(pfme.getErrorResponse()).build();
    }

    protected ResponseBuilder addVersionControlHeaders(ResponseBuilder rb) {
        return rb.header("X-MinorVersion", "0").header("X-PatchVersion", "0").header("X-LatestVersion", "1.0.0");
    }

    protected ResponseBuilder addLoggingHeaders(ResponseBuilder rb, UUID requestId) {
        if (requestId == null) {
            // Generate a random uuid if client does not embed requestId in rest request
            return rb.header("X-ONAP-RequestID", UUID.randomUUID());
        }
        return rb.header("X-ONAP-RequestID", requestId);
    }

    /**
     * Converts an object to a JSON string.
     *
     * @param object object to convert
     * @return a JSON string representing the object
     */
    protected String toJson(Object object) {
        if (object == null) {
            return null;
        }

        try {
            return coder.encode(object);

        } catch (CoderException e) {
            LOGGER.warn("cannot convert {} to JSON", object.getClass().getName(), e);
            return null;
        }
    }
}