/*-
 * ============LICENSE_START=======================================================
 * ONAP Policy API
 * ================================================================================
 * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
 * Modifications Copyright (C) 2022 Bell Canada. All rights reserved.
 * Modifications Copyright (C) 2022 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 * ============LICENSE_END=========================================================
 */

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

import java.util.UUID;
import org.onap.policy.api.main.exception.PolicyApiRuntimeException;
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.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;

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

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

    protected static final String EXTENSION_NAME = "interface info";

    protected static final String API_VERSION_NAME = "api-version";
    protected static final String API_VERSION = "1.0.0";

    protected static final String LAST_MOD_NAME = "last-mod-release";

    protected static final String AUTHORIZATION_TYPE = "basicAuth";

    protected static final String VERSION_MINOR_NAME = "X-MinorVersion";
    protected static final String VERSION_MINOR_DESCRIPTION =
        "Used to request or communicate a MINOR version back from the client"
            + " to the server, and from the server back to the client";

    protected static final String VERSION_PATCH_NAME = "X-PatchVersion";
    protected static final String VERSION_PATCH_DESCRIPTION = "Used only to communicate a PATCH version in a "
        + "response for troubleshooting purposes only, and will not be provided by" + " the client on request";

    protected static final String VERSION_LATEST_NAME = "X-LatestVersion";
    protected static final String VERSION_LATEST_DESCRIPTION = "Used only to communicate an API's latest version";

    public static final String REQUEST_ID_NAME = "X-ONAP-RequestID";
    protected static final String REQUEST_ID_HDR_DESCRIPTION = "Used to track REST transactions for logging purpose";
    protected static final String REQUEST_ID_PARAM_DESCRIPTION = "RequestID for http transaction";

    protected static final String AUTHENTICATION_ERROR_MESSAGE = "Authentication Error";
    protected static final String AUTHORIZATION_ERROR_MESSAGE = "Authorization Error";
    protected static final String SERVER_ERROR_MESSAGE = "Internal Server Error";
    protected static final String NOT_FOUND_MESSAGE = "Resource Not Found";
    protected static final String INVALID_BODY_MESSAGE = "Invalid Body";
    protected static final String INVALID_PAYLOAD_MESSAGE = "Not Acceptable Payload";
    protected static final String HTTP_CONFLICT_MESSAGE = "Delete Conflict, Rule Violation";
    protected static final String ERROR_MESSAGE_NO_POLICIES_FOUND = "No policies found";

    protected final Coder coder = new StandardCoder();

    protected <T> ResponseEntity<T> makeOkResponse(UUID requestId, T respEntity) {
        return makeResponse(requestId, respEntity, HttpStatus.OK.value());
    }

    protected <T> ResponseEntity<T> makeResponse(UUID requestId, T respEntity, int status) {
        return CommonRestController
            .addLoggingHeaders(addVersionControlHeaders(ResponseEntity.status(status)), requestId)
            .body(respEntity);
    }

    /**
     * Adds version headers to the response.
     *
     * @param respBuilder response builder
     * @return the response builder, with version headers
     */
    public static ResponseEntity.BodyBuilder addVersionControlHeaders(ResponseEntity.BodyBuilder respBuilder) {
        return respBuilder.header(VERSION_MINOR_NAME, "0").header(VERSION_PATCH_NAME, "0").header(VERSION_LATEST_NAME,
            API_VERSION);
    }

    /**
     * Adds logging headers to the response.
     *
     * @param respBuilder response builder
     * @return the response builder, with version logging
     */
    public static ResponseEntity.BodyBuilder addLoggingHeaders(ResponseEntity.BodyBuilder respBuilder, UUID requestId) {
        if (requestId == null) {
            // Generate a random uuid if client does not embed requestId in rest request
            return respBuilder.header(REQUEST_ID_NAME, UUID.randomUUID().toString());
        }

        return respBuilder.header(REQUEST_ID_NAME, requestId.toString());
    }

    /**
     * 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;
        }
    }

    @ExceptionHandler(value = {PolicyApiRuntimeException.class})
    protected ResponseEntity<Object> handleException(PolicyApiRuntimeException ex, WebRequest req) {
        LOGGER.warn(ex.getMessage(), ex.getCause());
        final var requestId = req.getHeader(CommonRestController.REQUEST_ID_NAME);
        final var status = ex.getErrorResponse().getResponseCode().getStatusCode();
        return CommonRestController.addLoggingHeaders(
            CommonRestController.addVersionControlHeaders(ResponseEntity.status(status)),
            requestId != null ? UUID.fromString(requestId) : ex.getRequestId()).body(ex.getErrorResponse());
    }
}