/*-
 * ============LICENSE_START=======================================================
 * SDC
 * ================================================================================
 * Copyright (C) 2017 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.openecomp.sdc.be.servlets;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.module.SimpleModule;
import fj.data.Either;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.openecomp.sdc.be.components.impl.ArtifactsBusinessLogic;
import org.openecomp.sdc.be.components.impl.ComponentBusinessLogic;
import org.openecomp.sdc.be.components.impl.ComponentInstanceBusinessLogic;
import org.openecomp.sdc.be.components.impl.ElementBusinessLogic;
import org.openecomp.sdc.be.components.impl.GroupBusinessLogic;
import org.openecomp.sdc.be.components.impl.MonitoringBusinessLogic;
import org.openecomp.sdc.be.components.impl.PolicyBusinessLogic;
import org.openecomp.sdc.be.components.impl.PolicyTypeBusinessLogic;
import org.openecomp.sdc.be.components.impl.ProductBusinessLogic;
import org.openecomp.sdc.be.components.impl.ResourceBusinessLogic;
import org.openecomp.sdc.be.components.impl.ServiceBusinessLogic;
import org.openecomp.sdc.be.components.lifecycle.LifecycleBusinessLogic;
import org.openecomp.sdc.be.components.scheduledtasks.ComponentsCleanBusinessLogic;
import org.openecomp.sdc.be.config.BeEcompErrorManager;
import org.openecomp.sdc.be.dao.api.ActionStatus;
import org.openecomp.sdc.be.dao.api.IElementDAO;
import org.openecomp.sdc.be.datatypes.enums.ComponentTypeEnum;
import org.openecomp.sdc.be.ecomp.converters.AssetMetadataConverter;
import org.openecomp.sdc.be.impl.ComponentsUtils;
import org.openecomp.sdc.be.impl.WebAppContextWrapper;
import org.openecomp.sdc.be.model.PropertyConstraint;
import org.openecomp.sdc.be.model.User;
import org.openecomp.sdc.be.model.operations.impl.PropertyOperation.PropertyConstraintJacksonDeserializer;
import org.openecomp.sdc.be.resources.data.auditing.AuditingActionEnum;
import org.openecomp.sdc.be.user.UserBusinessLogic;
import org.openecomp.sdc.common.api.Constants;
import org.openecomp.sdc.common.datastructure.Wrapper;
import org.openecomp.sdc.common.servlets.BasicServlet;
import org.openecomp.sdc.exception.ResponseFormat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.WebApplicationContext;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;
import java.util.Map;
import java.util.Map.Entry;
import java.util.function.Supplier;

public class BeGenericServlet extends BasicServlet {

    @Context
    protected HttpServletRequest servletRequest;

    private static final Logger log = LoggerFactory.getLogger(BeGenericServlet.class);

    /******************** New error response mechanism
     * @param requestErrorWrapper **************/

    protected Response buildErrorResponse(ResponseFormat requestErrorWrapper) {
        return Response.status(requestErrorWrapper.getStatus()).entity(gson.toJson(requestErrorWrapper.getRequestError())).build();
    }

    protected Response buildGeneralErrorResponse() {
        return buildErrorResponse(getComponentsUtils().getResponseFormat(ActionStatus.GENERAL_ERROR));
    }

    protected Response buildOkResponse(Object entity) {
        return buildOkResponseStatic(entity);
    }

    static public Response buildOkResponseStatic(Object entity) {
        return Response.status(Response.Status.OK)
                .entity(entity)
                .build();
    }

    protected Response buildOkResponse(ResponseFormat errorResponseWrapper, Object entity) {
        return buildOkResponse(errorResponseWrapper, entity, null);
    }

    protected Response buildOkResponse(ResponseFormat errorResponseWrapper, Object entity, Map<String, String> additionalHeaders) {
        int status = errorResponseWrapper.getStatus();
        ResponseBuilder responseBuilder = Response.status(status);
        if (entity != null) {
            if (log.isTraceEnabled())
                log.trace("returned entity is {}", entity.toString());
            responseBuilder = responseBuilder.entity(entity);
        }
        if (additionalHeaders != null) {
            for (Entry<String, String> additionalHeader : additionalHeaders.entrySet()) {
                String headerName = additionalHeader.getKey();
                String headerValue = additionalHeader.getValue();
                if (log.isTraceEnabled())
                    log.trace("Adding header {} with value {} to the response", headerName, headerValue);
                responseBuilder.header(headerName, headerValue);
            }
        }
        return responseBuilder.build();
    }

    /*******************************************************************************************************/
    protected Either<User, ResponseFormat> getUser(final HttpServletRequest request, String userId) {
        Either<User, ActionStatus> eitherCreator = getUserAdminManager(request.getSession().getServletContext()).getUser(userId, false);
        if (eitherCreator.isRight()) {
            log.info("createResource method - user is not listed. userId= {}", userId);
            ResponseFormat errorResponse = getComponentsUtils().getResponseFormat(ActionStatus.MISSING_INFORMATION);
            User user = new User("", "", userId, "", null, null);

            getComponentsUtils().auditResource(errorResponse, user, "", AuditingActionEnum.CHECKOUT_RESOURCE);
            return Either.right(errorResponse);
        }
        return Either.left(eitherCreator.left().value());

    }

    protected PolicyTypeBusinessLogic getPolicyTypeBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> PolicyTypeBusinessLogic.class);
    }

    protected UserBusinessLogic getUserAdminManager(ServletContext context) {
        return getClassFromWebAppContext(context, () -> UserBusinessLogic.class);
    }

    protected ResourceBusinessLogic getResourceBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ResourceBusinessLogic.class);
    }

    protected ComponentsCleanBusinessLogic getComponentCleanerBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ComponentsCleanBusinessLogic.class);
    }

    protected ServiceBusinessLogic getServiceBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ServiceBusinessLogic.class);
    }

    protected ProductBusinessLogic getProductBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ProductBusinessLogic.class);
    }

    protected ArtifactsBusinessLogic getArtifactBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ArtifactsBusinessLogic.class);
    }

    protected ElementBusinessLogic getElementBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> ElementBusinessLogic.class);
    }

    protected MonitoringBusinessLogic getMonitoringBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> MonitoringBusinessLogic.class);
    }

    protected AssetMetadataConverter getAssetUtils(ServletContext context) {
        return getClassFromWebAppContext(context, () -> AssetMetadataConverter.class);
    }

    protected LifecycleBusinessLogic getLifecycleBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> LifecycleBusinessLogic.class);
    }

    protected PolicyBusinessLogic getPolicyBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> PolicyBusinessLogic.class);
    }

    protected <T> T getClassFromWebAppContext(ServletContext context, Supplier<Class<T>> businessLogicClassGen) {
        WebAppContextWrapper webApplicationContextWrapper = (WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR);
        WebApplicationContext webApplicationContext = webApplicationContextWrapper.getWebAppContext(context);
        return webApplicationContext.getBean(businessLogicClassGen.get());
    }

    protected GroupBusinessLogic getGroupBL(ServletContext context) {

        WebAppContextWrapper webApplicationContextWrapper = (WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR);
        WebApplicationContext webApplicationContext = webApplicationContextWrapper.getWebAppContext(context);
        return webApplicationContext.getBean(GroupBusinessLogic.class);
    }

    protected ComponentInstanceBusinessLogic getComponentInstanceBL(ServletContext context, ComponentTypeEnum containerComponentType) {
        WebAppContextWrapper webApplicationContextWrapper = (WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR);
        WebApplicationContext webApplicationContext = webApplicationContextWrapper.getWebAppContext(context);
        return webApplicationContext.getBean(ComponentInstanceBusinessLogic.class);
    }

    protected IElementDAO getElementDao(Class<? extends IElementDAO> clazz, ServletContext context) {
        WebAppContextWrapper webApplicationContextWrapper = (WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR);

        WebApplicationContext webApplicationContext = webApplicationContextWrapper.getWebAppContext(context);

        return webApplicationContext.getBean(clazz);
    }

    protected ComponentsUtils getComponentsUtils() {
        ServletContext context = this.servletRequest.getSession().getServletContext();

        WebAppContextWrapper webApplicationContextWrapper = (WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR);
        WebApplicationContext webApplicationContext = webApplicationContextWrapper.getWebAppContext(context);
        return webApplicationContext.getBean(ComponentsUtils.class);
    }

    /**
     * Used to support Unit Test.<br>
     * Header Params are not supported in Unit Tests
     *
     * @return
     */
    protected String initHeaderParam(String headerValue, HttpServletRequest request, String headerName) {
        String retValue;
        if (headerValue != null) {
            retValue = headerValue;
        } else {
            retValue = request.getHeader(headerName);
        }
        return retValue;
    }

    protected String getContentDispositionValue(String artifactFileName) {
        return new StringBuilder().append("attachment; filename=\"").append(artifactFileName).append("\"").toString();
    }

    protected ComponentBusinessLogic getComponentBL(ComponentTypeEnum componentTypeEnum, ServletContext context) {
        ComponentBusinessLogic businessLogic;
        switch (componentTypeEnum) {
            case RESOURCE:
                businessLogic = getResourceBL(context);
                break;
            case SERVICE:
                businessLogic = getServiceBL(context);
                break;
            case PRODUCT:
                businessLogic = getProductBL(context);
                break;
            case RESOURCE_INSTANCE:
                businessLogic = getResourceBL(context);
                break;
            default:
                BeEcompErrorManager.getInstance().logBeSystemError("getComponentBL");
                throw new IllegalArgumentException("Illegal component type:" + componentTypeEnum.getValue());
        }
        return businessLogic;
    }

    protected <T> void convertJsonToObjectOfClass(String json, Wrapper<T> policyWrapper, Class<T> clazz, Wrapper<Response> errorWrapper) {
        T object = null;
        ObjectMapper mapper = new ObjectMapper()
                .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
                .configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
        try {
            log.trace("Starting to convert json to object. Json=\n{}", json);

            SimpleModule module = new SimpleModule("customDeserializationModule");
            module.addDeserializer(PropertyConstraint.class, new PropertyConstraintJacksonDeserializer());
            mapper.registerModule(module);

            object = mapper.readValue(json, clazz);
            if (object != null) {
                policyWrapper.setInnerElement(object);
            } else {
                BeEcompErrorManager.getInstance().logBeInvalidJsonInput("convertJsonToObject");
                log.debug("The object of class {} is null after converting from json. ", clazz);
                errorWrapper.setInnerElement(buildErrorResponse(getComponentsUtils().getResponseFormat(ActionStatus.INVALID_CONTENT)));
            }
        } catch (Exception e) {
            BeEcompErrorManager.getInstance().logBeInvalidJsonInput("convertJsonToObject");
            log.debug("The exception {} occured upon json to object convertation. Json=\n{}", e, json);
            errorWrapper.setInnerElement(buildErrorResponse(getComponentsUtils().getResponseFormat(ActionStatus.INVALID_CONTENT)));
        }
    }
}