/*-
 * ============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.annotation.JsonInclude.Include;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.google.common.annotations.VisibleForTesting;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;
import fj.data.Either;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Set;
import java.util.function.Supplier;
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 org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import org.openecomp.sdc.be.components.impl.ArtifactsBusinessLogic;
import org.openecomp.sdc.be.components.impl.BaseBusinessLogic;
import org.openecomp.sdc.be.components.impl.ComponentInstanceBusinessLogic;
import org.openecomp.sdc.be.components.impl.ElementBusinessLogic;
import org.openecomp.sdc.be.components.impl.GenericArtifactBrowserBusinessLogic;
import org.openecomp.sdc.be.components.impl.InputsBusinessLogic;
import org.openecomp.sdc.be.components.impl.OutputsBusinessLogic;
import org.openecomp.sdc.be.components.impl.PolicyBusinessLogic;
import org.openecomp.sdc.be.components.impl.ResourceBusinessLogic;
import org.openecomp.sdc.be.components.impl.ServiceBusinessLogic;
import org.openecomp.sdc.be.components.impl.exceptions.ByActionStatusComponentException;
import org.openecomp.sdc.be.components.impl.exceptions.ComponentException;
import org.openecomp.sdc.be.config.BeEcompErrorManager;
import org.openecomp.sdc.be.dao.api.ActionStatus;
import org.openecomp.sdc.be.datatypes.enums.ComponentTypeEnum;
import org.openecomp.sdc.be.datatypes.enums.DeclarationTypeEnum;
import org.openecomp.sdc.be.datatypes.tosca.ToscaDataDefinition;
import org.openecomp.sdc.be.impl.ComponentsUtils;
import org.openecomp.sdc.be.impl.WebAppContextWrapper;
import org.openecomp.sdc.be.model.ComponentInstInputsMap;
import org.openecomp.sdc.be.model.InputDefinition;
import org.openecomp.sdc.be.model.PropertyConstraint;
import org.openecomp.sdc.be.model.PropertyDefinition;
import org.openecomp.sdc.be.model.User;
import org.openecomp.sdc.be.model.operations.impl.PropertyOperation;
import org.openecomp.sdc.be.model.operations.impl.PropertyOperation.PropertyConstraintJacksonDeserializer;
import org.openecomp.sdc.be.model.operations.impl.UniqueIdBuilder;
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.log.wrappers.Logger;
import org.openecomp.sdc.common.servlets.BasicServlet;
import org.openecomp.sdc.exception.ResponseFormat;
import org.springframework.web.context.WebApplicationContext;

public class BeGenericServlet extends BasicServlet {

    private static final Logger log = Logger.getLogger(BeGenericServlet.class);
    private static final String PROPERTY_NAME_REGEX = "[a-zA-Z0-9._:-@]+";
    @Context
    protected HttpServletRequest servletRequest;
    protected ComponentsUtils componentsUtils;

    public BeGenericServlet(ComponentsUtils componentsUtils) {
        this.componentsUtils = componentsUtils;
    }

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

    /******************** 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);
    }

    public HttpServletRequest getServletRequest() {
        return servletRequest;
    }

    @VisibleForTesting
    public void setRequestServlet(HttpServletRequest request) {
        this.servletRequest = request;
    }

    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) {
        User user;
        try {
            user = getUserAdminManager(request.getSession().getServletContext()).getUser(userId, false);
            return Either.left(user);
        } catch (ComponentException ce) {
            log.info("createResource method - user is not listed. userId= {}", userId);
            ResponseFormat errorResponse = getComponentsUtils().getResponseFormat(ce);
            user = new User("", "", userId, "", null, null);
            getComponentsUtils().auditResource(errorResponse, user, "", AuditingActionEnum.CHECKOUT_RESOURCE);
            return Either.right(errorResponse);
        }
    }

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

    protected GenericArtifactBrowserBusinessLogic getGenericArtifactBrowserBL(ServletContext context) {
        return getClassFromWebAppContext(context, () -> GenericArtifactBrowserBusinessLogic.class);
    }

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

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

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

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

    <T> T getClassFromWebAppContext(final ServletContext context, final Supplier<Class<T>> businessLogicClassGen) {
        return getWebAppContext(context).getBean(businessLogicClassGen.get());
    }

    protected ComponentInstanceBusinessLogic getComponentInstanceBL(final ServletContext context) {
        return getClassFromWebAppContext(context, () -> ComponentInstanceBusinessLogic.class);
    }

    protected ComponentsUtils getComponentsUtils() {
        final ServletContext context = this.servletRequest.getSession().getServletContext();
        return getClassFromWebAppContext(context, () -> ComponentsUtils.class);
    }

    /**
     * Used to support Unit Test.<br> Header Params are not supported in Unit Tests
     *
     * @return
     */
    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();
    }

    <T> T convertJsonToObjectOfClass(String json, Class<T> clazz) {
        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);
            mapper.setSerializationInclusion(Include.NON_NULL);
            object = mapper.readValue(json, clazz);
            if (object != null) {
                return object;
            } else {
                BeEcompErrorManager.getInstance().logBeInvalidJsonInput("convertJsonToObject");
                log.debug("The object of class {} is null after converting from json. ", clazz);
                throw new ByActionStatusComponentException(ActionStatus.INVALID_CONTENT);
            }
        } catch (IOException e) {
            BeEcompErrorManager.getInstance().logBeInvalidJsonInput("convertJsonToObject");
            log.debug("The exception {} occurred upon json to object convertation. Json=\n{}", e, json);
            throw new ByActionStatusComponentException(ActionStatus.INVALID_CONTENT);
        }
    }

    protected Either<Map<String, PropertyDefinition>, ActionStatus> getPropertyModel(String componentId, String data) {
        JSONParser parser = new JSONParser();
        JSONObject root;
        try {
            Map<String, PropertyDefinition> properties = new HashMap<>();
            root = (JSONObject) parser.parse(data);
            Set entrySet = root.entrySet();
            Iterator iterator = entrySet.iterator();
            while (iterator.hasNext()) {
                Entry next = (Entry) iterator.next();
                String propertyName = (String) next.getKey();
                if (!isPropertyNameValid(propertyName)) {
                    return Either.right(ActionStatus.INVALID_PROPERTY_NAME);
                }
                JSONObject value = (JSONObject) next.getValue();
                Either<PropertyDefinition, ActionStatus> propertyDefinitionEither = getPropertyDefinitionFromJson(componentId, propertyName, value);
                if (propertyDefinitionEither.isRight()) {
                    return Either.right(propertyDefinitionEither.right().value());
                }
                properties.put(propertyName, propertyDefinitionEither.left().value());
            }
            return Either.left(properties);
        } catch (ParseException e) {
            log.info("Property conetnt is invalid - {}", data);
            return Either.right(ActionStatus.INVALID_CONTENT);
        }
    }

    protected boolean isPropertyNameValid(String propertyName) {
        return Objects.nonNull(propertyName) && propertyName.matches(PROPERTY_NAME_REGEX);
    }

    private Either<PropertyDefinition, ActionStatus> getPropertyDefinitionFromJson(String componentId, String propertyName, JSONObject value) {
        String jsonString = value.toJSONString();
        Either<PropertyDefinition, ActionStatus> convertJsonToObject = convertJsonToObject(jsonString, PropertyDefinition.class);
        if (convertJsonToObject.isRight()) {
            return Either.right(convertJsonToObject.right().value());
        }
        PropertyDefinition propertyDefinition = convertJsonToObject.left().value();
        String uniqueId = UniqueIdBuilder.buildPropertyUniqueId(componentId, propertyName);
        propertyDefinition.setUniqueId(uniqueId);
        return Either.left(propertyDefinition);
    }

    private Either<InputDefinition, ActionStatus> getInputDefinitionFromJson(String componentId, String inputName, JSONObject value) {
        String jsonString = value.toJSONString();
        Either<InputDefinition, ActionStatus> convertJsonToObject = convertJsonToObject(jsonString, InputDefinition.class);
        if (convertJsonToObject.isRight()) {
            return Either.right(convertJsonToObject.right().value());
        }
        InputDefinition inputDefinition = convertJsonToObject.left().value();
        String uniqueId = UniqueIdBuilder.buildPropertyUniqueId(componentId, inputName);
        inputDefinition.setUniqueId(uniqueId);
        return Either.left(inputDefinition);
    }

    protected Either<Map<String, PropertyDefinition>, ActionStatus> getPropertiesListForUpdate(String data) {
        Map<String, PropertyDefinition> properties = new HashMap<>();
        JSONParser parser = new JSONParser();
        JSONArray jsonArray;
        try {
            jsonArray = (JSONArray) parser.parse(data);
            for (Object jsonElement : jsonArray) {
                String propertyAsString = jsonElement.toString();
                Either<PropertyDefinition, ActionStatus> convertJsonToObject = convertJsonToObject(propertyAsString, PropertyDefinition.class);
                if (convertJsonToObject.isRight()) {
                    return Either.right(convertJsonToObject.right().value());
                }
                PropertyDefinition propertyDefinition = convertJsonToObject.left().value();
                properties.put(propertyDefinition.getName(), propertyDefinition);
            }
            return Either.left(properties);
        } catch (Exception e) {
            log.info("Property content is invalid - {}", data);
            return Either.right(ActionStatus.INVALID_CONTENT);
        }
    }

    protected String propertyToJson(Map.Entry<String, PropertyDefinition> property) {
        JSONObject root = new JSONObject();
        PropertyDefinition propertyDefinition = property.getValue();
        root.put(property.getKey(), getPropertyDefinitionJSONObject(propertyDefinition));
        propertyDefinition.getType();
        return root.toString();
    }

    private JSONObject getPropertyDefinitionJSONObject(PropertyDefinition propertyDefinition) {
        Either<String, ActionStatus> either = convertObjectToJson(propertyDefinition);
        if (either.isRight()) {
            return new JSONObject();
        }
        try {
            return (JSONObject) new JSONParser().parse(either.left().value());
        } catch (ParseException e) {
            log.info("failed to convert input to json");
            log.error("failed to convert to json", e);
            return new JSONObject();
        }
    }

    protected <T> Either<T, ActionStatus> convertJsonToObject(String data, Class<T> clazz) {
        T t = null;
        Type constraintType = new TypeToken<PropertyConstraint>() {
        }.getType();
        Gson gson = new GsonBuilder().registerTypeAdapter(constraintType, new PropertyOperation.PropertyConstraintDeserialiser()).create();
        try {
            log.trace("convert json to object. json=\n {}", data);
            t = gson.fromJson(data, clazz);
            if (t == null) {
                log.info("object is null after converting from json");
                return Either.right(ActionStatus.INVALID_CONTENT);
            }
        } catch (Exception e) {
            // INVALID JSON
            log.info("failed to convert from json");
            log.error("failed to convert from json", e);
            return Either.right(ActionStatus.INVALID_CONTENT);
        }
        return Either.left(t);
    }

    private Either<String, ActionStatus> convertObjectToJson(PropertyDefinition propertyDefinition) {
        Type constraintType = new TypeToken<PropertyConstraint>() {
        }.getType();
        Gson gson = new GsonBuilder().registerTypeAdapter(constraintType, new PropertyOperation.PropertyConstraintSerialiser()).create();
        try {
            log.trace("convert object to json. propertyDefinition= {}", propertyDefinition);
            String json = gson.toJson(propertyDefinition);
            if (json == null) {
                log.info("object is null after converting to json");
                return Either.right(ActionStatus.INVALID_CONTENT);
            }
            return Either.left(json);
        } catch (Exception e) {
            // INVALID JSON
            log.info("failed to convert to json");
            log.debug("failed to convert fto json", e);
            return Either.right(ActionStatus.INVALID_CONTENT);
        }
    }

    private OutputsBusinessLogic getOutputBL(final ServletContext context) {
        return getClassFromWebAppContext(context, () -> OutputsBusinessLogic.class);
    }

    private InputsBusinessLogic getInputBL(final ServletContext context) {
        return getClassFromWebAppContext(context, () -> InputsBusinessLogic.class);
    }

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

    private WebApplicationContext getWebAppContext(final ServletContext context) {
        return ((WebAppContextWrapper) context.getAttribute(Constants.WEB_APPLICATION_CONTEXT_WRAPPER_ATTR)).getWebAppContext(context);
    }

    protected <T> Either<T, ResponseFormat> parseToComponentInstanceMap(final String componentJson, final User user,
                                                                        final ComponentTypeEnum componentType, final Class<T> clazz) {
        return getComponentsUtils()
            .convertJsonToObjectUsingObjectMapper(componentJson, user, clazz, AuditingActionEnum.CREATE_RESOURCE, componentType);
    }

    protected Response declareProperties(String userId, String componentId, String componentType, String componentInstInputsMapObj,
                                         DeclarationTypeEnum typeEnum, HttpServletRequest request) {
        ServletContext context = request.getSession().getServletContext();
        String url = request.getMethod() + " " + request.getRequestURI();
        log.debug("(get) Start handle request of {}", url);
        try {
            BaseBusinessLogic businessLogic = getBlForDeclaration(typeEnum, context);
            // get modifier id
            User modifier = new User();
            modifier.setUserId(userId);
            log.debug("modifier id is {}", userId);
            ComponentTypeEnum componentTypeEnum = ComponentTypeEnum.findByParamName(componentType);
            Either<ComponentInstInputsMap, ResponseFormat> componentInstInputsMapRes = parseToComponentInstanceMap(componentInstInputsMapObj,
                modifier, componentTypeEnum, ComponentInstInputsMap.class);
            if (componentInstInputsMapRes.isRight()) {
                log.debug("failed to parse componentInstInputsMap");
                return buildErrorResponse(componentInstInputsMapRes.right().value());
            }
            Either<List<ToscaDataDefinition>, ResponseFormat> propertiesAfterDeclaration = businessLogic
                .declareProperties(userId, componentId, componentTypeEnum, componentInstInputsMapRes.left().value());
            if (propertiesAfterDeclaration.isRight()) {
                log.debug("failed to create inputs  for service: {}", componentId);
                return buildErrorResponse(propertiesAfterDeclaration.right().value());
            }
            Object properties = RepresentationUtils.toRepresentation(propertiesAfterDeclaration.left().value());
            return buildOkResponse(getComponentsUtils().getResponseFormat(ActionStatus.OK), properties);
        } catch (Exception e) {
            BeEcompErrorManager.getInstance().logBeRestApiGeneralError("Create inputs for service with id: " + componentId);
            log.debug("Properties declaration failed with exception", e);
            return buildErrorResponse(getComponentsUtils().getResponseFormat(ActionStatus.GENERAL_ERROR));
        }
    }

    public BaseBusinessLogic getBlForDeclaration(final DeclarationTypeEnum typeEnum, final ServletContext context) {
        switch (typeEnum) {
            case OUTPUT:
                return getOutputBL(context);
            case POLICY:
                return getPolicyBL(context);
            case INPUT:
                return getInputBL(context);
            default:
                throw new IllegalArgumentException("Invalid DeclarationTypeEnum");
        }
    }

    protected Either<Map<String, InputDefinition>, ActionStatus> getInputModel(String componentId, String data) {
        JSONParser parser = new JSONParser();
        JSONObject root;
        try {
            Map<String, InputDefinition> inputs = new HashMap<>();
            root = (JSONObject) parser.parse(data);
            Set entrySet = root.entrySet();
            Iterator iterator = entrySet.iterator();
            while (iterator.hasNext()) {
                Entry next = (Entry) iterator.next();
                String inputName = (String) next.getKey();
                if (!isInputNameValid(inputName)) {
                    return Either.right(ActionStatus.INVALID_INPUT_NAME);
                }
                JSONObject value = (JSONObject) next.getValue();
                Either<InputDefinition, ActionStatus> inputDefinitionEither = getInputDefinitionFromJson(componentId, inputName, value);
                if (inputDefinitionEither.isRight()) {
                    return Either.right(inputDefinitionEither.right().value());
                }
                inputs.put(inputName, inputDefinitionEither.left().value());
            }
            return Either.left(inputs);
        } catch (ParseException e) {
            log.warn("Input content is invalid - {}", data, e);
            return Either.right(ActionStatus.INVALID_CONTENT);
        }
    }

    protected boolean isInputNameValid(String inputName) {
        return Objects.nonNull(inputName) && inputName.matches(PROPERTY_NAME_REGEX);
    }
}