X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Fcharging-station%2Focpp%2FOCPPRequestService.ts;h=98c3081155bd2f350fe3a686c7909cd524166b52;hb=5398cecf45b4bdab604d0e6aff8a96dcc67d5ae9;hp=abef08086ade8629890df3403567cda2e9e5b4cc;hpb=ef6fa3fb6f4872fc57bae634ac3edb8164a0bc79;p=e-mobility-charging-stations-simulator.git

diff --git a/src/charging-station/ocpp/OCPPRequestService.ts b/src/charging-station/ocpp/OCPPRequestService.ts
index abef0808..98c30811 100644
--- a/src/charging-station/ocpp/OCPPRequestService.ts
+++ b/src/charging-station/ocpp/OCPPRequestService.ts
@@ -1,272 +1,476 @@
+import Ajv, { type JSONSchemaType, type ValidateFunction } from 'ajv';
+import ajvFormats from 'ajv-formats';
+
+import { OCPPConstants } from './OCPPConstants';
+import type { OCPPResponseService } from './OCPPResponseService';
+import { OCPPServiceUtils } from './OCPPServiceUtils';
+import type { ChargingStation } from '../../charging-station';
+import { OCPPError } from '../../exception';
+import { PerformanceStatistics } from '../../performance';
 import {
-  IncomingRequestCommand,
+  type ErrorCallback,
+  type ErrorResponse,
+  ErrorType,
+  type IncomingRequestCommand,
+  type JsonObject,
+  type JsonType,
+  MessageType,
+  type OCPPVersion,
+  type OutgoingRequest,
   RequestCommand,
-  ResponseType,
-  SendParams,
-} from '../../types/ocpp/Requests';
+  type RequestParams,
+  type Response,
+  type ResponseCallback,
+  type ResponseType,
+} from '../../types';
+import {
+  Constants,
+  cloneObject,
+  handleSendMessageError,
+  logger,
+  promiseWithTimeout,
+} from '../../utils';
 
-import type ChargingStation from '../ChargingStation';
-import Constants from '../../utils/Constants';
-import { EmptyObject } from '../../types/EmptyObject';
-import { ErrorType } from '../../types/ocpp/ErrorType';
-import { HandleErrorParams } from '../../types/Error';
-import { JsonType } from '../../types/JsonType';
-import { MessageType } from '../../types/ocpp/MessageType';
-import OCPPError from '../../exception/OCPPError';
-import type OCPPResponseService from './OCPPResponseService';
-import PerformanceStatistics from '../../performance/PerformanceStatistics';
-import Utils from '../../utils/Utils';
-import logger from '../../utils/Logger';
+const moduleName = 'OCPPRequestService';
 
-export default abstract class OCPPRequestService {
-  private static readonly instances: Map<string, OCPPRequestService> = new Map<
-    string,
-    OCPPRequestService
-  >();
+const defaultRequestParams: RequestParams = {
+  skipBufferingOnError: false,
+  triggerMessage: false,
+  throwError: false,
+};
 
-  protected readonly chargingStation: ChargingStation;
+export abstract class OCPPRequestService {
+  private static instance: OCPPRequestService | null = null;
+  private readonly version: OCPPVersion;
+  private readonly ajv: Ajv;
   private readonly ocppResponseService: OCPPResponseService;
+  private readonly jsonValidateFunctions: Map<RequestCommand, ValidateFunction<JsonType>>;
+  protected abstract jsonSchemas: Map<RequestCommand, JSONSchemaType<JsonType>>;
 
-  protected constructor(
-    chargingStation: ChargingStation,
-    ocppResponseService: OCPPResponseService
-  ) {
-    this.chargingStation = chargingStation;
+  protected constructor(version: OCPPVersion, ocppResponseService: OCPPResponseService) {
+    this.version = version;
+    this.ajv = new Ajv({
+      keywords: ['javaType'],
+      multipleOfPrecision: 2,
+    });
+    ajvFormats(this.ajv);
+    this.jsonValidateFunctions = new Map<RequestCommand, ValidateFunction<JsonType>>();
     this.ocppResponseService = ocppResponseService;
-    this.sendMessageHandler.bind(this);
-    this.sendResult.bind(this);
-    this.sendError.bind(this);
+    this.requestHandler = this.requestHandler.bind(this) as <
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      ReqType extends JsonType,
+      ResType extends JsonType,
+    >(
+      chargingStation: ChargingStation,
+      commandName: RequestCommand,
+      commandParams?: JsonType,
+      params?: RequestParams,
+    ) => Promise<ResType>;
+    this.sendMessage = this.sendMessage.bind(this) as (
+      chargingStation: ChargingStation,
+      messageId: string,
+      messagePayload: JsonType,
+      commandName: RequestCommand,
+      params?: RequestParams,
+    ) => Promise<ResponseType>;
+    this.sendResponse = this.sendResponse.bind(this) as (
+      chargingStation: ChargingStation,
+      messageId: string,
+      messagePayload: JsonType,
+      commandName: IncomingRequestCommand,
+    ) => Promise<ResponseType>;
+    this.sendError = this.sendError.bind(this) as (
+      chargingStation: ChargingStation,
+      messageId: string,
+      ocppError: OCPPError,
+      commandName: RequestCommand | IncomingRequestCommand,
+    ) => Promise<ResponseType>;
+    this.internalSendMessage = this.internalSendMessage.bind(this) as (
+      chargingStation: ChargingStation,
+      messageId: string,
+      messagePayload: JsonType | OCPPError,
+      messageType: MessageType,
+      commandName: RequestCommand | IncomingRequestCommand,
+      params?: RequestParams,
+    ) => Promise<ResponseType>;
+    this.buildMessageToSend = this.buildMessageToSend.bind(this) as (
+      chargingStation: ChargingStation,
+      messageId: string,
+      messagePayload: JsonType | OCPPError,
+      messageType: MessageType,
+      commandName: RequestCommand | IncomingRequestCommand,
+      responseCallback: ResponseCallback,
+      errorCallback: ErrorCallback,
+    ) => string;
+    this.validateRequestPayload = this.validateRequestPayload.bind(this) as <T extends JsonType>(
+      chargingStation: ChargingStation,
+      commandName: RequestCommand | IncomingRequestCommand,
+      payload: T,
+    ) => boolean;
+    this.validateIncomingRequestResponsePayload = this.validateIncomingRequestResponsePayload.bind(
+      this,
+    ) as <T extends JsonType>(
+      chargingStation: ChargingStation,
+      commandName: RequestCommand | IncomingRequestCommand,
+      payload: T,
+    ) => boolean;
   }
 
   public static getInstance<T extends OCPPRequestService>(
-    this: new (chargingStation: ChargingStation, ocppResponseService: OCPPResponseService) => T,
-    chargingStation: ChargingStation,
-    ocppResponseService: OCPPResponseService
+    this: new (ocppResponseService: OCPPResponseService) => T,
+    ocppResponseService: OCPPResponseService,
   ): T {
-    if (!OCPPRequestService.instances.has(chargingStation.hashId)) {
-      OCPPRequestService.instances.set(
-        chargingStation.hashId,
-        new this(chargingStation, ocppResponseService)
-      );
+    if (OCPPRequestService.instance === null) {
+      OCPPRequestService.instance = new this(ocppResponseService);
     }
-    return OCPPRequestService.instances.get(chargingStation.hashId) as T;
+    return OCPPRequestService.instance as T;
   }
 
-  public async sendResult(
+  public async sendResponse(
+    chargingStation: ChargingStation,
     messageId: string,
     messagePayload: JsonType,
-    commandName: IncomingRequestCommand
+    commandName: IncomingRequestCommand,
   ): Promise<ResponseType> {
     try {
-      // Send result message
+      // Send response message
       return await this.internalSendMessage(
+        chargingStation,
         messageId,
         messagePayload,
         MessageType.CALL_RESULT_MESSAGE,
-        commandName
+        commandName,
       );
     } catch (error) {
-      this.handleRequestError(commandName, error as Error);
+      handleSendMessageError(chargingStation, commandName, error as Error, {
+        throwError: true,
+      });
+      return null;
     }
   }
 
   public async sendError(
+    chargingStation: ChargingStation,
     messageId: string,
     ocppError: OCPPError,
-    commandName: IncomingRequestCommand
+    commandName: RequestCommand | IncomingRequestCommand,
   ): Promise<ResponseType> {
     try {
       // Send error message
       return await this.internalSendMessage(
+        chargingStation,
         messageId,
         ocppError,
         MessageType.CALL_ERROR_MESSAGE,
-        commandName
+        commandName,
       );
     } catch (error) {
-      this.handleRequestError(commandName, error as Error);
+      handleSendMessageError(chargingStation, commandName, error as Error);
+      return null;
     }
   }
 
   protected async sendMessage(
+    chargingStation: ChargingStation,
     messageId: string,
     messagePayload: JsonType,
     commandName: RequestCommand,
-    params: SendParams = {
-      skipBufferingOnError: false,
-      triggerMessage: false,
-    }
+    params?: RequestParams,
   ): Promise<ResponseType> {
+    params = {
+      ...defaultRequestParams,
+      ...params,
+    };
     try {
       return await this.internalSendMessage(
+        chargingStation,
         messageId,
         messagePayload,
         MessageType.CALL_MESSAGE,
         commandName,
-        params
+        params,
       );
     } catch (error) {
-      this.handleRequestError(commandName, error as Error, { throwError: false });
+      handleSendMessageError(chargingStation, commandName, error as Error, {
+        throwError: params.throwError,
+      });
+      return null;
+    }
+  }
+
+  private validateRequestPayload<T extends JsonType>(
+    chargingStation: ChargingStation,
+    commandName: RequestCommand | IncomingRequestCommand,
+    payload: T,
+  ): boolean {
+    if (chargingStation.stationInfo?.ocppStrictCompliance === false) {
+      return true;
+    }
+    if (this.jsonSchemas.has(commandName as RequestCommand) === false) {
+      logger.warn(
+        `${chargingStation.logPrefix()} ${moduleName}.validateRequestPayload: No JSON schema found for command '${commandName}' PDU validation`,
+      );
+      return true;
+    }
+    if (this.jsonValidateFunctions.has(commandName as RequestCommand) === false) {
+      this.jsonValidateFunctions.set(
+        commandName as RequestCommand,
+        this.ajv.compile<T>(this.jsonSchemas.get(commandName as RequestCommand)!).bind(this),
+      );
+    }
+    const validate = this.jsonValidateFunctions.get(commandName as RequestCommand)!;
+    payload = cloneObject<T>(payload);
+    OCPPServiceUtils.convertDateToISOString<T>(payload);
+    if (validate(payload)) {
+      return true;
+    }
+    logger.error(
+      `${chargingStation.logPrefix()} ${moduleName}.validateRequestPayload: Command '${commandName}' request PDU is invalid: %j`,
+      validate.errors,
+    );
+    // OCPPError usage here is debatable: it's an error in the OCPP stack but not targeted to sendError().
+    throw new OCPPError(
+      OCPPServiceUtils.ajvErrorsToErrorType(validate.errors),
+      'Request PDU is invalid',
+      commandName,
+      JSON.stringify(validate.errors, undefined, 2),
+    );
+  }
+
+  private validateIncomingRequestResponsePayload<T extends JsonType>(
+    chargingStation: ChargingStation,
+    commandName: RequestCommand | IncomingRequestCommand,
+    payload: T,
+  ): boolean {
+    if (chargingStation.stationInfo?.ocppStrictCompliance === false) {
+      return true;
+    }
+    if (
+      this.ocppResponseService.jsonIncomingRequestResponseSchemas.has(
+        commandName as IncomingRequestCommand,
+      ) === false
+    ) {
+      logger.warn(
+        `${chargingStation.logPrefix()} ${moduleName}.validateIncomingRequestResponsePayload: No JSON schema found for command '${commandName}' PDU validation`,
+      );
+      return true;
     }
+    if (
+      this.ocppResponseService.jsonIncomingRequestResponseValidateFunctions.has(
+        commandName as IncomingRequestCommand,
+      ) === false
+    ) {
+      this.ocppResponseService.jsonIncomingRequestResponseValidateFunctions.set(
+        commandName as IncomingRequestCommand,
+        this.ajv
+          .compile<T>(
+            this.ocppResponseService.jsonIncomingRequestResponseSchemas.get(
+              commandName as IncomingRequestCommand,
+            )!,
+          )
+          .bind(this),
+      );
+    }
+    const validate = this.ocppResponseService.jsonIncomingRequestResponseValidateFunctions.get(
+      commandName as IncomingRequestCommand,
+    )!;
+    payload = cloneObject<T>(payload);
+    OCPPServiceUtils.convertDateToISOString<T>(payload);
+    if (validate(payload)) {
+      return true;
+    }
+    logger.error(
+      `${chargingStation.logPrefix()} ${moduleName}.validateIncomingRequestResponsePayload: Command '${commandName}' reponse PDU is invalid: %j`,
+      validate.errors,
+    );
+    // OCPPError usage here is debatable: it's an error in the OCPP stack but not targeted to sendError().
+    throw new OCPPError(
+      OCPPServiceUtils.ajvErrorsToErrorType(validate.errors),
+      'Response PDU is invalid',
+      commandName,
+      JSON.stringify(validate.errors, undefined, 2),
+    );
   }
 
   private async internalSendMessage(
+    chargingStation: ChargingStation,
     messageId: string,
     messagePayload: JsonType | OCPPError,
     messageType: MessageType,
-    commandName?: RequestCommand | IncomingRequestCommand,
-    params: SendParams = {
-      skipBufferingOnError: false,
-      triggerMessage: false,
-    }
+    commandName: RequestCommand | IncomingRequestCommand,
+    params?: RequestParams,
   ): Promise<ResponseType> {
+    params = {
+      ...defaultRequestParams,
+      ...params,
+    };
     if (
-      (this.chargingStation.isInUnknownState() &&
+      (chargingStation.inUnknownState() === true &&
         commandName === RequestCommand.BOOT_NOTIFICATION) ||
-      (!this.chargingStation.getOcppStrictCompliance() &&
-        this.chargingStation.isInUnknownState()) ||
-      this.chargingStation.isInAcceptedState() ||
-      (this.chargingStation.isInPendingState() && params.triggerMessage)
+      (chargingStation.stationInfo?.ocppStrictCompliance === false &&
+        chargingStation.inUnknownState() === true) ||
+      chargingStation.inAcceptedState() === true ||
+      (chargingStation.inPendingState() === true &&
+        (params.triggerMessage === true || messageType === MessageType.CALL_RESULT_MESSAGE))
     ) {
       // eslint-disable-next-line @typescript-eslint/no-this-alias
       const self = this;
       // Send a message through wsConnection
-      return Utils.promiseWithTimeout(
-        new Promise((resolve, reject) => {
-          const messageToSend = this.buildMessageToSend(
-            messageId,
-            messagePayload,
-            messageType,
-            commandName,
-            responseCallback,
-            rejectCallback
-          );
-          if (this.chargingStation.getEnableStatistics()) {
-            this.chargingStation.performanceStatistics.addRequestStatistic(
-              commandName,
-              messageType
-            );
-          }
-          // Check if wsConnection opened
-          if (this.chargingStation.isWebSocketConnectionOpened()) {
-            // Yes: Send Message
-            const beginId = PerformanceStatistics.beginMeasure(commandName);
-            // FIXME: Handle sending error
-            this.chargingStation.wsConnection.send(messageToSend);
-            PerformanceStatistics.endMeasure(commandName, beginId);
-          } else if (!params.skipBufferingOnError) {
-            // Buffer it
-            this.chargingStation.bufferMessage(messageToSend);
-            const ocppError = new OCPPError(
-              ErrorType.GENERIC_ERROR,
-              `WebSocket closed for buffered message id '${messageId}' with content '${messageToSend}'`,
-              commandName,
-              (messagePayload?.details as JsonType) ?? {}
-            );
-            if (messageType === MessageType.CALL_MESSAGE) {
-              // Reject it but keep the request in the cache
-              return reject(ocppError);
-            }
-            return rejectCallback(ocppError, false);
-          } else {
-            // Reject it
-            return rejectCallback(
-              new OCPPError(
-                ErrorType.GENERIC_ERROR,
-                `WebSocket closed for non buffered message id '${messageId}' with content '${messageToSend}'`,
-                commandName,
-                (messagePayload?.details as JsonType) ?? {}
-              ),
-              false
-            );
-          }
-          // Response?
-          if (messageType !== MessageType.CALL_MESSAGE) {
-            // Yes: send Ok
-            return resolve(messagePayload);
-          }
-
+      return promiseWithTimeout(
+        new Promise<ResponseType>((resolve, reject) => {
           /**
            * Function that will receive the request's response
            *
-           * @param payload
-           * @param requestPayload
+           * @param payload -
+           * @param requestPayload -
            */
-          async function responseCallback(
-            payload: JsonType | string,
-            requestPayload: JsonType
-          ): Promise<void> {
-            if (self.chargingStation.getEnableStatistics()) {
-              self.chargingStation.performanceStatistics.addRequestStatistic(
+          const responseCallback = (payload: JsonType, requestPayload: JsonType): void => {
+            if (chargingStation.stationInfo?.enableStatistics === true) {
+              chargingStation.performanceStatistics?.addRequestStatistic(
                 commandName,
-                MessageType.CALL_RESULT_MESSAGE
+                MessageType.CALL_RESULT_MESSAGE,
               );
             }
             // Handle the request's response
-            try {
-              await self.ocppResponseService.handleResponse(
+            self.ocppResponseService
+              .responseHandler(
+                chargingStation,
                 commandName as RequestCommand,
                 payload,
-                requestPayload
-              );
-              resolve(payload);
-            } catch (error) {
-              reject(error);
-            } finally {
-              self.chargingStation.requests.delete(messageId);
-            }
-          }
+                requestPayload,
+              )
+              .then(() => {
+                resolve(payload);
+              })
+              .catch((error) => {
+                reject(error);
+              })
+              .finally(() => {
+                chargingStation.requests.delete(messageId);
+              });
+          };
 
           /**
            * Function that will receive the request's error response
            *
-           * @param error
-           * @param requestStatistic
+           * @param error -
+           * @param requestStatistic -
            */
-          function rejectCallback(error: OCPPError, requestStatistic = true): void {
-            if (requestStatistic && self.chargingStation.getEnableStatistics()) {
-              self.chargingStation.performanceStatistics.addRequestStatistic(
+          const errorCallback = (error: OCPPError, requestStatistic = true): void => {
+            if (
+              requestStatistic === true &&
+              chargingStation.stationInfo?.enableStatistics === true
+            ) {
+              chargingStation.performanceStatistics?.addRequestStatistic(
                 commandName,
-                MessageType.CALL_ERROR_MESSAGE
+                MessageType.CALL_ERROR_MESSAGE,
               );
             }
             logger.error(
-              `${self.chargingStation.logPrefix()} Error %j occurred when calling command %s with message data %j`,
+              `${chargingStation.logPrefix()} Error occurred at ${OCPPServiceUtils.getMessageTypeString(
+                messageType,
+              )} command ${commandName} with PDU %j:`,
+              messagePayload,
               error,
-              commandName,
-              messagePayload
             );
-            self.chargingStation.requests.delete(messageId);
+            chargingStation.requests.delete(messageId);
             reject(error);
+          };
+
+          if (chargingStation.stationInfo?.enableStatistics === true) {
+            chargingStation.performanceStatistics?.addRequestStatistic(commandName, messageType);
+          }
+          const messageToSend = this.buildMessageToSend(
+            chargingStation,
+            messageId,
+            messagePayload,
+            messageType,
+            commandName,
+            responseCallback,
+            errorCallback,
+          );
+          let sendError = false;
+          // Check if wsConnection opened
+          const wsOpened = chargingStation.isWebSocketConnectionOpened() === true;
+          if (wsOpened) {
+            const beginId = PerformanceStatistics.beginMeasure(commandName);
+            try {
+              chargingStation.wsConnection?.send(messageToSend);
+              logger.debug(
+                `${chargingStation.logPrefix()} >> Command '${commandName}' sent ${OCPPServiceUtils.getMessageTypeString(
+                  messageType,
+                )} payload: ${messageToSend}`,
+              );
+            } catch (error) {
+              logger.error(
+                `${chargingStation.logPrefix()} >> Command '${commandName}' failed to send ${OCPPServiceUtils.getMessageTypeString(
+                  messageType,
+                )} payload: ${messageToSend}:`,
+                error,
+              );
+              sendError = true;
+            }
+            PerformanceStatistics.endMeasure(commandName, beginId);
+          }
+          const wsClosedOrErrored = !wsOpened || sendError === true;
+          if (wsClosedOrErrored && params?.skipBufferingOnError === false) {
+            // Buffer
+            chargingStation.bufferMessage(messageToSend);
+            // Reject and keep request in the cache
+            return reject(
+              new OCPPError(
+                ErrorType.GENERIC_ERROR,
+                `WebSocket closed or errored for buffered message id '${messageId}' with content '${messageToSend}'`,
+                commandName,
+                (messagePayload as JsonObject)?.details ?? Constants.EMPTY_FROZEN_OBJECT,
+              ),
+            );
+          } else if (wsClosedOrErrored) {
+            const ocppError = new OCPPError(
+              ErrorType.GENERIC_ERROR,
+              `WebSocket closed or errored for non buffered message id '${messageId}' with content '${messageToSend}'`,
+              commandName,
+              (messagePayload as JsonObject)?.details ?? Constants.EMPTY_FROZEN_OBJECT,
+            );
+            // Reject response
+            if (messageType !== MessageType.CALL_MESSAGE) {
+              return reject(ocppError);
+            }
+            // Reject and remove request from the cache
+            return errorCallback(ocppError, false);
+          }
+          // Resolve response
+          if (messageType !== MessageType.CALL_MESSAGE) {
+            return resolve(messagePayload);
           }
         }),
-        Constants.OCPP_WEBSOCKET_TIMEOUT,
+        OCPPConstants.OCPP_WEBSOCKET_TIMEOUT,
         new OCPPError(
           ErrorType.GENERIC_ERROR,
           `Timeout for message id '${messageId}'`,
           commandName,
-          (messagePayload?.details as JsonType) ?? {}
+          (messagePayload as JsonObject)?.details ?? Constants.EMPTY_FROZEN_OBJECT,
         ),
         () => {
-          messageType === MessageType.CALL_MESSAGE &&
-            this.chargingStation.requests.delete(messageId);
-        }
+          messageType === MessageType.CALL_MESSAGE && chargingStation.requests.delete(messageId);
+        },
       );
     }
     throw new OCPPError(
       ErrorType.SECURITY_ERROR,
-      `Cannot send command ${commandName} payload when the charging station is in ${this.chargingStation.getRegistrationStatus()} state on the central server`,
-      commandName
+      `Cannot send command ${commandName} PDU when the charging station is in ${chargingStation.getRegistrationStatus()} state on the central server`,
+      commandName,
     );
   }
 
   private buildMessageToSend(
+    chargingStation: ChargingStation,
     messageId: string,
     messagePayload: JsonType | OCPPError,
     messageType: MessageType,
-    commandName?: RequestCommand | IncomingRequestCommand,
-    responseCallback?: (payload: JsonType | string, requestPayload: JsonType) => Promise<void>,
-    rejectCallback?: (error: OCPPError, requestStatistic?: boolean) => void
+    commandName: RequestCommand | IncomingRequestCommand,
+    responseCallback: ResponseCallback,
+    errorCallback: ErrorCallback,
   ): string {
     let messageToSend: string;
     // Type of message
@@ -274,18 +478,29 @@ export default abstract class OCPPRequestService {
       // Request
       case MessageType.CALL_MESSAGE:
         // Build request
-        this.chargingStation.requests.set(messageId, [
+        this.validateRequestPayload(chargingStation, commandName, messagePayload as JsonType);
+        chargingStation.requests.set(messageId, [
           responseCallback,
-          rejectCallback,
+          errorCallback,
           commandName,
-          messagePayload,
+          messagePayload as JsonType,
         ]);
-        messageToSend = JSON.stringify([messageType, messageId, commandName, messagePayload]);
+        messageToSend = JSON.stringify([
+          messageType,
+          messageId,
+          commandName,
+          messagePayload,
+        ] as OutgoingRequest);
         break;
       // Response
       case MessageType.CALL_RESULT_MESSAGE:
         // Build response
-        messageToSend = JSON.stringify([messageType, messageId, messagePayload]);
+        this.validateIncomingRequestResponsePayload(
+          chargingStation,
+          commandName,
+          messagePayload as JsonType,
+        );
+        messageToSend = JSON.stringify([messageType, messageId, messagePayload] as Response);
         break;
       // Error Message
       case MessageType.CALL_ERROR_MESSAGE:
@@ -293,34 +508,21 @@ export default abstract class OCPPRequestService {
         messageToSend = JSON.stringify([
           messageType,
           messageId,
-          messagePayload?.code ?? ErrorType.GENERIC_ERROR,
-          messagePayload?.message ?? '',
-          messagePayload?.details ?? { commandName },
-        ]);
+          (messagePayload as OCPPError)?.code ?? ErrorType.GENERIC_ERROR,
+          (messagePayload as OCPPError)?.message ?? '',
+          (messagePayload as OCPPError)?.details ?? { commandName },
+        ] as ErrorResponse);
         break;
     }
     return messageToSend;
   }
 
-  private handleRequestError(
-    commandName: RequestCommand | IncomingRequestCommand,
-    error: Error,
-    params: HandleErrorParams<EmptyObject> = { throwError: true }
-  ): void {
-    logger.error(
-      this.chargingStation.logPrefix() + ' Request command %s error: %j',
-      commandName,
-      error
-    );
-    if (params?.throwError) {
-      throw error;
-    }
-  }
-
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  public abstract sendMessageHandler<Request extends JsonType, Response extends JsonType>(
+  public abstract requestHandler<ReqType extends JsonType, ResType extends JsonType>(
+    chargingStation: ChargingStation,
     commandName: RequestCommand,
+    // FIXME: should be ReqType
     commandParams?: JsonType,
-    params?: SendParams
-  ): Promise<Response>;
+    params?: RequestParams,
+  ): Promise<ResType>;
 }