import { ArgumentsHost, Catch, ExceptionFilter, HttpStatus } from '@nestjs/common';
import { MicroServiceError } from './micro-service-error';
import { MicroServiceErrorResponseInterface } from './interfaces';
import { AppLogger } from '../logger';
import { HttpArgumentsHost } from '@nestjs/common/interfaces';
import { MicroServiceExceptionUtil } from './utils';

@Catch(Error)
export class MicroServiceExceptionFilter implements ExceptionFilter {

  private readonly TAG: string = `${this.constructor.name}`;

  catch(exception: any, host: ArgumentsHost) {

    const ctx: HttpArgumentsHost = host.switchToHttp();
    const response = ctx.getResponse();

    let microServiceErrorResponse: MicroServiceErrorResponseInterface;

    if (exception instanceof MicroServiceError) {
      microServiceErrorResponse = MicroServiceExceptionUtil.buildMicroServiceErrorResponse(exception);
    } else {
      microServiceErrorResponse = MicroServiceExceptionUtil.buildUnknownErrorResponse();
    }

    AppLogger.error(exception.stack, this.TAG);

    const status: number = microServiceErrorResponse.statusCode ? microServiceErrorResponse.statusCode : HttpStatus.INTERNAL_SERVER_ERROR;
    response
      .status(status)
      .json({ error: microServiceErrorResponse });
  }

}