import ObjectID from 'bson-objectid';
import apm from 'elastic-apm-node';
import {
  utilities as nestWinstonModuleUtilities,
  WinstonModule,
} from 'nest-winston';
import winston, { transport } from 'winston';
import { ElasticsearchTransport } from 'winston-elasticsearch';

import { ecsFormat } from '@elastic/ecs-winston-format';

import { AppConfig } from '../app.config';

export function createLoggerModule(appConfig: AppConfig) {

  const transports: transport[] = [
    new winston.transports.Console({
      level: process.env.NODE_ENV !== 'production' ? 'debug' : 'info',
      format: winston.format.combine(
        winston.format.timestamp(),
        winston.format.ms(),
        nestWinstonModuleUtilities.format.nestLike(appConfig.appName, {
          colors: true,
          prettyPrint: true,
        })
      )
    }),
  ];
  if (appConfig.logger?.esNode) {
    const format = ecsFormat({
      convertReqRes: true,
      convertErr: true,
      apmIntegration: !!appConfig.logger.apmUrl,
    });
    const esTransport = new ElasticsearchTransport({
      indexPrefix: appConfig.appName,
      apm: appConfig.logger.apmUrl ? apm.start({
        serverUrl: appConfig.logger.apmUrl,
        logLevel: "info",
        serviceName: appConfig.appName,
        useElasticTraceparentHeader: true,
      }) : undefined,
      format: format,
      useTransformer: false,
      level: process.env.NODE_ENV !== 'production' ? 'debug' : 'info',
      clientOpts: {
        enableMetaHeader: true,
        maxResponseSize: 10000000,
        generateRequestId: () => { new ObjectID(Date.now()).toHexString() },
        name: appConfig.appName,
        node: appConfig.logger.esNode,
        auth: {
          username: appConfig.logger.esUsername,
          password: appConfig.logger.esPassword,
        },
      }
    });
    transports.push(esTransport);
  }

  const module = WinstonModule.forRoot({
    transports: transports
  });
  return module;
}