import bunyan, { Stream } from 'bunyan';
import { LoggingBunyan } from '@google-cloud/logging-bunyan';
import { ILogger, LoggerTransportArgs } from '../logger';
import { Writable } from 'stream';
import { gcpServiceContext } from '../../integrations/gcp';

const PrettyStream = require('bunyan-prettystream');
const stringify = require('json-stringify-safe');

class FixMessageKeyStream extends Writable {
  write(chunk: any) {
    return process.stdout.write(
      stringify({
        ...chunk,
        message: chunk.msg,
        msg: undefined,
      }) + '\n'
    );
  }
}

export function createBunyanLogger(args: LoggerTransportArgs): ILogger {
  const loggingBunyan = new LoggingBunyan({
    logName: 'logger_api_log',
    serviceContext: gcpServiceContext,
  });

  const streams: Stream[] = args.gcpLogging
    ? [
        {
          level: args.level,
          type: 'raw',
          stream: new FixMessageKeyStream(),
        },
        loggingBunyan.stream(args.level),
      ]
    : [];

  return bunyan.createLogger({
    name: args.name,
    streams,
  });
}