webvideo-transcript-summary-web-api/src/modules/summary/SummaryService.ts

import {
  createSummarizer,
  SummarizerEventEmitter,
  OPENAI_API_VERSION,
} from '@modal-sh/webvideo-transcript-summary-core';
import { Readable } from '../../packages/event-emitter-to-readable-stream';
import * as config from '../../config';

export interface SummaryService {
  createSummaryStream(transcriptText: string): NodeJS.ReadableStream;
}

export class SummaryServiceImpl implements SummaryService {
  private readonly summarizer: SummarizerEventEmitter;

  constructor() {
    // noop
    this.summarizer = createSummarizer({
      apiKey: config.openAi.apiKey,
      organizationId: config.openAi.organizationId,
      apiVersion: OPENAI_API_VERSION,
    });
  }

  createSummaryStream(transcriptText: string) {
    const stream = Readable.fromEventEmitter(
      this.summarizer,
    ) as unknown as NodeJS.ReadableStream & { tokenCount: number };
    this.summarizer.summarize(transcriptText);
    return stream;
  }
}