استریم فایل های باینری و base64

import { Controller, Get, Param, Res } from '@nestjs/common';
import { Response } from 'express';
import { createReadStream } from 'fs';
import { readFile } from 'fs/promises';
import { join } from 'path';
import { Readable } from 'stream';

@Controller('templates')
export class TemplatesController {
  @Get('csv')
  getCsvTemplate(@Res() res: Response): void {
    const file = createReadStream(join(process.cwd(), 'template.csv'));

    res.set({
      'Content-Type': 'text/csv',
      'Content-Disposition': 'attachment; filename="template.csv"'
    });
    file.pipe(res);
  }

  @Get('pdf/:id')
  async getPdfTemplate(
    @Param('id') id: string,
    @Res() res: Response
  ): Promise<void> {
    const fileBase64 = await readFile(
      join(process.cwd(), 'template.pdf'),
      'base64'
    );
    // const fileBase64 = await apiCall();
    const fileBuffer = Buffer.from(fileBase64, 'base64');
    const fileStream = Readable.from(fileBuffer);

    res.set({
      'Content-Type': 'application/pdf',
      'Content-Disposition': `attachment; filename="template_${id}.pdf"`
    });
    fileStream.pipe(res);
  }
}