fairnesscoop / permacoop

import {Inject} from '@nestjs/common';

import {QueryHandler} from '@nestjs/cqrs';

import {IFileRepository} from 'src/Domain/File/Repository/IFileRepository';

import {DownloadFileQuery} from './DownloadFileQuery';

import {IFileStorage} from 'src/Application/IFileStorage';

import {DownloadedFileView} from '../View/DownloadedFileView';

import {FileNotFoundException} from 'src/Domain/File/Exception/FileNotFoundException';

@QueryHandler(DownloadFileQuery)

export class DownloadFileQueryHandler {

  constructor(

    @Inject('IFileRepository')

    private readonly fileRepository: IFileRepository,

    @Inject('IFileStorage')

    public readonly fileStorage: IFileStorage

  ) {}

  public async execute(query: DownloadFileQuery): Promise<DownloadedFileView> {

    const file = await this.fileRepository.findOneById(query.id);

    if (!file) {

      throw new FileNotFoundException();

    }

    const buffer = await this.fileStorage.download(file);

    if (!buffer) {

      throw new FileNotFoundException();

    }

    return new DownloadedFileView(

      file.getOriginalName(),

      file.getMimeType(),

      buffer

    );

  }

}