/*
 * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
 *
 * SPDX-License-Identifier: AGPL-3.0-only
 */
import { Inject, Injectable } from '@nestjs/common';
import { Client } from 'minio';
import { URL } from 'url';

import mediaConfiguration, { MediaConfig } from '../../config/media.config';
import { MediaBackendError } from '../../errors/errors';
import { ConsoleLoggerService } from '../../logger/console-logger.service';
import { MediaBackend } from '../media-backend.interface';
import { BackendData } from '../media-upload.entity';
import { BackendType } from './backend-type.enum';

@Injectable()
export class S3Backend implements MediaBackend {
  private config: MediaConfig['backend']['s3'];
  private client: Client;

  constructor(
    private readonly logger: ConsoleLoggerService,
    @Inject(mediaConfiguration.KEY)
    private mediaConfig: MediaConfig,
  ) {
    this.logger.setContext(S3Backend.name);
    if (mediaConfig.backend.use === BackendType.S3) {
      this.config = mediaConfig.backend.s3;
      const url = new URL(this.config.endPoint);
      const secure = url.protocol === 'https:'; // url.protocol contains a trailing ':'
      const endpoint = `${url.hostname}${url.pathname}`;
      let port = parseInt(url.port);
      if (isNaN(port)) {
        port = secure ? 443 : 80;
      }
      this.client = new Client({
        endPoint: endpoint.substr(0, endpoint.length - 1), // remove trailing '/'
        port: port,
        useSSL: secure,
        accessKey: this.config.accessKeyId,
        secretKey: this.config.secretAccessKey,
      });
    }
  }

  async saveFile(
    buffer: Buffer,
    fileName: string,
  ): Promise<[string, BackendData]> {
    try {
      await this.client.putObject(this.config.bucket, fileName, buffer);
      this.logger.log(`Uploaded file ${fileName}`, 'saveFile');
      return [this.getUrl(fileName), null];
    } catch (e) {
      this.logger.error((e as Error).message, (e as Error).stack, 'saveFile');
      throw new MediaBackendError(`Could not save '${fileName}' on S3`);
    }
  }

  async deleteFile(fileName: string, _: BackendData): Promise<void> {
    try {
      await this.client.removeObject(this.config.bucket, fileName);
      const url = this.getUrl(fileName);
      this.logger.log(`Deleted ${url}`, 'deleteFile');
      return;
    } catch (e) {
      this.logger.error((e as Error).message, (e as Error).stack, 'saveFile');
      throw new MediaBackendError(`Could not delete '${fileName}' on S3`);
    }
  }

  private getUrl(fileName: string): string {
    const url = new URL(this.config.endPoint);
    const port = url.port !== '' ? `:${url.port}` : '';
    const bucket = this.config.bucket;
    return `${url.protocol}//${url.hostname}${port}${url.pathname}${bucket}/${fileName}`;
  }
}