import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { randomUUID } from 'crypto';
import { createClient, WebDAVClient } from 'webdav';
import { StorageProvider } from './storage-provider';

/// Nextcloud (or any WebDAV server) as file storage backend.
@Injectable()
export class WebDavStorageProvider implements StorageProvider {
  private readonly client: WebDAVClient;

  constructor(config: ConfigService) {
    this.client = createClient(config.getOrThrow<string>('WEBDAV_URL'), {
      username: config.getOrThrow<string>('WEBDAV_USERNAME'),
      password: config.getOrThrow<string>('WEBDAV_PASSWORD'),
    });
  }

  async upload(kcId: string, filename: string, data: Buffer): Promise<string> {
    const dir = `/${kcId}`;
    if (!(await this.client.exists(dir))) {
      await this.client.createDirectory(dir, { recursive: true });
    }
    const storageKey = `${dir}/${randomUUID()}-${filename}`;
    await this.client.putFileContents(storageKey, data, { overwrite: false });
    return storageKey;
  }

  async download(storageKey: string): Promise<Buffer> {
    const content = await this.client.getFileContents(storageKey);
    return Buffer.isBuffer(content) ? content : Buffer.from(content as ArrayBuffer);
  }

  async delete(storageKey: string): Promise<void> {
    await this.client.deleteFile(storageKey);
  }
}