import { type JSONNode } from '@redneckz/json-op';
import glob from 'glob';
import path from 'path/posix';
import { promisify } from 'util';
import { readJSON } from '../fs/readJSON';
import type { FileAPI, FilePath, ListFilesOptions } from './FileAPI';

const find = promisify(glob);

export class FileSystemAPI implements FileAPI {
  public static readonly inst: FileAPI = new FileSystemAPI();

  constructor(private readonly basePath?: string) {}

  async listFiles({ dir, ext, size }: ListFilesOptions): Promise<FilePath[]> {
    const files: string[] = await find(`*${ext}`, { cwd: dir, matchBase: true });
    return files.slice(0, size).map(_ => (dir ? path.join(dir, _) : _));
  }

  async downloadFiles(options: ListFilesOptions): Promise<[FilePath, JSONNode][]> {
    const files = await this.listFiles(options);
    return Promise.all(files.map(async _ => [_, await this.readJSON(_)]));
  }

  async countFiles(options: ListFilesOptions): Promise<number> {
    const files = await this.listFiles(options);
    return files.length;
  }

  async readJSON<T extends JSONNode = JSONNode>(filePath: FilePath): Promise<T> {
    return readJSON(this.basePath ? path.join(this.basePath, filePath) : filePath);
  }
}