smartbucket/ts/classes.metadata.ts

import * as plugins from './plugins.js';

import { File } from './classes.file.js';

export class MetaData {
  // static
  public static async createForFile(optionsArg: {
    file: File;
  }) {
    const metaData = new MetaData();
    metaData.fileRef = optionsArg.file;

    // lets find the existing metadata file
    metaData.metadataFile = await metaData.fileRef.parentDirectoryRef.getFile({
      name: metaData.fileRef.name + '.metadata',
      createWithContents: '{}',
    });

    return metaData;
  }

  // instance
  /**
   * the file that contains the metadata
   */
  metadataFile: File;

  /**
   * the file that the metadata is for
   */
  fileRef: File;
  
  public async getFileType(optionsArg?: {
    useFileExtension?: boolean;
    useMagicBytes?: boolean;
  }): Promise<string> {
    if (optionsArg && optionsArg.useFileExtension || optionsArg.useFileExtension === undefined) {
      return plugins.path.extname(this.fileRef.name);
    }
  };
  
  /**
   * gets the size of the fileRef
   */
  public async getSizeInBytes(): Promise<number> {
    const stat = await this.fileRef.parentDirectoryRef.bucketRef.fastStat({
      path: this.fileRef.getBasePath(),
    });
    return stat.size;
  };

  private prefixCustomMetaData = 'custom_';

  public async storeCustomMetaData<T = any>(optionsArg: {
    key: string;
    value: T;
  }) {
    const json = await this.metadataFile.getContentsAsString();
    const parsed = await JSON.parse(json);
    parsed[this.prefixCustomMetaData + optionsArg.key] = optionsArg.value;
    await this.metadataFile.updateWithContents({
      contents: JSON.stringify(parsed),
    });
  }

  public async getCustomMetaData<T = any>(optionsArg: {
    key: string;
  }): Promise<T> {
    const json = await this.metadataFile.getContentsAsString();
    const parsed = await JSON.parse(json);
    return parsed[this.prefixCustomMetaData + optionsArg.key];
  }

  public async deleteCustomMetaData(optionsArg: {
    key: string;
  }) {
    const json = await this.metadataFile.getContentsAsString();
    const parsed = await JSON.parse(json);
    delete parsed[this.prefixCustomMetaData + optionsArg.key];
    await this.metadataFile.updateWithContents({
      contents: JSON.stringify(parsed),
    });
  }

  /**
   * set a lock on the ref file
   * @param optionsArg
   */
  public async setLock(optionsArg: {
    lock: string;
    expires: Date;
  }) {
    
  }

  /**
   * remove the lock on the ref file
   * @param optionsArg 
   */
  public async removeLock(optionsArg: {
    force: boolean;
  }) {

  }
}