const { files: filesDb } = require('../utils/database/index');

/**
 * @typedef {Object} FileData
 *
 * @property {string} _id - file id
 * @property {string} name - original file name
 * @property {string} filename - name of uploaded file
 * @property {string} path - path to uploaded file
 * @property {string} mimetype - file MIME type
 * @property {number} size - size of the file in
 */

/**
 * @class File
 * @class File model
 *
 * @property {string} _id - file id
 * @property {string} name - original file name
 * @property {string} filename - name of uploaded file
 * @property {string} path - path to uploaded file
 * @property {string} mimetype - file MIME type
 * @property {number} size - size of the file in
 */
class File {
  /**
   * Find and return model of file with given id
   * @param {string} _id - file id
   * @returns {Promise<File>}
   */
  static async get(_id) {
    const data = await filesDb.findOne({ _id });

    return new File(data);
  }

  /**
   * Find and return model of file with given id
   * @param {string} filename - uploaded filename
   * @returns {Promise<File>}
   */
  static async getByFilename(filename) {
    const data = await filesDb.findOne({ filename });

    return new File(data);
  }

  /**
   * Find all files which match passed query object
   *
   * @param {Object} query
   * @returns {Promise<File[]>}
   */
  static async getAll(query = {}) {
    const docs = await filesDb.find(query);

    return Promise.all(docs.map(doc => new File(doc)));
  }

  /**
   * @constructor
   *
   * @param {FileData} data
   */
  constructor(data = {}) {
    if (data === null) {
      data = {};
    }

    if (data._id) {
      this._id = data._id;
    }

    this.data = data;
  }

  /**
   * Set FileData object fields to internal model fields
   *
   * @param {FileData} fileData
   */
  set data(fileData) {
    const { name, filename, path, mimetype, size } = fileData;

    this.name = name || this.name;
    this.filename = filename || this.filename;
    this.path = path ? this.processPath(path) : this.path;
    this.mimetype = mimetype || this.mimetype;
    this.size = size || this.size;
  }

  /**
   * Return FileData object
   *
   * @returns {FileData}
   */
  get data() {
    return {
      _id: this._id,
      name: this.name,
      filename: this.filename,
      path: this.path,
      mimetype: this.mimetype,
      size: this.size
    };
  }

  /**
   * Save or update file data in the database
   *
   * @returns {Promise<File>}
   */
  async save() {
    if (!this._id) {
      const insertedRow = await filesDb.insert(this.data);

      this._id = insertedRow._id;
    } else {
      await filesDb.update({ _id: this._id }, this.data);
    }

    return this;
  }

  /**
   * Remove file data from the database
   *
   * @returns {Promise<File>}
   */
  async destroy() {
    await filesDb.remove({ _id: this._id });

    delete this._id;

    return this;
  }

  /**
   * Removes unnecessary public folder prefix
   * @param {string} path
   * @return {string}
   */
  processPath(path) {
    return path.replace(/^public/, '');
  }

  /**
   * Return readable file data
   *
   * @returns {FileData}
   */
  toJSON() {
    return this.data;
  }
}

module.exports = File;