'use strict';

const Stream = require('stream');
const Util = require('util');

/**
 * This stream is used to read tarballs from repository.
 * @param {*} options
 * @return {Object}
 */
function ReadTarball(options) {
  const self = new Stream.PassThrough(options);
  Object.setPrototypeOf(self, ReadTarball.prototype);

  // called when data is not needed anymore
  add_abstract_method(self, 'abort');

  return self;
}

Util.inherits(ReadTarball, Stream.PassThrough);

/**
 * This stream is used to upload tarballs to a repository.
 * @param {*} options
 * @return {Object}
 */
function UploadTarball(options) {
  const self = new Stream.PassThrough(options);
  Object.setPrototypeOf(self, UploadTarball.prototype);

  // called when user closes connection before upload finishes
  add_abstract_method(self, 'abort');

  // called when upload finishes successfully
  add_abstract_method(self, 'done');

  return self;
}

Util.inherits(UploadTarball, Stream.PassThrough);

/**
 * This function intercepts abstract calls and replays them allowing.
 * us to attach those functions after we are ready to do so
 * @param {*} self
 * @param {*} name
 */
function add_abstract_method(self, name) {
  self._called_methods = self._called_methods || {};
  self.__defineGetter__(name, function() {
    return function() {
      self._called_methods[name] = true;
    };
  });
  self.__defineSetter__(name, function(fn) {
    delete self[name];
    self[name] = fn;
    if (self._called_methods && self._called_methods[name]) {
      delete self._called_methods[name];
      self[name]();
    }
  });
}

module.exports.readTarballStream = ReadTarball;
module.exports.uploadTarballStream = UploadTarball;