import * as Collections from '../utils/collections';
import Util from '../util';
import TransportManager from '../transports/transport_manager';
import * as Errors from '../errors';
import Strategy from './strategy';
import TransportStrategy from './transport_strategy';
import StrategyOptions from '../strategies/strategy_options';
import { Config } from '../config';
import Runtime from 'runtime';

const { Transports } = Runtime;

export var defineTransport = function(
  config: Config,
  name: string,
  type: string,
  priority: number,
  options: StrategyOptions,
  manager?: TransportManager
): Strategy {
  var transportClass = Transports[type];
  if (!transportClass) {
    throw new Errors.UnsupportedTransport(type);
  }

  var enabled =
    (!config.enabledTransports ||
      Collections.arrayIndexOf(config.enabledTransports, name) !== -1) &&
    (!config.disabledTransports ||
      Collections.arrayIndexOf(config.disabledTransports, name) === -1);

  var transport;
  if (enabled) {
    options = Object.assign(
      { ignoreNullOrigin: config.ignoreNullOrigin },
      options
    );

    transport = new TransportStrategy(
      name,
      priority,
      manager ? manager.getAssistant(transportClass) : transportClass,
      options
    );
  } else {
    transport = UnsupportedStrategy;
  }

  return transport;
};

var UnsupportedStrategy: Strategy = {
  isSupported: function() {
    return false;
  },
  connect: function(_, callback) {
    var deferred = Util.defer(function() {
      callback(new Errors.UnsupportedStrategy());
    });
    return {
      abort: function() {
        deferred.ensureAborted();
      },
      forceMinPriority: function() {}
    };
  }
};