/// <reference path="../../typings/es6-promise/es6-promise.d.ts" />
/// <reference path="../../typings/rx/rx.all.d.ts" />

// HACK: workaround for Traceur behavior.
// It expects all transpiled modules to contain this marker.
// TODO: remove this when we no longer use traceur
export var __esModule = true;

import {int, global, isPresent} from 'angular2/src/facade/lang';
import {List} from 'angular2/src/facade/collection';
import * as Rx from 'rx';

export class PromiseWrapper {
  static resolve(obj): Promise<any> { return Promise.resolve(obj); }

  static reject(obj): Promise<any> { return Promise.reject(obj); }

  // Note: We can't rename this method into `catch`, as this is not a valid
  // method name in Dart.
  static catchError<T>(promise: Promise<T>, onError: (error: any) => T | Thenable<T>): Promise<T> {
    return promise.catch(onError);
  }

  static all(promises: List<Promise<any>>): Promise<any> {
    if (promises.length == 0) return Promise.resolve([]);
    return Promise.all(promises);
  }

  static then<T>(promise: Promise<T>, success: (value: any) => T | Thenable<T>,
                 rejection: (error: any) => T | Thenable<T>): Promise<T> {
    return promise.then(success, rejection);
  }

  static completer() {
    var resolve;
    var reject;

    var p = new Promise(function(res, rej) {
      resolve = res;
      reject = rej;
    });

    return {promise: p, resolve: resolve, reject: reject};
  }

  static setTimeout(fn: Function, millis: int) { global.setTimeout(fn, millis); }

  static isPromise(maybePromise): boolean { return maybePromise instanceof Promise; }
}


export class ObservableWrapper {
  static subscribe(emitter: EventEmitter, onNext, onThrow = null, onReturn = null) {
    return emitter.observer({next: onNext, throw: onThrow, return: onReturn});
  }

  static callNext(emitter: EventEmitter, value: any) { emitter.next(value); }

  static callThrow(emitter: EventEmitter, error: any) { emitter.throw(error); }

  static callReturn(emitter: EventEmitter) { emitter.return (null); }
}

// TODO: vsavkin change to interface
export class Observable {
  observer(generator: any) {}
}

/**
 * Use Rx.Observable but provides an adapter to make it work as specified here:
 * https://github.com/jhusain/observable-spec
 *
 * Once a reference implementation of the spec is available, switch to it.
 */
export class EventEmitter extends Observable {
  _subject: Rx.Subject<any>;

  constructor() {
    super();
    this._subject = new Rx.Subject<any>();
  }

  observer(generator) {
    var immediateScheduler = (<any>Rx.Scheduler).immediate;
    return this._subject.observeOn(immediateScheduler)
        .subscribe((value) => { setTimeout(() => generator.next(value)); },
                   (error) => generator.throw ? generator.throw(error) : null,
                   () => generator.return ? generator.return () : null);
  }

  toRx(): Rx.Observable<any> { return this._subject; }

  next(value) { this._subject.onNext(value); }

  throw(error) { this._subject.onError(error); }

  return (value) { this._subject.onCompleted(); }
}