http.js

import xhr            from 'superagent'
import { Observable } from 'rx'

/** body
* @description returns the body of a supplied response
* @param {Object} response the response from the xhr request
* @return {Any} what ever the body is
*/
function body (response) {
  return response.body
}


/** respond
* @description deals with the response of an xhr request
* @param {Function} resolve promise resolve function
* @param {Function} reject  promise reject function
* @param {Function} fn transform response function
* @returns {Function} function that can be used in the xhr callback
*/
function respond (resolve, reject, fn = body) {
  return function (err, res) {
    if (res.ok) return resolve(fn(res))
    return reject(err)
  }
}


/** http
* @description standardized http requests
* @param {String} method the http method to be used
* @param {Strung} url the url to make the request to
* @param {Object} data any data that needs to be sent along with the reqeust
* @param {Object} opts any additional options ie: headers and stuff
* @return {Promise} then(res) or catch(err)
*/
export function http (method, url, data = {}, opts = {}) {
  return new Promise((resolve, reject) =>
    xhr(method, url)
      .send(data)
      .set(opts)
      .end(respond( resolve, reject, body ))
  )
}


/** get post del
* @description returns a response from the supplied arguments
* @param {String} url the url to request a response from
* @param {Object} data the data to be passed along with the request
* @param {Object} opts any additional options that need to be passed with the request
* @return {Promise} then(res) or catch(err)
*/
export const get  = http.bind(null, `GET`)
export const post = http.bind(null, `POST`)
export const del  = http.bind(null, `DELETE`)


/** get$
* @description returns an observable stream of results from the given options
* @param {String} url the url to request
* @param {Object} data the data to be passed along with the request
* @param {Object} opts any options that need to be passed with the resquest
* @return {Observable} an observable stream of responses
*/
export function get$ (...args) {
  return Observable.fromPromise(get(...args))
}


/** post$
* @description returns an observable stream of results from the given options
* @param {String} url the url to request
* @param {Object} data the data to be passed along with the request
* @param {Object} opts any options that need to be passed with the resquest
* @return {Observable} an observable stream of responses
*/
export function post$ (...args) {
  return Observable.fromPromise(post(...args))
}


/** del$
* @description returns an observable stream of results from the given options
* @param {String} url the url to request
* @param {Object} data the data to be passed along with the request
* @param {Object} opts any options that need to be passed with the resquest
* @return {Observable} an observable stream of responses
*/
export function del$ (...args) {
  return Observable.fromPromise(del(...args))
}


/** poll$
* @description returns an observable stream of results from the given options
* @param {Number} rate the number in ms of how often to make the request
* @param {String} url the url to request
* @param {Object} data the data to be passed along with the request
* @param {Object} opts any options that need to be passed with the resquest
* @return {Observable} an observable stream of responses
*/
export function poll$ (rate, ...args) {
  return Observable
    .interval(rate)
    .flatMap(() => get$(...args))
    .merge(get$(...args))
}