ajaxq.coffee

class AjaxQ
  initialize: (options) ->
    _.extend(this, Backbone.Events)
    @options = _.clone(options)
    _.extend(@options, max:3)

    @waiting = []
    @requests = []

  enqueue: (k) ->
    this.trigger("enqueue")
    @waiting.push(k)
    this.consume()

  push: (k) -> this.enqueue(k)

  consume: () ->
    return this unless @requests.length < @options.max
    return this unless @requests.length > 0

    this.trigger("consume")

    k = @waiting.shift()
    xhr = k()
    @requests.push(xhr)

    xhr.complete () =>
      index = _.indexOf(@requests, xhr)

      # Check if the queue is aborted
      delete @requests[index] if index >= 0

      setTimeout (=> this.consume()), 10

  abort: () ->
    this.trigger("aborting")

    $.Deferred (dfd) =>
      for xhr in @requests
        xhr.abort()

      @requests = []
      @waiting = []

      this.trigger("aborted")

      setTimeout (=> dfd.resolve()), 10

    dfd

  hasRunningRequest: () -> @requests.length > 0
  hasWaitingRequest: () -> @waiting.length > 0
  isEmpty: () -> not(this.hasRunningRequest()) and not(this.hasWaitingRequest())

window.AjaxQ = AjaxQ

@queue = new AjaxQ(max:6)

@queue.enqueue => @model.fetch()
@queue.enqueue => @collection.fetch()
@queue.enqueue => @account.save()