/**
 * Jasmine RequestAnimationFrame: a set of helpers for testing funcionality
 * that uses requestAnimationFrame under the Jasmine BDD framework for JavaScript.
 */
;(function () {

  var index = 0
  var callbacks = []

  function MockRAF (global) {
    this.realRAF = global.requestAnimationFrame
    this.realCAF = global.cancelAnimationFrame
    this.realPerf = global.performance
    this.nextTime = 0

    var _this = this

    /**
         * Mock for window.requestAnimationFrame
         */
    this.mockRAF = function (fn) {
      if (typeof fn !== 'function') {
        throw new Error('You should pass a function to requestAnimationFrame')
      }

      callbacks[index++] = fn

      return index
    }

    /**
         * Mock for window.cancelAnimationFrame
         */
    this.mockCAF = function (requestID) {
      callbacks.splice(requestID, 1)
    }

    this.mockPerf = {
      now: function () {
        return _this.nextTime
      }
    }

    /**
         * Install request animation frame mocks.
         */
    this.install = function () {
      global.requestAnimationFrame = _this.mockRAF
      global.cancelAnimationFrame = _this.mockCAF
      global.performance = _this.mockPerf
    }

    /**
         * Uninstall request animation frame mocks.
         */
    this.uninstall = function () {
      global.requestAnimationFrame = _this.realRAF
      global.cancelAnimationFrame = _this.realCAF
      global.performance = _this.realPerf
      _this.nextTime = 0
      callbacks = []
    }

    /**
         * Simulate animation frame readiness.
         */
    this.tick = function (dt) {
      _this.nextTime += (dt || 1)

      var fns = callbacks; var fn; var i

      callbacks = []
      index = 0

      for (i in fns) {
        fn = fns[i]
        fn(_this.nextTime)
      }
    }
  }

  jasmine.RequestAnimationFrame = new MockRAF(window)
}())