import FSM from 'ember-fsm';

let trafficSignal = FSM.Machine.create({
  events: {
    cycle: {
      transitions: [
        { initialized: 'red' },
        { red: 'green' },
        { green: 'amber' },
        { amber: 'red' }
      ]
    },

    powerDown: {
      transition: { $all: 'off' }
    }
  }
});

trafficSignal.get('currentState');
// "initialized"

trafficSignal.send('cycle');
trafficSignal.get('currentState');
// "red"

trafficSignal.send('cycle');
trafficSignal.get('currentState')
// "green"

import FSM from 'ember-fsm';

let SleepyFSM = FSM.Machine.extend({
  // Here is where you define your state machine's state-specific configuration.
  // This section is optional.
  states: {
    // The default initial state is "initialized"
    initialState: 'awake'

    // If you'd like, you can choose to explicitly define the names of your
    // states:
    knownStates: ['sleeping', 'angry', 'awake', 'initialized', 'failed'],

    // You can define global per-state callbacks, they will fire whenever the
    // state will be entered, was entered, will be exited, or was exited.
    sleeping: {
      willEnter() { },
      didEnter() { },
      willExit() { },
      didExit() { }
    }
  },

  // Here's where you define your state machine's events, it is required.
  events: {
    sleep: {
      // You can define global per-event callbacks. These will fire for any
      // transition before or after this event.
      before() { },
      after() { },

      // This is where the event's transitions are defined, it is also aliased
      // to "transition". It can accept either a single object like one in the
      // array below, or an array of transition definition objects:
      transitions: [
        { awake: 'sleeping', doUnless: 'unableToSleep' },
        { awake: 'angry', doIf: 'unableToSleep' },
        { sleeping: '$same' }
      ]
    },

    // By default this error event is injected into your state machine for you,
    // you can override it and provide your own transitions and callbacks if
    // you'd like.
    error: {
      transition: { $all: 'failed' }
    }
  }
});

let fsm = SleepyFSM.create();
fsm.send('sleep');

import Ember from 'ember';
import FSM from 'ember-fsm';

// controllers/upload.js
export default Ember.Controller.extend(FSM.Stateful, {
  needs: 'notifier',

  actions: {
    uploadFile(file) {
      this.set('file', file);
      this.sendStateEvent('addFile');
    }
  },

  fsmStates: {
    initialState: 'nofile'
  },

  fsmEvents: {
    addFile: {
      transitions: {
        from:   ['nofile', 'failed'],
        to:     'ready',
        before: 'checkFile',
      }
    },

    startUpload: {
      transitions: {
        from:     'ready',
        to:       'uploading',
        before:   'getUploadURL',
        didEnter: 'performUpload',
        after:    'finishedUpload'
      }
    },

    finishUpload: {
      transition: { uploading: 'nofile', didEnter: 'reset' }
    }
  },

  reset() {
    this.set('file', null);
  },

  checkFile() {
    let file = this.get('file');

    if (file.size > 0) {
      return;
    } else {
      this.get('controllers.notifier').warn('file must have content');
      FSM.reject(); // A helper for throwing an error
    }
  },

  getUploadURL() {
    let fileName = this.get('file.name');

    let xhr = Ember.$.ajax('/api/signed_uploads', {
      type: 'put',
      data: { file: { name: fileName } }
    });

    xhr.then((payload) => {
      Ember.run(() => {
        this.set('uploadToURL', payload.signed_upload.url);
      });
    });

    return xhr; // Causes transition to block until promise is settled
  },

  performUpload() {
    return Ember.$.ajax(this.get('uploadToURL'), {
      type: 'put',
      data: this.get('file')
    });
  },

  finishedUpload() {
    this.get('controllers.notifier').success('Upload complete');
    this.sendStateEvent('finishUpload');
  }
});