require 'spec_helper'

Multiflow.persistence = :none

class Robot
  include Multiflow

  stateflow do
    initial :green

    state :green, :yellow, :red

    event :change_color do
      transitions :from => :green, :to => :yellow
      transitions :from => :yellow, :to => :red
      transitions :from => :red, :to => :green
    end
  end
end

class Car
  include Multiflow

  stateflow do
    initial :parked

    state :parked do
      enter do
        "Entering parked"
      end

      exit do
        "Exiting parked"
      end
    end

    state :driving do
      enter do
        "Entering parked"
      end
    end

    event :drive do
      transitions :from => :parked, :to => :driving
    end

    event :park do
      transitions :from => :driving, :to => :parked
    end
  end
end

class Bob
  include Multiflow

  stateflow do
    state :yellow, :red, :purple

    event :change_hair_color do
      transitions :from => :purple, :to => :yellow
      transitions :from => :yellow, :to => :red
      transitions :from => :red, :to => :purple
    end
  end
end

class Dater
  include Multiflow

  stateflow do
    state :single, :dating, :married

    event :take_out do
      transitions :from => :single, :to => :dating
    end

    event :gift do
      transitions :from => :dating, :to => [:single, :married], :decide => :girls_mood?
    end

    event :blank_decision do
      transitions :from => :single, :to => [:single, :married], :decide => :girls_mood?
    end

    event :fail do
      transitions :from => :dating, :to => [:single, :married]
    end
  end

  def girls_mood?
  end
end

class Priority
  include Multiflow

  stateflow do
    initial :medium
    state :low, :medium, :high

    event :low do
      transitions :from => any, :to => :low
    end

    event :medium do
      transitions :from => any, :to => :medium
    end

    event :high do
      transitions :from => any, :to => :high
    end
  end
end

class Stater
  include Multiflow

  stateflow do
    initial :bill

    state :bob, :bill

    event :lolcats do
      transitions :from => :bill, :to => :bob
    end
  end
end

describe Multiflow do
  describe "class methods" do
    it "should respond to stateflow block to setup the intial stateflow" do
      Robot.should respond_to(:stateflow)
    end

    it "should respond to the machine attr accessor" do
      Robot.should respond_to(:machine_state)
    end

    it "should return all active persistence layers" do
      Set[*Multiflow::Persistence.active.should] == Set[:active_record, :mongo_mapper, :mongoid, :none]
    end
  end

  describe "instance methods" do
    before(:each) do
      @r = Robot.new
    end

    it "should respond to current state" do
      @r.should respond_to(:current_state)
    end

    it "should respond to the current state setter" do
      @r.should respond_to(:set_current_state)
    end

    it "should respond to the current machine" do
      @r.should respond_to(:machine_state)
    end

    it "should respond to load from persistence" do
      @r.should respond_to(:load_from_persistence)
    end

    it "should respond to save to persistence" do
      @r.should respond_to(:save_to_persistence)
    end
  end

  describe "initial state" do
    it "should set the initial state" do
      robot = Robot.new
      robot.current_state.name.should == :green
    end

    it "should return true for green?" do
      robot = Robot.new
      robot.green?.should be_true
    end

    it "should return false for yellow?" do
      robot = Robot.new
      robot.yellow?.should be_false
    end

    it "should return false for red?" do
      robot = Robot.new
      robot.red?.should be_false
    end

    it "should set the initial state to the first state set" do
      bob = Bob.new
      bob.current_state.name.should == :yellow
      bob.yellow?.should be_true
    end
  end

  it "robot class should contain red, yellow and green states" do
    robot = Robot.new
    robot.machine_state.states.keys.should include(:red, :yellow, :green)
  end

  describe "firing events" do
    let(:robot) { Robot.new }
    let(:event) { :change_color }
    subject { robot }

    it "should raise an exception if the event does not exist" do
      lambda { robot.send(:fire_event, robot.machine_state, :fake) }.should raise_error(Multiflow::NoEventFound)
    end

    shared_examples_for "an entity supporting state changes" do
      context "when firing" do
        after(:each) { subject.send(event_method) }
        it "should call the fire method on event" do
          subject.machine_state.events[event].should_receive(:fire)
        end

        it "should call the fire_event method" do
          subject.should_receive(:fire_event).with(subject.machine_state, event, {:save=>persisted})
        end
      end

      it "should update the current state" do
        subject.current_state.name.should == :green
        subject.send(event_method)
        subject.current_state.name.should == :yellow
      end
    end

    describe "bang event" do
      let(:event_method) { :change_color! }
      let(:persisted)    { true }
      it_should_behave_like "an entity supporting state changes"
    end

    describe "non-bang event" do
      let(:event_method) { :change_color }
      let(:persisted)    { false }
      it_should_behave_like "an entity supporting state changes"
    end

    describe "before filters" do
      before(:each) do
        @car = Car.new
      end

      it "should call the exit state before filter on the exiting old state" do
        @car.machine_state.states[:parked].should_receive(:execute_action).with(:exit, @car)
        @car.drive!
      end

      it "should call the enter state before filter on the entering new state" do
        @car.machine_state.states[:driving].should_receive(:execute_action).with(:enter, @car)
        @car.drive!
      end
    end
  end

  describe "persistence" do
    it "should attempt to persist the new state and the name should be a string" do
      robot = Robot.new
      robot.should_receive(:save_to_persistence).with(robot.machine_state, "yellow", {:save=>true})
      robot.change_color!
    end

    it "should attempt to read the initial state from the persistence" do
      robot = Robot.new

      def robot.load_from_persistence(machine)
        :red
      end

      robot.current_state.name.should == :red
    end
  end

  describe "dynamic to transitions" do
    it "should raise an error without any decide argument" do
      date = Dater.new

      def date.load_from_persistence(machine)
        :dating
      end

      lambda { date.fail! }.should raise_error(Multiflow::IncorrectTransition)
    end

    it "should raise an error if the decision method does not return a valid state" do
      date = Dater.new

      def date.girls_mood?
        :lol
      end

      lambda { date.blank_decision! }.should raise_error(Multiflow::NoStateFound, "Decision did not return a state that was set in the 'to' argument")
    end

    it "should raise an error if the decision method returns blank/nil" do
      date = Dater.new

      def date.girls_mood?
      end

      lambda { date.blank_decision! }.should raise_error(Multiflow::NoStateFound, "Decision did not return a state that was set in the 'to' argument")
    end

    it "should calculate the decide block or method and transition to the correct state" do
      date = Dater.new

      def date.load_from_persistence(machine)
        :dating
      end

      date.current_state.name.should == :dating

      def date.girls_mood?
        :single
      end

      date.gift!

      date.current_state.name.should == :single
    end
  end

  describe "transitions from any" do
    it "should properly change state" do
      priority = Priority.new
      priority.low!
      priority.should be_low
      priority.medium!
      priority.should be_medium
      priority.high!
      priority.should be_high
    end
  end

  describe 'sub-classes of Multiflow\'d classes' do
    subject { Class.new(Stater) }

    it 'shouldn\'t raise an exception' do
      expect { subject.new.lolcats! }.not_to raise_exception
    end
  end

end