require 'rspec'
require 'rspec/its'

require 'pry'
require 'ostruct'
require 'metacosm'

include Metacosm

require 'support/fizz_buzz'
require 'support/village'

class GivenWhenThen < Struct.new(:given_events,:when_command,:then_event_class)
  include RSpec::Matchers

  def when(*commands)
    @when_commands ||= []
    commands.each do |command|
      @when_commands.push command
    end
    self
  end

  def expect_events(evts)
    @then_events = evts
    verify!
    self
  end

  def expect_query(query, to_find:)
    @query = query
    @expected_query_results = to_find
    verify!
    self
  end

  protected

  def verify!
    clean_slate!
    receive_events!
    fire_commands!

    validate_events!
    validate_query!

    self
  end

  private

  def clean_slate!
    PassiveRecord.drop_all
    Simulation.current.clear!
    self
  end

  def receive_events!
    unless self.given_events.nil?
      self.given_events.each do |evt| 
        sim.receive(evt, record: false)
      end
    end
    self
  end

  def fire_commands!
    unless @when_commands.nil?
      @when_commands.each do |cmd|
        sim.apply(cmd)
      end
    end
    self
  end

  def validate_events!
    if @then_event_class
      expect(@then_event_class).to eq(sim.events.last.class) 
    end

    if @then_events
      expect(@then_events).to match_array(sim.events) 
    end

    if @then_event_attrs
      @then_event_attrs.each do |k,v|
        expect(sim.events.last.send(k)).to eq(v)
      end
    end

    self
  end

  def validate_query!
    if @query
      expect(@query.execute).to eq(@expected_query_results)
    end
    self
  end

  def sim
    @sim ||= Simulation.current
  end
end

module Metacosm
  module SpecHelpers
    def given_no_activity
      GivenWhenThen.new
    end

    def given_events(events)
      GivenWhenThen.new(events)
    end
  end
end

RSpec.configure do |c|
  c.include Metacosm::SpecHelpers
end