require 'spec_helper'
require 'eeny-meeny/models/experiment'
require 'eeny-meeny/models/variation'

def experiment_with_time(time = {})
  experiment_options = {
      name: 'Test 1',
      variations: {
          a: { name: 'A' },
          b: { name: 'B' }}
  }.merge(time)
  described_class.new(:experiment_1,
                      **experiment_options)
end

describe EenyMeeny::Experiment do
  describe 'when initialized' do

    context 'with weighted variations' do
      subject do
        described_class.new(:experiment_1,
                            name: 'Test 1',
                            variations: {
                                a: { name: 'A', weight: 0.5 },
                                b: { name: 'B', weight: 0.3 }})
      end

      it 'sets the instance variables' do
        expect(subject.id).to eq(:experiment_1)
        expect(subject.name).to eq('Test 1')
        expect(subject.variations).to be_a Array
        expect(subject.variations.size).to eq(2)
      end

      it "has a 'total_weight' equal to the sum of the variation weights" do
        expect(subject.total_weight).to eq(0.8)
      end

      describe '#pick_variation' do
        it 'picks a variation' do
          expect(subject.pick_variation).to be_a EenyMeeny::Variation
        end
      end
    end

    context 'with non-weighted variations' do
      subject do
        described_class.new(:experiment_1,
                            name: 'Test 1',
                            variations: {
                                a: { name: 'A' },
                                b: { name: 'B' }})
      end

      it 'sets the instance variables' do
        expect(subject.id).to eq(:experiment_1)
        expect(subject.name).to eq('Test 1')
        expect(subject.variations).to be_a Array
        expect(subject.variations.size).to eq(2)
      end

      it "has a 'total_weight' equal to the number of the variation weights" do
        expect(subject.total_weight).to eq(2)
      end

      describe '#find_variation' do
        context 'given an existing variation id' do
          it 'returns the given variation' do
            variation = subject.find_variation(:a)
            expect(variation).to be_a EenyMeeny::Variation
            expect(variation.id).to eq(:a)
          end
        end

        context 'given a non-existing variation id' do
          it 'returns nil' do
            expect(subject.find_variation(:this_does_not_exist)).to be_nil
          end
        end
      end

      describe '#pick_variation' do
        it 'picks a variation' do
          expect(subject.pick_variation).to be_a EenyMeeny::Variation
        end
      end

      describe '#active?' do
        context 'when the experiment neither have a start_at or end_at time' do
          it 'returns true' do
            expect(subject.active?).to be true
          end
        end

        context 'when the experiment only have an end_at time' do
          context 'and the current time < end_at' do
            it 'returns true' do
              instance = experiment_with_time(end_at: (Time.zone.now+3600).iso8601)
              expect(instance.active?).to be true
            end
          end

          context 'and the current time > end_at' do
            it 'returns false' do
              instance = experiment_with_time(end_at: (Time.zone.now-3600).iso8601)
              expect(instance.active?).to be false
            end
          end
        end

        context 'when the experiment only have a start_at time' do
          context 'and the current time < start_at' do
            it 'returns false' do
              instance = experiment_with_time(start_at: (Time.zone.now+3600).iso8601)
              expect(instance.active?).to be false
            end
          end

          context 'and the current time > start_at' do
            it 'returns true' do
              instance = experiment_with_time(start_at: (Time.zone.now-3600).iso8601)
              expect(instance.active?).to be true
            end
          end
        end

        context 'when the experiment both have a start_at and end_at time' do
          context 'and current_time < start_at' do
            it 'returns false' do
              instance = experiment_with_time(start_at: (Time.zone.now+3600).iso8601,
                                              end_at: (Time.zone.now+7200).iso8601)
              expect(instance.active?).to be false
            end
          end

          context 'and current_time > start_at and current time < end_at' do
            it 'returns true' do
              instance = experiment_with_time(start_at: (Time.zone.now-3600).iso8601,
                                              end_at: (Time.zone.now+7200).iso8601)
              expect(instance.active?).to be true
            end
          end

          context 'and current time > start_at and current time > end_at' do
            it 'returns false' do
              instance = experiment_with_time(start_at: (Time.zone.now-7200).iso8601,
                                              end_at: (Time.zone.now-3600).iso8601)
              expect(instance.active?).to be false
            end
          end
        end
      end
    end
  end

  describe '.find_all' do
    context 'when the EenyMeeny is configured with experiments', experiments: true do
      it 'returns those experiments' do
        instances = described_class.find_all
        expect(instances).to be_a Array
        expect(instances.size).to eq(2)
        instances.each do |instance|
          expect(instance).to be_a EenyMeeny::Experiment
        end
      end
    end

    context 'when EenyMeeny is not configured with experiments' do
      it 'returns an empty array' do
        expect(described_class.find_all).to eq([])
      end
    end
  end

  describe '.find_by_id' do
    context 'when EenyMeeny is configured with experiments', experiments: true do
      context 'and the given id exists' do
        it 'returns the experiment' do
          expect(described_class.find_by_id(:my_page)).to be_a EenyMeeny::Experiment
        end
      end

      context 'and the given id does not exist' do
        it 'returns nil' do
          expect(described_class.find_by_id(:experiment_missing)).to be_nil
        end
      end
    end

    context 'when EenyMeeny is not configured with experiments' do
      it 'returns nil' do
        expect(described_class.find_by_id(:experiment_missing)).to be_nil
      end
    end
  end

end