require 'spec_helper'

# TODO change some of these tests to use Rack::Test

describe Split::Helper do
  include Split::Helper

  before(:each) do
    Split.redis.flushall
    @session = {}
    params = nil
  end

  describe "ab_test" do
    it "should assign a random alternative to a new user when there are an equal number of alternatives assigned" do
      ab_test('link_color', 'blue', 'red')
      ['red', 'blue'].should include(ab_user['link_color'])
    end

    it "should increment the participation counter after assignment to a new user" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')

      previous_red_count = Split::Alternative.new('red', 'link_color').participant_count
      previous_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

      ab_test('link_color', 'blue', 'red')

      new_red_count = Split::Alternative.new('red', 'link_color').participant_count
      new_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

      (new_red_count + new_blue_count).should eql(previous_red_count + previous_blue_count + 1)
    end

    it "should return the given alternative for an existing user" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative = ab_test('link_color', 'blue', 'red')
      repeat_alternative = ab_test('link_color', 'blue', 'red')
      alternative.should eql repeat_alternative
    end

    it 'should always return the winner if one is present' do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      experiment.winner = "orange"

      ab_test('link_color', 'blue', 'red').should == 'orange'
    end

    it "should allow the alternative to be force by passing it in the params" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      @params = {'link_color' => 'blue'}
      alternative = ab_test('link_color', 'blue', 'red')
      alternative.should eql('blue')
      alternative = ab_test('link_color', {'blue' => 1}, 'red' => 5)
      alternative.should eql('blue')
      @params = {'link_color' => 'red'}
      alternative = ab_test('link_color', 'blue', 'red')
      alternative.should eql('red')
      alternative = ab_test('link_color', {'blue' => 5}, 'red' => 1)
      alternative.should eql('red')
    end

    it "should allow passing a block" do
      alt = ab_test('link_color', 'blue', 'red')
      ret = ab_test('link_color', 'blue', 'red') { |alternative| "shared/#{alternative}" }
      ret.should eql("shared/#{alt}")
    end

    it "should allow the share of visitors see an alternative to be specificed" do
      ab_test('link_color', {'blue' => 0.8}, {'red' => 20})
      ['red', 'blue'].should include(ab_user['link_color'])
    end

    it "should allow alternative weighting interface as a single hash" do
      ab_test('link_color', {'blue' => 0.01}, 'red' => 0.2)
      experiment = Split::Experiment.find('link_color')
      experiment.alternative_names.should eql(['blue', 'red'])
    end

    it "should only let a user participate in one experiment at a time" do
      ab_test('link_color', 'blue', 'red')
      ab_test('button_size', 'small', 'big')
      ab_user['button_size'].should eql('small')
      big = Split::Alternative.new('big', 'button_size')
      big.participant_count.should eql(0)
      small = Split::Alternative.new('small', 'button_size')
      small.participant_count.should eql(0)
    end

    it "should let a user participate in many experiment with allow_multiple_experiments option" do
      Split.configure do |config|
        config.allow_multiple_experiments = true
      end
      link_color = ab_test('link_color', 'blue', 'red')
      button_size = ab_test('button_size', 'small', 'big')
      ab_user['button_size'].should eql(button_size)
      button_size_alt = Split::Alternative.new(button_size, 'button_size')
      button_size_alt.participant_count.should eql(1)
    end
  end

  describe 'finished' do
    before(:each) do
      @experiment_name = 'link_color'
      @alternatives = ['blue', 'red']
      @experiment = Split::Experiment.find_or_create(@experiment_name, *@alternatives)
      @alternative_name = ab_test(@experiment_name, *@alternatives)
      @previous_completion_count = Split::Alternative.new(@alternative_name, @experiment_name).completed_count
    end

    it 'should increment the counter for the completed alternative' do
      finished(@experiment_name)
      new_completion_count = Split::Alternative.new(@alternative_name, @experiment_name).completed_count
      new_completion_count.should eql(@previous_completion_count + 1)
    end

    it "should set experiment's finished key if reset is false" do
      finished(@experiment_name, :reset => false)
      session[:split].should eql(@experiment.key => @alternative_name, @experiment.finished_key => true)
    end

    it 'should not increment the counter if reset is false and the experiment has been already finished' do
      2.times { finished(@experiment_name, :reset => false) }
      new_completion_count = Split::Alternative.new(@alternative_name, @experiment_name).completed_count
      new_completion_count.should eql(@previous_completion_count + 1)
    end

    it "should clear out the user's participation from their session" do
      session[:split].should eql(@experiment.key => @alternative_name)
      finished(@experiment_name)
      session[:split].should == {}
    end

    it "should not clear out the users session if reset is false" do
      session[:split].should eql(@experiment.key => @alternative_name)
      finished(@experiment_name, :reset => false)
      session[:split].should eql(@experiment.key => @alternative_name, @experiment.finished_key => true)
    end

    it "should reset the users session when experiment is not versioned" do
      session[:split].should eql(@experiment.key => @alternative_name)
      finished(@experiment_name)
      session[:split].should eql({})
    end

    it "should reset the users session when experiment is versioned" do
      @experiment.increment_version
      @alternative_name = ab_test(@experiment_name, *@alternatives)

      session[:split].should eql(@experiment.key => @alternative_name)
      finished(@experiment_name)
      session[:split].should eql({})
    end

    it "should do nothing where the experiment was not started by this user" do
      session[:split] = nil
      lambda { finished('some_experiment_not_started_by_the_user') }.should_not raise_exception
    end
  end

  describe 'conversions' do
    it 'should return a conversion rate for an alternative' do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative_name = ab_test('link_color', 'blue', 'red')

      previous_convertion_rate = Split::Alternative.new(alternative_name, 'link_color').conversion_rate
      previous_convertion_rate.should eql(0.0)

      finished('link_color')

      new_convertion_rate = Split::Alternative.new(alternative_name, 'link_color').conversion_rate
      new_convertion_rate.should eql(1.0)
    end
  end

  describe 'when user is a robot' do
    before(:each) do
      @request = OpenStruct.new(:user_agent => 'Googlebot/2.1 (+http://www.google.com/bot.html)')
    end

    describe 'ab_test' do
      it 'should return the control' do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
        alternative = ab_test('link_color', 'blue', 'red')
        alternative.should eql experiment.control.name
      end

      it "should not increment the participation count" do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')

        previous_red_count = Split::Alternative.new('red', 'link_color').participant_count
        previous_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

        ab_test('link_color', 'blue', 'red')

        new_red_count = Split::Alternative.new('red', 'link_color').participant_count
        new_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

        (new_red_count + new_blue_count).should eql(previous_red_count + previous_blue_count)
      end
    end
    describe 'finished' do
      it "should not increment the completed count" do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
        alternative_name = ab_test('link_color', 'blue', 'red')

        previous_completion_count = Split::Alternative.new(alternative_name, 'link_color').completed_count

        finished('link_color')

        new_completion_count = Split::Alternative.new(alternative_name, 'link_color').completed_count

        new_completion_count.should eql(previous_completion_count)
      end
    end
  end
  describe 'when ip address is ignored' do
    before(:each) do
      @request = OpenStruct.new(:ip => '81.19.48.130')
      Split.configure do |c|
        c.ignore_ip_addresses << '81.19.48.130'
      end
    end

    describe 'ab_test' do
      it 'should return the control' do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
        alternative = ab_test('link_color', 'blue', 'red')
        alternative.should eql experiment.control.name
      end

      it "should not increment the participation count" do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')

        previous_red_count = Split::Alternative.new('red', 'link_color').participant_count
        previous_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

        ab_test('link_color', 'blue', 'red')

        new_red_count = Split::Alternative.new('red', 'link_color').participant_count
        new_blue_count = Split::Alternative.new('blue', 'link_color').participant_count

        (new_red_count + new_blue_count).should eql(previous_red_count + previous_blue_count)
      end
    end
    describe 'finished' do
      it "should not increment the completed count" do
        experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
        alternative_name = ab_test('link_color', 'blue', 'red')

        previous_completion_count = Split::Alternative.new(alternative_name, 'link_color').completed_count

        finished('link_color')

        new_completion_count = Split::Alternative.new(alternative_name, 'link_color').completed_count

        new_completion_count.should eql(previous_completion_count)
      end
    end
  end

  describe 'versioned experiments' do
    it "should use version zero if no version is present" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative_name = ab_test('link_color', 'blue', 'red')
      experiment.version.should eql(0)
      session[:split].should eql({'link_color' => alternative_name})
    end

    it "should save the version of the experiment to the session" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      experiment.reset
      experiment.version.should eql(1)
      alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color:1' => alternative_name})
    end

    it "should load the experiment even if the version is not 0" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      experiment.reset
      experiment.version.should eql(1)
      alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color:1' => alternative_name})
      return_alternative_name = ab_test('link_color', 'blue', 'red')
      return_alternative_name.should eql(alternative_name)
    end

    it "should reset the session of a user on an older version of the experiment" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color' => alternative_name})
      alternative = Split::Alternative.new(alternative_name, 'link_color')
      alternative.participant_count.should eql(1)

      experiment.reset
      experiment.version.should eql(1)
      alternative = Split::Alternative.new(alternative_name, 'link_color')
      alternative.participant_count.should eql(0)

      new_alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split]['link_color:1'].should eql(new_alternative_name)
      new_alternative = Split::Alternative.new(new_alternative_name, 'link_color')
      new_alternative.participant_count.should eql(1)
    end

    it "should cleanup old versions of experiments from the session" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color' => alternative_name})
      alternative = Split::Alternative.new(alternative_name, 'link_color')
      alternative.participant_count.should eql(1)

      experiment.reset
      experiment.version.should eql(1)
      alternative = Split::Alternative.new(alternative_name, 'link_color')
      alternative.participant_count.should eql(0)

      new_alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color:1' => new_alternative_name})
    end

    it "should only count completion of users on the current version" do
      experiment = Split::Experiment.find_or_create('link_color', 'blue', 'red')
      alternative_name = ab_test('link_color', 'blue', 'red')
      session[:split].should eql({'link_color' => alternative_name})
      alternative = Split::Alternative.new(alternative_name, 'link_color')

      experiment.reset
      experiment.version.should eql(1)

      finished('link_color')
      alternative = Split::Alternative.new(alternative_name, 'link_color')
      alternative.completed_count.should eql(0)
    end
  end

  context 'when redis is not available' do

    before(:each) do
      Split.stub(:redis).and_raise(Errno::ECONNREFUSED.new)
    end

    context 'and db_failover config option is turned off' do

      before(:each) do
        Split.configure do |config|
          config.db_failover = false
        end
      end

      describe 'ab_test' do
        it 'should raise an exception' do
          lambda {
            ab_test('link_color', 'blue', 'red')
          }.should raise_error(Errno::ECONNREFUSED)
        end
      end

      describe 'finished' do
        it 'should raise an exception' do
          lambda {
            finished('link_color')
          }.should raise_error(Errno::ECONNREFUSED)
        end
      end

      describe "disable split testing" do

        before(:each) do
          Split.configure do |config|
            config.enabled = false
          end
        end

        after(:each) do
          Split.configure do |config|
            config.enabled = true
          end
        end

        it "should not attempt to connect to redis" do

          lambda {
            ab_test('link_color', 'blue', 'red')
          }.should_not raise_error(Errno::ECONNREFUSED)
        end

        it "should return control variable" do
          ab_test('link_color', 'blue', 'red').should eq('blue')
          lambda {
            finished('link_color')
          }.should_not raise_error(Errno::ECONNREFUSED)
        end

      end


    end

    context 'and db_failover config option is turned on' do

      before(:each) do
        Split.configure do |config|
          config.db_failover = true
        end
      end

      describe 'ab_test' do
        it 'should not raise an exception' do
          lambda {
            ab_test('link_color', 'blue', 'red')
          }.should_not raise_error(Errno::ECONNREFUSED)
        end
        it 'should call db_failover_on_db_error proc with error as parameter' do
          Split.configure do |config|
            config.db_failover_on_db_error = proc do |error|
              error.should be_a(Errno::ECONNREFUSED)
            end
          end
          Split.configuration.db_failover_on_db_error.should_receive(:call)
          ab_test('link_color', 'blue', 'red')
        end
        it 'should always use first alternative' do
          ab_test('link_color', 'blue', 'red').should eq('blue')
          ab_test('link_color', {'blue' => 0.01}, 'red' => 0.2).should eq('blue')
          ab_test('link_color', {'blue' => 0.8}, {'red' => 20}).should eq('blue')
          ab_test('link_color', 'blue', 'red') do |alternative|
            "shared/#{alternative}"
          end.should eq('shared/blue')
        end

        context 'and db_failover_allow_parameter_override config option is turned on' do
          before(:each) do
            Split.configure do |config|
              config.db_failover_allow_parameter_override = true
            end
          end

          context 'and given an override parameter' do
            it 'should use given override instead of the first alternative' do
              @params = {'link_color' => 'red'}
              ab_test('link_color', 'blue', 'red').should eq('red')
              ab_test('link_color', 'blue', 'red', 'green').should eq('red')
              ab_test('link_color', {'blue' => 0.01}, 'red' => 0.2).should eq('red')
              ab_test('link_color', {'blue' => 0.8}, {'red' => 20}).should eq('red')
              ab_test('link_color', 'blue', 'red') do |alternative|
                "shared/#{alternative}"
              end.should eq('shared/red')
            end
          end
        end
      end

      describe 'finished' do
        it 'should not raise an exception' do
          lambda {
            finished('link_color')
          }.should_not raise_error(Errno::ECONNREFUSED)
        end
        it 'should call db_failover_on_db_error proc with error as parameter' do
          Split.configure do |config|
            config.db_failover_on_db_error = proc do |error|
              error.should be_a(Errno::ECONNREFUSED)
            end
          end
          Split.configuration.db_failover_on_db_error.should_receive(:call)
          finished('link_color')
        end
      end


    end

  end

end