# coding: utf-8
require File.expand_path(File.dirname(__FILE__) + '/spec_helper')

describe "MutuallyExclusiveCollection" do

  context "non-arbitrage methods" do
    before(:each) do    
      @good_team = FixedOdds.from_s '-275'
      @draw = FixedOdds.from_s '+429'
      @bad_team = FixedOdds.from_s '+915'

      @events = MutuallyExclusiveCollection.new [@draw, @bad_team, @good_team]
    end

    subject { @events }

    its(:most_likely) { should == @good_team }
    its(:least_likely) { should == @bad_team }
    its(:in_descending_probability) { should == [@good_team, @draw, @bad_team] }
    its(:in_ascending_probability) { should == [@bad_team, @draw, @good_team] }
  end

  context "empty array" do
    before(:each) do
      @bookmaker = MutuallyExclusiveCollection.new []
    end

    specify { @bookmaker.bookmakers_return_rate.should be_nil }
  end

  context "decimal odds arbitrage" do
    before(:each) do
      @bookmaker1outcome1 = FixedOdds.from_s '2.25'
      @bookmaker1outcome2 = FixedOdds.from_s '4.9'
      @bookmaker2outcome1 = FixedOdds.from_s '2.43'
      @bookmaker2outcome2 = FixedOdds.from_s '3.85'

      @bookmaker1 = MutuallyExclusiveCollection.new [@bookmaker1outcome1, @bookmaker1outcome2]
      @bookmaker2 = MutuallyExclusiveCollection.new [@bookmaker2outcome1, @bookmaker2outcome2]

      @bookmaker_vulnerable_to_arbitrage = MutuallyExclusiveCollection.new [@bookmaker2outcome1, @bookmaker1outcome2]
    end

    specify { @bookmaker1.should_not be_arbitrageable }
    specify { @bookmaker2.should_not be_arbitrageable } 
    specify { @bookmaker_vulnerable_to_arbitrage.should be_arbitrageable }

    specify { @bookmaker1.bookmakers_return_rate.should be_within(0.0001).of(0.0534) }
    specify { @bookmaker2.bookmakers_return_rate.should be_within(0.0001).of(0.0478) }

    specify { @bookmaker_vulnerable_to_arbitrage.profit_on_stake('£100'.to_money).should == '£4.63'.to_money }
    specify { @bookmaker_vulnerable_to_arbitrage.profit_percentage.should be_within(0.001).of(0.046) }
  end

  context "fractional odds arbitrage" do
    before(:each) do
      @odds1 = FixedOdds.from_s '2/1'
      @odds2 = FixedOdds.from_s '3/1'

      @bookmaker_vulnerable_to_arbitrage = MutuallyExclusiveCollection.new [@odds1, @odds2]
    end

    subject { @bookmaker_vulnerable_to_arbitrage }

    specify { @bookmaker_vulnerable_to_arbitrage.should be_arbitrageable }
    its(:profit_percentage) { should be_within(0.001).of(0.2) }
    specify { @bookmaker_vulnerable_to_arbitrage.profit_on_stake('£500'.to_money).should == '£100'.to_money }
  end

  context "more than two mutually exclusive events" do
    before(:each) do
      @odds1 = FixedOdds.from_s '2.3'
      @odds2 = FixedOdds.from_s '8.0'
      @odds3 = FixedOdds.from_s '18.0'

      @bookmaker_vulnerable_to_arbitrage = MutuallyExclusiveCollection.new [@odds1, @odds2, @odds3]
    end

    subject { @bookmaker_vulnerable_to_arbitrage }

    specify { @bookmaker_vulnerable_to_arbitrage.should be_arbitrageable }
    its(:profit_percentage) { should be_within(0.0000001).of(0.02996) }

    describe "#percentages" do
      it "gives the percentages to put on each bet" do
        percentages = @bookmaker_vulnerable_to_arbitrage.percentages
        percentages.should have(3).items
        percentages[@odds1].should be_within(0.0001).of(0.7922)
        percentages[@odds2].should be_within(0.0001).of(0.1472)
        percentages[@odds3].should be_within(0.0001).of(0.0606)
      end
    end

    describe "#stakes_for_total_stake" do
      it "gives the right amounts" do
        total = Money.parse '£500'
        amounts = @bookmaker_vulnerable_to_arbitrage.stakes_for_total_stake total
        amounts.should have(3).items
        amounts[@odds1].should == '£396.14'.to_money
        amounts[@odds2].should == '£73.57'.to_money
        amounts[@odds3].should == '£30.29'.to_money
        amounts.values.reduce(:+).should == total
      end
    end

    specify { @bookmaker_vulnerable_to_arbitrage.profit_on_stake('£500'.to_money).should == '£14.98'.to_money }

    describe "#stakes_for_profit" do
      it "gives the right amounts" do
        amounts = @bookmaker_vulnerable_to_arbitrage.stakes_for_profit '£750'.to_money
        amounts.should have(3).items
        amounts[@odds1].should == '£19833.33'.to_money
        amounts[@odds2].should == '£3683.33'.to_money
        amounts[@odds3].should == '£1516.67'.to_money
        amounts.values.reduce(:+).should == '£25033.33'.to_money
      end
    end

    specify { @bookmaker_vulnerable_to_arbitrage.stake_to_profit('£750'.to_money).should == '£25033.33'.to_money }
  end

  context "different events with same odds" do
    before(:each) do
      @odds1 = FixedOdds.from_s '15/1'
      @odds2 = FixedOdds.from_s '15/1'

      @bookmaker_vulnerable_to_arbitrage = MutuallyExclusiveCollection.new [@odds1, @odds2]
    end

    specify { @bookmaker_vulnerable_to_arbitrage.should be_arbitrageable }
    specify { @bookmaker_vulnerable_to_arbitrage.profit_on_stake('£100'.to_money).should == '£650'.to_money }

    describe "#percentages" do
      it "gives the percentages to put on each bet" do
        percentages = @bookmaker_vulnerable_to_arbitrage.percentages
        percentages.should have(2).items
        percentages[@odds1].should be_within(0.0001).of(0.5)
        percentages[@odds2].should be_within(0.0001).of(0.5)
      end
    end
  end
end