require 'spec_helper'

module Arel
  describe Attribute do
    before do
      @relation = Table.new(:users)
      @attribute = @relation[:id]
    end

    describe 'Attribute::Transformations' do
      describe '#as' do
        it "manufactures an aliased attributed" do
          @attribute.as(:alias).should == Attribute.new(@relation, @attribute.name, :alias => :alias, :ancestor => @attribute)
        end
      end

      describe '#bind' do
        it "manufactures an attribute with the relation bound and self as an ancestor" do
          derived_relation = @relation.where(@relation[:id].eq(1))
          @attribute.bind(derived_relation).should == Attribute.new(derived_relation, @attribute.name, :ancestor => @attribute)
        end

        it "returns self if the substituting to the same relation" do
          @attribute.bind(@relation).should == @attribute
        end
      end

      describe '#to_attribute' do
        describe 'when the given relation is the same as the attributes relation' do
          it "returns self" do
            @attribute.to_attribute(@relation).should == @attribute
          end
        end

        describe 'when the given relation differs from the attributes relation' do
          it 'binds to the new relation' do
            @attribute.to_attribute(new_relation = @relation.alias).should == @attribute.bind(new_relation)
          end
        end
      end
    end

    describe '#column' do
      it "returns the corresponding column in the relation" do
        @attribute.column.should == @relation.column_for(@attribute)
      end
    end

    describe '#engine' do
      it "delegates to its relation" do
        Attribute.new(@relation, :id).engine.should == @relation.engine
      end
    end

    describe 'Attribute::Congruence' do
      describe '/' do
        before do
          @aliased_relation = @relation.alias
          @doubly_aliased_relation = @aliased_relation.alias
        end

        describe 'when dividing two unrelated attributes' do
          it "returns 0.0" do
            (@relation[:id] / @relation[:name]).should == 0.0
          end
        end

        describe 'when dividing two matching attributes' do
          it 'returns a the highest score for the most similar attributes' do
            check((@aliased_relation[:id] / @relation[:id]).should == (@aliased_relation[:id] / @relation[:id]))
            (@aliased_relation[:id] / @relation[:id]).should < (@aliased_relation[:id] / @aliased_relation[:id])
          end
        end
      end
    end

    describe 'Attribute::Predications' do
      before do
        @attribute = Attribute.new(@relation, :name)
      end

      describe '#eq' do
        it "manufactures an equality predicate" do
          @attribute.eq('name').should == Predicates::Equality.new(@attribute, 'name')
        end
      end

      describe '#lt' do
        it "manufactures a less-than predicate" do
          @attribute.lt(10).should == Predicates::LessThan.new(@attribute, 10)
        end
      end

      describe '#lteq' do
        it "manufactures a less-than or equal-to predicate" do
          @attribute.lteq(10).should == Predicates::LessThanOrEqualTo.new(@attribute, 10)
        end
      end

      describe '#gt' do
        it "manufactures a greater-than predicate" do
          @attribute.gt(10).should == Predicates::GreaterThan.new(@attribute, 10)
        end
      end

      describe '#gteq' do
        it "manufactures a greater-than or equal-to predicate" do
          @attribute.gteq(10).should == Predicates::GreaterThanOrEqualTo.new(@attribute, 10)
        end
      end

      describe '#matches' do
        it "manufactures a match predicate" do
          @attribute.matches(/.*/).should == Predicates::Match.new(@attribute, /.*/)
        end
      end

      describe '#in' do
        it "manufactures an in predicate" do
          @attribute.in(1..30).should == Predicates::In.new(@attribute, (1..30))
        end
      end
    end

    describe Attribute::Expressions do
      before do
        @attribute = Attribute.new(@relation, :name)
      end

      describe '#count' do
        it "manufactures a count Expression" do
          @attribute.count.should == Count.new(@attribute)
        end
      end

      describe '#sum' do
        it "manufactures a sum Expression" do
          @attribute.sum.should == Sum.new(@attribute)
        end
      end

      describe '#maximum' do
        it "manufactures a maximum Expression" do
          @attribute.maximum.should == Maximum.new(@attribute)
        end
      end

      describe '#minimum' do
        it "manufactures a minimum Expression" do
          @attribute.minimum.should == Minimum.new(@attribute)
        end
      end

      describe '#average' do
        it "manufactures an average Expression" do
          @attribute.average.should == Average.new(@attribute)
        end
      end
    end

    describe Attribute::Orderings do
      describe '#asc' do
        it 'manufactures an ascending ordering' do
          @attribute.asc.should == Ascending.new(@attribute)
        end
      end

      describe '#desc' do
        it 'manufactures a descending ordering' do
          @attribute.desc.should == Descending.new(@attribute)
        end
      end
    end
  end
end