require 'test/spec'
require 'solve'

context "Solve" do
  specify "works for single variables" do
    v = Solve::Variable.new(:v)
    r = nil
    solve(v == 5) { |r|
      r[:v].should.equal 5
    }
    r.should.be.kind_of Hash
  end
  
  specify "works for &" do
    u = Solve::Variable.new(:u)
    v = Solve::Variable.new(:v)
    r = nil
    solve((u == 2) & (v == 5)) { |r|
      r[:u].should.equal 2
      r[:v].should.equal 5
    }
    r.should.be.kind_of Hash
  end

  specify "works for |" do
    u = Solve::Variable.new(:u)
    v = Solve::Variable.new(:v)
    n = 0
    solve((u == 2) | (v == 5)) { |r|
      n += 1
      case n
      when 1
        r[:u].should.equal 2
      when 2
        r[:v].should.equal 5
      end
    }
    n.should.be 2
  end

  specify "works for indirect variables" do
    u = Solve::Variable.new(:u)
    v = Solve::Variable.new(:v)
    r = nil
    solve((u == 5) & (v == u)) { |r|
      r[:u].should.equal 5
      r[:v].should.equal 5
    }
    r.should.be.kind_of Hash
  end

  specify "works for multiple &" do
    a, b, c = Solve.variables :a, :b, :c
    solve((a == 1) & (b == 2) & (c == a)) { |r|
      r.should.equal({:a => 1, :b => 2, :c => a})
    }
  end

  specify "works for multiple |" do
    a, b, c = Solve.variables :a, :b, :c
    rs = {}
    solve((a == 1) | (b == 2) | (c == a)) { |r|
      rs.update r
    }
    rs.should.equal({:a => 1, :b => 2, :c => a})
  end

  specify "works for mixed | and &" do
    a, b, c = Solve.variables :a, :b, :c
    solve((a == 1) & (b == 2) & ((c == a) | (c == b))).should.equal \
      [{:a=>1, :b=>2, :c=>1},
       {:a=>1, :b=>2, :c=>2}]
  end

  specify "works for ranges" do
    a = Solve::Variable.new :a
    solve(a.oneof(1..4)).should.equal [{:a => 1},{:a => 2},{:a => 3},{:a => 4}]
  end

  specify "works with negation" do
    a = Solve::Variable.new :a
    solve(a.oneof(1..4) & ~(a == 2)).should.equal [{:a => 1},{:a => 3},{:a => 4}]
  end

end