#!/usr/bin/ruby

$:.unshift File.join(File.dirname(__FILE__), "..", "lib")

require 'test/unit'
require 'OneOfEqualsConstraint'
require 'Variable'
require 'Domain'

module ConstraintSolver
    class OneOfEqualsConstraintTest < Test::Unit::TestCase
	def setup
	    @x = Variable.new("x", Domain.new([ 1, 2 ].to_set))
	    @y = Variable.new("y", Domain.new([ 1, 2 ].to_set))
	    @constraint = OneOfEqualsConstraint.new([ @x, @y ], 2)
	end

	def testConstructor
	    assert_raise(ArgumentError) { OneOfEqualsConstraint.new }
	    assert_raise(ArgumentError) { OneOfEqualsConstraint.new([], 1) }
	    assert_nothing_raised { OneOfEqualsConstraint.new([ @x, @y ], 2) }
	    assert_nothing_raised { OneOfEqualsConstraint.new([ @x, @y ], 2, 0) }
	end

	def testAssigned
	    assert_equal(false, @constraint.allAssigned?)
	    @x.value = 1
	    assert_equal(false, @constraint.allAssigned?)
	    @y.value = 1
	    assert_equal(true, @constraint.allAssigned?)
	    @x.reset
	    @y.reset
	end

	def testInclude
	    assert_equal(true, @constraint.include?(@x))
	    assert_equal(true, @constraint.include?(@y))
	    assert_equal(false, @constraint.include?(Variable.new("2", [ 3 ].to_set)))
	end

	def testHolds
	    assert_equal(true, @constraint.holds?)
	    @x.value = 1
	    @y.value = 1
	    assert_equal(false, @constraint.holds?)
	    @x.value = 2
	    @y.value = 2
	    assert_equal(true, @constraint.holds?)
	    @x.value = 1
	    @y.value = 2
	    assert_equal(true, @constraint.holds?)
	    @x.value = 2
	    @y.value = 1
	    assert_equal(true, @constraint.holds?)
	end

	def testEquals
	    assert_equal(OneOfEqualsConstraint.new([ @x, @y ], 2), @constraint)
	    assert_not_equal(OneOfEqualsConstraint.new([ Variable.new("z", Domain.new([ 1, 2 ].to_set)), @y ], 2), @constraint)
	    assert_not_equal(OneOfEqualsConstraint.new([ @x, @y ], 1), @constraint)
	end

	def testRevise
	    assert_equal([ [], 0, false ], @constraint.revise)
	    @y.value = 2
	    assert_equal([ [], 0, false ], @constraint.revise)
	    @y.value = 1
	    assert_equal([ [ @x ], 0, false ], @constraint.revise)
	    assert_equal([ 2 ].to_set, @x.domain.values)
	    @y.reset
	    @x.domain.undoPruning
	end
	
	def testFaulty
	    x = Variable.new("x", Domain.new([ 1, 2 ].to_set))
	    y = Variable.new("y", Domain.new([ 1, 2 ].to_set))
	    constraint = OneOfEqualsConstraint.new([ x, y ], 3)
	    y.value = 1
	    assert_equal([ [ x ], 0, true ], constraint.revise)
	end
    end
end