require 'test/unit'
require 'rgl/adjacency'

include RGL
include RGL::Edge

class TestUnDirectedGraph < Test::Unit::TestCase

  def setup
    @dg = AdjacencyGraph.new
    [[1,2],[2,3],[3,2],[2,4]].each do |(src,target)| 
      @dg.add_edge(src, target)
    end
  end

  def test_empty_graph
	dg = AdjacencyGraph.new
	assert(dg.empty?)
	assert(!dg.directed?)
	assert(!dg.has_edge?(2,1))
	assert(!dg.has_vertex?(3))
	# Non existend vertex result in a Name Error because each_key is
	# called for nil
	assert_raises(NoVertexError) {dg.out_degree(3)}
	assert_equal([],dg.vertices)
	assert_equal(0,dg.size)
	assert_equal(0,dg.num_vertices)
	assert_equal(0,dg.num_edges)
	assert_equal(UnDirectedEdge,dg.edge_class)
	assert([].eql?(dg.edges))
	assert([].eql?(dg.to_a))
  end

  def test_add
	dg = AdjacencyGraph.new
	dg.add_edge(1,2)
	assert(!dg.empty?)
	assert(dg.has_edge?(1,2))
	assert(dg.has_edge?(2,1), "Backwards edge not included!")
	assert(dg.has_vertex?(1) && dg.has_vertex?(2))
	assert(!dg.has_vertex?(3))

	assert_equal([1,2],dg.vertices.sort)
	assert([DirectedEdge.new(1,2)].eql?(dg.edges))
	assert_equal("(1=2)",dg.edges.to_s)

	assert_equal([2],dg.adjacent_vertices(1))
	assert_equal([1],dg.adjacent_vertices(2))

	assert_equal(1,dg.out_degree(1))
	assert_equal(1,dg.out_degree(2))
  end

  def test_edges
    assert_equal(3, @dg.edges.length)
	edges = [[1,2],[2,3],[2,4]].map {|x| UnDirectedEdge.new(*x)}
    assert_equal(edges, @dg.edges.sort)
#    assert_equal([0,1,2,3], @dg.edges.map {|l| l.info}.sort)
  end

  def test_vertices
    assert_equal([1,2,3,4], @dg.vertices.sort)
  end

  def test_edges_from_to?
    assert @dg.has_edge?(1,2)
    assert @dg.has_edge?(2,3)
    assert @dg.has_edge?(3,2)
    assert @dg.has_edge?(2,4)
    assert @dg.has_edge?(2,1)
    assert !@dg.has_edge?(3,1)
    assert !@dg.has_edge?(4,1)
    assert @dg.has_edge?(4,2)
  end

  def test_remove_edges
	@dg.remove_edge 1,2
	assert !@dg.has_edge?(1,2), "(1,2) should not be an edge any more."
	@dg.remove_edge 1,2
	assert !@dg.has_edge?(2,1)
	@dg.remove_vertex 3
	assert !@dg.has_vertex?(3), "3 should not be a vertex any more."
	assert !@dg.has_edge?(2,3)
	assert_equal([UnDirectedEdge.new(2,4)],@dg.edges)
  end

  def test_add_vertices
	dg = AdjacencyGraph.new
	dg.add_vertices 1,3,2,4
	assert_equal dg.vertices.sort, [1,2,3,4]

	dg.remove_vertices 1,3
	assert_equal dg.vertices.sort, [2,4]

	dg.remove_vertices 1,3,Object		# ones again
	assert_equal dg.vertices.sort, [2,4]
  end

  def test_reverse
    assert_equal(@dg, @dg.reverse)
  end
end
