class TestDijkstra

# File test/dijkstra_test.rb, line 10
def setup
  @graph = AdjacencyGraph[1,2, 1,3, 2,3, 2,4, 3,4]

  @edge_weights = {
      [1, 2] => 10,
      [1, 3] => 1,
      [2, 3] => 1,
      [2, 4] => 1,
      [3, 4] => 10
  }

  @edge_weights_lambda = lambda { |edge| @edge_weights[edge] }
end

# File test/dijkstra_test.rb, line 131
def test_edge_weights_map_object_in_argument
  weights_map = EdgePropertiesMap.new(@edge_weights, @graph.directed?)
  dijkstra    = DijkstraAlgorithm.new(@graph, weights_map, DijkstraVisitor.new(@graph))

  assert_equal([1, 3, 2, 4], dijkstra.shortest_path(1, 4))
end

# File test/dijkstra_test.rb, line 126
def test_missing_edge_weight
  @edge_weights.delete([2, 3])
  assert_raises(ArgumentError, 'weight of edge (2, 3) is not defined') { shortest_path(1, 5) }
end

# File test/dijkstra_test.rb, line 116
def test_negative_edge_weight
  @edge_weights[[2, 3]] = -7
  assert_raises(ArgumentError, 'weight of edge (2, 3) is negative') { shortest_path(1, 5) }
end

# File test/dijkstra_test.rb, line 121
def test_negative_edge_weight_with_lambda
  @edge_weights[[2, 3]] = -7
  assert_raises(ArgumentError, 'weight of edge (2, 3) is negative') { shortest_path(1, 5, @edge_weights_lambda) }
end

# File test/dijkstra_test.rb, line 36
def test_path_for_unreachable_vertex
  @graph.add_vertex(5)
  assert_equal(nil, shortest_path(1, 5))
end

# File test/dijkstra_test.rb, line 24
def test_shortest_path_search
  assert_equal([1, 3, 2, 4], shortest_path(1, 4))
end

# File test/dijkstra_test.rb, line 28
def test_shortest_path_search_with_lambda
  assert_equal([1, 3, 2, 4], shortest_path(1, 4, @edge_weights_lambda))
end

# File test/dijkstra_test.rb, line 32
def test_shortest_path_to_the_source
  assert_equal([1], shortest_path(1, 1))
end

# File test/dijkstra_test.rb, line 41
def test_shortest_paths_search
  assert_equal(
      {
          1 => [1],
          2 => [1, 3, 2],
          3 => [1, 3],
          4 => [1, 3, 2, 4]
      },
      shortest_paths(1)
  )
end

# File test/dijkstra_test.rb, line 53
def test_shortest_paths_search_with_lambda
  assert_equal(
      {
          1 => [1],
          2 => [1, 3, 2],
          3 => [1, 3],
          4 => [1, 3, 2, 4]
      },
      shortest_paths(1, @edge_weights_lambda)
  )
end

# File test/dijkstra_test.rb, line 65
def test_shortest_paths_search_with_unreachable_vertex
  @graph.add_vertex(5)

  assert_equal(
      {
          1 => [1],
          2 => [1, 3, 2],
          3 => [1, 3],
          4 => [1, 3, 2, 4],
          5 => nil
      },
      shortest_paths(1)
  )
end

# File test/dijkstra_test.rb, line 80
def test_visitor
  visitor = DijkstraVisitor.new(@graph)

  events = []

  %w[examine_vertex examine_edge edge_relaxed edge_not_relaxed finish_vertex].each do |event|
    visitor.send("set_#{event}_event_handler") { |*args| events << { event.to_sym => args } }
  end

  @graph.dijkstra_shortest_paths(@edge_weights, 1, visitor)

  assert_equal(
      [
          { :examine_vertex => [1] },
          { :examine_edge   => [1, 2] },
          { :edge_relaxed   => [1, 2] },
          { :examine_edge   => [1, 3] },
          { :edge_relaxed   => [1, 3] },
          { :finish_vertex  => [1] },
          { :examine_vertex => [3] },
          { :examine_edge   => [3, 2] },
          { :edge_relaxed   => [3, 2] },
          { :examine_edge   => [3, 4] },
          { :edge_relaxed   => [3, 4] },
          { :finish_vertex  => [3] },
          { :examine_vertex => [2] },
          { :examine_edge   => [2, 4] },
          { :edge_relaxed   => [2, 4] },
          { :finish_vertex  => [2] },
          { :examine_vertex => [4] },
          { :finish_vertex  => [4] },
      ],
      events
  )
end