"""
    Unit tests for degree centrality.
"""


import networkx as nx
from networkx.testing import almost_equal

class TestDegreeCentrality:
    def setup_method(self):

        self.K = nx.krackhardt_kite_graph()
        self.P3 = nx.path_graph(3)
        self.K5 = nx.complete_graph(5)

        F = nx.Graph()  # Florentine families
        F.add_edge('Acciaiuoli', 'Medici')
        F.add_edge('Castellani', 'Peruzzi')
        F.add_edge('Castellani', 'Strozzi')
        F.add_edge('Castellani', 'Barbadori')
        F.add_edge('Medici', 'Barbadori')
        F.add_edge('Medici', 'Ridolfi')
        F.add_edge('Medici', 'Tornabuoni')
        F.add_edge('Medici', 'Albizzi')
        F.add_edge('Medici', 'Salviati')
        F.add_edge('Salviati', 'Pazzi')
        F.add_edge('Peruzzi', 'Strozzi')
        F.add_edge('Peruzzi', 'Bischeri')
        F.add_edge('Strozzi', 'Ridolfi')
        F.add_edge('Strozzi', 'Bischeri')
        F.add_edge('Ridolfi', 'Tornabuoni')
        F.add_edge('Tornabuoni', 'Guadagni')
        F.add_edge('Albizzi', 'Ginori')
        F.add_edge('Albizzi', 'Guadagni')
        F.add_edge('Bischeri', 'Guadagni')
        F.add_edge('Guadagni', 'Lamberteschi')
        self.F = F

        G = nx.DiGraph()
        G.add_edge(0, 5)
        G.add_edge(1, 5)
        G.add_edge(2, 5)
        G.add_edge(3, 5)
        G.add_edge(4, 5)
        G.add_edge(5, 6)
        G.add_edge(5, 7)
        G.add_edge(5, 8)
        self.G = G

    def test_degree_centrality_1(self):
        d = nx.degree_centrality(self.K5)
        exact = dict(zip(range(5), [1] * 5))
        for n, dc in d.items():
            assert almost_equal(exact[n], dc)

    def test_degree_centrality_2(self):
        d = nx.degree_centrality(self.P3)
        exact = {0: 0.5, 1: 1, 2: 0.5}
        for n, dc in d.items():
            assert almost_equal(exact[n], dc)

    def test_degree_centrality_3(self):
        d = nx.degree_centrality(self.K)
        exact = {0: .444, 1: .444, 2: .333, 3: .667, 4: .333,
                 5: .556, 6: .556, 7: .333, 8: .222, 9: .111}
        for n, dc in d.items():
            assert almost_equal(exact[n], float("%5.3f" % dc))

    def test_degree_centrality_4(self):
        d = nx.degree_centrality(self.F)
        names = sorted(self.F.nodes())
        dcs = [0.071, 0.214, 0.143, 0.214, 0.214, 0.071, 0.286,
               0.071, 0.429, 0.071, 0.214, 0.214, 0.143, 0.286, 0.214]
        exact = dict(zip(names, dcs))
        for n, dc in d.items():
            assert almost_equal(exact[n], float("%5.3f" % dc))

    def test_indegree_centrality(self):
        d = nx.in_degree_centrality(self.G)
        exact = {0: 0.0, 1: 0.0, 2: 0.0, 3: 0.0, 4: 0.0,
                 5: 0.625, 6: 0.125, 7: 0.125, 8: 0.125}
        for n, dc in d.items():
            assert almost_equal(exact[n], dc)

    def test_outdegree_centrality(self):
        d = nx.out_degree_centrality(self.G)
        exact = {0: 0.125, 1: 0.125, 2: 0.125, 3: 0.125,
                 4: 0.125, 5: 0.375, 6: 0.0, 7: 0.0, 8: 0.0}
        for n, dc in d.items():
            assert almost_equal(exact[n], dc)

    def test_small_graph_centrality(self):
        G = nx.empty_graph(create_using=nx.DiGraph)
        assert {} == nx.degree_centrality(G)
        assert {} == nx.out_degree_centrality(G)
        assert {} == nx.in_degree_centrality(G)

        G = nx.empty_graph(1, create_using=nx.DiGraph)
        assert {0: 1} == nx.degree_centrality(G)
        assert {0: 1} == nx.out_degree_centrality(G)
        assert {0: 1} == nx.in_degree_centrality(G)