import pytest
import networkx as nx
from networkx.testing import assert_edges_equal


def test_union_attributes():
    g = nx.Graph()
    g.add_node(0, x=4)
    g.add_node(1, x=5)
    g.add_edge(0, 1, size=5)
    g.graph['name'] = 'g'

    h = g.copy()
    h.graph['name'] = 'h'
    h.graph['attr'] = 'attr'
    h.nodes[0]['x'] = 7

    gh = nx.union(g, h, rename=('g', 'h'))
    assert set(gh.nodes()) == set(['h0', 'h1', 'g0', 'g1'])
    for n in gh:
        graph, node = n
        assert gh.nodes[n] == eval(graph).nodes[int(node)]

    assert gh.graph['attr'] == 'attr'
    assert gh.graph['name'] == 'h'  # h graph attributes take precendent


def test_intersection():
    G = nx.Graph()
    H = nx.Graph()
    G.add_nodes_from([1, 2, 3, 4])
    G.add_edge(1, 2)
    G.add_edge(2, 3)
    H.add_nodes_from([1, 2, 3, 4])
    H.add_edge(2, 3)
    H.add_edge(3, 4)
    I = nx.intersection(G, H)
    assert set(I.nodes()) == set([1, 2, 3, 4])
    assert sorted(I.edges()) == [(2, 3)]


def test_intersection_attributes():
    g = nx.Graph()
    g.add_node(0, x=4)
    g.add_node(1, x=5)
    g.add_edge(0, 1, size=5)
    g.graph['name'] = 'g'

    h = g.copy()
    h.graph['name'] = 'h'
    h.graph['attr'] = 'attr'
    h.nodes[0]['x'] = 7

    gh = nx.intersection(g, h)
    assert set(gh.nodes()) == set(g.nodes())
    assert set(gh.nodes()) == set(h.nodes())
    assert sorted(gh.edges()) == sorted(g.edges())

    h.remove_node(0)
    pytest.raises(nx.NetworkXError, nx.intersection, g, h)


def test_intersection_multigraph_attributes():
    g = nx.MultiGraph()
    g.add_edge(0, 1, key=0)
    g.add_edge(0, 1, key=1)
    g.add_edge(0, 1, key=2)
    h = nx.MultiGraph()
    h.add_edge(0, 1, key=0)
    h.add_edge(0, 1, key=3)
    gh = nx.intersection(g, h)
    assert set(gh.nodes()) == set(g.nodes())
    assert set(gh.nodes()) == set(h.nodes())
    assert sorted(gh.edges()) == [(0, 1)]
    assert sorted(gh.edges(keys=True)) == [(0, 1, 0)]


def test_difference():
    G = nx.Graph()
    H = nx.Graph()
    G.add_nodes_from([1, 2, 3, 4])
    G.add_edge(1, 2)
    G.add_edge(2, 3)
    H.add_nodes_from([1, 2, 3, 4])
    H.add_edge(2, 3)
    H.add_edge(3, 4)
    D = nx.difference(G, H)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == [(1, 2)]
    D = nx.difference(H, G)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == [(3, 4)]
    D = nx.symmetric_difference(G, H)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == [(1, 2), (3, 4)]


def test_difference2():
    G = nx.Graph()
    H = nx.Graph()
    G.add_nodes_from([1, 2, 3, 4])
    H.add_nodes_from([1, 2, 3, 4])
    G.add_edge(1, 2)
    H.add_edge(1, 2)
    G.add_edge(2, 3)
    D = nx.difference(G, H)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == [(2, 3)]
    D = nx.difference(H, G)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == []
    H.add_edge(3, 4)
    D = nx.difference(H, G)
    assert set(D.nodes()) == set([1, 2, 3, 4])
    assert sorted(D.edges()) == [(3, 4)]


def test_difference_attributes():
    g = nx.Graph()
    g.add_node(0, x=4)
    g.add_node(1, x=5)
    g.add_edge(0, 1, size=5)
    g.graph['name'] = 'g'

    h = g.copy()
    h.graph['name'] = 'h'
    h.graph['attr'] = 'attr'
    h.nodes[0]['x'] = 7

    gh = nx.difference(g, h)
    assert set(gh.nodes()) == set(g.nodes())
    assert set(gh.nodes()) == set(h.nodes())
    assert sorted(gh.edges()) == []

    h.remove_node(0)
    pytest.raises(nx.NetworkXError, nx.intersection, g, h)


def test_difference_multigraph_attributes():
    g = nx.MultiGraph()
    g.add_edge(0, 1, key=0)
    g.add_edge(0, 1, key=1)
    g.add_edge(0, 1, key=2)
    h = nx.MultiGraph()
    h.add_edge(0, 1, key=0)
    h.add_edge(0, 1, key=3)
    gh = nx.difference(g, h)
    assert set(gh.nodes()) == set(g.nodes())
    assert set(gh.nodes()) == set(h.nodes())
    assert sorted(gh.edges()) == [(0, 1), (0, 1)]
    assert sorted(gh.edges(keys=True)) == [(0, 1, 1), (0, 1, 2)]


def test_difference_raise():
    G = nx.path_graph(4)
    H = nx.path_graph(3)
    pytest.raises(nx.NetworkXError, nx.difference, G, H)
    pytest.raises(nx.NetworkXError, nx.symmetric_difference, G, H)


def test_symmetric_difference_multigraph():
    g = nx.MultiGraph()
    g.add_edge(0, 1, key=0)
    g.add_edge(0, 1, key=1)
    g.add_edge(0, 1, key=2)
    h = nx.MultiGraph()
    h.add_edge(0, 1, key=0)
    h.add_edge(0, 1, key=3)
    gh = nx.symmetric_difference(g, h)
    assert set(gh.nodes()) == set(g.nodes())
    assert set(gh.nodes()) == set(h.nodes())
    assert sorted(gh.edges()) == 3 * [(0, 1)]
    assert (sorted(sorted(e) for e in gh.edges(keys=True)) ==
                 [[0, 1, 1], [0, 1, 2], [0, 1, 3]])


def test_union_and_compose():
    K3 = nx.complete_graph(3)
    P3 = nx.path_graph(3)

    G1 = nx.DiGraph()
    G1.add_edge('A', 'B')
    G1.add_edge('A', 'C')
    G1.add_edge('A', 'D')
    G2 = nx.DiGraph()
    G2.add_edge('1', '2')
    G2.add_edge('1', '3')
    G2.add_edge('1', '4')

    G = nx.union(G1, G2)
    H = nx.compose(G1, G2)
    assert_edges_equal(G.edges(), H.edges())
    assert not G.has_edge('A', 1)
    pytest.raises(nx.NetworkXError, nx.union, K3, P3)
    H1 = nx.union(H, G1, rename=('H', 'G1'))
    assert (sorted(H1.nodes()) ==
                 ['G1A', 'G1B', 'G1C', 'G1D',
                  'H1', 'H2', 'H3', 'H4', 'HA', 'HB', 'HC', 'HD'])

    H2 = nx.union(H, G2, rename=("H", ""))
    assert (sorted(H2.nodes()) ==
                 ['1', '2', '3', '4',
                  'H1', 'H2', 'H3', 'H4', 'HA', 'HB', 'HC', 'HD'])

    assert not H1.has_edge('NB', 'NA')

    G = nx.compose(G, G)
    assert_edges_equal(G.edges(), H.edges())

    G2 = nx.union(G2, G2, rename=('', 'copy'))
    assert (sorted(G2.nodes()) ==
                 ['1', '2', '3', '4', 'copy1', 'copy2', 'copy3', 'copy4'])

    assert sorted(G2.neighbors('copy4')) == []
    assert sorted(G2.neighbors('copy1')) == ['copy2', 'copy3', 'copy4']
    assert len(G) == 8
    assert nx.number_of_edges(G) == 6

    E = nx.disjoint_union(G, G)
    assert len(E) == 16
    assert nx.number_of_edges(E) == 12

    E = nx.disjoint_union(G1, G2)
    assert sorted(E.nodes()) == [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

    G = nx.Graph()
    H = nx.Graph()
    G.add_nodes_from([(1, {'a1': 1})])
    H.add_nodes_from([(1, {'b1': 1})])
    R = nx.compose(G, H)
    assert R.nodes == {1: {'a1': 1, 'b1': 1}}


def test_union_multigraph():
    G = nx.MultiGraph()
    G.add_edge(1, 2, key=0)
    G.add_edge(1, 2, key=1)
    H = nx.MultiGraph()
    H.add_edge(3, 4, key=0)
    H.add_edge(3, 4, key=1)
    GH = nx.union(G, H)
    assert set(GH) == set(G) | set(H)
    assert (set(GH.edges(keys=True)) ==
                 set(G.edges(keys=True)) | set(H.edges(keys=True)))


def test_disjoint_union_multigraph():
    G = nx.MultiGraph()
    G.add_edge(0, 1, key=0)
    G.add_edge(0, 1, key=1)
    H = nx.MultiGraph()
    H.add_edge(2, 3, key=0)
    H.add_edge(2, 3, key=1)
    GH = nx.disjoint_union(G, H)
    assert set(GH) == set(G) | set(H)
    assert (set(GH.edges(keys=True)) ==
                 set(G.edges(keys=True)) | set(H.edges(keys=True)))


def test_compose_multigraph():
    G = nx.MultiGraph()
    G.add_edge(1, 2, key=0)
    G.add_edge(1, 2, key=1)
    H = nx.MultiGraph()
    H.add_edge(3, 4, key=0)
    H.add_edge(3, 4, key=1)
    GH = nx.compose(G, H)
    assert set(GH) == set(G) | set(H)
    assert (set(GH.edges(keys=True)) ==
                 set(G.edges(keys=True)) | set(H.edges(keys=True)))
    H.add_edge(1, 2, key=2)
    GH = nx.compose(G, H)
    assert set(GH) == set(G) | set(H)
    assert (set(GH.edges(keys=True)) ==
                 set(G.edges(keys=True)) | set(H.edges(keys=True)))


def test_full_join_graph():
    # Simple Graphs
    G = nx.Graph()
    G.add_node(0)
    G.add_edge(1, 2)
    H = nx.Graph()
    H.add_edge(3, 4)

    U = nx.full_join(G, H)
    assert set(U) == set(G) | set(H)
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H))

    # Rename
    U = nx.full_join(G, H, rename=('g', 'h'))
    assert set(U) == set(['g0', 'g1', 'g2', 'h3', 'h4'])
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H))

    # Rename graphs with string-like nodes
    G = nx.Graph()
    G.add_node("a")
    G.add_edge("b", "c")
    H = nx.Graph()
    H.add_edge("d", "e")

    U = nx.full_join(G, H, rename=('g', 'h'))
    assert set(U) == set(['ga', 'gb', 'gc', 'hd', 'he'])
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H))

    # DiGraphs
    G = nx.DiGraph()
    G.add_node(0)
    G.add_edge(1, 2)
    H = nx.DiGraph()
    H.add_edge(3, 4)

    U = nx.full_join(G, H)
    assert set(U) == set(G) | set(H)
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G)*len(H) * 2)

    # DiGraphs Rename
    U = nx.full_join(G, H, rename=('g', 'h'))
    assert set(U) == set(['g0', 'g1', 'g2', 'h3', 'h4'])
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H) * 2)


def test_full_join_multigraph():
    # MultiGraphs
    G = nx.MultiGraph()
    G.add_node(0)
    G.add_edge(1, 2)
    H = nx.MultiGraph()
    H.add_edge(3, 4)

    U = nx.full_join(G, H)
    assert set(U) == set(G) | set(H)
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H))

    # MultiGraphs rename
    U = nx.full_join(G, H, rename=('g', 'h'))
    assert set(U) == set(['g0', 'g1', 'g2', 'h3', 'h4'])
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H))

    # MultiDiGraphs
    G = nx.MultiDiGraph()
    G.add_node(0)
    G.add_edge(1, 2)
    H = nx.MultiDiGraph()
    H.add_edge(3, 4)

    U = nx.full_join(G, H)
    assert set(U) == set(G) | set(H)
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H) * 2)

    # MultiDiGraphs rename
    U = nx.full_join(G, H, rename=('g', 'h'))
    assert set(U) == set(['g0', 'g1', 'g2', 'h3', 'h4'])
    assert len(U) == len(G) + len(H)
    assert (len(U.edges()) ==
                 len(G.edges()) + len(H.edges()) + len(G) * len(H) * 2)


def test_mixed_type_union():
    G = nx.Graph()
    H = nx.MultiGraph()
    pytest.raises(nx.NetworkXError, nx.union, G, H)
    pytest.raises(nx.NetworkXError, nx.disjoint_union, G, H)
    pytest.raises(nx.NetworkXError, nx.intersection, G, H)
    pytest.raises(nx.NetworkXError, nx.difference, G, H)
    pytest.raises(nx.NetworkXError, nx.symmetric_difference, G, H)
    pytest.raises(nx.NetworkXError, nx.compose, G, H)