#!/usr/bin/env python

import pytest


import networkx as nx
from networkx.testing import assert_nodes_equal
from .test_graph import BaseGraphTester, BaseAttrGraphTester, TestGraph
from .test_graph import TestEdgeSubgraph as TestGraphEdgeSubgraph


class BaseDiGraphTester(BaseGraphTester):
    def test_has_successor(self):
        G = self.K3
        assert G.has_successor(0, 1) == True
        assert G.has_successor(0, -1) == False

    def test_successors(self):
        G = self.K3
        assert sorted(G.successors(0)) == [1, 2]
        with pytest.raises(nx.NetworkXError):
            G.successors(-1)

    def test_has_predecessor(self):
        G = self.K3
        assert G.has_predecessor(0, 1) == True
        assert G.has_predecessor(0, -1) == False

    def test_predecessors(self):
        G = self.K3
        assert sorted(G.predecessors(0)) == [1, 2]
        with pytest.raises(nx.NetworkXError):
            G.predecessors(-1)

    def test_edges(self):
        G = self.K3
        assert sorted(G.edges()) == [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)]
        assert sorted(G.edges(0)) == [(0, 1), (0, 2)]
        assert sorted(G.edges([0, 1])) == [(0, 1), (0, 2), (1, 0), (1, 2)]
        with pytest.raises(nx.NetworkXError):
            G.edges(-1)

    def test_edges_data(self):
        G = self.K3
        all_edges = [(0, 1, {}), (0, 2, {}), (1, 0, {}), (1, 2, {}), (2, 0, {}), (2, 1, {})]
        assert sorted(G.edges(data=True)) == all_edges
        assert sorted(G.edges(0, data=True)) == all_edges[:2]
        assert sorted(G.edges([0, 1], data=True)) == all_edges[:4]
        with pytest.raises(nx.NetworkXError):
            G.edges(-1, True)

    def test_out_edges(self):
        G = self.K3
        assert sorted(G.out_edges()) == [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)]
        assert sorted(G.out_edges(0)) == [(0, 1), (0, 2)]
        with pytest.raises(nx.NetworkXError):
            G.out_edges(-1)

    def test_out_edges_dir(self):
        G = self.P3
        assert sorted(G.out_edges()) == [(0, 1), (1, 2)]
        assert sorted(G.out_edges(0)) == [(0, 1)]
        assert sorted(G.out_edges(2)) == []

    def test_out_edges_data(self):
        G = nx.DiGraph([(0, 1, {'data': 0}), (1, 0, {})])
        assert sorted(G.out_edges(data=True)) == [(0, 1, {'data': 0}), (1, 0, {})]
        assert sorted(G.out_edges(0, data=True)) == [(0, 1, {'data': 0})]
        assert sorted(G.out_edges(data='data')) == [(0, 1, 0), (1, 0, None)]
        assert sorted(G.out_edges(0, data='data')) == [(0, 1, 0)]

    def test_in_edges_dir(self):
        G = self.P3
        assert sorted(G.in_edges()) == [(0, 1), (1, 2)]
        assert sorted(G.in_edges(0)) == []
        assert sorted(G.in_edges(2)) == [(1, 2)]

    def test_in_edges_data(self):
        G = nx.DiGraph([(0, 1, {'data': 0}), (1, 0, {})])
        assert sorted(G.in_edges(data=True)) == [(0, 1, {'data': 0}), (1, 0, {})]
        assert sorted(G.in_edges(1, data=True)) == [(0, 1, {'data': 0})]
        assert sorted(G.in_edges(data='data')) == [(0, 1, 0), (1, 0, None)]
        assert sorted(G.in_edges(1, data='data')) == [(0, 1, 0)]

    def test_degree(self):
        G = self.K3
        assert sorted(G.degree()) == [(0, 4), (1, 4), (2, 4)]
        assert dict(G.degree()) == {0: 4, 1: 4, 2: 4}
        assert G.degree(0) == 4
        assert list(G.degree(iter([0]))) == [
                     (0, 4)]  # run through iterator

    def test_in_degree(self):
        G = self.K3
        assert sorted(G.in_degree()) == [(0, 2), (1, 2), (2, 2)]
        assert dict(G.in_degree()) == {0: 2, 1: 2, 2: 2}
        assert G.in_degree(0) == 2
        assert list(G.in_degree(iter([0]))) == [(0, 2)]  # run through iterator

    def test_in_degree_weighted(self):
        G = self.K3
        G.add_edge(0, 1, weight=0.3, other=1.2)
        assert sorted(G.in_degree(weight='weight')) == [(0, 2), (1, 1.3), (2, 2)]
        assert dict(G.in_degree(weight='weight')) == {0: 2, 1: 1.3, 2: 2}
        assert G.in_degree(1, weight='weight') == 1.3
        assert sorted(G.in_degree(weight='other')) == [(0, 2), (1, 2.2), (2, 2)]
        assert dict(G.in_degree(weight='other')) == {0: 2, 1: 2.2, 2: 2}
        assert G.in_degree(1, weight='other') == 2.2
        assert list(G.in_degree(iter([1]), weight='other')) == [(1, 2.2)]

    def test_out_degree_weighted(self):
        G = self.K3
        G.add_edge(0, 1, weight=0.3, other=1.2)
        assert sorted(G.out_degree(weight='weight')) == [(0, 1.3), (1, 2), (2, 2)]
        assert dict(G.out_degree(weight='weight')) == {0: 1.3, 1: 2, 2: 2}
        assert G.out_degree(0, weight='weight') == 1.3
        assert sorted(G.out_degree(weight='other')) == [(0, 2.2), (1, 2), (2, 2)]
        assert dict(G.out_degree(weight='other')) == {0: 2.2, 1: 2, 2: 2}
        assert G.out_degree(0, weight='other') == 2.2
        assert list(G.out_degree(iter([0]), weight='other')) == [(0, 2.2)]

    def test_out_degree(self):
        G = self.K3
        assert sorted(G.out_degree()) == [(0, 2), (1, 2), (2, 2)]
        assert dict(G.out_degree()) == {0: 2, 1: 2, 2: 2}
        assert G.out_degree(0) == 2
        assert list(G.out_degree(iter([0]))) == [(0, 2)]

    def test_size(self):
        G = self.K3
        assert G.size() == 6
        assert G.number_of_edges() == 6

    def test_to_undirected_reciprocal(self):
        G = self.Graph()
        G.add_edge(1, 2)
        assert G.to_undirected().has_edge(1, 2)
        assert not G.to_undirected(reciprocal=True).has_edge(1, 2)
        G.add_edge(2, 1)
        assert G.to_undirected(reciprocal=True).has_edge(1, 2)

    def test_reverse_copy(self):
        G = nx.DiGraph([(0, 1), (1, 2)])
        R = G.reverse()
        assert sorted(R.edges()) == [(1, 0), (2, 1)]
        R.remove_edge(1, 0)
        assert sorted(R.edges()) == [(2, 1)]
        assert sorted(G.edges()) == [(0, 1), (1, 2)]

    def test_reverse_nocopy(self):
        G = nx.DiGraph([(0, 1), (1, 2)])
        R = G.reverse(copy=False)
        assert sorted(R.edges()) == [(1, 0), (2, 1)]
        with pytest.raises(nx.NetworkXError):
            R.remove_edge(1, 0)

    def test_reverse_hashable(self):
        class Foo(object):
            pass
        x = Foo()
        y = Foo()
        G = nx.DiGraph()
        G.add_edge(x, y)
        assert_nodes_equal(G.nodes(), G.reverse().nodes())
        assert [(y, x)] == list(G.reverse().edges())


class BaseAttrDiGraphTester(BaseDiGraphTester, BaseAttrGraphTester):
    pass


class TestDiGraph(BaseAttrDiGraphTester, TestGraph):
    """Tests specific to dict-of-dict-of-dict digraph data structure"""

    def setup_method(self):
        self.Graph = nx.DiGraph
        # build dict-of-dict-of-dict K3
        ed1, ed2, ed3, ed4, ed5, ed6 = ({}, {}, {}, {}, {}, {})
        self.k3adj = {0: {1: ed1, 2: ed2}, 1: {0: ed3, 2: ed4}, 2: {0: ed5, 1: ed6}}
        self.k3edges = [(0, 1), (0, 2), (1, 2)]
        self.k3nodes = [0, 1, 2]
        self.K3 = self.Graph()
        self.K3._adj = self.K3._succ = self.k3adj
        self.K3._pred = {0: {1: ed3, 2: ed5}, 1: {0: ed1, 2: ed6}, 2: {0: ed2, 1: ed4}}
        self.K3._node = {}
        self.K3._node[0] = {}
        self.K3._node[1] = {}
        self.K3._node[2] = {}

        ed1, ed2 = ({}, {})
        self.P3 = self.Graph()
        self.P3._adj = {0: {1: ed1}, 1: {2: ed2}, 2: {}}
        self.P3._succ = self.P3._adj
        self.P3._pred = {0: {}, 1: {0: ed1}, 2: {1: ed2}}
        self.P3._node = {}
        self.P3._node[0] = {}
        self.P3._node[1] = {}
        self.P3._node[2] = {}

    def test_data_input(self):
        G = self.Graph({1: [2], 2: [1]}, name="test")
        assert G.name == "test"
        assert sorted(G.adj.items()) == [(1, {2: {}}), (2, {1: {}})]
        assert sorted(G.succ.items()) == [(1, {2: {}}), (2, {1: {}})]
        assert sorted(G.pred.items()) == [(1, {2: {}}), (2, {1: {}})]

    def test_add_edge(self):
        G = self.Graph()
        G.add_edge(0, 1)
        assert G.adj == {0: {1: {}}, 1: {}}
        assert G.succ == {0: {1: {}}, 1: {}}
        assert G.pred == {0: {}, 1: {0: {}}}
        G = self.Graph()
        G.add_edge(*(0, 1))
        assert G.adj == {0: {1: {}}, 1: {}}
        assert G.succ == {0: {1: {}}, 1: {}}
        assert G.pred == {0: {}, 1: {0: {}}}

    def test_add_edges_from(self):
        G = self.Graph()
        G.add_edges_from([(0, 1), (0, 2, {'data': 3})], data=2)
        assert G.adj == {0: {1: {'data': 2}, 2: {'data': 3}}, 1: {}, 2: {}}
        assert G.succ == {0: {1: {'data': 2}, 2: {'data': 3}}, 1: {}, 2: {}}
        assert G.pred == {0: {}, 1: {0: {'data': 2}}, 2: {0: {'data': 3}}}

        with pytest.raises(nx.NetworkXError):
            G.add_edges_from([(0,)])  # too few in tuple
        with pytest.raises(nx.NetworkXError):
            G.add_edges_from([(0, 1, 2, 3)])  # too many in tuple
        with pytest.raises(TypeError):
            G.add_edges_from([0])  # not a tuple

    def test_remove_edge(self):
        G = self.K3
        G.remove_edge(0, 1)
        assert G.succ == {0: {2: {}}, 1: {0: {}, 2: {}}, 2: {0: {}, 1: {}}}
        assert G.pred == {0: {1: {}, 2: {}}, 1: {2: {}}, 2: {0: {}, 1: {}}}
        with pytest.raises(nx.NetworkXError):
            G.remove_edge(-1, 0)

    def test_remove_edges_from(self):
        G = self.K3
        G.remove_edges_from([(0, 1)])
        assert G.succ == {0: {2: {}}, 1: {0: {}, 2: {}}, 2: {0: {}, 1: {}}}
        assert G.pred == {0: {1: {}, 2: {}}, 1: {2: {}}, 2: {0: {}, 1: {}}}
        G.remove_edges_from([(0, 0)])  # silent fail


class TestEdgeSubgraph(TestGraphEdgeSubgraph):
    """Unit tests for the :meth:`DiGraph.edge_subgraph` method."""

    def setup_method(self):
        # Create a doubly-linked path graph on five nodes.
        G = nx.DiGraph(nx.path_graph(5))
        # Add some node, edge, and graph attributes.
        for i in range(5):
            G.nodes[i]['name'] = 'node{}'.format(i)
        G.edges[0, 1]['name'] = 'edge01'
        G.edges[3, 4]['name'] = 'edge34'
        G.graph['name'] = 'graph'
        # Get the subgraph induced by the first and last edges.
        self.G = G
        self.H = G.edge_subgraph([(0, 1), (3, 4)])

    def test_pred_succ(self):
        """Test that nodes are added to predecessors and successors.

        For more information, see GitHub issue #2370.

        """
        G = nx.DiGraph()
        G.add_edge(0, 1)
        H = G.edge_subgraph([(0, 1)])
        assert list(H.predecessors(0)) == []
        assert list(H.successors(0)) == [1]
        assert list(H.predecessors(1)) == [0]
        assert list(H.successors(1)) == []