from sqlalchemy import exc
from sqlalchemy.testing import assert_raises
from sqlalchemy.testing import eq_
from sqlalchemy.testing import fixtures
from sqlalchemy.testing.util import conforms_partial_ordering
from sqlalchemy.util import topological


class DependencySortTest(fixtures.TestBase):
    def assert_sort(self, tuples, allitems=None):
        if allitems is None:
            allitems = self._nodes_from_tuples(tuples)
        else:
            allitems = self._nodes_from_tuples(tuples).union(allitems)
        result = list(topological.sort(tuples, allitems))
        assert conforms_partial_ordering(tuples, result)

    def assert_sort_deterministic(self, tuples, allitems, expected):
        result = list(topological.sort(tuples, allitems))
        assert conforms_partial_ordering(tuples, result)
        assert result == expected

    def _nodes_from_tuples(self, tups):
        s = set()
        for tup in tups:
            s.update(tup)
        return s

    def test_sort_one(self):
        rootnode = "root"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        subnode1 = "subnode1"
        subnode2 = "subnode2"
        subnode3 = "subnode3"
        subnode4 = "subnode4"
        subsubnode1 = "subsubnode1"
        tuples = [
            (subnode3, subsubnode1),
            (node2, subnode1),
            (node2, subnode2),
            (rootnode, node2),
            (rootnode, node3),
            (rootnode, node4),
            (node4, subnode3),
            (node4, subnode4),
        ]
        self.assert_sort(tuples)

    def test_sort_two(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        node6 = "node6"
        node7 = "node7"
        tuples = [
            (node1, node2),
            (node3, node4),
            (node4, node5),
            (node5, node6),
            (node6, node2),
        ]
        self.assert_sort(tuples, [node7])

    def test_sort_three(self):
        node1 = "keywords"
        node2 = "itemkeyowrds"
        node3 = "items"
        node4 = "hoho"
        tuples = [
            (node1, node2),
            (node4, node1),
            (node1, node3),
            (node3, node2),
        ]
        self.assert_sort(tuples)

    def test_sort_deterministic_one(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        node6 = "node6"
        allitems = [node6, node5, node4, node3, node2, node1]
        tuples = [(node6, node5), (node2, node1)]
        expected = [node6, node4, node3, node2, node5, node1]
        self.assert_sort_deterministic(tuples, allitems, expected)

    def test_sort_deterministic_two(self):
        node1 = 1
        node2 = 2
        node3 = 3
        node4 = 4
        node5 = 5
        node6 = 6
        allitems = [node6, node5, node4, node3, node2, node1]
        tuples = [(node6, node5), (node4, node3), (node2, node1)]
        expected = [node6, node4, node2, node5, node3, node1]
        self.assert_sort_deterministic(tuples, allitems, expected)

    def test_raise_on_cycle_one(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        tuples = [
            (node4, node5),
            (node5, node4),
            (node1, node2),
            (node2, node3),
            (node3, node1),
            (node4, node1),
        ]
        allitems = self._nodes_from_tuples(tuples)

        try:
            list(topological.sort(tuples, allitems))
            assert False
        except exc.CircularDependencyError as err:
            eq_(err.cycles, {"node1", "node3", "node2", "node5", "node4"})
            eq_(
                err.edges,
                {
                    ("node3", "node1"),
                    ("node4", "node1"),
                    ("node2", "node3"),
                    ("node1", "node2"),
                    ("node4", "node5"),
                    ("node5", "node4"),
                },
            )

    def test_raise_on_cycle_two(self):

        # this condition was arising from ticket:362 and was not treated
        # properly by topological sort

        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        tuples = [
            (node1, node2),
            (node3, node1),
            (node2, node4),
            (node3, node2),
            (node2, node3),
        ]
        allitems = self._nodes_from_tuples(tuples)

        try:
            list(topological.sort(tuples, allitems))
            assert False
        except exc.CircularDependencyError as err:
            eq_(err.cycles, {"node1", "node3", "node2"})
            eq_(
                err.edges,
                {
                    ("node3", "node1"),
                    ("node2", "node3"),
                    ("node3", "node2"),
                    ("node1", "node2"),
                    ("node2", "node4"),
                },
            )

    def test_raise_on_cycle_three(self):
        question, issue, providerservice, answer, provider = (
            "Question",
            "Issue",
            "ProviderService",
            "Answer",
            "Provider",
        )
        tuples = [
            (question, issue),
            (providerservice, issue),
            (provider, question),
            (question, provider),
            (providerservice, question),
            (provider, providerservice),
            (question, answer),
            (issue, question),
        ]
        allitems = self._nodes_from_tuples(tuples)
        assert_raises(
            exc.CircularDependencyError,
            list,
            topological.sort(tuples, allitems),
        )

        # TODO: test find_cycles

    def test_large_sort(self):
        tuples = [(i, i + 1) for i in range(0, 1500, 2)]
        self.assert_sort(tuples)

    def test_ticket_1380(self):

        # ticket:1380 regression: would raise a KeyError

        tuples = [(id(i), i) for i in range(3)]
        self.assert_sort(tuples)

    def test_find_cycle_one(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        tuples = [
            (node1, node2),
            (node3, node1),
            (node2, node4),
            (node3, node2),
            (node2, node3),
        ]
        eq_(
            topological.find_cycles(tuples, self._nodes_from_tuples(tuples)),
            {node1, node2, node3},
        )

    def test_find_multiple_cycles_one(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        node6 = "node6"
        node7 = "node7"
        node8 = "node8"
        node9 = "node9"
        tuples = [  # cycle 1 cycle 2 cycle 3 cycle 4, but only if cycle
            # 1 nodes are present
            (node1, node2),
            (node2, node4),
            (node4, node1),
            (node9, node9),
            (node7, node5),
            (node5, node7),
            (node1, node6),
            (node6, node8),
            (node8, node4),
            (node3, node1),
            (node3, node2),
        ]
        allnodes = {
            node1,
            node2,
            node3,
            node4,
            node5,
            node6,
            node7,
            node8,
            node9,
        }
        eq_(
            topological.find_cycles(tuples, allnodes),
            {
                "node8",
                "node1",
                "node2",
                "node5",
                "node4",
                "node7",
                "node6",
                "node9",
            },
        )

    def test_find_multiple_cycles_two(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        node6 = "node6"
        tuples = [  # cycle 1 cycle 2
            (node1, node2),
            (node2, node4),
            (node4, node1),
            (node1, node6),
            (node6, node2),
            (node2, node4),
            (node4, node1),
        ]
        allnodes = {node1, node2, node3, node4, node5, node6}
        # node6 only became present here once [ticket:2282] was addressed.
        eq_(
            topological.find_cycles(tuples, allnodes),
            {"node1", "node2", "node4", "node6"},
        )

    def test_find_multiple_cycles_three(self):
        node1 = "node1"
        node2 = "node2"
        node3 = "node3"
        node4 = "node4"
        node5 = "node5"
        node6 = "node6"
        tuples = [  # cycle 1 cycle 2 cycle3 cycle4
            (node1, node2),
            (node2, node1),
            (node2, node3),
            (node3, node2),
            (node2, node4),
            (node4, node2),
            (node2, node5),
            (node5, node6),
            (node6, node2),
        ]
        allnodes = {node1, node2, node3, node4, node5, node6}
        eq_(topological.find_cycles(tuples, allnodes), allnodes)

    def test_find_multiple_cycles_four(self):
        tuples = [
            ("node6", "node2"),
            ("node15", "node19"),
            ("node19", "node2"),
            ("node4", "node10"),
            ("node15", "node13"),
            ("node17", "node11"),
            ("node1", "node19"),
            ("node15", "node8"),
            ("node6", "node20"),
            ("node14", "node11"),
            ("node6", "node14"),
            ("node11", "node2"),
            ("node10", "node20"),
            ("node1", "node11"),
            ("node20", "node19"),
            ("node4", "node20"),
            ("node15", "node20"),
            ("node9", "node19"),
            ("node11", "node10"),
            ("node11", "node19"),
            ("node13", "node6"),
            ("node3", "node15"),
            ("node9", "node11"),
            ("node4", "node17"),
            ("node2", "node20"),
            ("node19", "node10"),
            ("node8", "node4"),
            ("node11", "node3"),
            ("node6", "node1"),
        ]
        allnodes = ["node%d" % i for i in range(1, 21)]
        eq_(
            topological.find_cycles(tuples, allnodes),
            {
                "node11",
                "node10",
                "node13",
                "node15",
                "node14",
                "node17",
                "node19",
                "node20",
                "node8",
                "node1",
                "node3",
                "node2",
                "node4",
                "node6",
            },
        )