from alembic.testing.env import clear_staging_env, staging_env
from alembic.testing import assert_raises_message, eq_
from alembic import util
from alembic.testing.fixtures import TestBase


env = None
a, b, c, d, e = None, None, None, None, None
cfg = None


class RevisionPathTest(TestBase):

    @classmethod
    def setup_class(cls):
        global env
        env = staging_env()
        global a, b, c, d, e
        a = env.generate_revision(util.rev_id(), '->a', refresh=True)
        b = env.generate_revision(util.rev_id(), 'a->b', refresh=True)
        c = env.generate_revision(util.rev_id(), 'b->c', refresh=True)
        d = env.generate_revision(util.rev_id(), 'c->d', refresh=True)
        e = env.generate_revision(util.rev_id(), 'd->e', refresh=True)

    @classmethod
    def teardown_class(cls):
        clear_staging_env()

    def test_upgrade_path(self):

        eq_(
            env._upgrade_revs(e.revision, c.revision),
            [
                (d.module.upgrade, c.revision, d.revision, d.doc),
                (e.module.upgrade, d.revision, e.revision, e.doc),
            ]
        )

        eq_(
            env._upgrade_revs(c.revision, None),
            [
                (a.module.upgrade, None, a.revision, a.doc),
                (b.module.upgrade, a.revision, b.revision, b.doc),
                (c.module.upgrade, b.revision, c.revision, c.doc),
            ]
        )

    def test_relative_upgrade_path(self):
        eq_(
            env._upgrade_revs("+2", a.revision),
            [
                (b.module.upgrade, a.revision, b.revision, b.doc),
                (c.module.upgrade, b.revision, c.revision, c.doc),
            ]
        )

        eq_(
            env._upgrade_revs("+1", a.revision),
            [
                (b.module.upgrade, a.revision, b.revision, b.doc),
            ]
        )

        eq_(
            env._upgrade_revs("+3", b.revision),
            [
                (c.module.upgrade, b.revision, c.revision, c.doc),
                (d.module.upgrade, c.revision, d.revision, d.doc),
                (e.module.upgrade, d.revision, e.revision, e.doc),
            ]
        )

    def test_invalid_relative_upgrade_path(self):
        assert_raises_message(
            util.CommandError,
            "Relative revision -2 didn't produce 2 migrations",
            env._upgrade_revs, "-2", b.revision
        )

        assert_raises_message(
            util.CommandError,
            r"Relative revision \+5 didn't produce 5 migrations",
            env._upgrade_revs, "+5", b.revision
        )

    def test_downgrade_path(self):

        eq_(
            env._downgrade_revs(c.revision, e.revision),
            [
                (e.module.downgrade, e.revision, e.down_revision, e.doc),
                (d.module.downgrade, d.revision, d.down_revision, d.doc),
            ]
        )

        eq_(
            env._downgrade_revs(None, c.revision),
            [
                (c.module.downgrade, c.revision, c.down_revision, c.doc),
                (b.module.downgrade, b.revision, b.down_revision, b.doc),
                (a.module.downgrade, a.revision, a.down_revision, a.doc),
            ]
        )

    def test_relative_downgrade_path(self):
        eq_(
            env._downgrade_revs("-1", c.revision),
            [
                (c.module.downgrade, c.revision, c.down_revision, c.doc),
            ]
        )

        eq_(
            env._downgrade_revs("-3", e.revision),
            [
                (e.module.downgrade, e.revision, e.down_revision, e.doc),
                (d.module.downgrade, d.revision, d.down_revision, d.doc),
                (c.module.downgrade, c.revision, c.down_revision, c.doc),
            ]
        )

    def test_invalid_relative_downgrade_path(self):
        assert_raises_message(
            util.CommandError,
            "Relative revision -5 didn't produce 5 migrations",
            env._downgrade_revs, "-5", b.revision
        )

        assert_raises_message(
            util.CommandError,
            r"Relative revision \+2 didn't produce 2 migrations",
            env._downgrade_revs, "+2", b.revision
        )

    def test_invalid_move_rev_to_none(self):
        assert_raises_message(
            util.CommandError,
            "Revision %s is not an ancestor of base" % b.revision,
            env._downgrade_revs, b.revision[0:3], None
        )

    def test_invalid_move_higher_to_lower(self):
        assert_raises_message(
            util.CommandError,
            "Revision %s is not an ancestor of %s" % (c.revision, b.revision),
            env._downgrade_revs, c.revision[0:4], b.revision
        )