"""TestCases for checking that it does not segfault when a DBEnv object
is closed before its DB objects.
"""

import os
import unittest

from .test_all import db, test_support, verbose, get_new_environment_path, get_new_database_path

# We're going to get warnings in this module about trying to close the db when
# its env is already closed.  Let's just ignore those.
try:
    import warnings
except ImportError:
    pass
else:
    warnings.filterwarnings('ignore',
                            message='DB could not be closed in',
                            category=RuntimeWarning)


#----------------------------------------------------------------------

class DBEnvClosedEarlyCrash(unittest.TestCase):
    def setUp(self):
        self.homeDir = get_new_environment_path()
        self.filename = "test"

    def tearDown(self):
        test_support.rmtree(self.homeDir)

    def test01_close_dbenv_before_db(self):
        dbenv = db.DBEnv()
        dbenv.open(self.homeDir,
                   db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                   0o666)

        d = db.DB(dbenv)
        d2 = db.DB(dbenv)
        d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)

        self.assertRaises(db.DBNoSuchFileError, d2.open,
                self.filename+"2", db.DB_BTREE, db.DB_THREAD, 0o666)

        d.put("test","this is a test")
        self.assertEqual(d.get("test"), "this is a test", "put!=get")
        dbenv.close()  # This "close" should close the child db handle also
        self.assertRaises(db.DBError, d.get, "test")

    def test02_close_dbenv_before_dbcursor(self):
        dbenv = db.DBEnv()
        dbenv.open(self.homeDir,
                   db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                   0o666)

        d = db.DB(dbenv)
        d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)

        d.put("test","this is a test")
        d.put("test2","another test")
        d.put("test3","another one")
        self.assertEqual(d.get("test"), "this is a test", "put!=get")
        c=d.cursor()
        c.first()
        next(c)
        d.close()  # This "close" should close the child db handle also
     # db.close should close the child cursor
        self.assertRaises(db.DBError,c.__next__)

        d = db.DB(dbenv)
        d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
        c=d.cursor()
        c.first()
        next(c)
        dbenv.close()
    # The "close" should close the child db handle also, with cursors
        self.assertRaises(db.DBError, c.__next__)

    def test03_close_db_before_dbcursor_without_env(self):
        import os.path
        path=os.path.join(self.homeDir,self.filename)
        d = db.DB()
        d.open(path, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)

        d.put("test","this is a test")
        d.put("test2","another test")
        d.put("test3","another one")
        self.assertEqual(d.get("test"), "this is a test", "put!=get")
        c=d.cursor()
        c.first()
        next(c)
        d.close()
    # The "close" should close the child db handle also
        self.assertRaises(db.DBError, c.__next__)

    def test04_close_massive(self):
        dbenv = db.DBEnv()
        dbenv.open(self.homeDir,
                   db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                   0o666)

        dbs=[db.DB(dbenv) for i in range(16)]
        cursors=[]
        for i in dbs :
            i.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)

        dbs[10].put("test","this is a test")
        dbs[10].put("test2","another test")
        dbs[10].put("test3","another one")
        self.assertEqual(dbs[4].get("test"), "this is a test", "put!=get")

        for i in dbs :
            cursors.extend([i.cursor() for j in range(32)])

        for i in dbs[::3] :
            i.close()
        for i in cursors[::3] :
            i.close()

    # Check for missing exception in DB! (after DB close)
        self.assertRaises(db.DBError, dbs[9].get, "test")

    # Check for missing exception in DBCursor! (after DB close)
        self.assertRaises(db.DBError, cursors[101].first)

        cursors[80].first()
        next(cursors[80])
        dbenv.close()  # This "close" should close the child db handle also
    # Check for missing exception! (after DBEnv close)
        self.assertRaises(db.DBError, cursors[80].__next__)

    def test05_close_dbenv_delete_db_success(self):
        dbenv = db.DBEnv()
        dbenv.open(self.homeDir,
                   db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                   0o666)

        d = db.DB(dbenv)
        d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)

        dbenv.close()  # This "close" should close the child db handle also

        del d
        try:
            import gc
        except ImportError:
            gc = None
        if gc:
            # force d.__del__ [DB_dealloc] to be called
            gc.collect()

    def test06_close_txn_before_dup_cursor(self) :
        dbenv = db.DBEnv()
        dbenv.open(self.homeDir,db.DB_INIT_TXN | db.DB_INIT_MPOOL |
                db.DB_INIT_LOG | db.DB_CREATE)
        d = db.DB(dbenv)
        txn = dbenv.txn_begin()
        if db.version() < (4,1) :
            d.open(self.filename, dbtype = db.DB_HASH, flags = db.DB_CREATE)
        else :
            d.open(self.filename, dbtype = db.DB_HASH, flags = db.DB_CREATE,
                    txn=txn)
        d.put("XXX", "yyy", txn=txn)
        txn.commit()
        txn = dbenv.txn_begin()
        c1 = d.cursor(txn)
        c2 = c1.dup()
        self.assertEquals(("XXX", "yyy"), c1.first())
        import warnings
        # Not interested in warnings about implicit close.
        warnings.simplefilter("ignore")
        txn.commit()
        warnings.resetwarnings()
        self.assertRaises(db.DBCursorClosedError, c2.first)

    if db.version() > (4,3,0) :
        def test07_close_db_before_sequence(self):
            import os.path
            path=os.path.join(self.homeDir,self.filename)
            d = db.DB()
            d.open(path, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
            dbs=db.DBSequence(d)
            d.close()  # This "close" should close the child DBSequence also
            dbs.close()  # If not closed, core dump (in Berkeley DB 4.6.*)

#----------------------------------------------------------------------

def test_suite():
    suite = unittest.TestSuite()
    suite.addTest(unittest.makeSuite(DBEnvClosedEarlyCrash))
    return suite


if __name__ == '__main__':
    unittest.main(defaultTest='test_suite')