# mssql/zxjdbc.py
# Copyright (C) 2005-2016 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

"""
.. dialect:: mssql+zxjdbc
    :name: zxJDBC for Jython
    :dbapi: zxjdbc
    :connectstring: mssql+zxjdbc://user:pass@host:port/dbname\
[?key=value&key=value...]
    :driverurl: http://jtds.sourceforge.net/

    .. note:: Jython is not supported by current versions of SQLAlchemy.  The
       zxjdbc dialect should be considered as experimental.

"""
from ...connectors.zxJDBC import ZxJDBCConnector
from .base import MSDialect, MSExecutionContext
from ... import engine


class MSExecutionContext_zxjdbc(MSExecutionContext):

    _embedded_scope_identity = False

    def pre_exec(self):
        super(MSExecutionContext_zxjdbc, self).pre_exec()
        # scope_identity after the fact returns null in jTDS so we must
        # embed it
        if self._select_lastrowid and self.dialect.use_scope_identity:
            self._embedded_scope_identity = True
            self.statement += "; SELECT scope_identity()"

    def post_exec(self):
        if self._embedded_scope_identity:
            while True:
                try:
                    row = self.cursor.fetchall()[0]
                    break
                except self.dialect.dbapi.Error:
                    self.cursor.nextset()
            self._lastrowid = int(row[0])

        if (self.isinsert or self.isupdate or self.isdelete) and \
                self.compiled.returning:
            self._result_proxy = engine.FullyBufferedResultProxy(self)

        if self._enable_identity_insert:
            table = self.dialect.identifier_preparer.format_table(
                self.compiled.statement.table)
            self.cursor.execute("SET IDENTITY_INSERT %s OFF" % table)


class MSDialect_zxjdbc(ZxJDBCConnector, MSDialect):
    jdbc_db_name = 'jtds:sqlserver'
    jdbc_driver_name = 'net.sourceforge.jtds.jdbc.Driver'

    execution_ctx_cls = MSExecutionContext_zxjdbc

    def _get_server_version_info(self, connection):
        return tuple(
            int(x)
            for x in connection.connection.dbversion.split('.')
        )

dialect = MSDialect_zxjdbc
