#!/usr/bin/env python
# -*- coding: utf-8  -*-
################################################################################
#
#  PySQLBase7 -- SQLAlchemy driver/dialect for Centura SQLBase v7
#  Copyright © 2010 Lance Edgar
#
#  This file is part of PySQLBase7.
#
#  PySQLBase7 is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  PySQLBase7 is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with PySQLBase7.  If not, see <http://www.gnu.org/licenses/>.
#
################################################################################


from sqlalchemy.engine import default
from sqlalchemy import types


class SQLBase7Dialect(default.DefaultDialect):

    name = 'sqlbase7'

    type_map = {
        'CHAR'          : types.CHAR,
        'DATE'          : types.DATE,
        'DECIMAL'       : types.DECIMAL,
        'FLOAT'         : types.FLOAT,
        'SMALLINT'      : types.SMALLINT,
        'TIME'          : types.TIME,
        'TIMESTMP'      : types.TIMESTAMP,
        'VARCHAR'       : types.VARCHAR,
        }

    def _check_unicode_returns(self, connection):
        return False

    def get_table_names(self, schema=None, connection=None):
        cursor = schema.connection.cursor()
        table_names = [row.NAME for row in cursor.execute(
                "SELECT NAME FROM SYSADM.SYSTABLES WHERE REMARKS IS NOT NULL"
                )]
        cursor.close()
        return table_names

    def get_columns(self, connection, table_name, schema=None, **kw):
        cursor = connection.connection.cursor()
        columns = []

        for row in cursor.execute("SELECT NAME,COLTYPE,NULLS FROM SYSADM.SYSCOLUMNS WHERE TBNAME = '%s'" % table_name):

            columns.append({
                    'name'              : row.NAME,
                    'type'              : self.type_map[row.COLTYPE],
                    'nullable'          : row.NULLS == 'Y',
                    'default'           : None,
                    'autoincrement'     : False,
                    })

        cursor.close()
        return columns

    def get_primary_keys(self, connection, table_name, schema=None, **kw):
        cursor = connection.connection.cursor()
        primary_keys = [row.COLNAME for row in cursor.execute(
                "SELECT COLNAME FROM SYSADM.SYSPKCONSTRAINTS WHERE NAME = '%s' ORDER BY PKCOLSEQNUM" % table_name
                )]
        cursor.close()
        return primary_keys

    def get_foreign_keys(self, connection, table_name, schema=None, **kw):
        return []

    def get_indexes(self, connection, table_name, schema=None, **kw):
        return []